Graphene-Coated Hollow Fiber Membrane as the Cathode in Anaerobic Electrochemical Membrane Bioreactors--Effect of Configuration and Applied Voltage on Performance and Membrane Fouling.

Electrically conductive, graphene-coated, hollow-fiber porous membranes were used as cathodes in anaerobic electrochemical membrane bioreactors (AnEMBRs) operated at different applied voltages (0.7 and 0.9 V) using a new rectangular reactor configuration compared to a previous tubular design (0.7 V). The onset of biofouling was delayed and minimized in rectangular reactors operated at 0.9 V compared to those at 0.7 V due to higher rates of hydrogen production. Maximum transmembrane pressures for the rectangular reactor were only 0.10 bar (0.7 V) or 0.05 bar (0.9 V) after 56 days of operation compared to 0.46 bar (0.7 V) for the tubular reactor after 52 days. The thickness of the membrane biofouling layer was approximately 0.4 µm for rectangular reactors and 4 µm for the tubular reactor. Higher permeate quality (TSS = 0.05 mg/L) was achieved in the rectangular AnEMBR than that in the tubular AnEMBR (TSS = 17 mg/L), likely due to higher current densities that minimized the accumulation of cells in suspension. These results show that the new rectangular reactor design, which had increased rates of hydrogen production, successfully delayed the onset of cathode biofouling and improved reactor performance.

Defluoridation of groundwater using aluminum-coated bauxite: Optimization of synthesis process conditions and equilibrium study.

There is no known effective treatment for fluoride-related health disorders, hence prevention through water defluoridation is necessary. This study explored the possibility of modifying the physico-chemical properties of bauxite, a locally available material in many countries including Ghana, by thermal treatment and an aluminum coating, for water defluoridation. The study mainly focused on investigating the effects of varying synthesis process conditions on the defluoridation efficiency of Granular Aluminum Coated Bauxite (GACB). GACB performed better than raw bauxite (RB) and was able to reduce fluoride concentration in groundwater from 5 ± 0.2 mg/L to ≤ 1.5 mg/L, World Health Organization (WHO) guideline. Based on nonlinear Chi-square (χ(2)) analysis, the best-fitting isotherm model for the fluoride-GACB system was in the order: Freundlich > Redlich-Perterson ≈ Langmuir > Temkin. The fluoride adsorption capacity of GACB (qmax = 12.29 mg/g) based on the Langmuir model was found to be either comparable or higher than the capacities of some reported fluoride adsorbents. Aluminum (Al) coating procedures optimized in this study could therefore be a useful approach for synthesizing an effective fluoride adsorbent using bauxite, a locally available material. Kinetic and isotherm analysis, thermodynamic calculations, as well as FTIR and Raman analysis suggested the mechanism of fluoride adsorption onto GACB was complex and involved both physical adsorption and chemisorption processes.

A novel anaerobic electrochemical membrane bioreactor (AnEMBR) with conductive hollow-fiber membrane for treatment of low-organic strength solutions.

A new anaerobic treatment system that combined a microbial electrolysis cell (MEC) with membrane filtration using electrically conductive, porous, nickel-based hollow-fiber membranes (Ni-HFMs) was developed to treat low organic strength solution and recover energy in the form of biogas. This new system is called an anaerobic electrochemical membrane bioreactor (AnEMBR). The Ni-HFM served the dual function as the cathode for hydrogen evolution reaction (HER) and the membrane for filtration of the effluent. The AnEMBR system was operated for 70 days with synthetic acetate solution having a chemical oxygen demand (COD) of 320 mg/L. Removal of COD was >95% at all applied voltages tested. Up to 71% of the substrate energy was recovered at an applied voltage of 0.7 V as methane rich biogas (83% CH4; <1% H2) due to biological conversion of the hydrogen evolved at the cathode to methane. A combination of factors (hydrogen bubble formation, low cathode potential and localized high pH at the cathode surface) contributed to reduced membrane fouling in the AnEMBR compared to the control reactor (open circuit voltage). The net energy required to operate the AnEMBR system at an applied voltage of 0.7 V was significantly less (0.27 kWh/m3) than that typically needed for wastewater treatment using aerobic membrane bioreactors (1-2 kWh/m3).

