| 1. |
- Abba, S. I., et al.
(author)
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Effluents quality prediction by using nonlinear dynamic block-oriented models : A system identification approach
- 2021
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In: Desalination and Water Treatment. - : Desalination Publications. - 1944-3994 .- 1944-3986. ; 218, s. 52-62
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Journal article (peer-reviewed)abstract
- The dynamic and complex municipal wastewater treatment plant (MWWTP) process should be handled efficiently to safeguard the excellent quality of effluents characteristics. Most of the available mathematical models do not efficiently capture the MWWTP process, in such cases, the data-driven models are reliable and indispensable for effective modeling of effluents characteristics. In the present research, two nonlinear system identification (NSI) models namely; Hammerstein-Wiener model (HW) and nonlinear autoregressive with exogenous (NARX) neural network model, and a classical autoregressive (AR) model were proposed to predict the characteristics of the effluent of total suspended solids (TSSeff) and pHeff from Nicosia MWWTP in Cyprus. In order to attain the optimal models, two different combinations of input variables were cast through auto-correla-tion function and partial auto-correlation analysis. The prediction accuracy was evaluated using three statistical indicators the determination coefficient (DC), root mean square error (RMSE) and correlation coefficient (CC). The results of the appraisal indicated that the HW model outperformed NARX and AR models in predicting the pHeff, while the NARX model performed better than the HW and AR models for TSSeff prediction. It was evident that the accuracy of the HW increased averagely up to 18% with regards to the NARX model for pHeff . Likewise, the TSSeff performance increased averagely up to 25% with regards to the HW model. Also, in the validation phase, the HW model yielded DC, RMSE, and CC of 0.7355, 0.1071, and 0.8578 for pHeff, while the NARX model yielded 0.9804, 0.0049 and 0.9902 for TSSeff, respectively. For comparison with the traditional AR, the results showed that both HW and NARX models outperformed in (TSSeff) and pHeff prediction at the study location. Hence, the outcomes determined that the NSI model (i.e., HW and NARX) are reliable and resilient modeling tools that could be adopted for pHeff and TSSeff prediction.
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| 2. |
- Ambashta, Ritu D., et al.
(author)
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Supported iron-based catalysts under influence of static magnetic field for the removal of TBP and EDTA
- 2015
-
In: Desalination and Water Treatment. - : Informa UK Limited. - 1944-3994 .- 1944-3986. ; 54:10, s. 2700-2709
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Journal article (peer-reviewed)abstract
- Zerovalent metals offer decontamination of organic toxins in aqueous medium. In the present study, alumina-based iron and iron-nickel in the presence and the absence of magnetic field for the decontamination of tributyl phosphate (TBP) and ethylene diamine tetraacetic acid (EDTA) has been compared. TBP decontamination was improved in the presence of zerovalent metals. EDTA decontamination was not enhanced in the presence of zerovalent metals. The decontamination of TBP using iron-based alumina was higher than iron-nickel. The surface interaction on alumina surface, as characterized by attentuated total reflectance-Fourier transform infrared spectroscopy, and the surface interaction on metallic elements, as characterized by evaluating the magnetic moment values helped to understand the reason for the difference in role of alumina-based iron and iron-nickel on decontamination of TBP and EDTA.
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| 3. |
- Asim, Muhammad, et al.
(author)
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Experimental analysis of solar thermal integrated MD system for cogeneration of drinking water and hot water for single family villa in Dubai using flat plate and evacuated tube solar collectors
- 2017
-
In: Desalination and Water Treatment. - : DESALINATION PUBL. - 1944-3994 .- 1944-3986. ; 92, s. 46-59
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Journal article (peer-reviewed)abstract
- This paper presents the experimental analysis performed on solar thermal integrated membrane distillation (MD) system using flat plate and evacuated tube collectors. The system will be utilized for cogeneration of drinking water and domestic hot water for single family in Dubai comprising of four to five members. Experiments have been performed in Ras Al Khaimah Research and Innovation Centre (RAKRIC) facility. The experimental setup has been installed to achieve the required production of 15-25 L/d of drinking water and 250 L/d of hot water for domestic purposes. Experiments have been performed on MD setup at optimized flow rates of 6 L/min on hot side and 3 L/min on cold side for producing the desired distillate. The hot side and cold side MD temperature has been maintained between 60 degrees C and 70 degrees C, and 20 degrees C and 30 degrees C. The total annual energy demand comes out to be 8,223 kWh (6,000 kWh is for pure water and 2,223 kWh for hot water). The optimum aperture areas for flat plate and evacuated tube collector field have been identified as 8.5 and 7.5 m(2), respectively. Annual energy consumption per liter for pure water production is 1, 0.85 and 0.7 kWh/L for different MD hot and cold inlet temperatures.
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| 4. |
- Asim, Muhammad, et al.
(author)
-
Feasibility analysis of solar combi-system for simultaneous production of pure drinking water via membrane distillation and domestic hot water for single-family villa : pilot plant setup in Dubai
- 2016
-
In: Desalination and Water Treatment. - : Taylor & Francis. - 1944-3994 .- 1944-3986. ; 57:46, s. 21674-21684
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Journal article (peer-reviewed)abstract
- This paper presents the feasibility study of installation of a solar-driven integrated MD desalination system for simultaneous production of pure drinking water and solar domestic hot water in United Arab Emirates (UAE) for a single-family villa comprising of 4-5 persons. In order to satisfy the current and future demand of water for domestic purposes, the desalination of seawater is considered to be one of the most effective and strategic technique in UAE. The stress on the underground water aquifers, rapid industrial growth, and increase in urban population in UAE results in the tremendous increase in fresh water demand during the past few decades. Since the local municipalities also provide the desalinated fresh water to the people but they mostly rely on bottled water for drinking purpose. In this paper, the pilot setup plant is designed, commissioned, and installed on site in UAE using air gap membrane distillation desalination process to fulfill the demand of 15-25 L/d of pure drinking water and 250 L/d of domestic hot water for a single-family villa. Experimental analyses have been performed on this setup during summer on flat plate solar collectors having different aperture areas (Experiments have been performed for aperture area of 11.9 m(2) in this research study for feasibility purpose). The average hot-side temperature ranges from 50 to 70 degrees C and average cold-side temperature of 35 degrees C.
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| 5. |
- Bashitialshaaer, Raed, et al.
(author)
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Environmental Assessment of Brine Discharge and Wastewater in the Arabian Gulf
- 2011
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In: Desalination and Water Treatment. - : Informa UK Limited. - 1944-3986 .- 1944-3994. ; 25, s. 276-285
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Journal article (peer-reviewed)abstract
- This study assesses the environmental effects of brine discharge into the Arabian/Persian Gulf and the option of mixing with wastewater to reduce the salt content in the discharge. The Arabian Gulf region occupies about 3.3% of the world area and has 1.0, 2.0 and 2.2% of the total world population in the years 1950, 2008 and 2050 (prognosis) respectively. The study area desalination capacities were obtained as 50, 40 and 45% of total world capacity at the end of 1996, 2008 and 2050 (prognosis) respectively. The trend towards increased recovery ratio in the desalination plants was considered as one important environmental factor. This will significantly increase the brine salt concentration from 1.5 to more than 2 times the seawater. The allocation of wastewater and brine is important for the Arabian Gulf. Straightforward water and salt mass balances were used to calculate residual flow, exchange flow and exchange time in the Arabian Gulf. For example, at zero wastewater discharge from 1996 to 2008, the net volume in the Arabian Gulf decreased by 7.4 million m3/day, the exchange volume increased by 69 million m3/day, and the mixing time decreased by 22.5 days. Discharging a mix of brine and wastewater in the Arabian Gulf reduces the water and salt exchange between the Gulf and the Indian Ocean. Nutrients in wastewater may cause problems such as eutrophication in the Gulf if the exchange of water is low or if wastewater is discharged to the Gulf with insufficient treatment.
