| 1. |
- Abi Nassif, L., et al.
(författare)
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Reduction of potential ennoblement of stainless steel in natural seawater by an ecofriendly biopolymer
- 2020
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Ingår i: Journal of Environmental Chemical Engineering. - : Elsevier Ltd. - 2213-3437. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- The effect of biofilm formation on passive stainless steel in seawater environments is of primary importance since it leads to potential ennoblement of surfaces and subsequently to localized corrosion such as pitting and crevice corrosion. This study aims at developing an ecofriendly alginate biopolymer containing both non-toxic calcium and a limited amount of biocidal zinc ions which inhibits this effect. For this purpose, calcium alginate containing less than 1 % of zinc ions localized in the vicinity of the steel surface in natural and renewed seawater is demonstrated to reduce significantly the ennoblement process of steel. After 1 month of immersion, a mass loss of only 4 % of the active material is observed authorizing thereby long-term protection of steel in real environment.
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| 2. |
- Atasoy, Merve, PhD, 1990-, et al.
(författare)
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Butyric acid dominant volatile fatty acids production : Bio-Augmentation of mixed culture fermentation by Clostridium butyricum
- 2020
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Ingår i: Journal of Environmental Chemical Engineering. - : Elsevier Ltd. - 2213-3437. ; 8:6
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Tidskriftsartikel (refereegranskat)abstract
- The most sustainable and environmentally friendly butyric acid production method is fermentation; however, low production yield and high substrate cost limit the competition with petrol-based production. The study is aimed to enhance butyric acid production via bioaugmentated mixed culture by Clostridium butyricum. Anaerobic sequencing batch reactors (bioaugmented and control) were operated under alkali pH (pH 10) at 35 °C and fed by dairy industry wastewater as substrate. The performance of bioaugmentation was monitored in three stages: before the application, during the application (C. butyricum was injected as %10 of active reactor volume on a daily basis for seven days), after bioaugmentation. The VFA concentration and composition (by GC-FID) with the copy gene number of C. butyricum (by Q-PCR) were monitored in the bioaugmented reactor during the operation. The bioaugmentation of C. butyricum increased butyric acid production (mgCOD L-1) from 260 ± 36 to 2889 ± 180. The total VFA production (mgCOD L-1) was increased from 1434 ± 217 to 4642 ± 1778 in control and bioaugmented reactors, respectively. There was a positive correlation between the gene copies of C. butyricum with butyric, hexanoic, n-heptanoic, valeric acids production. Furthermore, the bioaugmented mixed culture had better performance than pure culture regarding butyric acid production. The cycle analysis showed that the similar butyric acid production efficiency would be obtained in the first 6 h in the bioaugmented reactor, in the first 14 h in the control reactor of the cycle. The study provides a fundamental solution to step forward to achieve next-generation biorefineries by using both monocultures modularity and mixed culture robustness and stability regarding.
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| 3. |
- Cao, Zhejian, et al.
(författare)
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Carbon-reinforced MgCl2 composites with high structural stability as robust ammonia carriers for selective catalytic reduction system
- 2020
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Ingår i: Journal of Environmental Chemical Engineering. - : Elsevier. - 2213-3437. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- Novel carbon-MgCl2 composites were designed as robust ammonia carriers for selective catalytic reduction (SCR) system, with graphite (Gt) and graphene nanoplatelets aggregates (GNA) as additives to MgCl2. The cylindrically pelletized composites manifested high structural stability above the melting temperature of MgCl2 with 95 % mass retention, whereas the pure MgCl2 pellets completely lost their structural integrity. With the support of carbon additives, molten MgCl2 in the composites was isolated and retained the sample-to-holder angle of 90°, contrary to pure MgCl2 of 5.7° contact angle at 1073 K. Furthermore, the composites demonstrated rapid ammonia sorption and desorption kinetics, due to the enhanced surface area and creation of additional microporosity. Our results demonstrated that 20 wt.% GNA-80 wt.% MgCl2 (GNA20) composite presented 83 % faster kinetics in ammonia sorption and 73% faster in the first-2-minutes of desorption compared to the pure MgCl2. The enhancement of both structural stability and sorption kinetics makes the GNA20 composite a robust ammonia carrier.
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| 4. |
- Ghanim, Bashir, et al.
