| 1. |
- Abd Ali, Ziad T., et al.
(författare)
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Predominant mechanisms for the removal of nickel metal ion from aqueous solution using cement kiln dust
- 2020
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Ingår i: Journal of Water Process Engineering. - : Elsevier BV. - 2214-7144. ; 33
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Tidskriftsartikel (refereegranskat)abstract
- The experimental methodology achieved in the present study signified that the adsorption and precipitation were main mechanisms occurred together in the removal of nickel from aqueous solution by sorption using cement kiln dust (CKD) byproduct as sorbent. Finding the contribution of each mechanism in the removal process and derivation an analytical model for finding the portion of precipitation were the focal points of this work. Results proved that pure precipitation was increased with the increase of CKD dosage and metal concentration where total removal (adsorption-precipitation) ranged from 45 to 100%. The SEM micrographs of the CKD sorbent before and after sorption process certified that there was crystal precipitates on the surface of the CKD. Also, these graphs in combination with FT-IR tests proved that [Ni(OH2)n]+2 (n=4-6) species were bonded with CKD and insoluble hydroxide species may be precipitated onto the CaO surfaces by co-precipitation, while K–O, Si-O and Ca-O groups enhanced the adsorption mechanism.
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| 2. |
- Almuktar, Suhad A.A.A.N., et al.
(författare)
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Assessment of capsicum annuum l. Grown in controlled and semi-controlled environments irrigated with greywater treated by floating wetland systems
- 2021
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Ingår i: agronomy. - : MDPI AG. - 2073-4395. ; 11:9
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Tidskriftsartikel (refereegranskat)abstract
- Accumulation of trace elements, including heavy metals, were evaluated in soil and fruits of chilli plants (Capsicum annuum L.) grown under both laboratory-controlled and semi-controlled greenhouse location conditions. Chilli plant biomass growth in different development stages and fruit productivity were evaluated and compared with each other for the impact of growth boundary conditions and water quality effects. Treated synthetic greywaters by different operational design set-ups of floating treatment wetland systems were recycled for watering chillies in both locations. Effluents of each individual group of treatment set-up systems were labelled to feed sets of three replicates of chilli plants in both locations. Results revealed that the treated synthetic greywater (SGW) complied with thresholds for irrigation water, except for high concentrations (HC) of phosphates, total suspended soils, and some trace elements, such as cadmium. Chilli plants grew in both locations with different growth patterns in each development stage. First blooming and high counts of flowers were observed in the laboratory. Higher fruit production was noted for greenhouse plants: 2266 chilli fruits with a total weight of 16.824 kg with an expected market value of GBP 176.22 compared to 858 chilli fruits from the laboratory with a weight of 3.869 kg and an estimated price of GBP 17.61. However, trace element concentrations were detected in chilli fruits with the ranking order of occurrence as: Mg > Ca > Na > Fe > Zn > Al > Mn > Cu > Cd > Cr > Ni > B. The highest concentrations of accumulated Cd (3.82 mg/kg), Cu (0.56 mg/kg), and Na (0.56 mg/kg) were recorded in chilli fruits from the laboratory, while greater accumulations of Ca, Cd, Cu, Mn, and Ni with concentrations of 4.73, 1.30, 0.20, 0.21, and 0.24 mg/kg, respectively, were linked to fruits from the greenhouse. Trace elements in chilli plant soils followed the trend: Mg > Fe > Al > Cr > Mn > Cd > Cu > B. The accumulated concentrations in either chilli fruits or the soil were above the maximum permissible thresholds, indicating the need for water quality improvements.
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| 3. |
- Almuktar, Suhad A.A.A.N., et al.