Characterization of bacterial and archaeal communities in air-cathode microbial fuel cells, open circuit and sealed-off reactors.

A large percentage of organic fuel consumed in a microbial fuel cell (MFC) is lost as a result of oxygen transfer through the cathode. In order to understand how this oxygen transfer affects the microbial community structure, reactors were operated in duplicate using three configurations: closed circuit (CC; with current generation), open circuit (OC; no current generation), and sealed off cathodes (SO; no current, with a solid plate placed across the cathode). Most (98 %) of the chemical oxygen demand (COD) was removed during power production in the CC reactor (maximum of 640 ± 10 mW/m(2)), with a low percent of substrate converted to current (coulombic efficiency of 26.5 ± 2.1 %). Sealing the cathode reduced COD removal to 7 %, but with an open cathode, there was nearly as much COD removal by the OC reactor (94.5 %) as the CC reactor. Oxygen transfer into the reactor substantially affected the composition of the microbial communities. Based on analysis of the biofilms using 16S rRNA gene pyrosequencing, microbes most similar to Geobacter were predominant on the anodes in the CC MFC (72 % of sequences), but the most abundant bacteria were Azoarcus (42 to 47 %) in the OC reactor, and Dechloromonas (17 %) in the SO reactor. Hydrogenotrophic methanogens were most predominant, with sequences most similar to Methanobacterium in the CC and SO reactor, and Methanocorpusculum in the OC reactors. These results show that oxygen leakage through the cathode substantially alters the bacterial anode communities, and that hydrogenotrophic methanogens predominate despite high concentrations of acetate. The predominant methanogens in the CC reactor most closely resembled those in the SO reactor, demonstrating that oxygen leakage alters methanogenic as well as general bacterial communities.

Recovery of Critical Metals from Aqueous Sources.

Critical metals, identified from supply, demand, imports, and market factors, include rare earth elements (REE), platinum group metals, precious metals, and other valuable metals such as lithium, cobalt, nickel, and uranium. Extraction of metals from U.S. saline aqueous, emphasizing saline, sources is explored as an alternative to hardrock ore mining. Potential aqueous sources include seawater, desalination brines, oil-and-gas produced waters, geothermal aquifers, and acid mine drainage, among others. A feasibility assessment reveals opportunities for recovery of lithium, strontium, magnesium, and several REE from select sources, in quantities significant for U.S. manufacturing and for reduction of U.S. reliance on international supply chains. This is a conservative assessment given that water quality data are lacking for a significant number of critical metals in certain sources. The technology landscape for extraction and recovery of critical metals from aqueous sources is explored, identifying relevant processes along with knowledge gaps. Our analysis indicates that aqueous mining would result in much lower environmental impacts on water, air, and land than ore mining. Preliminary assessments of the economics and energy consumption of recovery show potential for recovery of critical metals.

Kinetic and thermodynamic aspects of adsorption of arsenic onto granular ferric hydroxide (GFH).

Relatively limited information is available regarding the impacts of temperature on the adsorption kinetics and equilibrium capacities of granular ferric hydroxide (GFH) for arsenic (V) and arsenic (III) in an aqueous solution. In general, very little information is available on the kinetics and thermodynamic aspects of adsorption of arsenic compounds onto other iron oxide-based adsorbents as well. In order to gain an understanding of the adsorption process kinetics, a detailed study was conducted in a controlled batch system. The effects of temperature and pH on the adsorption rates of arsenic (V) and arsenic (III) were investigated. Reaction rate constants were calculated at pH levels of 6.5 and 7.5. Rate data are best described by a pseudo first-order kinetic model at each temperature and pH condition studied. At lower pH values, arsenic (V) exhibits greater removal rates than arsenic (III). An increase in temperature increases the overall adsorption reaction rate constant values for both arsenic (V) and arsenic (III). An examination of thermodynamic parameters shows that the adsorption of arsenic (V) as well as arsenic (III) by GFH is an endothermic process and is spontaneous at the specific temperatures investigated.