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| 6. |
- Daneshvar, Ehsan, et al.
(author)
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Application of response surface methodology for the biosorption of Acid Blue 25 dye using raw and HCl-treated macroalgae
- 2015
-
In: Desalination and Water Treatment. - : Informa UK Limited. - 1944-3994 .- 1944-3986. ; 53:6, s. 1710-1723
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Journal article (peer-reviewed)abstract
- The present study was conducted to optimize the various experimental conditions, such as biomass loading, initial C.I. Acid Blue 25 (AB25) dye concentration, and initial solution pH for biosorption of dye on raw and HCl-treated brown alga, Padina australis and red alga, Jania adhaerens. Biosorption process was optimized in a batch system under Box-Behnken design. Second-order polynomial equation was successfully used to describe the effects of studied variables on response. The quadratic models exhibited higher R-2 values, significant p-values, and insignificant lack-of-fit p-values showed high adequacy for predicting the response. Chemically modified red alga exhibited better AB25 dye biosorption capacity as compared to modified brown alga. Maximum dye removal efficiencies of 77.34, 71.28, 50.56, and 85.19% for P. australis, HCl-treated P. australis, J. adhaerens, and HCl-treated J. adhaerens, respectively, were obtained at optimal conditions. The surface modification on tested algal biomass was found to be strongly dependent on their cell wall constituents.
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| 7. |
- Elginoz, Nilay, et al.
(author)
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Construction of a large water treatment plant : appraisal of environmental hotspots
- 2019
-
In: Desalination and Water Treatment. - : DESALINATION PUBL. - 1944-3994 .- 1944-3986. ; 172, s. 309-315
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Journal article (peer-reviewed)abstract
- The objective of this study is to examine the environmental impacts arising from the construction phase of a large conventional water treatment plant located in Istanbul by adopting a life cycle assessment methodology. The facility has a maximum flow rate of 400,000 m(3)/d and serves a population of about 2,600,000. A conventional treatment technology composed of rock and fine screens, aeration, coagulation-flocculation units, clarifiers, filters, chlorination, and sludge handling units, is used in the plant. The functional unit is 1,000 kg (1 m(3)) treated water. The investigated environmental impact categories are: global warming potential (GWP), acidification potential (AP), eutrophication potential (EP), abiotic depletion potential fossil (ADP fossil), freshwater aquatic ecotoxicity potential (FAETP), human toxicity potential ( HTP), marine aquatic ecotoxicity potential (MAETP), and terrestrial ecotoxicity potential (TETP). The main contributors to GWP, AP, EP, and HTP are concrete and structural steel. FAETP and TETP are mostly arising due to the polyvinyl chloride pipelines and membranes, and the concrete used. The main shares in MAETP are concrete, aluminum, and structural steel. Transportation does not have a significant contribution to environmental impacts.
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| 8. |
- Ezoddin, Maryam, et al.
(author)
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Equilibrium sampling through membrane based on a hollow fiber for determination of naproxen and diclofenac in sludge slurry using Taguchi orthogonal array experimental design
- 2014
-
In: Desalination and Water Treatment. - : Informa UK Limited. - 1944-3986 .- 1944-3994. ; 52:13-15, s. 2472-2480
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Journal article (peer-reviewed)abstract
- A three-phase hollow fiber liquid phase microextraction (HF-LPME) method was evaluated for the extraction and preconcentration of naproxen and diclofenac using a polypropylene membrane followed by analysis using HPLC or LC/MS. In this technique, the drugs were extracted into di-n-hexyl ether immobilized in the wall pores of a porous hollow fiber from 50mL of sludge slurry sample as a donor phase with pH 3, and then back-extracted into the acceptor phase located in the lumen of the hollow fiber. Experimental factors were studied in 16 trials using a Taguchi orthogonal array experimental design with an OA(16) (4(5)) matrix. The significance of these factors was investigated using analysis of variance. The extraction time was statistically demonstrated as the main factor for the extraction of naproxen and diclofenac, while ionic strength played the role of the second most important factor for HF-LPME extraction of diclofenac. The method permitted a detection limit of 0.2-0.7ngg(-1) with relative standard deviation values of 3-5%. Enrichment factors of 2,300 for naproxen and 1,400 for diclofenac were achieved. The method was applied to determine naproxen and diclofenac in sewage sludge from sewage treatment plant, Kallby (Lund, Sweden).
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| 9. |
- Faisal, Ayad A. H., et al.
(author)
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A mathematical model for simulation the removal of cadmium and chromium from groundwater using scrap iron and aluminum as permeable reactive barrier
- 2022
-
In: Desalination and Water Treatment. - : Desalination Publications. - 1944-3994 .- 1944-3986. ; 259, s. 186-196
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Journal article (peer-reviewed)abstract
- The present work is represented by the derivation of mathematical model and solving the model analytically using the method of separation of variables to describe the migration of the contaminant metal ions through a column packed with bed of permeable reactive barrier (PRB). The validity of the solution can be evaluated through the simulation of cadmium and chromium ions using scrap iron and/or aluminum by-products in the form of wastes that if not utilized to treat waste by waste can impose further burden over the ecosystem. Breakthrough curves proved that the increase of metal ions velocity will decrease the capturing of the ions; therefore, the distribu-tion coefficient and the retardation factor also decrease. Furthermore, the increase of barrier depth will increase the longevity of PRB because this will delay the migration of contaminant. A mathematical model has acceptable ability in the representation of experimental measurements with Nash-€“Sutcliff efficiency coefficients greater than 0.98. The longevity of the PRB was estimated for the field scale to be 210 and 250 d to produce contaminant effluent beyond 100 cm barrier matrix within the environmental permissible concentrations. Although groundwater velocity is highly variable, a proposed velocity of 0.25 cm/min which is assumed to be analogous to the groundwater velocity has revealed prolonged longevity of 7.02 y for the capture of chromium.
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| 10. |
- Faisal, Ayad A.H., et al.
(author)
-
Using different materials as a permeable reactive barrier for remediation of groundwater contaminated with landfill’s leachate
- 2020
-
In: Desalination and Water Treatment. - : Desalination Publications. - 1944-3994 .- 1944-3986. ; 175, s. 152-163
-
Journal article (peer-reviewed)abstract
- The present study investigates the utilization of the waterworks sludge by-product that generated from water supply treatment plant for the remediation of simulated groundwater contaminated with leachate spilled from the sanitary landfill by permeable reactive barrier (PRB) technology. Batch sorption experiments were conducted for describing the interaction between the acetogenic phase (pH=5.5±0.1) of leachate contaminated with cadmium (Cd(II)), ammonia nitrogen (NH3–N) or dissolved organic matter (COD) and waterworks sludge. Also, conventional sorbents such as the activated carbon and amberlite ion-exchange resin were tested to evaluate their ability in compar-ison with waterworks sludge in the remediation process. Results proved that the Langmuir model describes well the sorption data with maximum sorption capacities of 5.634, 14.908 and 3.938mg/g for Cd(II) onto sludge, NH3–N onto resin and COD onto activated carbon, respectively. The batch and column tests signified that the sludge, resin, and carbon can be used for removing Cd(II), NH3–N, and COD, respectively. The multi-layered bed of sorbents under consideration has a remarkable ability in the remediation of a leachate contaminated with Cd(II), NH3–N, and COD. Finally, the Yan model is more representative than Thomas and Belter models for characterization of the contaminants propagation in the column packed with single sorbent.