(författare)
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Contaminations of soil and two capsicum annuum generations irrigated by reused urban wastewater treated by different reed beds
- 2018
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Ingår i: International Journal of Environmental Research and Public Health. - : MDPI AG. - 1661-7827 .- 1660-4601. ; 15:8
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Tidskriftsartikel (refereegranskat)abstract
- Background: In order to save potable water, this study aims to evaluate the contamination of soil and Capsicum annuum L. (chilli) watered with urban wastewater (sewage) pre-treated by various wetland systems. Methods: The appropriateness of wetland outflow for irrigation when applying reused wastewater with high contamination of minerals and pathogens was assessed. The impact of wastewaters pre-treated by various wetlands on soil and harvest was tested in terms of mineral and biological contamination risk. Results: The wetlands met the standards for irrigation water for most water quality variables. However, the thresholds for key water quality parameters were significantly (p < 0.05) exceeded. The highest values for total coliforms, ammonium-nitrogen, phosphorus and potassium were 157,072 CFU/100 mL, 8.5 mg/L, 5.0 mg/L, and 7.0 mg/L, respectively. The harvest was moderately polluted only by zinc according to vegetable quality standards (threshold of 50 mg/kg). Zinc concentrations for Filters 2, 4, 6, 7 and 8 were 35.8, 60.6, 65.1, 65.5 and 53.2 mg/kg, respectively. No bacterial contamination was detected. Conclusions: Treatment of domestic wastewater applying constructed wetlands and subsequent recycling of the treated wastewater for irrigation of crops is a good substitute to the traditional application of drinking water for irrigation purposes.
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| 4. |
- Almuktar, Suhad A.A.A.N., et al.
(författare)
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Recycling of domestic wastewater treated by vertical-flow wetlands for irrigation of two consecutive Capsicum annuum generations
- 2017
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Ingår i: Ecological Engineering. - : Elsevier BV. - 0925-8574. ; 107, s. 82-98
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Tidskriftsartikel (refereegranskat)abstract
- Due to water scarcity, there is great interest in reusing various nutrient-rich wastewaters. The aim of this article is consequently to evaluate if domestic wastewater treated by various wetland systems can be successfully recycled to irrigate generations of commercial crops such as Chilli (Capsicum annuum) grown in compost within a laboratory environment to obtain a cultivar adapted to domestic wastewater. The corresponding objectives were to assess the irrigation water for long-term growth when applying recycled wastewater, the impact of various wastewaters subject to the wetland characteristics, the impact of treated wastewater volume for irrigation, and the economic return of different experimental set-ups in terms of marketable yields. The vertical-flow wetlands treated domestic wastewater well, meeting the irrigation water quality standards for most water quality parameters, except for phosphorus (4.2 ± 0.48 mg/l), ammonia-nitrogen (4.2 ± 2.64 mg/l), potassium (7.0 ± 3.03 mg/l) and total coliforms (69647 ± 64852.6 CFU/100 ml), which showed high values significantly (p < 0.05) exceeding common thresholds set for irrigation applications of 2 mg/l, 5 mg/l, 2 mg/l, and 1000 CFU/100 ml. Chilli generations were grown successfully when applying wastewater treated by wetlands and organic soil. High Chilli generation yields concerning economic return were linked with wetlands containing small aggregates with long contact and resting times and fed with a high inflow loading rate (undiluted wastewater), releasing more nutrients into their effluent producing the best fruit quality with respect to weight, length and width resulting in a greater marketable profit of about 46% compared with the others. First generation Chilli plants were grown with considerably shorter heights and produced abundant fruit numbers, which were harvested earlier than their mothers due to the reduction (approximately 55%) of irrigation water volume used for them compared to their mothers. However, excessive nutrients applied on mother plants via irrigation water resulted in better fruit quality regarding dimensions and weights compared with their corresponding first generation plants, leading to a greater marketable profit by about 25%.
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| 5. |
- Almuktar, Suhad A.A.A.N., et al.
(författare)
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Wetlands for wastewater treatment and subsequent recycling of treated effluent : a review
- 2018
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Ingår i: Environmental Science and Pollution Research. - : Springer Science and Business Media LLC. - 0944-1344 .- 1614-7499. ; 25:24, s. 23595-23623
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Tidskriftsartikel (refereegranskat)abstract
- Due to water scarcity challenges around the world, it is essential to think about non-conventional water resources to address the increased demand in clean freshwater. Environmental and public health problems may result from insufficient provision of sanitation and wastewater disposal facilities. Because of this, wastewater treatment and recycling methods will be vital to provide sufficient freshwater in the coming decades, since water resources are limited and more than 70% of water are consumed for irrigation purposes. Therefore, the application of treated wastewater for agricultural irrigation has much potential, especially when incorporating the reuse of nutrients like nitrogen and phosphorous, which are essential for plant production. Among the current treatment technologies applied in urban wastewater reuse for irrigation, wetlands were concluded to be the one of the most suitable ones in terms of pollutant removal and have advantages due to both low maintenance costs and required energy. Wetland behavior and efficiency concerning wastewater treatment is mainly linked to macrophyte composition, substrate, hydrology, surface loading rate, influent feeding mode, microorganism availability, and temperature. Constructed wetlands are very effective in removing organics and suspended solids, whereas the removal of nitrogen is relatively low, but could be improved by using a combination of various types of constructed wetlands meeting the irrigation reuse standards. The removal of phosphorus is usually low, unless special media with high sorption capacity are used. Pathogen removal from wetland effluent to meet irrigation reuse standards is a challenge unless supplementary lagoons or hybrid wetland systems are used.