Solute transport model for trace organic neutral and charged compounds through nanofiltration and reverse osmosis membranes.

Rejection of trace organic compounds, including disinfection by-products (DBPs) and pharmaceutical active compounds (PhACs), by high-pressure membranes has become a focus of public interest internationally in both drinking water treatment and wastewater reclamation/reuse. The ability to simulate, or even predict, the rejection of these compounds by high-pressure membranes, encompassing nanofiltration (NF) and reverse osmosis (RO), will improve process economics and expand membrane applications. The objective of this research is to develop a membrane transport model to account for diffusive and convective contributions to solute transport and rejection. After completion of cross-flow tests and diffusion cell tests with target compounds, modeling efforts were performed in accordance with a non-equilibrium thermodynamic transport equation. Comparing the percentages of convection and diffusion contributions to transport, convection is dominant for most compounds, but diffusion is important for more hydrophobic non-polar compounds. Convection is also more dominant for looser membranes (i.e., NF). In addition, higher initial compound concentrations and greater J(0)/k ratios contribute to solute fluxes more dominated by convection. Given the treatment objective of compound rejection, compound transport and rejection trends are inversely related.

Membrane fouling and anti-fouling strategies using RO retentate from a municipal water recycling plant as the feed for osmotic power generation.

RO retentate from a municipal water recycling plant is considered as a potential feed stream for osmotic power generation in this paper. The feasibility of using RO retentate from a municipal water recycling plant was examined from two aspects: (a) the membrane fouling propensity of RO retentate, and (b) the efficacy of anti-fouling strategies. The membranes used in this study were the inner selective thin film composite polyethersulfone (TFC/PES) hollow fiber membranes, which possessed a high water permeability and good mechanical strength. Scaling by phosphate salts was found to be one possible inorganic fouling on the innermost layer of the PES membrane, whereas silica fouling was observed to be the governing fouling on the outmost surface of the PES membrane. Two anti-fouling pretreatments, i.e., pH adjustment and anti-scalant pre-treatment for the feed stream, were studied and found to be straightforward and effective. Using RO retentate at pH 7.2 as the feed and 1 M NaCl as the draw solution, the average power density was 7.3 W/m(2) at 20 bar. The average power density increased to 12.6 W/m(2) by modifying RO retentate with an initial pH value of 5.5 using HCl and to 13.4 W/m(2) by adding 1.1 mM ethylenediaminetetraacetic acid (EDTA). Moreover, the flux recovery of the fouled membranes, without the indicated pretreatments, reached 84.9% using deionized (DI) water flushing and 95.0% using air bubbling under a high crossflow velocity of 23.3 cm/s (Re = 2497) for 30 min. After pretreatment by pH adjustment, the flux recovery increased to 94.6% by DI water flushing and 100.0% by air bubbling. After pretreatment by adding 1.1 mM EDTA into RO retentate, flux was almost fully restored by physical cleaning by DI water flushing and air bubbling. These results provide insight into developing an effective pretreatment by either pH adjustment or EDTA addition before PRO and physical cleaning methods by DI water flushing and air bubbling for membrane used in osmotic power generation.

A novel integrated thermal-/membrane-based solar energy-driven hybrid desalination system: Concept description and simulation results.