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| 11. |
- Garcia-Martin, Noemi, et al.
(author)
-
Sugar reduction in white and red musts with nanofiltration membranes
- 2011
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In: Desalination and Water Treatment. - : Balaban Publishers. - 1944-3994 .- 1944-3986. ; 27:1-3, s. 167-174
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Journal article (peer-reviewed)abstract
- In recent years the alcohol content of wine increases mainly due to climate change. Moreover, at present, consumers are increasingly demanding more aromatic and less alcoholic wines, it is due to the greater social awareness in the alcohol consumption and the regulations of the alcoholic products. The aim of this work is the reduction of sugar in the grape must to obtain wines with a slight reduction of their alcoholic degree. A reduction of sugar has been by performing two successive stages of nanofiltration. To this end, we have worked with two types of musts: one from the Verdejo variety of white grapes and the other from red grapes of the Tinta de Toro variety. Each must has been fermented both after treatment and, to be used as control, without any filtration in order to check the effectiveness of the process. Once fermentation is completed, wide-ranging analysis have been used to study all possible changes in the characteristics of the wine from a chemical point of view. The alcohol reduction reached by the wines obtained after nanofiltration and mixing of both white and red musts has been satisfactory.
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| 12. |
- Hansson, Henrik, 1978-, et al.
(author)
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Electrocoagulation coupled to activated carbon sorption/filtration for treatment of cleaning wastewaters from wood-based industry
- 2014
-
In: Desalination and Water Treatment. - London : Taylor & Francis Group. - 1944-3994 .- 1944-3986. ; 52:28-30, s. 5243-5251
-
Journal article (peer-reviewed)abstract
- The objective of this investigation was to study the use of a coupled treatment (electrocoagulation(EC) and sorption/filtration treatment) with different sequencing to reduce the organic pollutantsmeasured as chemical oxygen demand (COD) of five highly polluted wastewater streamsgenerated after washing surfaces and machinery in the wooden floor industry and to evaluate,how different sequencing of these treatment units affects the overall system efficiency. On thebasis of preliminary studies, an EC reactor (1.0 L) was constructed with monopolar electrodes inparallel connection in an array of four Al electrodes with surface area of 93.2 cm2and an appliedcurrent density of 161 A m–2. This reactor was coupled to a sorption/filtration unit with coalactivated carbon. The EC reactor was tested in two different sequences (before and after the sorption/filtration unit). The overall COD reduction varied from 2% ± 0.5% to 77% ± 2.9%, dependingon the sequence and the treated wastewater stream. The best result from efficiency andoperational viewpoints was obtained with the EC reactor placed after the sorption/filtrationcolumn. The increase in efficiency is likely to be due to the removal by sorption in the activatedcarbon of compounds that interfere with EC. Additionally, as desired, the use of EC before thesorption unit extended the activated carbon lifetime.
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| 13. |
- Herrmann, Inga, 1978-, et al.
(author)
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Discharge of indicator bacteria from on-site wastewater treatment systems
- 2017
-
In: Desalination and Water Treatment. - : Desalination Publications. - 1944-3994 .- 1944-3986. ; 91, s. 365-373
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Journal article (peer-reviewed)abstract
- Small-scale on-site wastewater treatment facilities present the risk of microbial pollution of groundwaterused for drinking water and surface water used for recreational purposes. This study assessedthe discharge of indicator bacteria, total coliform, Escherichia coli, intestinal enterococci and Clostridiumperfringens, by flow-proportional sampling from 12 full-scale on-site treatment systems featuringbiological treatment units (mainly sand filters) and alkaline filter beds for phosphorus treatment(P-filters). Correlations of effluent bacterial concentrations with pH, total and dissolved organic carbon,filter age and hydraulic load were evaluated. The bacterial concentrations in the effluents ofthe sand filters were considerable. The concentrations for excellent bathing water quality set in theEU bathing water directive, 200 and 500 colony forming units (cfu)/100 mL for intestinal enterococciand E. coli, respectively, were exceeded in three (intestinal enterococci) and one (E. coli) of the eightinvestigated sand filters. In one of the sand filters, effluent E. coli concentrations were high althoughno obvious malfunction of the filter was observed. In the effluent from the other investigated biologicaltreatment units (a trickling fibre filter, two units with attached growth treatment and one aeratedactivated sludge technique), bacterial concentrations were very high (75,000 cfu/100 mL of Clostridiumperfringens and 85,000 cfu per 100 mL of total coliform), possibly because of a shorter retention time ofthe wastewater in these facilities, missing aeration and little time between start-up and measurements.Three and four of the nine investigated P-filters exceeded excellent bathing water quality in coastalwaters as stipulated by the EU bathing water directive in respect of E. coli and intestinal enterococci,respectively.
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| 14. |
- Karacal, Pelin Nur, et al.
(author)
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Environmental burdens of cataphoresis process
- 2019
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In: Desalination and Water Treatment. - : DESALINATION PUBL. - 1944-3994 .- 1944-3986. ; 172, s. 301-308
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Journal article (peer-reviewed)abstract
- The objective of this study is to appraise the environmental burdens of a cataphoresis process, most widely used surface coating operation in automotive sector. An industry having an annual production of around 6,100 trucks and busses is investigated by adopting life cycle assessment methodology. This study is a pioneering one performed with the actual data obtained from a Turkish automotive factory. The impact categories evaluated are climate change, acidification potential, particulate matter and respiratory inorganics, photochemical ozone formation, ecotoxicity freshwater potential, terrestrial eutrophication potential, freshwater eutrophication potential, marine eutrophication potential, human toxicity midpoint cancer effects, ozone depletion potential, and resource depletion (water). The total energy consumption of the cataphoresis process is approximately 12.5 kWh/m(2). Electrodeposition coating and the following ultrafiltration water rinse baths are the main sources of the environmental impacts. The contribution of transportation has insignificant effects on environmental impacts for all categories. Furthermore, energy consumption has substantial influence on almost all of the environmental impact categories. The results related to various energy scenarios conducted with wind, photovoltaic and hard coal instead of Turkish grid electricity indicate the usage of wind energy lowers all impacts.
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| 15. |
- Karimineghlani, Parvin, et al.