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| 6. |
- Abed, Suhail N., et al.
(författare)
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Phytoremediation performance of floating treatment wetlands with pelletized mine water sludge for synthetic greywater treatment
- 2019
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Ingår i: Journal of Environmental Health Science & Engineering (Online). - : Springer Science and Business Media LLC. - 2052-336X. ; 17:2, s. 581-608
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Buckets containing floating reed (Phragmites australis) simulated floating treatment wetlands (FTWs) and were used to improve the remediation performance of synthetic greywater (SGW). The aim of the study was to investigate the behaviour of FTWs for treatment of key contaminants within artificial greywater. Methods: Pelletized ochre based on acid mine water sludge was introduced to selected FTWs, because of its capability in sequestration phosphorus and other trace elements. The impact of the following four operational variables were tested in the experimental set-ups of the FTWs (four replicates each): pollutant strength (high- (HC) and low- (LC) concentrations), treatment time (2- or 7-days of hydraulic retention time (HRT)), presence or absence of macrophytes (P. australis) and cement-ochre pellets. Results: The results showed that 5 - day biochemical oxygen demand (BOD) and chemical oxygen demands (COD) were significantly (p < 0.05) reduced in all wetlands. Nitrate-nitrogen (NO3-N) concentrations were significantly (p < 0.05) higher, and those measurements for PO4-P were significantly (p < 0.05) lower than the corresponding ones determined for the influent. The existence of ochre pellets with P. australis significantly (p < 0.05) decreased B, Cd, Cr, Cu, Mg, Ni and Zn concentrations, but increased Al, Ca, Fe and K concentrations in the effluent, with the exception of sodium (Na). Conclusions: The FTW performances can be improved by utilising ochre-cement pellets to increase the pH of greywater. The presence of P. australis acts as a buffer to neutralise the pH of SGW. Rhizomes and biofilms mitigate increases in turbidity, TSS and colour values.
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| 7. |
- Abed, Suhail N., et al.
(författare)
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Remediation of synthetic greywater in mesocosm—Scale floating treatment wetlands
- 2017
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Ingår i: Ecological Engineering. - : Elsevier BV. - 0925-8574. ; 102, s. 303-319
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Tidskriftsartikel (refereegranskat)abstract
- Two different chemical recipes comprising various pollutants were selected to create high (HC) and low (LC) levels of contaminated synthetic greywaters (SGW). Remediation in macrocosm–scale floating treatment wetlands (FTW) vegetated with Phragmites australis (Cav.) Trin. ex Steud. (common reed) was investigated under natural weather conditions. The presence or absence of vegetation, short or long contact time of treatment, and low or high contamination loads are the main operational variables in the experimental set-up design of the FTW. The focus on removal processes (other than sedimentation) such as the role of macrophytes in phytoremediation was achieved by agitation of the treated outflow before sampling. To assess the impact of interactions between the experimental operational variables on removal performances of FTW, different approaches of statistical analysis were applied. The results revealed that total suspended solids (TSS) and turbidity values dropped significantly (p < 0.05) in the presence of vegetation compared with those values from unvegetated wetlands. The presence of vegetation can significantly (p < 0.05) improve the biodegradation possibility of greywater by increasing the five-day biochemical oxygen demand (BOD) and decreasing the chemical oxygen demand (COD) concentrations. In vegetated FTW, higher removal rates of COD can be achieved when treating HC-SGS compared to LC-SGW. However, no significant differences (p > 0.05) in the removal of BOD was noted. Significant increases (p < 0.05) in BOD concentrations have been recorded with increasing contact time of treatment, while high removals of COD have been recorded. The presence of vegetation in wetlands affected significantly (p < 0.05) the decrease of dissolved oxygen (DO) concentrations in outflow of both types of greywater. If limited sources of organic matter are available, vegetation has significantly (p < 0.05) enhanced the nutrient balance with increasing nitrate-nitrogen (NO3-N) and decreasing ortho-phosphate-phosphorus (PO4-P) concentrations in the outflow. Furthermore, significant increases (p < 0.05) in ammonia-nitrogen (NH4-N) and DO were observed with increasing contact time, while TSS, turbidity, and NO3-N concentrations significantly decreased (p < 0.05). In addition, yellow leaves and considerably lower growth rates were observed for the hydroponic plant rhizomes of P. australis, which might be an effect of light-induced fluorescein degradation due to the relatively open water surfaces of the wetlands.
