Removal of emerging micropollutants by activated sludge process and membrane bioreactors and the effects of micropollutants on membrane fouling: A review

Besha, Abreham Tesfaye; Gebreyohannes, Abaynesh Yihdego; Tufa, Ramato Ashu; Bekele, Dawit; Curcio, Efrem; Giorno, Lidietta

doi:10.1016/j.jece.2017.04.027

Cited by 227 publications

(89 citation statements)

References 175 publications

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“…Besha et al [111] reviewed the advantages of MBR compared with conventional activated sludge process including high effluent quality, decreased reactor volume, elevated solid retention time (SRT) and high MLSS, low sludge yield, and easier operation.…”

Section: Ombrmentioning

confidence: 99%

Research on Forward Osmosis Membrane Technology Still Needs Improvement in Water Recovery and Wastewater Treatment

Shi

2019

Water

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Forward osmosis (FO) has become an evolving membrane separation technology to recover water due to its strong retention capacity, sustainable membrane fouling, etc. Although a good deal of research has been extensively investigated in the past decades, major challenges still remain as follows: (1) the novel FO membrane material properties, which significantly influence the fouling of the FO membranes, the intolerance reverse solute flux (RSF), the high concentration polarization (CP), and the low permeate flux; (2) novel draw solution preparation and utilization; (3) salinity build-up in the FO system; (4) the successful implementation of the FO process. This work critically reviews the last five years’ literature in development of the novel FO membrane material, structure in modification, and preparation, including comparison and analysis on the traditional and novel draw solutes coupled with their effects on FO performance; application in wastewater treatment, especially hybrid system and integrated FO system; fouling mechanism; and cleaning strategy as discussed in the literature. The current barriers of the research results in each hotspot and the areas that can be improved are also analyzed in detail. The research hotspots in the research and development of the novel membrane materials in various countries and regions have been compared in recent years, and the work of variation in pop research hotspots in the past 10 years has been analyzed and the ideas that fill the blank gaps also have been proposed.

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Section: Ombrmentioning

confidence: 99%

Research on Forward Osmosis Membrane Technology Still Needs Improvement in Water Recovery and Wastewater Treatment

Shi

2019

Water

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“…The value ranges from close to zero to almost complete removal. For example, the removal efficiency of carbamazepine is less than 20% with ASP and MBR and up to 93% with MBR-NF and higher than 99% with MBR-RO, MBR-PAC, and MBR-GAC [52]. The use of combinations of different complementary technologies has produced promising results.…”

Section: Micropollutant Treatment Studies With Mbr Applicationsmentioning

confidence: 99%

Efficient Removal Approach of Micropollutants in Wastewater Using Membrane Bioreactor

Mert¹,

Özengi̇n²,

Doğan³

et al. 2018

Wastewater and Water Quality

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In the recent past years, micropollutants that are pharmaceutically active compounds (PhACs) have been used extensively and have been discovered in raw sewage, wastewater treatment plants, effluents, surface, and groundwater with concentrations from ng/L to several μg/L. Even though many of these compounds are still not determined online, monitoring technology improvements progressed. Today's wastewater treatment plants are not constructed to remove these micropollutants yet. Conventional activated sludge processes are used in the treatment of municipal wastewater but are not specifically designed for the removal of micropollutants. The remaining pharmaceuticals mix into surface waters. At that stage, they can adversely affect the aquatic environment and may cause issues for drinking water production. As the conventional methods are insufficient for removing the micropollutants, other alternative treatment methods can be applied such as coagulation-flocculation, activated carbon adsorption (powdered activated carbon and granular activated carbon), advanced oxidation processes, membrane processes, and membrane bioreactor. It has been observed that membrane bioreactor (MBR) can achieve higher and more consistent micropollutants removal. The removal of micropollutants is based on physicochemical properties of micropollutants and the conditions of treatment. Due to recent technical innovations and cost reductions of the actual membranes, the membrane bioreactor takes attention. In this study, membrane bioreactor experiments for micropollutants in drinking use, wastewater, and surface waters were investigated in detail based on literature investigations, and the feasibility of this method was evaluated.