(author)
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Optimization of lead ions adsorption on hydrolyzed polyacrylonitrile fibers using central composite design
- 2017
-
In: Desalination and Water Treatment. - : Desalination Publications. - 1944-3994 .- 1944-3986. ; 83, s. 133-143
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Journal article (peer-reviewed)abstract
- Optimization of lead ions (Pb++) adsorption on the hydrolyzed polyacrylonitrile (PAN) fibers was reported by using statistical approach. Electrospinning of PAN solutions in dimethylformamide (DMF) was performed with different concentrations. The electrospun fibres, with various diame-ters, were then hydrolyzed in a sodium hydroxide solution (NaOH) for different reaction times and temperatures. Response surface methodology (RSM) helped optimizing the hydrolysis reaction con-ditions to maximize the adsorption capacity of the PAN fibers. The maximum value of adsorption capacity was experimentally determined to be 141 mg/g with the optimized values of hydrolysis reaction time, temperature and fiber diameter being 61.6°C, 82.1 min and 280 nm, respectively. The as-prepared electrospun fibers, hydrolyzed fibers and fibers after adsorption process were charac-terized by scanning electron microscope (SEM). Experimental adsorption data fit very well with the Langmuir isotherm model. It was found that Pb++ ions adsorption on the nanofibers was 20 times higher than that on microfibers under the same conditions. Adsorption kinetics followed the second order kinetics model. © 2017 Desalination Publications. All rights reserved.
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| 16. |
- Khattab, Ibrahim A., et al.
(author)
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Photocatalytic degradation of azo dye Reactive Red 15 over synthesized titanium and zinc oxides photocatalysts : a comparative study
- 2012
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In: Desalination and Water Treatment. - : Informa UK Limited. - 1944-3994 .- 1944-3986. ; 48:1-3, s. 120-129
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Journal article (peer-reviewed)abstract
- Nanoparticle TiO2 and ZnO were prepared by facile method. The XRD pattern study shows that there is no obvious difference in crystal composition of various shapes of TiO2 and ZnO. The photocatalytic degradation of Reactive Red 15, commonly used as a textile dye, using synthesized titanium and zinc oxides was investigated. The effects of influential parameters such as initial pH, catalyst loading, initial dye concentration and addition of hydrogen peroxide were studied. The degradation efficiency was expressed by the removal of color and chemical oxygen demand (COD). The study reveals that: (1) Both catalysts, under corresponding optimal conditions, can be employed as an effective photocatalyst for the elimination of color and COD from dye wastewater. Also, ZnO is more efficient catalyst than TiO2; (2) Addition of proper amount of hydrogen peroxide improves both the decolorization and the degradation of the dye; (3) The photocatalytic degradation of Reactive Red 15, in the presence of both photocatalysts, obeyed pseudo-first order kinetics. The biodegradability ratio BOD5/COD increases from original zero up to 0.52 and 0.6 within 90 minutes irradiation time using 1 and 0.75 g/L TiO2 and ZnO, respectively.
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| 17. |
- Koutahzadeh, N., et al.
(author)
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Biosorption of hexavalent chromium from aqueous solution by six brown macroalgae
- 2013
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In: Desalination and Water Treatment. - : Informa UK Limited. - 1944-3994 .- 1944-3986. ; 51:31-33, s. 6021-6030
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Journal article (peer-reviewed)abstract
- The biosorption potential of six brown macroalgae viz. Nizamuddina zanardinii, Stoechospermum marginatum, Cystoseira indica, Dictyota cervicornis, Padina australis, and Sargassum glaucescens, for the removal of hexavalent chromium (Cr(VI)) was investigated in the present study. Optimum conditions were determined by studying the effect of initial solution pH, biomass dosage, initial Cr(VI) concentration, and contact time on Cr(VI) removal by the macroalgae. Cr(VI) sorption was found to be highly pH dependent and maximum sorption was obtained at pH 1.0. Freundlich isotherm model showed the best fit with the equilibrium data. The removal rate of Cr(VI) was relatively rapid during the first 30min, although the rate decreased gradually and the sorption reached equilibrium in about 70min for S. marginatum, 90min for N. zanardinii, and 150min for D. cervicornis, P. australis, S. glaucescens, and C. indica. Different kinetic models such as pseudo-first-order, pseudo-second-order, and intra-particle diffusion model were tested, and the experimental data was in agreement with the pseudo-second-order model. The results of the present study suggest that brown macroalgae could be used as effective biosorbents for Cr(VI) removal from aqueous solution.
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| 18. |
- Kullab, Alaa, et al.
(author)
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Experimental evaluation of a modified air-gap membrane distillation prototype
- 2013
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In: Desalination and Water Treatment. - : Informa UK Limited. - 1944-3994 .- 1944-3986. ; 51:25-27, s. 4998-5004
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Journal article (peer-reviewed)abstract
- Modifications were implemented on a semi-commercial air-gap membrane distillation prototype to assess experimentally any improvement in its performance. The main changes were in the air-gap domain with focus on reducing the conductive heat transfer losses by reducing the physical support that separates the membrane from the condensation surface. Moreover, several feed channel spacers were tested as well and assessed based on their effect in increasing the mass transfer and imposed pressure drop. Results show that the modifications increased slightly the distillate mass flow rate by 9-11% and reduced the conductive heat losses by 20-24%. Spacer effect was found to be mainly in imposed pressure drop within the tested types.
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| 19. |
- Kumar, Nutakki Tirumala Uday, et al.
(author)
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Experimental modeling of an air-gap membrane distillation module and simulation of a solar thermal integrated system for water purification
- 2017
-
In: Desalination and Water Treatment. - : DESALINATION PUBL. - 1944-3994 .- 1944-3986. ; 84, s. 123-134
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Journal article (peer-reviewed)abstract
- Membrane distillation is a novel process that could be adapted effectively for many water purification applications. In recent years, several bench, pilot and commercial scale membrane distillation systems with production capacities ranging from 20 L/d to 50 m(3)/d were developed and tested. In this work, a single cassette air-gap membrane distillation (AGMD) module was characterized to identify the effect of process parameters on distillate flux and thermal efficiency. Favorable conditions to obtain distillate flow rate of 1.5-3 kg/h were determined on a bench scale experimental setup. Factorial design of experiments was conducted and response surface methodology (RSM) was applied to develop an empirical regression model relating operating parameters with AGMD system performance indicators. Operating parameters including hot feed inlet temperature (T-Hin), cold feed inlet temperature (T-Cin), feed flow rate (V-f) and feed conductivity (C-f) were considered. Distillate flux (J(d)) and specific performance ratio (SPR) were selected as the performance indicators for the modeling. The developed regression model using RSM was tested by analysis of variance. Regression analysis showed agreement with the experimental data fitted with second-order polynomial model having determination coefficient (R-2) values of 0.996 and 0.941 for J(d) and SPR, respectively. Numerical optimization has been carried out to identify optimal set of operating conditions for achieving desired operation. Also, dynamic simulation of the membrane distillation module integrated solar thermal system has been reported along with validation of the system model by comparing with the experimental data obtained from a pilot scale setup located in UAE.
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| 20. |
- Larché, Nicolas, et al.