(författare)
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Application of KOH modified seaweed hydrochar as a biosorbent of Vanadium from aqueous solution : Characterisations, mechanisms and regeneration capacity
- 2020
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Ingår i: Journal of Environmental Chemical Engineering. - : Elsevier Ltd. - 2213-3437. ; 8:5
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Tidskriftsartikel (refereegranskat)abstract
- Vanadium exists as a mobile and toxic trace metal in many alkaline residue leachates. Its removal and recovery not only reduces a global environmental risk but is also critical to the emergence of innovative technologies and the circular economy. In parallel, the use of treated biomass feedstock is receiving increased attention as a low cost adsorbent for toxic metals in wastewater. This study investigated the adsorption of Vanadium (V) from aqueous solution by KOH modified seaweed (Ascophyllum nodosum) hydrochar (HCKOH). The results showed that HCKOH is an effective V(V) adsorbent, achieving maximum uptake of 12.3 mg g-1 at solution pH 4, 60 min contact time and temperature 293 K. The kinetics followed a pseudo second order model with film diffusion controlling the overall adsorption rate. The type I adsorption isotherm was well fitted to a Langmuir model (qm = 12.3 mg g-1, R2 = 0.970, RMSE = 0.66) and a thermodynamic study indicated that the V(V) adsorption was both exothermic and spontaneous. The low enthalpy change (-10.97 kJ mol-1) indicated a weak binding of V(V) to HCKOH pointing to the possibility of V recovery. The impact of co-existing cations on V(V) uptake was negligible for Na(I) and Ga (III) but was reduced slightly for Al(III). Desorption and re-adsorption results (3 cycles) indicated that HCKOH has reusable potential to remove and recover V(V) from waste leachates. © 2020 The Author(s).
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| 5. |
- Liem-Nguyen, Van, et al.
(författare)
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Removal mechanism of arsenic (V) by stainless steel slags obtained from scrap metal recycling
- 2020
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Ingår i: Journal of Environmental Chemical Engineering. - : Elsevier. - 2213-3437. ; 8:4
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Tidskriftsartikel (refereegranskat)abstract
- With this study, the removal mechanisms of arsenate by steel slag and its potential for treatment of contaminated water were elucidated. While original slag showed a poor fit to the Langmuir equation (R2 = 0.960), washed slag (the original slag is washed by low pH water solutions to remove readily soluble oxides) conformed better (R2 = 0.995). An initial pH of 2.0 give optimal adsorption, with a strong impact from the chemical speciation observed with highest efficiency for the fully protonated (OH)3AsO form. Adsorption capacity of the slag is 4.0 mg g−1, while together with precipitation the retention capacity reaches 13.7 mg g−1. However, removal by precipitation is a non-steady process due to re-dissolution of Ca3(AsO4)2(s). The washed slag shows a similar adsorption capacity to the original one but has not as strong alkaline properties. Batch experiment shows fast adsorption kinetics and column loading tests indicate an instant adsorption kinetics with 80 % As(V) removal for a 10 mg L−1 As(V) solution by 1.0 g of washed slag using a solution flowrate of 1 mL min−1. Common ions like sulfate, carbonate, chloride, iron(III), humic acid and fulvic acid do not significantly interfere with the removal efficiency. In combination with limited hazardous metals leaching, the slag is thus appropriate for use as a filter material for treatment of contaminated water and it has been successfully applied as filter material for treatment of arsenate spiked natural water sample with average removal efficiency of 84 % (solid to liquid ratio of 200).
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| 6. |
- Mohamed Idris, Z., et al.
(författare)
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Amino-functionalised silica-grafted molecularly imprinted polymers for chloramphenicol adsorption
- 2020
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Ingår i: Journal of Environmental Chemical Engineering. - : Elsevier BV. - 2213-3437. ; 8:5
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Tidskriftsartikel (refereegranskat)abstract
- This research investigated the liquid-phase removal of chloramphenicol (CAP), an emerging contaminant using molecularly imprinted polymers (MIPs). CAP adsorption profiles, equilibrium, and kinetics were analysed. The adsorption performance was compared between MIPs and non-imprinted polymers (NIPs), both with silica or without silica grafting. The imprinting factor (IF) values for the Si@MIPs-CAP were significantly higher than the IF values for MIPs-CAP adsorbent at pH 8. The kinetics of CAP adsorption was fitted to pseudo-second-order kinetics models for MIPs-CAP (R2 = 0.9998) and Si@MIPs-CAP (R2 = 0.9999). The adsorption isotherm of Si@MIPs-CAP was well represented by the Langmuir model (R2 = 0.9991), while the Freundlich isotherm model (R2 = 0.9998) provided the best fit for MIPs-CAP. The maximum monolayer adsorption capacities, Qmax, for Si@MIPs-CAP (32.26 mg g−1) were higher than the Qmax for Si@NIPs-CAP (29.6 mg g−1). These results suggested that the silica-grafted molecularly imprinted polymers can be employed as a potential water-compatible adsorbent for the selective adsorption and removal of CAP from aqueous phase.
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| 7. |
- Morgan-Sagastume, Fernando, et al.