In this paper, a hybrid desalination system consisting of vacuum membrane distillation (VMD) and adsorption desalination (AD) units, designated as VMD-AD cycle, is proposed. The synergetic integration of the VMD and AD is demonstrated where a useful effect of the AD cycle is channelled to boost the operation of the VMD process, namely the low vacuum environment to maintain the high pressure gradient across the microporous hydrophobic membrane. A solar-assisted multi-stage VMD-AD hybrid desalination system with temperature modulating unit is first designed, and its performance is then examined with a mathematical model of each component in the system and compared with the VMD-only system with temperature modulating and heat recovery units. The total water production and water recovery ratio of a solar-assisted 24-stage VMD-AD hybrid system are found to be about 21% and 23% higher, respectively, as compared to the VMD-only system. For the solar-assisted 24-stage VMD-AD desalination system having 150 m(2) of evacuated-tube collectors and 10 m(3) seawater storage tanks, both annual collector efficiency and solar fraction are close to 60%.

Transparent exopolymer particles (TEP) removal efficiency by a combination of coagulation and ultrafiltration to minimize SWRO membrane fouling.

This study investigated the impact of coagulation on the transformation between colloidal and particulate transparent exopolymer particles (TEP) in seawater; and the effectiveness of a combined pretreatment consisting of coagulation and UF on minimizing TEP fouling of seawater reverse osmosis (SWRO) membranes. Coagulation with ferric chloride at pH 5 substantially transformed colloidal TEP (0.1-0.4) into particulate TEP (>0.4) leading to a better membrane fouling control. Both 50 and 100 kDa molecular weight cut-off (MWCO) UF membranes removed most of particulate and colloidal TEP without the assistance of coagulation, but coagulation is still necessary for better UF fouling control. The improvement of combined SWRO pretreatment with coagulation and 50 kDa UF membranes was not that much significant compared to UF pretreatment with 50 KDa alone. Therefore, the minimal coagulant dosage for seawater containing TEP should be based on the UF fouling control requirements rather than removal efficiency.

Disinfection by-product formation during seawater desalination: A review.

Due to increased freshwater demand across the globe, seawater desalination has become the technology of choice in augmenting water supplies in many parts of the world. The use of chemical disinfection is necessary in desalination plants for pre-treatment to control both biofouling as well as the post-disinfection of desalinated water. Although chlorine is the most commonly used disinfectant in desalination plants, its reaction with organic matter produces various disinfection by-products (DBPs) (e.g., trihalomethanes [THMs], haloacetic acids [HAAs], and haloacetonitriles [HANs]), and some DBPs are regulated in many countries due to their potential risks to public health. To reduce the formation of chlorinated DBPs, alternative oxidants (disinfectants) such as chloramines, chlorine dioxide, and ozone can be considered, but they also produce other types of DBPs. In addition, due to high levels of bromide and iodide concentrations in seawater, highly cytotoxic and genotoxic DBP species (i.e., brominated and iodinated DBPs) may form in distribution systems, especially when desalinated water is blended with other source waters having higher levels of organic matter. This article reviews the knowledge accumulated in the last few decades on DBP formation during seawater desalination, and summarizes in detail, the occurrence of DBPs in various thermal and membrane plants involving different desalination processes. The review also identifies the current challenges and future research needs for controlling DBP formation in seawater desalination plants and to reduce the potential toxicity of desalinated water.

Attenuation of trace organic compounds (TOrCs) in bioelectrochemical systems.

Microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) are two types of microbial bioelectrochemical systems (BESs) that use microorganisms to convert chemical energy in wastewaters into useful energy products such as (bio)electricity (MFC) or hydrogen gas (MEC). These two systems were evaluated for their capacity to attenuate trace organic compounds (TOrCs), commonly found in municipal wastewater, under closed circuit (current generation) and open circuit (no current generation) conditions, using acetate as the carbon source. A biocide was used to evaluate attenuation in terms of biotransformation versus sorption. The difference in attenuation observed before and after addition of the biocide represented biotransformation, while attenuation after addition of a biocide primarily indicated sorption. Attenuation of TOrCs was similar in MFCs and MECs for eight different TOrCs, except for caffeine and trimethoprim where slightly higher attenuation was observed in MECs. Electric current generation did not enhance attenuation of the TOrCs except for caffeine, which showed slightly higher attenuation under closed circuit conditions in both MFCs and MECs. Substantial sorption of the TOrCs occurred to the biofilm-covered electrodes, but no consistent trend could be identified regarding the physico-chemical properties of the TOrCs tested and the extent of sorption. The octanol-water distribution coefficient at pH 7.4 (log DpH 7.4) appeared to be a reasonable predictor for sorption of some of the compounds (carbamazepine, atrazine, tris(2-chloroethyl) phosphate and diphenhydramine) but not for others (N,N-Diethyl-meta-toluamide). Atenolol also showed high levels of sorption despite being the most hydrophilic in the suite of compounds studied (log DpH 7.4 = -1.99). Though BESs do not show any inherent advantages over conventional wastewater treatment, with respect to TOrC removal, overall removals in BESs are similar to that reported for conventional wastewater systems, implying the possibility of using BESs for energy production in wastewater treatment without adversely impacting TOrC attenuations.

Improved method for measuring transparent exopolymer particles (TEP) and their precursors in fresh and saline water.

Transparent exopolymer particles (TEP) and their precursors produced by phyto-/bacterio-planktons in fresh and marine aquatic environments are increasingly considered as a major contributor to organic/particulate and biological fouling in micro-/ultra-filtration and reverse osmosis membrane (RO) systems. However, currently established methods which are based on Alcian blue (AB) staining and spectrophotometric techniques do not measure TEP-precursors and have the tendency to overestimate concentration in brackish/saline water samples due to interference of salinity on AB staining. Here we propose a new semi-quantitative method which allows measurement of both TEP and their colloidal precursors without the interference of salinity. TEP and their precursors are first retained on 10 kDa membrane, rinsed with ultra-pure water, and re-suspended in ultra-pure water by sonication and stained with AB, followed by exclusion of TEP-AB precipitates by filtration and absorbance measurement of residual AB. The concentration is then determined based on the reduction of AB absorbance due to reaction with acidic polysaccharides, blank correction and calibration with Xanthan gum standard. The extraction procedure allows concentration of TEP and their pre-cursors which makes it possible to analyse samples with a wide range of concentrations (down to <0.1 mg Xeq/L). This was demonstrated through application of the method for monitoring these compounds in algal cultures and a full-scale RO plant. The monitoring also revealed that concentrations of the colloidal precursors were substantially higher than the concentration of TEP themselves. In the RO plant, complete TEP removal was observed over the pre-treatment processes (coagulation-sedimentation-filtration and ultrafiltration) but the TEP precursors were not completely removed, emphasising the importance of measuring this colloidal component to better understand the role of TEP and acidic polysaccharides in RO membrane fouling.

Treatment of a colored groundwater by ozone-biofiltration: pilot studies and modeling interpretation.

Pilot studies investigated the fates of color, dissolved organic carbon (DOC), and biodegradable organic matter (BOM) by the tandem of ozone plus biofiltration for treating a source water having significant color (50 cu) and DOC (3.2 mg/l). Transferred ozone doses were from 1.0 to 1.8 g O3/g C. Rapid biofilters used sand, anthracite, or granular activated carbon as media with empty-bed contact time (EBCT) up to 9 min. The pilot studies demonstrated that ozonation plus biofiltration removed most color and substantial DOC, and increasing the transferred ozone dose enhanced the removals. For the highest ozone dose, removals were as high as 90% for color and 38% for DOC. While most of the color removal took place during ozonation, most DOC removal occurred in the biofilters, particularly when the ozone dose was high. Compared to sand and anthracite biofilters, the GAC biofilter gave the best performance for color and DOC removal, but some of this enhanced performance was caused by adsorption, since the GAC was virgin at the beginning of the pilot studies. Backwashing events had no noticeable impact of the performance of the biofilters. The Transient-State, Multiple-Species Biofilm Model (TSMSBM) was used to interpret the experimental results. Model simulations show that soluble microbial products, which comprised a significant part of the effluent BOM, offset the removal of original BOM, a factor that kept the removal of DOC relatively constant over the range of EBCTs of 3.5-9 min. Although improved biofilm retention, represented by a small detachment rate, allowed more total biofilm accumulation and greater removal of original BOM, it also caused more release of soluble microbial products and the build up of inert biomass in the biofilm. Backwashing had little impact on biofilter performance, because it did not remove more than 25% of the biofilm under any condition simulated.