(author)
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Corrosion and corrosion management investigations in seawater reverse osmosis desalination plants
- 2013
-
In: Desalination and Water Treatment. - : Taylor and Francis Inc.. - 1944-3994 .- 1944-3986. ; 51:7-9, s. 1744-1761
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Journal article (peer-reviewed)abstract
- To comply with the demanding operational conditions of seawater reverse osmosis (SWRO) process, both in terms of corrosion resistance and mechanical properties, the conventional metallic material selection was often stainless steel for seawater and brines handling units (e.g. pumps, valves and piping). However, many cases of corrosion failures of stainless steel in SWRO desalination units have been reported often attributed to un-adapted stainless steel grade selection and/or to the particular aggressive conditions in "warm" regions where many recent desalination plants are built (high ambient temperature, severe biofouling, etc.). The operational corrosion risk will actually highly depend on the material composition, on the metallurgy (i.e. cast or wrought), on the service conditions and on the geometrical configuration of the concerned units in contact with seawater. Considering all these parameters, a proper material selection should avoid corrosion issue. For existing corrosion, cathodic protection (CP) may be an efficient solution to stop or to control the propagation of the degradation. However, the CP for materials used in SWRO desalination plants and in its specific operational conditions (i.e. high pressure, velocity and confinements) is not well documented; as a result, an adapted CP design is not always possible from existing data. The present paper reviews some corrosion cases of stainless steel and copper-based alloys in SWRO desalination plants. Solutions to manage existing corrosion of metallic materials in SWRO plants are discussed and focus is done on CP of stainless steel elements. Some results of an ongoing investigation about the CP for the specific operational conditions of SWRO desalination plant are presented and discussed.
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| 21. |
- Larché, Nicolas, et al.
(author)
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Corrosion of stainless steel components in seawater reverse osmosis desalination plants—investigations on adapted internal cathodic protection
- 2015
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In: Desalination and Water Treatment. - : Taylor and Francis Inc.. - 1944-3994 .- 1944-3986. ; 55:9, s. 2478-2490
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Journal article (peer-reviewed)abstract
- Abstract: Stainless steel is widely used in seawater reverse osmosis units (SWRO) for both good mechanical and corrosion resistance properties. However, many corrosion failures of stainless steel in SWRO desalination units have been reported. These failures may often be attributed to un-adapted stainless steel grade selection and/or to the particular aggressive seawater conditions in “warm” regions (high ambient temperature, severe biofouling, etc.). Cathodic protection (CP) is a well-known efficient system to prevent corrosion of metallic materials in seawater. It is successfully used in the oil and gas industry to protect carbon steel structures exposed in open-sea. However, the specific service conditions of SWRO units may seriously affect the efficiency of such anti-corrosion system (high flow rates, large stainless steel surfaces affected by biofouling, confinement limiting protective cathodic current flow, etc.). Hence, CP in SWRO units should be considered with special care and modeling appears as useful tool to assess an appropriate CP design. However, there is a clear lack of CP data that could be transposed to SWRO service conditions (i.e. stainless steel, effect of biofouling, high flow rate, etc.). From this background a Join Industry Program was initiated including laboratory exposures, field measurements in a full scale SWRO desalination plant, and modeling work using PROCOR software. The present paper reviews the main parameters affecting corrosion of stainless steel alloys in seawater reverse osmosis units. CP on specific stainless steel devices was investigated in order to assess its actual efficiency for SWRO units. Severe environmental conditions were intentionally used to promote corrosion on the tested stainless steel products in order to evaluate the efficiency of CP. The study includes a modeling work aiming at predicting and designing adapted CP protection to modeled stainless steel units. An excellent correlation between modeling work and field measurements was found.
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| 22. |
- Larche, Nicolas, et al.
(author)
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Review of material selection and corrosion in seawater reverse osmosis desalination plants
- 2011
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In: Desalination and Water Treatment. - : Taylor and Francis Inc.. - 1944-3994 .- 1944-3986. ; 31:1-3, s. 121-133
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Journal article (peer-reviewed)abstract
- Seawater desalination infrastructures require a careful material selection with high corrosion resistance. The high seawater temperatures in warm regions, where many desalination plants are developed, must be clearly considered regarding the corrosion of materials. To comply with the operational characteristics of seawater reverse osmosis (SWRO) process (high pressure, high chloride content and dissolved oxygen content at saturation values), the conventional material selection was stainless steel with sufficient pitting resistant equivalent number. However, many cases of corrosion failures of stainless steel in SWRO desalination units have been reported. In most cases the cause of the failures was attributed to the use of not enough alloyed grades. However, high alloy stainless steels are also susceptible to crevice and pitting corrosion in seawater. The operational corrosion risk will highly depend on the stainless steel composition, on the metallurgy (i.e. cast or wrought), on the service conditions, and on the geometrical configuration of the confined zones in contact with seawater. The present paper reviews the corrosion performance of metallic materials used for SWRO desalination plants. It focuses on the corrosion behaviour of several stainless steel grades. Recent corrosion failures of stainless steel pumps used in SWRO desalination plant in the Mediterranean Sea are also discussed.
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| 23. |
- Liu, Shuang, et al.
(author)
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Review and prospects of desalination as a water supply method in China
- 2013
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In: Desalination and Water Treatment. - : Informa UK Limited. - 1944-3986 .- 1944-3994. ; 51:22-24, s. 4291-4301
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Journal article (peer-reviewed)abstract
- With the development of urbanization and deterioration of water environment, the fresh water shortage in eastern coastal cities of China is more and more serious. Desalination, as the only way to increase the amount of fresh water, should be more applied in this region, while the actual development is not as expected for some reasons. The study reviews the desalination status in China from the perspective such as driving force, investment, cost, policy, safety and energy. The analysis of problems makes the recommendations how to develop desalination market and make desalination as a safety water supply. In addition, the study compares desalination with wastewater reuse in water quality, cost, management, public acceptance and so on and discusses the proposal for integrated utilization of different unconventional water sources.
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| 24. |
- Makzoom, Sima, et al.
(author)
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Evaluating the efficiency of cellulose nanofibers in DEHP removal from water
- 2017
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In: Desalination and Water Treatment. - : Desalination Publications. - 1944-3994 .- 1944-3986. ; 77, s. 229-236
-
Journal article (peer-reviewed)abstract
- The removal of di(2-ethylhexyl)phthalate (DEHP) from aqueous solutions by cellulose nanofibers (CNFs), derived from softwood, was studied. The optimum conditions of four factors at four levels including the DEHP concentration (1–10 mg/L), adsorbent dose (0.5–3 g/L), contact time (30–180 min), and pH (3–9) in a batch system was investigated by the design of experiment software. The Isotherm Fitting Tool software was used to fit isotherm parameters to experimental data. The maximum removal efficiency, (74.1%), was obtained at a DEHP concentration of 10 mg/L, an adsorbent dose of 0.5 g/L, a contact time of 30 min, and a pH of 7. The amount of DEHP adsorbed per unit weight of adsorbent (qe) in the optimum conditions was 14.8 mg/g. The system was well corresponded by the generalized Langmuir–Freundlich model. The results showed that extracted CNF from softwood has a good potential for treatment of polluted aqueous solutions by DEHP.
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| 25. |
- Malmsten, Madelene, et al.
(author)
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Cost analysis of urban water supply and waste water treatment processes to support decisions and policy making : application to a number of Swedish communities
- 2010
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In: Desalination and Water Treatment. - : Informa UK Limited. - 1944-3994 .- 1944-3986. ; 18:1-3, s. 327-340
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Journal article (peer-reviewed)abstract
- An econometric model has been developed that represents the cost structure of water supply and waste water treatment in an urban area. This paper proposes a method to capture the financial characteristics of the underlying organisation and addresses the steps and the conceptualisation in order to create a cost structure for municipal water utilities. The estimation procedure is based on a multivariate regression approach and the cost structure is represented by a parametrical expression (cost function). This function has been used for the purpose of analysing the observed system in terms of efficiency, technology, capacity, financial state etc. In the mathematical formula the estimated parameters relate certain system input components to costs, which are important in order to understand the key drivers. An empirical analysis is undertaken for a number of utilities in Sweden.
