NiAlFe LTH /MoS2 p-n junction heterostructure composite as an effective visible-light-driven photocatalyst for enhanced degradation of organic dye under high alkaline conditions.

Designing of an effectual heterostructure photocatalyst for catalytic organic pollutant exclusion has been the subject of rigorous research intended to resolve the related environmental aggravation. Fabricating p-n junctions is an effective strategy to promote electron-hole separation of semiconductor photocatalysts as well as enhance the organic toxin degradation performance. In this study, a series of n-type NiAlFe-layered triple hydroxide (LTH) loaded with various ratios of p-type MoS2 was synthesized for forming a heterostructure LTH/MoS2 (LMs) by an in situ hydrothermal strategy. The photocatalysts were characterized by XRD, SEM&EDX, TEM, FT-IR, XPS, as well as UV-vis DRS. The photoactivity of photocatalysts was tested by the degradation of Indigo Carmine (IC) dye. The optimized catalyst (LM1) degrades 100% of indigo dye in high alkaline pH under UV light for 100 min. Besides, the degradation rate of LM1 is 15 times higher than that of pristine NiAlFe-LTH. The enhanced photoactivity is attributed to the synergistic effect between NiAlFe-LTH and MoS2 as well as the p-n junction formation.

Non-destructive monitoring and prediction of fouling by organic matters and residual anionic coagulant during membrane process.

Physical fouling characteristics on silicon carbide (SiC) membranes induced by various organic matter compounds vary depending on the presence of calcium ions (Ca2+). Both destructive techniques (morphological surface analysis) and non-destructive techniques (fouling properties monitoring) were used to determine the fouling mechanisms and behavior during the membrane filtration systems. Destructive analysis and a modified Hermia model were employed to assess the fouling mechanisms. Fouling behavior was also analyzed through non-destructive monitoring techniques including optical coherence tomography (OCT) and three-dimensional laser scanning confocal microscopy (3D-LSM). At concentrations of 10, 30, and 100 mg/L without Ca2+, the flux decreased by 57-95% for humic acid (HA) and anionic polyacrylamide (APAM). APAM exhibited a notable removal rate of up to 56% without Ca2+. At concentration of 10, 30, and 100 mg/L in the absence of Ca2+, the flux decreased by 6-8% for sodium alginate (SA). However, the addition of Ca2+ led to a reduction in the flux for SA by up to 91% and resulted in a removal rate of 40%. Furthermore, addition of Ca2+ led to an alteration of the fouling characteristics of HA and SA. In the case of HA, higher concentrations resulted in elevated thickness and roughness with correlation coefficients of 0.991 and 0.992, respectively. For SA, increased SA concentration led to a thicker (correlation coefficient of 0.999) but smoother surfaces (correlation coefficients of 0.502). Monitoring of these physical characteristics of the fouling layer through non-destructive analysis is crucial for effective fouling management, optimization of the system performance and extending the lifespan of the membrane. By continuously assessing the fouling layer thickness and surface roughness, we expect to be able to provide insights on the fouling behavior, identify trends, that can help scientists and engineers to make informed decisions regarding fouling control strategies in future.

Effect of NaOCl and ClO2 on seawater desalination using reverse osmosis with cartridge filtration as the pretreatment during the algal bloom.

Increased seawater temperature leads to harmful algal blooms (HABs), which releases toxic materials and extracellular polymeric substances (EPS) that are harmful to both humans and the environment. Reverse osmosis (RO) with cartridge filter (CF) as the pretreatment process is often used for desalination process. However, the EPS causes severe fouling on the CF, and RO membrane. Disinfectants, such as NaOCl and ClO2, are commonly used to remove biofouling, because they can oxidize and kill microorganisms. Therefore, our study aims to utilize NaOCl and ClO2 during the CF-RO process to minimize the algal growth within the system and minimize the fouling induced by EPS. Results from this study show that CF can remove more than 50% of protein and 14% of polysaccharides but is not effective in removing toxins. However, with disinfectants, toxic materials were completely oxidized. Improved removal of EPS with CF improved overall performance. The flux reduction in RO process without disinfection was over 60%, however, the flux decline was about 44% and 10% with NaOCl and ClO2, respectively. Both disinfectants were found to be effective, however use of ClO2 is recommended because it is less damaging the membrane, yet more effective in enhancing the performance.

Ultrahigh-porosity Ranunculus-like MgO adsorbent coupled with predictive deep belief networks: A transformative method for phosphorus treatment.