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| 8. |
- Abed, Suhail N., et al.
(författare)
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Treatment of contaminated greywater using pelletised mine water sludge
- 2017
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Ingår i: Journal of Environmental Management. - : Elsevier BV. - 0301-4797. ; 197, s. 10-23
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Tidskriftsartikel (refereegranskat)abstract
- Precipitated sludge (ochre) obtained from a mine water treatment plant was considered as an adsorbent substance for pollutants, since ochre is relatively free from problematic levels of toxic elements, which could impair on the quality of water to be treated. Artificially created ochre pellets from mixing Portland cement with raw ochre sludge were utilised to remediate either high (HC) or low (LC) contaminated synthetic greywater (SGW) in mesocosm–scale stabilisation ponds at 2–day and 7–day contact times under real weather conditions in Salford. After a specific retention time, treated SGW was agitated before sampling to evaluate pollutant removal mechanisms (other than sedimentation) such as adsorption by ochre pellets, before replacing the treated water with new inflow SGW. The results showed that cement–ochre pellets have a high ability to adsorb ortho–phosphate–phosphorous (PO4–P) significantly (p < 0.05) by 70.7% and 56.0% at 7–day contact time for HC–SGW and LC–SGW, respectively. After the experiment, an analysis revealed that elements such as boron (B), cadmium (Cd), magnesium (Mg), manganese (Mn), nickel (Ni) and zinc (Zn) accumulated significantly (p < 0.05) within the ochre pellets. The notable accumulation of Cd within ochre pellets reflects the significant (p < 0.05) remediation of greywater during the first 35 and 20 successive times of treatment for HC–SGW at 2– and 7–day contact times, respectively. Cadmium was still adsorbed significantly (p < 0.05) during the treatment of LC–SGW. However, the calcium (Ca) content decreased significantly (p < 0.05) within ochre pellets treating both types of greywaters due to mobilisation. The corresponding increases of Ca in greywater were significant (p < 0.05).
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| 9. |
- Rahi, Muna A., et al.
(författare)
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Biochemical performance modelling of non-vegetated and vegetated vertical subsurface-flow constructed wetlands treating municipal wastewater in hot and dry climate
- 2020
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Ingår i: Journal of Water Process Engineering. - : Elsevier BV. - 2214-7144. ; 33
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Tidskriftsartikel (refereegranskat)abstract
- Wastewater treatment and subsequent effluent recycling for non-drinking purposes such as irrigation contributes to the mitigation of the pressure on freshwater resources. In this study, two vertical sub-surface flow constructed wetland (VSSF-CW) pilot plants were operated to treat municipal wastewater and their effluents were reused for irrigation purposes. One of the wetlands was vegetated with Phragmites australis (Cav.) Trin. ex Steud. (common reed) to compare its efficiency of pollutant removals with the non-vegetated system, which had the same design. COMSOL Multiphysics 3.5a was operated for the Activated Sludge Model 2 (ASM2) to predict the chemical oxygen demand (COD) and ammonia-nitrogen (NH4-N) concentrations. The effluent quality of both treatment systems was assessed for several parameters. Computer simulations show a good compliance between the measured and predicted values of COD and NH4-N for the vegetated system. The calibrated model could be effectively used to predict the behaviours of those parameters as a function of time. Moreover, the effluents of both vegetated (VFp) and non-vegetated (VF) VSSF-CW were significantly (p < 0.05) improved compared to influent. Significant (p < 0.05) effects due to the presence of P. australis were observed for removals of total suspended solids (TSS), 5-day biochemical oxygen demand (BOD5), COD, NH4-N and ortho-phosphate-phosphorus (PO4-P). However, significant increases (p < 0.05) were noted for electrical conductivity (EC), total dissolved solids (TDS), nitrate-nitrogen (NO3-N) and sulphate (SO4) of both effluents compared to the raw wastewater. Except for EC, NH4-N and SO4, all water quality parameters complied with irrigation water standards.
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