(författare)
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Mixed-culture polyhydroxyalkanoate (PHA) production integrated into a food-industry effluent biological treatment: A pilot-scale evaluation
- 2020
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Ingår i: Journal of Environmental Chemical Engineering. - : Elsevier. - 2213-3437. ; 8:6
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Tidskriftsartikel (refereegranskat)abstract
- Production of a mixed microbial culture (MMC) biomass for polyhydroxyalkanoate (PHA) production was integrated into the wastewater treatment (WWT) of a potato-starch factory. A pilot-scale on-site evaluation was conducted over ten months, with inherent water quality variations including organic composition, temperature, and pH. The wastewater was rich in acetate and the organic matter content fluctuated from 50 to 90 % with respect to volatile fatty acids (VFAs). The PHA accumulation potential (PAP) of the surplus biomass, nevertheless, remained from 0.40 to 0.70 gPHA/gVSS. Biomass PAP characteristics were benchmarked at both pilot and laboratory scales using different feedstocks and accumulation methods. The resultant co-polymer type could be readily shifted by changes in feedstock VFA content. Selected polymer batches were recovered at pilot scale as commercial-quality prototype materials for development of PHA-based wood-fibre composites. WWT performance with 98 % organic contaminant removal remained consistent throughout. The good settleability of the pilot-scale biomass was in contrast to the poorly settleable biomass from the factory’s full-scale activated sludge. Metered nitrogen and phosphorus addition ensured stable WWT without major nitrification levels. Successful robust outcomes of both feast-famine selection principles and WWT can be translated and integrated into the full-scale WWT by a proposed adaptation to existing infrastructure. Analogous aerobic feast enrichment is proposed to be achievable with continuous or intermittent flow through a process selector/zone. This pilot-scale experience under actual field conditions of industrial WWT provides further evidence for the technical viability to produce biomass for PHA production while maintaining standards in effluent water quality.
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| 8. |
- Sandberg, Mats, et al.
(författare)
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Paper machine manufactured photocatalysts : Lateral variations
- 2020
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Ingår i: Journal of Environmental Chemical Engineering. - : Elsevier BV. - 2213-3437. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Paper machine manufacturing of photocatalysts can enable low cost devices for removal of low concentratedpollutants. Lateral variations originating from the paper making process leads to variations of the catalyticactivity over the paper area. Paper machine manufactured papers made from tetrapodal ZnO whiskers and kraftpulp were investigated in this test geometry using simulated solar light. Photocatalytic ZnO papers were laminatedbetween polyethylene sheets and an indicator solution seeped into the laminated photocatalytic paper, tocreate a test geometry where the indicator ink is confined to a small volume between the polyethylene sheets.The photocatalyst papers exhibited surprisingly similar photocatalytic behavior although having different catalystloading 15, 30 and 45 wt percent. All papers exhibited lateral variations that peaked during the conversion.The results show that production of effective photocatalytic composite papers can be scaled.Further, the results show that variations must be considered for photocatalytic papers.
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| 9. |
- Simoes Dos Reis, Glaydson, et al.
(författare)
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Removal of captopril pharmaceutical from synthetic pharmaceutical-industry wastewaters: Use of activated carbon derived from Butia catarinensis
- 2020
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Ingår i: Journal of Environmental Chemical Engineering. - : Elsevier BV. - 2213-3437. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- A high surface area activated carbon was produced from the seed of Butia catarinensis (Bc), which was utilized for removing captopril from synthetic pharmaceutical industry wastewaters. The activated carbon was made by mixing ZnCl2 and Bc at a proportion of 1:1 and pyrolyzed at 600° (ABc-600). The material was characterized by the Boehm titration, hydrophilic/ hydrophobic ratio, elemental analysis, TGA, FTIR, and N2 isotherm (surface area (SBET), total pore volume (TPV), and pore size distribution (PSD)). The characterization data showed that the adsorbent displayed a hydrophilic surface due to the presence of several polar groups. The carbon material presented a TPV of 0.392 cm3 g−1, and SBET of 1267 m2 g−1. The equilibrium and kinetics data were suitably fitted to Liu isotherm and Avrami-fractional-order. The employment of the ABc-600 in the treatment of synthetic pharmaceutical industry wastewater exhibited high effectiveness in their removals (up to 99.0 %).
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| 10. |
- Sörengård, Mattias, et al.