Phosphorus is a nonrenewable material with a finite supply on Earth; however, due to the rapid growth of the manufacturing industry, phosphorus contamination has become a global concern. Therefore, this study highlights the remarkable potential of ranunculus-like MgO (MO4-MO6) as superior adsorbents for phosphate removal and recovery. Furthermore, MO6 stands out with an impressive adsorption capacity of 596.88 mg/g and a high efficacy across a wide pH range (2-10) under varying coexisting ion concentrations. MO6 outperforms the top current adsorbents for phosphate removal. The process follows Pseudo-second-order and Langmuir models, indicating chemical interactions between the phosphate species and homogeneous MO6 monolayer. MO6 maintains 80 % removal and 96 % recovery after five cycles and adheres to the WHO and EUWFD regulations for residual elements in water. FT-IR and XPS analyses further reveal the underlying mechanisms, including ion exchange, electrostatic, and acid-base interactions. Ten machine learning (ML) models were applied to simultaneously predict multi-criteria (sorption capacity, removal efficiency, final pH, and Mg leakage) affected by 15 diverse environmental conditions. Traditional ML models and deep neural networks have poor accuracy, particularly for removal efficiency. However, a breakthrough was achieved by the developed deep belief network (DBN) with unparalleled performance (MAE = 1.3289, RMSE = 5.2552, R2 = 0.9926) across all output features, surpassing all current studies using thousands of data points for only one output factor. These captivating MO6 and DBN models also have immense potential for effectively applying in the real water test with error < 5 %, opening immense horizons for transformative methods, particularly in phosphate removal and recovery.

Fabricated magnetic adsorption - Forward osmosis membrane hybrid system for hydroponic irrigation from rich arsenic-containing heavy metal water stream.

Solidification of soluble arsenic from extremely acidic water and direct use of recovery water have been the major challenges in global water management, with the urgent need for new treatment system development. Thus, magnetic adsorption - fertilizer drawn forward osmosis (FDFO) hybrid system with a novel adsorbent and fertilizer mixture to solve the drawbacks of each process was developed with the ultimate goals of metal removal and direct reuse for hydroponic irrigation. Magnetic metal-organic framework-based adsorbent (CMM) was synthesized with various promising capabilities, i.e., wide pH range efficiency, strong pH adjustment, good stability, fast adsorption (1 h), and oxidation (40 min), high capacity (175 and 126 mg/g for As(III), As(V)), strong magnetization (75 emu/g), complete separation by a magnet, excellent interference-tolerance and reusability. In the FDFO system, a massive water volume (50 times higher than the initial draw solution with suitable nutrients for hydroponics irrigation with acceptable NaCl levels was obtained for the first time up to now. However, low As(III) rejection (50%) required the FDFO process to improve more. After integrating with magnetic adsorption, nearly 100% of As was removed. The pH of feed solutions adjusted from extremely acidic to close to neutral conditions further solidified metal by precipitation and membrane separation processes, leading to almost no detection of metals in the final draw solution. Also, favorable nutrients and excellent reusability were obtained. This hybrid process would generally offer an environmentally sustainable and high efficiency for decontaminating As-containing heavy metal water for hydroponic irrigation.

Nanobubbles in water and wastewater treatment systems: Small bubbles making big difference.

Since the discovery of nanobubbles (NBs) in 1994, NBs have been attracting growing attention for their fascinating properties and have been studied for application in various environmental fields, including water and wastewater treatment. However, despite the intensive research efforts on NBs' fundamental properties, especially in the past five years, controversies and disagreements in the published literature have hindered their practical implementation. So far, reviews of NB research have mainly focused on NBs' role in specific treatment processes or general applications, highlighting proof-of-concept and success stories primarily at the laboratory scale. As such, there lacks a rigorous review that authenticates NBs' potential beyond the bench scale. This review aims to provide a comprehensive and up-to-date analysis of the recent progress in NB research in the field of water and wastewater treatment at different scales, along with identifying and discussing the challenges and prospects of the technology. Herein, we systematically analyze (1) the fundamental properties of NBs and their relevancy to water treatment processes, (2) recent advances in NB applications for various treatment processes beyond the lab scale, including over 20 pilot and full-scale case studies, (3) a preliminary economic consideration of NB-integrated treatment processes (the case of NB-flotation), and (4) existing controversies in NBs research and the outlook for future research. This review is organized with the aim to provide readers with a step-by-step understanding of the subject matter while highlighting key insights as well as knowledge gaps requiring research to advance the use of NBs in the wastewater treatment industry.

An efficient data-driven desalination approach for the element-scale forward osmosis (FO)-reverse osmosis (RO) hybrid systems.