Kinetic study on the sorption of dissolved natural organic matter onto different aquifer materials: the effects of hydrophobicity and functional groups.

The subsurface sorption of Suwannee River fulvic acid (SRFA) and humic acid (SRHA) onto a synthetic aquifer material (iron-oxide-coated quartz) and two natural aquifer materials (Ringold sediment and Bemidji soils) was studied in both batch and column experiments. The hypothesis that hydrophobic effects followed by ligand exchange are the dominant mechanism contributing to the chemical sorption happening between dissolved natural organic matter (NOM) and the mineral surfaces is supported by observations of several phenomena: nonlinear isotherms, faster sorption rates versus slower desorption rates, phosphate competition, a solution pH increase during NOM sorption, and functional groups and aromaticity-related sorption. In addition, high-pressure size exclusion chromatography (HPSEC) and carboxylic acidity showed that lower molecular weight NOM components of SRHA are preferentially sorbed to iron oxide, a result in contrast to that for SRFA. Phosphate increased the desorption of sorbed NOM as well as soil organic matter. All of these trends support ligand exchange as the dominant reaction between NOM and the iron oxide surfaces; however, if the soil surface has been occupied by soil organic matter, then the sorption of NOM is more due to hydrophobic effect.

Transport of anthracene and benz(a)anthracene through iron-quartz and three aquifer materials in laboratory columns.

In groundwater systems, dissolved natural organic matter (NOM) can influence the mobility of organic contaminants by altering the contaminant behavior in water and solid phases. The transport of anthracene and benz(a)anthracene (B(a)A) was studied in the presence and absence of NOM and/or soil organic matter (SOM) in column experiments. The results show that sorption are related to the properties of polycyclic aromatic hydrocarbons (PAHs), NOM and SOM. In the Fe-quartz media, the amount of NOM (20 mg/l) in solution had a little effect on increasing the apparent solubility of anthracene and countering increased anthracene sorption. In the natural (Bemidji) soil, Suwannee river fulvic acid (SRFA, 20 mg/l) and Suwannee river humic acid (SRHA) in water did not compete with SOM for anthracene, indicating that SOM has higher partition efficiency for anthracene. It was also observed that slow diffusion through an organic phase apparently caused most of the observed tailing in column breakthrough curves (BTCs). Even though the fOC of washed Bemidji sediment was very low, the transport of B(a)A was retarded significantly, however, and the transport of B(a)A was shown to be facilitated by dissolved NOM.

Irreversible membrane fouling abatement through pre-deposited layer of hierarchical porous carbons.

In this work, dual-templated hierarchical porous carbons (HPCs), produced from a coupled ice-hard templating approach, are shown to be a highly effective solution to the commonly occurring problem of irreversible fouling of low-pressure membranes used for pre-treatment in wastewater reuse. For the first time, dual-templated HPCs, along with their respective counterparts - single-templated meso-porous carbon (MPCs) (without macropores) - are tested in terms of their fouling reduction capacity and ability to remove different effluent organic matter fractions present in wastewater and compared with a commercially available powdered activated carbon (PAC). The synthesized HPCs provided exceptional fouling abatement, a 4-fold higher fouling reduction as compared to the previously reported best performing commercial PAC and ∼2.5-fold better fouling reduction than their respective mesoporous counterpart. Thus, it is shown that not only mesoporosity, but macroporosity is also necessary to achieve high fouling reduction, thus emphasizing the need for dual templating. In the case of HPCs, the pre-deposition technique is also found to outperform the traditional sorbent-feed mixing approach, mainly in terms of removal of fouling components. Based on their superior performance, a high permeability (ultra-low-pressure) membrane consisting of the synthesized HPC pre-deposited on a large pore size membrane support (0.45 µm membrane), is shown to give excellent pre-treatment performance for wastewater reuse application.