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| 26. |
- Mc Conville, Jennifer R, 1978, et al.
(author)
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Is the Swedish wastewater sector ready for a transition to source separation?
- 2017
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In: Desalination and Water Treatment. - : Desalination Publications. - 1944-3994 .- 1944-3986. ; 91, s. 320-328
-
Journal article (peer-reviewed)abstract
- Source separation of urine for recycling has been applied in small-scale and decentralized wastewater systems in Sweden for the past 25 years and for blackwater for pollution control even longer. The Swedish experience with source separating nutrient recycling systems is relatively well documented; however, few reports have specifically studied the potential for expansion of this practice. The aim of this study is to fill this knowledge gap by assessing the status of source-separating technologies in Sweden based on transition theory. This study uses a multi-level perspective to determine how ready the Swedish wastewater sector is for transitioning to alternative systems. Given the stability of the existing sewage wastewater regime, it seems unlikely that changes within the regime will lead to a quick and large-scale transition to source separation. Instead, the initiative must come from the niche itself, exploiting institutional cracks in the regime and opportunities from shifting trends in the landscape. If source separation is to be mainstreamed in Sweden, it will need to break into markets within the wastewater jurisdictions. In order to do so, further knowledge needs to be developed that will overcome glitches with immature technologies, uncertain legal conditions/status, investigate potential risks, and clearly define complementary system advantages. This may require the use of new perspectives that focus on holistic sustainable use of resources, including other nutrients than phosphorous, and taking into account global issues such as planetary boundaries and effects from climate change, such as water scarcity. This knowledge can then be used to establish guidelines, norms, and standards, as well as clarify the legislative structures that can support such a transition. There is also a strong need to improve knowledge dissemination regarding best-practices for implementing source-separation technologies and supporting organizational structures. Similarly, support for entrepreneurial activities within the niche needs to increase, not least through strengthening social networks and communication platforms.
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| 27. |
- Meroufel, Abdelkader, et al.
(author)
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Crevice corrosion behavior of stainless steels and nickel-based alloy in the natural seawater – Effect of crevice geometry, temperature and seawater world location
- 2017
-
In: Desalination and Water Treatment. - : Desalination Publications. - 1944-3994 .- 1944-3986. ; 69, s. 202-209
-
Journal article (peer-reviewed)abstract
- Crevice corrosion is one of the main corrosion problems for metallic alloys used in reverse osmosis (RO) desalination plants. This type of corrosion depends on many factors, that is, alloy composition and/or metallurgy, seawater location, biofilm, temperature, service conditions and crevice geometry. Corrosivity of gulf seawater was compared with the heated Brest seawater (France) for different stainless steels and nickel-based alloy. Maintaining the same experimental conditions, similarity of crevice corrosion performance in both sites relied on the tested alloys. Both crevice corrosion initiation and propagation were evaluated and compared with previous studies. Duplex S32205 and nickel-based N06625 suffered from crevice corrosion contrary to the superaustenitic S31266. However, corrosion results of superduplex S32750 and superaustenitic S31254 were reported very randomly, confirming the “borderline” behavior of these grades in some seawater applications. The impact of the results on the RO plants materials selection is outlined.
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| 28. |
- Morling, S., et al.
(author)
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Biological nitrogen removal at low water temperatures - long term experience
- 2011
-
In: DESALINATION AND WATER TREATMENT. - : Informa UK Limited. - 1944-3994 .- 1944-3986. ; 25:1-3, s. 226-232
-
Journal article (peer-reviewed)abstract
- Many earlier publication presented the lowest temperature of 10 degrees C as feasible for nitrification process. The article evaluates long-term experience with biological nitrogen removal at low temperatures (between 2 and 10 degrees C), studied at four wastewater treatment plants operated with SBR-technology: Holbaek (Denmark), Nowy Targ (Poland), Nynashamn and Skaulo (Sweden). Influence if nitrogen loads and COD/N ratio on nitrification rate was studied. Despite of operation at low temperatures during 3-4 months of the year good relation between the nitrogen load and the specific nitrification rate has been obtained. Long-term studies regarding nitrification, temperature and SRT demonstrated that the actually needed (aerated) SRT were lower than the normally recommended values. In some cases the nitrification was maintained at a lower efficiency even during non-aerated phases due to remaining free oxygen in the reactor that is used for nitrification.
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| 29. |
- Nutakki, Tirumala Uday Kumar, et al.
(author)
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Techno-economic optimization of solar thermal integrated membrane distillation for cogeneration of heat and pure water
- 2017
-
In: Desalination and Water Treatment. - : Desalination Publications. - 1944-3994 .- 1944-3986. ; 98, s. 16-30
-
Journal article (peer-reviewed)abstract
- The aim of this paper is to evaluate optimum design criteria for developing solar thermal integrated membrane distillation system for cogeneration of pure water and heat. The temporal and seasonal variability of the driving variables, such as ambient temperature and solar irradiance requires dynamic simulation of combined system using tools such as TRNSYS. Dynamic simulation and parametric analysis enables to design a functional system and then optimizes the design. In this study, the application of cogeneration system for residential households in United Arab Emirates is considered for per capita production of 4l/day of pure water and 50l/day of domestic hot water. The performance of cogeneration is optimized by varying various design parameters such as collector tilt angle, thermal storage volume and area of the solar collector field. Cogeneration solar fraction and payback period are considered as performance indicators for energetic and economic optimization. Further simulations are extended from small to large family application and for utilizing either flat plate (FPC) or evacuated tubular collector (ETC) systems. Optimized cogeneration system utilizes more than 80% of the available solar energy gain and operates at 45% and 60% collector efficiencies for FPC and ETC systems respectively Also, combined and system efficiencies of the cogeneration system are compared with standalone operational efficiencies for solar heaters and solar membrane distillation systems. Results show that, cogeneration operation reduces 6–16% of thermal energy demand and also enables 25% savings in electrical energy demand. Payback period could be reduced by 2.5–3 years by switching from regular solar water heating to cogeneration systems along with 4-fold increase in net cumulative savings.
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| 30. |
- Panasiuk, Oleksandr, 1986-, et al.
(author)
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The feasibility of using flap gates as constriction flow meters for estimating sanitary sewer overflows (SSO)
- 2019
-
In: Desalination and Water Treatment. - : Desalination Publications. - 1944-3994 .- 1944-3986. ; 155, s. 113-119
-
Journal article (peer-reviewed)abstract
- Increased awareness of the negative effects of sanitary sewer overflow (SSO) events on human health and aquatic life led to the development of various control measures, of which implementation is impeded by the lack of information on SSO occurrences, flows and volumes. The collection of such information requires data acquisition systems, which can be costly and are fully utilized just during limited time periods of the year. In search for inexpensive approaches to SSO monitoring, the feasibility of using existing flap gate installations, serving for prevention of back-up flows into sewers, as constriction flow meters was investigated, with promising results. An experimental pilotscale setup was designed to allow steady water flow through a flap gate built into a partition wall between two chambers. The stabilized water heads in the chambers and the flow rate through the flap gate were measured, for both dry and submerged flap gate conditions, and five flap gate sizes (200, 300, 400, 500 and 600 mm), with relatively heavy covers (6–102 kg). The measured data were used to develop flow rating curves, by non-linear regression, in the form Q = f (ΔH), where Q is the discharge through the flap gate and ΔH is the pressure differential upstream and downstream of the gate. The regression curves fitted the experimental data with high precision (R2 >0.99). The use of flow rating curves for estimation of the SSO volume was discussed. This study demonstrated that the water head measurements upstream and downstream of the flap gate can provide a reliable, accurate and inexpensive method for quantification of the SSO discharges and volumes.