Freshwater shortages are a consequence of the rapid increase in population, and desalination of saltwater has gained popularity as an alternative water treatment method in recent years. To date, the forward osmosis-reverse osmosis (FO-RO) hybrid technology has been proposed as a low-energy and environmentally friendly next-generation seawater desalination process. Scaling up the FO-RO hybrid system significantly affects the success of a commercial-scale process. However, neither the ideal structure nor the membrane components for plate-and-frame FO (PFFO) and spiral-wound FO (SWFO) are known. This study aims to explore and optimize the performance of SWFO-RO and PFFO-RO hybrid element-scale systems in the desalination of seawater. The results showed that both hybrid systems could yield high water recovery under optimal operating conditions. The prediction of the system performance (water flux and reverse salt flux) by artificial intelligence was considerably better (R > 0.99, root mean square error <5%) than that of conventional mass balance models. A Markov-based decision tree successfully classified the water flux level in hybrid systems. An optimal set of operational conditions for each membrane system was proposed. For example, in RO, a combination of the feed solution (FS) flow rate (≥17.5 L/min), FS concentration (<17,500 ppm), and operation pressure (<35 bar) would result in high water permeability (>40 LMH). In addition, five SWFO elements and four PFFO elements should be the optimal numbers of FO membranes in the hybrid FO-RO system for effective seawater desalination, especially for long-term operation.

Predicting the removal efficiency of pharmaceutical and personal care products using heated metal oxides as adsorbents based on their physicochemical characteristics.

Pharmaceutical and personal care products (PPCPs) are emerging pollutants that are commonly found in the environment and exist predominantly in nondegradable forms. Several attempts have been made to remove PPCPs via conventional wastewater treatment processes; however, these processes have limitations, such as high costs and insufficient removal efficiencies. Adsorption is a promising alternative for removing PPCPs because it is inexpensive, highly reusable, and easy to operate. Therefore, this study aims to determine the contributing characteristics that can be used to predict the adsorption behaviour of PPCPs based on their physicochemical properties, with heated metal oxide adsorbents (HMOAs). HAOP (heated aluminium oxide particles) and HIOP (heated iron oxide particles) with particle sizes below 38 µm were used. Results from the Brunauer-Emmett-Teller (BET) analysis show that HIOP has higher surface area and smaller pore size (113.7 ± 26.3 m2/g and 5.4 ± 1.8 nm) than HAOP (14.5 ± 0.6 m2/g and 18.6 ± 3.1 nm), which suggest that HIOP would show superior adsorption rates compared to HAOP. The adsorption mechanism is identified based on three major physicochemical properties of PPCPs: molecular weight (M.W.), octanol-water partition coefficient (log Kow), and acid dissociation constant (pKa). The results suggest that the most dominant factor that contributes to the adsorption of PPCPs on to HMOAs is the M.W., where the larger the molecular size, the better the adsorption efficiency. The tests conducted with varying log Kow values revealed that the hydrophilicity of the adsorbent influences the adsorption performance. It was found that HIOP exhibits better removal efficiencies with hydrophilic PPCPs (up to 83%) than with hydrophobic PPCPs (48%), while HAOP exhibits better removal efficiencies with hydrophobic PPCPs (86%) than with hydrophilic PPCPs, with less than 10% removal. Unlike the M.W. and pKa values, the log Kow does not exhibit any visible trend. Therefore, the adsorption behaviour can be predicted with the M.W. and pKa values of the PPCPs, when HAOP and HIOP are used as adsorbents.

Effect of biocarriers on the nitrification and microbial community in moving bed biofilm reactor for anaerobic digestion effluent treatment.

The performance of a moving bed biofilm reactor (MBBR) depends largely on the type of biofilm carrier used. However, how different carriers affect the nitrification process, particularly when treating anaerobic digestion effluents, is not completely understood. This study aimed to evaluate the nitrification performance of two distinct biocarriers in MBBRs over a 140-d operation period, with a gradually decreasing hydraulic retention time (HRT) from 20 to 10 d. Reactor 1 (R1) was filled with fiber balls, whereas a Mutag Biochip was used for reactor 2 (R2). At an HRT of 20 d, the ammonia removal efficiency of both reactors was >95%. However, as the HRT was reduced, the ammonia removal efficiency of R1 gradually declined, ultimately dropping to 65% at a 10-d HRT. In contrast, the ammonia removal efficiency of R2 consistently exceeding 99% throughout the long-term operation. R1 exhibited partial nitrification, whereas R2 exhibited complete nitrification. Analysis of microbial communities showed that the abundance and diversity of bacterial communities, particularly nitrifying bacteria such as Hyphomicrobium sp. And Nitrosomonas sp., in R2 was higher than that in R1. In conclusion, the choice of biocarrier significantly impact the abundance and diversity of microbial communities in MBBR systems. Therefore, these factors should be closely monitored to ensure the efficient treatment of high-strength ammonia wastewater.