(författare)
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Adsorption behavior of per- and polyfluoralkyl substances (PFASs) to 44 inorganic and organic sorbents and use of dyes as proxies for PFAS sorption
- 2020
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Ingår i: International Journal of Chemical and Environmental Engineering. - : Elsevier BV. - 2078-0737. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Per- and polyfluoralkyl substances (PFASs) are a major concern in pollution of drinking water sources and aquatic environments. This study investigated the sorption behavior of 17 PFASs of varying chain lengths and functional groups to 44 conventional and novel inorganic and organic sorbents with potential in treatment of PFAS-contaminated water or soil. For the first time, a large number of sorbents were tested for a wide variety of PFASs in batch sorption experiments under controlled experimental set-up. Also, the sorption behavior of four different dyes (methylene blue, crystal violet, indigo carmine, rose bengal) was also determined, to assess whether dyes can be used as a proxy for PFAS sorption. Of the 44 sorbents tested, PFASs sorbed best (mean > 99.9 %) to activated carbons (granulated and pulverized (n = 5)). Sorption of PFASs to magnesium chloride-fortified biochar, Moringa seed, and pyrolytic carbon waste was 17- to 25-fold higher than to sand. Sorption generally increased with increasing perfluorocarbon chain length and based as follows on functional group: fluorotelomer sulfonic acids (FTSAs) < perfluoroalkyl carboxylates (PFCAs) < perfluoroalkane sulfonates (PFSAs) < perfluorooctanesulfonamide (FOSA). Principal component analysis revealed that electrostatic sorption dominated for shorter-chained PFASs and that hydrophobic sorption dominated for longer-chained PFASs. All four dyes tested proved suitable as proxies for sorption of PFASs. In particular, methylene blue correlated best to short-chain PFASs (e.g., perfluorohexanoate (PFHxA)) and rose bengal to longer homologues (i.e., per-fluorooctanesulfonate (PFOS)).
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| 11. |
- Sörengård, Mattias, et al.
(författare)
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Non-target and suspect screening strategies for electrodialytic soil remediation evaluation: Assessing changes in the molecular fingerprints and per- and polyfluoroalkyl substances (PFASs)
- 2020
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Ingår i: Journal of Environmental Chemical Engineering. - : Elsevier BV. - 2213-3437. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Contamination of soils with organic pollutants is an increasing global problem, so novel soil remediation techniques are urgently needed. One such technique is electrokinetic remediation, in which an electric field is applied over the soil to extract contaminants. Previous evaluations of the technique have been limited to a few specific compounds. In this study, we integrated the latest advances in high-resolution mass spectrometry (HRMS) to identify molecular fingerprints, and used the results to improve the mechanistic understanding necessary for successful remediation. A laboratory-scale 0.38 mA cm(-2) electrodialytic treatment was applied for 21 days to a contaminated soil from a firefighter training facility in Sweden. Non-target analysis allowed generic evaluation of changes in the soil organic fraction by tentatively determining the elemental composition of compounds present. The results showed that smaller oxygen-rich molecules were significantly transported to the anode by electromigration, while larger hydrogen-saturated molecules were transported to the cathode by electroosmotic flow. Wide suspect screening with >3000 per- and polyfluoroalkyl substances (PFASs) tentatively identified seven new PFASs in the test soil, including perfluoroheptanesulfonic acid (PFHpS), and PFASs with butoxy, ethoxy, ethanol, and ethylcyclohexanesulfonate functional groups.
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| 12. |
- Zonja, Bozo
(författare)
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Toxicity tests in wastewater and drinking water treatment processes: A complementary assessment tool to be on your radar
- 2020
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Ingår i: Journal of Environmental Chemical Engineering. - : Elsevier BV. - 2213-3437. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Wastewater discharges from cities and industries, especially megacities, and intensive livestock can be considered as main sources of pollution of our rivers and groundwater. Water pollution, therefore, constitutes a major threat to both aquatic ecosystems and human health. Here we address the influence of chemical pollution in waste- and drinking water, their associated potential toxicological effects, as well as, the available technologies for their removal.This opinion paper provides illustrative selected examples covering a broad range for both drinking water and wastewater treatment processes, for which a battery of toxicity tests is applied for their risk assessment. The examples are classified based on five hot topics: (i) Bioassays for toxicity evaluation, (ii) Toxicity of municipal wastewaters, (iii) Toxicity of pharmaceutical residues and hospital wastewaters, (iv) Toxicity of other non-urban effluent examples, and (v) Drinking water treatment processes and toxicity evaluation. 'Chemical analysis combined with batteries of bioassays covering a broad range of endpoints: cytotoxicity, endocrine disruption, genotoxicity, and other types seem to be good way to assess performance/efficiency of the water treatment processes when removing chemical contaminants.. Altogether, while recognizing that water treatment is a cornerstone for water pollution reduction, providing safe water for both human use and its return back to the aquatic environment will be undoubtedly enhanced with the use of ecotoxicity biomonitoring.
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