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| 31. |
- Santo, C.E., et al.
(author)
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Sulphide removal from petroleum refinery wastewaters by catalytic oxidation
- 2012
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In: Desalination and Water Treatment. - : Informa UK Limited. - 1944-3994 .- 1944-3986. ; 46:1-3, s. 256-263
-
Journal article (peer-reviewed)abstract
- The catalytic oxidation of sulphides present in oil refinery wastewaters was investigated in the present study. The wastewaters were obtained from the wastewater treatment plant of the oil refinery in Matosinhos (Portugal), Galp Energia. Air, NaOCl and H2O2 were chosen as oxidants and Fe3+ and Mn2+ as the two catalysts to assess the effective combination of catalyst-oxidant for sulphide removal after oil separation in parallel plate interceptors. Primarily, air (oxygen) was used as the oxidant and the efficiency of two catalysts (Fe3+ and Mn2+) for sulphide removal was evaluated. Experimental data suggested that Fe3+ catalysed sulphide removal in the presence of oxygen was more effective than Mn2+ catalysed reaction. In a subsequent study, oxygen was replaced by NaOCl and H2O2, and the potential of various catalyst-oxidant combinations, NaOCl + [Fe3+], NaOCl + [Mn2+], H2O2 + [Fe3+], H2O2 + [Mn2+], was assessed. The NaOCl + [Fe3+] combination achieved the maximum sulphide oxidation. Pseudo-first-order and pseudo-second-order reaction models were fitted to the kinetic experimental data. The influence of temperature on the kinetic rate was also investigated.
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| 32. |
- Shafiq, Muhammad, et al.
(author)
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Estimation of ion adsorption using iterative analytical model in capacitive deionization process
- 2018
-
In: Desalination and Water Treatment. - : Desalination Publ. - 1944-3994 .- 1944-3986. ; 116, s. 75-82
-
Journal article (peer-reviewed)abstract
- Capacitive deionization (CDI) is an upcoming technique that can replace existing processes for removing and recuperating metal ions from dilute industrial waste waters. CDI removes ions via electrosorption on to its electrode surfaces, the efficiency of which is a function of CDI electrode properties that progressively change during continued operation. As such a need exists to develop a model to predict CDI performance over elongated periods which is independent of electrode properties and has negligible error values. By applying a first order non-linear dynamic model (FONDM) with inputs independent of the electrode characteristics, we propose a universal model that can predict CDI ion adsorption capacity with changes in applied potential, flow rate and electrolyte temperature to within 5% of the experimentally obtained results. The model was verified using activated carbon cloth (ACC) as a test electrode and aqueous sodium chloride solution as electrolyte, with a good prediction for ion electrosorption efficiency and time dependent electrosorption dynamics. The simplicity of the model makes it easy to adapt for various applications and in the development of intelligent control systems for CDI units in practical settings.
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| 33. |
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| 34. |
- Svensson, Henric, et al.
(author)
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Treatment of wood leachate with high polyphenols content by peat and carbon-containing fly ash filters
- 2015
-
In: Desalination and Water Treatment. - 1944-3994 .- 1944-3986. ; 53:8, s. 2041-2048
-
Journal article (peer-reviewed)abstract
- In the present study, two combinations of filter materials in filter/columns were examined for removal of total organic carbon (TOC) and polyphenols (PP) found in storm water runoff from wood storage areas in a wooden floor industry. One filter/column was packed with peat mixed with carbon-containing fly ash, while another filter/column contained only peat (without ash). The mixture of peat and ash has shown faster and higher removal capacity for TOC and faster removal with the same final removal capacity for PP (in grams of pollutant per kg of sorbent) at the saturation point. The superiority observed for the peat and ash filter is presumably due to the unique characteristics of peat and ash, which enhanced the treatment efficiency when used together in a mixture. Based on the observed results, filters formed by peat and carbon-containing ashes proved to be a potentially low-cost option for the treatment of storm water generated at storage areas of wood materials such as logs, sawdust and wood chips.
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| 35. |
- Svensson, Henric, 1984-, et al.
(author)
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Treatment of wood leachate with high polyphenols content by peat and carbon-containing fly ash filters
- 2015
-
In: Desalination and Water Treatment. - : Informa UK Limited. - 1944-3994 .- 1944-3986. ; 53:8, s. 2041-2048
-
Journal article (peer-reviewed)abstract
- In the present study, two combinations of filter materials in filter/columns were examined for removal of total organic carbon (TOC) and polyphenols (PP) found in storm water runoff from wood storage areas in a wooden floor industry. One filter/column was packed with peat mixed with carbon-containing fly ash, while another filter/column contained only peat (without ash). The mixture of peat and ash has shown faster and higher removal capacity for TOC and faster removal with the same final removal capacity for PP (in grams of pollutant per kg of sorbent) at the saturation point. The superiority observed for the peat and ash filter is presumably due to the unique characteristics of peat and ash, which enhanced the treatment efficiency when used together in a mixture. Based on the observed results, filters formed by peat and carbon-containing ashes proved to be a potentially low-cost option for the treatment of storm water generated at storage areas of wood materials such as logs, sawdust and wood chips.
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| 36. |
- Yalamacilar, Busra Burcu, et al.
(author)
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Benchmarking industrial water purification systems with the aid of life cycle assessment
- 2021
-
In: Desalination and Water Treatment. - : Desalination Publications. - 1944-3994 .- 1944-3986. ; 211, s. 422-431
-
Journal article (peer-reviewed)abstract
- Water is among the essential inputs of many industrial production processes. Substantial amounts of water with varying qualities is of importance in running quite a number of industrial sectors. The water quality requirements necessitate the application of different water purification systems. This study concentrates on comparing the environmental impacts of reverse osmosis and an ion exchange system that treat the water supplied from a well to a quality suitable for boiler water makeup. Life cycle assessment methodology is adopted for this evaluation. Purification system with the ion exchanger requires 18.6% less energy in comparison with the reverse osmosis system. However, substantially higher environmental impacts are obtained for the ion exchanger system when compared with the treatment scheme of reverse osmosis. Hence, the reverse osmosis system should be favored. Changing the source of energy from the grid mix to wind power is observed to further reduce abiotic depletion potential (fossil), human toxicity potential, acidification potential, eutrophication potential, and terrestric ecotoxicity potential for the reverse osmosis system.
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| 37. |
- Zhang, Wen, et al.