QSAR models for oxidation of organic micropollutants in water based on ozone and hydroxyl radical rate constants and their chemical classification.

Ozonation is an oxidation process for the removal of organic micropollutants (OMPs) from water and the chemical reaction is governed by second-order kinetics. An advanced oxidation process (AOP), wherein the hydroxyl radicals (OH radicals) are generated, is more effective in removing a wider range of OMPs from water than direct ozonation. Second-order rate constants (k(OH) and k(O3) are good indices to estimate the oxidation efficiency, where higher rate constants indicate more rapid oxidation. In this study, quantitative structure activity relationships (QSAR) models for O(3) and AOP processes were developed, and rate constants, k(OH) and [Formula: see text] , were predicted based on target compound properties. The k(O3) and k(OH) values ranged from 5 * 10(-4) to 10(5) M(-1)s(-1) and 0.04 to 18 * (10(9)) M(-1) s(-1), respectively. Several molecular descriptors which potentially influence O(3) and OH radical oxidation were identified and studied. The QSAR-defining descriptors were double bond equivalence (DBE), ionisation potential (IP), electron-affinity (EA) and weakly-polar component of solvent accessible surface area (WPSA), and the chemical and statistical significance of these descriptors was discussed. Multiple linear regression was used to build the QSAR models, resulting in high goodness-of-fit, r(2) (>0.75). The models were validated by internal and external validation along with residual plots.

Appropriate drinking water treatment processes for organic micropollutants removal based on experimental and model studies - a multi-criteria analysis study.

The presence of organic micropollutants (OMPs), pharmaceuticals and personal care products (PPCPs) in potable water is of great environmental and public health concern. OMPs are included in the priority list of contaminants in United States EPA and European framework directives. Advanced treatment processes such as reverse osmosis, nanofiltration, ozonation and adsorption are the usual industry-recommended processes for OMPs removal, however, natural systems, e.g., riverbank filtration and constructed wetlands, are also potentially efficient options for OMPs removal. In this study, a decision support system (DSS) based on multi-criteria analysis (MCA) was created to compare processes for OMPs removal under various criteria. Multi-criteria analysis (MCA), a transparent and reliable procedure, was adopted. Models were built for both experimental and predicted percent-removals for a range of OMPs reflecting different physicochemical properties. The experimental percent-removals for several processes (riverbank filtration (RBF), ozonation, advanced oxidation, adsorption, reverse osmosis, and nanofiltration) were considered. The predicted percent-removals were taken from validated quantitative structure activity relationship (QSAR) models. Analytical methods to detect OMPs in water are very laborious, thus a modeling approach such as QSAR is an attractive option. A survey among two groups of participants including academics (PhD students and post-doctoral research associates) and industry (managers and operators) representatives was conducted to assign weights for the following criteria: treatability, costs, technical considerations, sustainability and time. The process rankings varied depending on the contaminant species and personal preferences (weights). The results indicated that RBF and oxidation were preferable over adsorption and membranes processes. The results also suggest that the use of a hybrid treatment process, e.g., combining a natural system with an advanced treatment (oxidation) process, may provide benefits for OMPs removal. The proposed DSS can be used as a screening tool for experimental planning or a feasibility study preceding the main treatment system selection and design. It can also be considered as an aid in assessing a multi-barrier approach to remove OMPs.