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“…These disadvantages can be overcome by reusing immobilized photosensitizers in the water treatment, which has many environmental and economic benefits. Therefore, the green chemistry approach is an original and innovative way to remove impurities from the water environment.The growing problem of the presence of micropollutants in the environment has demonstrated a need to find new, effective methods regarding removal or degradation [11][12][13]. Currently, there are no legal regulations in relation to contaminants of emerging concern [14,15].…”

mentioning

confidence: 99%

“…The growing problem of the presence of micropollutants in the environment has demonstrated a need to find new, effective methods regarding removal or degradation [11][12][13]. Currently, there are no legal regulations in relation to contaminants of emerging concern [14,15].…”

mentioning

confidence: 99%

Heterogeneous Oxidation of Phenolic Compounds with Photosensitizing Catalysts Incorporated into Chitosan

et al. 2019

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The increasing amount of hazardous micropollutants in the aqueous environment has recently become a concern, especially because they are not usually included in environmental monitoring programs. There is also limited knowledge regarding their behavior in the environment and their toxicity. This paper presents results regarding the heterogeneous photosensitized oxidation of 10 phenolic compounds under visible light. All of the selected compounds are classified as pollutants of emerging concern. For the first time, the application of photosensitizing catalysts incorporated into a chitosan carrier was investigated from several points of view, namely, structure characterization, singlet oxygen generation potential, photodegradation ability, biodegradability, and toxicity assessment. It was found that compounds of different origins were degraded with high effectivity. Photoactive chitosan was stable and could be reused for at least 12 cycles without losing its photocatalytic activity. The Hammett constants for all of the degraded compounds were determined. Improved biodegradability after the treatment was achieved for almost all compounds, apart from 4-hydroxybenzoic acid, and only slightly for 2-phenylphenol. The acute toxicity was assessed using bioluminescent Vibrio fischeri bacteria, indicating lower toxicity than the parent compounds.Photosensitized oxidation is undoubtedly one of the most important photochemical methods, since it does not generate any additional pollutants [5]. Moreover, the advantage of photosensitized oxidation is the photooxidation of hard-degradable compounds by singlet oxygen generated in the presence of air and solar radiation [5][6][7], therefore, photosensitized oxidation is classified as a green chemistry process. Moreover, because the heterogeneous process is considered to leave no residue, no sludge is produced from the process. Furthermore, if the immobilized photosensitizer remains unchanged throughout the process, the photocatalyst can easily be reused.Two general mechanisms of photosensitized oxidation for such reactions are well-known as Type I, also called the radical-involving mechanism, and Type II, the singlet oxygen mechanism [8,9]. Our previous research showed that singlet oxygen could be used for water purification. For this kind of area, the immobilization of photosensitizers onto various materials (heterogeneous system) is a desirable approach due to the easy separation from the reaction mixture and the preparation for reuse. Moreover, in homogenous systems (where the photosensitizer is dissolved in a water solution), the photosensitizer undergoes photobleaching, resulting in a rapid decrease in yield. Immobilized photosensitizers exhibit the advantages of good activity, stability against photobleaching, and repeated use [10]. Immobilization of a photosensitizer is associated with a decrease in the quantum yield of singlet oxygen [8,9]. This may be due to limitations in oxygen diffusion into and from the carrier material [9]. These disadvantages can be overcome by reusi...

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Removal of emerging micropollutants by activated sludge process and membrane bioreactors and the effects of micropollutants on membrane fouling: A review

Cited by 227 publications

References 175 publications

Research on Forward Osmosis Membrane Technology Still Needs Improvement in Water Recovery and Wastewater Treatment

Research on Forward Osmosis Membrane Technology Still Needs Improvement in Water Recovery and Wastewater Treatment

Efficient Removal Approach of Micropollutants in Wastewater Using Membrane Bioreactor

Heterogeneous Oxidation of Phenolic Compounds with Photosensitizing Catalysts Incorporated into Chitosan

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