(author)
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Removal of micropollutants and nutrients in household wastewater using organic and inorganic sorbents
- 2018
-
In: Desalination and Water Treatment. - : Desalination Publications. - 1944-3994 .- 1944-3986. ; 120, s. 88-108
-
Journal article (peer-reviewed)abstract
- The efficiency of five organic and five inorganic sorbents in removing 19 organic micropollutants (MPs), phosphorus, nitrogen, and dissolved organic carbon (DOC) was tested in a two-week column experiment using household wastewater spiked with pharmaceuticals (n = 6), biocides/pesticides (n = 4), organophosphates (n = 3), a fragrance, a UV-stablizer, a food additive, a rubber additive, a plasticizer and a surfactant. Two types of granular activated carbon (GAC), two types of lignite, a pine bark product, and five mineral-based sorbents were tested. All the organic sorbents except pine bark achieved better removal efficiencies of DOC (on average, 70 +/- 27%) and MPs (93 +/- 11%) than the inorganic materials (DOC: 44 +/- 7% and MPs: 66 +/- 38%). However, the organic sorbents (i.e. GAC and xyloid lignite) removed less phosphorus (46 +/- 18%), while sorbents with a high calcium or iron content (i.e. Polonite (R) and lignite) generally removed phosphorus more efficiently (93 +/- 3%). Ammonium- nitrogen was well removed by sorbents with a pH between 7 and 9, with an average removal of 87%, whereas lignite (pH 4) showed the lowest removal efficiency (50%). Some MPs were well removed by all sorbents (>= 97%) including biocides (hexachlorobenzene, triclosan and terbutryn), organophosphates (tributylphosphate, tris-(1,3-dichloro-2-propyl) phosphate and triphenylphosphate) and one fragrance (galaxolide). The pesticide 2,6-dichlorobenzamide and the pharmaceutical diclofenac were poorly removed by the pine bark and inorganic sorbents (on average, 4%), while organic sorbents achieved high removal of these chemicals (87%).
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| 38. |
- Zhang, Yunfan, et al.
(author)
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Photo-corrosion inhibition of Ag3PO4 by polyaniline coating
- 2016
-
In: Desalination and Water Treatment. - : Informa UK Limited. - 1944-3994 .- 1944-3986. ; 57:29, s. 13394-13403
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Journal article (peer-reviewed)abstract
- In this paper, polyaniline-coated silver phosphate has been successfully prepared via a facile chemisorption method in order to improve the stability of Ag3PO4 under light irradiation. The crystalline phase, band gap energy, and microstructure of the obtained PANI/Ag3PO4 composites were characterized by X-ray diffraction, UV-vis diffuse reflection spectroscopy, scanning electron microscopy, and transmission electron microscopy, respectively. The photocatalytic degradation of methlylene blue was performed to test the activities of PANI/Ag3PO4 composites with different coating amounts and the results indicate that the stabilities of PANI/Ag3PO4 composites were successfully enhanced. The correlation between photocatalytic performance and the properties of PANI/Ag3PO4 composites is discussed in detail.
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| 39. |
- Dalahmeh, Sahar
(author)
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Analysis of some pharmaceuticals in surface water in Jordan
- 2020
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In: Desalination and Water Treatment. - : Desalination Publications. - 1944-3994. ; 176, s. 38-44
-
Journal article (peer-reviewed)abstract
- A quantitative assessment of pharmaceuticals in surface water in Jordan was conducted using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to evaluate the occurrence, source and distribution of 18 pharmaceutical compounds. Grab samples were collected in the summer from the effluent of two dams in Jordan. Among all of the pharmaceuticals analyzed, the results showed that 10 pharmaceutical compounds were detected in the effluent of King Talal Dam including 1,7-dimethylxanthine, acetaminophen, amphetamine, caffeine, carbamazepine, cotinine, phenazone, sulfamethoxazole, sulfamethazine, trimethoprim. However, four pharmaceutical compounds detected in the effluent of Mujib Dam include 1,7-dimethylxanthine, caffeine, cotinine, phenazone. Moreover, eight pharmaceutical compounds were not detected in both dams (<0.005 mu g/L) including cimetidine, diphenhydramine, MDA, MDMA, methamphetamine, morphine, sulfachloropyridazine and thiabendazole. The results also indicated that the compound detected at the highest concentration levels in King Talal Dam was carbamazepine at concentration of 0.358 mu g/L. It is very clear that the occurrence of pharmaceuticals at King Talal Dam is higher than in Mujib Dam. This is mainly due to the fact that King Talal Dam is receiving runoff water and treated wastewater from the wastewater treatment plant (WWTP), while the Mujib Dam is only receiving surface runoff water. This is consistent with many studies reported in the literature that municipal WWTPs are considered a primary source for the discharge of pharmaceuticals and personal care products into surface waters.
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| 40. |
- Eldeeb, Tarek M., et al.
(author)
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Novel three-dimensional chitosan-carbon nanotube–PVA nanocomposite hydrogel for removal of Cr6+ from wastewater
- 2020
-
In: Desalination and Water Treatment. - : Desalination Publications. - 1944-3994. ; 184, s. 163-177
-
Journal article (peer-reviewed)abstract
- A novel hybrid nanocomposite adsorbent was prepared by encapsulation of multi-walled carbon nano-tubes within polyvinyl alcohol/chitosan hydrogel (Cs/MWCNT/PVA) and cross-linked with glu-taraldehyde. The chemical reactions between the components affected the position and intensities of the infrared bands. This nanocomposite has excellent Cr6+ ions adsorption efficiency. The optimal conditions of the process as a function of the solution pH, contact time, ionic strength, and sorbent weight were investigated. The batch equilibrium experiments revealed that the most suitable pH for chromium adsorption was at 1.5. The maximum adsorption capacity for the hydrogel was 217.4 mg g–1 as estimated by the Langmuir model. Other isotherm models, such as Freundlich and Temkin, were used to analyze the experimental data and the models’ parameters were evaluated. The pseudo-first and second-order, Elovich, intraparticle diffusion, and film diffusion kinetic models were also inves-tigated. The obtained results enabled to estimate the possibility to use the Cs/MWCNT/PVA hydrogel in the removal of Cr6+ ions from wastewater by adsorption.
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| 41. |
- Gutierrez, Leonardo, et al.
(author)
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Nanomechanical characterization of recalcitrant foulants and hollow fibemembranes in ultrafiltration systems
- 2018
-
In: Desalination and Water Treatment. - : Desalination Publications. - 1944-3994. ; 136, s. 49-64
-
Journal article (peer-reviewed)abstract
- Long-term nanomechanical changes of polymeric ultrafiltration (UF) membranes caused by fouling/cleaning agents in water treatment are not well established in the literature. The goal of this study was to investigate the nanomechanical properties of polymeric UF hollow fiber membranes operating at a pilot-scale for 449 d and subjected to a low-quality feed (i.e., high turbidity/TOC content). Quantitative nanomechanical mapping technique was used to measure the deformation, dissipation, modulus, adhesion, and roughness of the polymeric structures of commercial Aquaflex virgin membranes, harvested membranes, and foulant layers. Results indicated that the recalcitrant and heterogeneous nature of the foulants absorbed on harvested membranes showed low elastic properties, and high modulus, adhesion, and roughness. The strong affinity of these foulants towards membrane surface would alter membrane characteristics and influence subsequent fouling behaviour. The cleaning process and extended operation did not significantly affect the nanomechanical properties of membranes. Despite the low-quality feed, the three modules were only subjected to 37 chemi-cal-enhanced backwashes and filtered a total volume of 2.155 m3. These results indicate the importance of operating conditions (i.e., frequency of backwash/cleaning/disinfection steps) and feed quality on the long-term changes of UF membranes and would assist in identifying research directions that are necessary to minimize membrane fouling/ageing.
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