High-efficient and rapid removal of anionic and cationic dyes using a facile synthesized sole adsorbent NiAlFe-layered triple hydroxide (LTH).

It would be extremely momentous to familiarize a low-cost sole adsorbent NiAlFe-layered triple hydroxides (LTHs) having a strong sorption affinity towards both anionic and cationic dyes. Using the urea hydrolysis hydrothermal method LTHs were fabricated and by altering the ratio of participant metal cations the adsorbent was optimized. BET analysis revealed that the optimized LTHs possess an elevated surface area (160.04 m2/g) while TEM and FESEM analysis portrayed the stacked sheets-like 2D morphology. LTHs were employed for the amputation of anionic congo red (CR) and cationic brilliant green (BG) dye. The adsorption study showed that within 20 and 60 min, respectively, maximum adsorption capacities were achieved at 57.47 mg/g and 192.30 mg/g for CR and BG dye. Adsorption isotherm, kinetics, and thermodynamics study revealed that both chemisorptions with physisorptions were the assertive factor for the dye encapsulation. This enhanced adsorption performance of the optimized LTH for the anionic dye is attributed to its inherent anions exchange properties and new bond formation with the adsorbent skeleton. Whereas for the cationic dye, it was because of the formation of strong hydrogen bonds, and electrostatic interaction. Morphological manipulation of LTHs, formulates the optimized adsorbent LTH111, provokes the adsorbent for this elevated adsorption performance. Overall, this study revealed that LTHs have a high potential for the effectual remediation of dyes from wastewater as a sole adsorbent at a low cost.

Application of MnFe2O4 magnetic silica-covered ethylenediaminetetraacetic acid-functionalized nanomaterials to the draw solution in forward osmosis.

Forward osmosis (FO) is an emerging and promising water treatment technology. However, selection of an optimal draw solution (DS) is essential for efficient FO process operations. In this study, the potential of ethylenediaminetetraacetic acid (EDTA) functionalized SiO2-covered magnetic nanoparticles (MNPs) as DS in FO process were investigated. The MNPs were synthesized and characterized for their morphology, size distribution, magnetic behavior, and dispersibility. Investigations were carried out to determine the effects of DS concentration and MNPs type, utilizing bare, SiO2 covered, and EDTA coated MNPs at concentrations of 20, 40, and 60 g/L. Furthermore, water flux generation capability and rejection efficiency of octanoic acid (OC) was evaluated with EDTA-MNPs as DS in FO mode (active layer facing feed solution) and PRO mode (active layer facing draw solution). Our results showed that a maximum water flux of 9.59 ± 2 LMH in FO mode, and 11.104 ± 2 LMH in PRO mode was achieved using 60 g/L of EDTA-MNPs. Additionally, we investigated the reusability of the EDTA-coated MNPs and found that their recovery was higher than (>90%) with no aggregation. The stability of EDTA-MNPs was due to strong covalent linkages between their four carboxylate groups and the hydrophilic SiO2 surface layer, which resulted in steric hindrance and prevented their aggregation. Finally, we assessed the rejection efficiency of OC at different pH values and found that it was low (30-39%) at pH values below pKa and high (90-97%) at pH values above pKa. Owing to internal concentration polarization, the rejection of OC in FO mode was (10-20%) higher than in PRO mode. The findings demonstrate EDTA-coated MNPs have significant potentials as an effective DS in FO process .

Impact of pre-coagulation on the ceramic membrane process during oil-water emulsion separation: Fouling behavior and mechanism.

Coagulation has been evaluated as an economical and effective pre-treatment method for controlling membrane fouling. We investigated the influence of the pre-coagulation of oil-water (O/W) emulsions on the formation of membrane fouling in the ceramic membrane process. The results confirmed that pre-coagulation effectively mitigated the fouling formation on the ceramic membrane surface during the O/W emulsion separation. The mechanism of mitigating membrane fouling by pre-coagulation was proposed, owing to the reduction in the zeta potential value of oil droplets by pre-coagulation, resulting in weak electrostatic attraction between oil droplets and ceramic membrane surfaces, and an increase in the size of the oil droplets by pre-coagulation, leading the formation of a cake layer fouling. In addition, the decrease in the hydrophobicity of oil droplets by pre-coagulation resulted in alleviating the hydrophobic interaction between oil droplets and membrane surface. The proposed fouling mechanism was supported by the characterization of the virgin and fouled membrane surfaces and the analysis of the fouling resistance ability of the membranes. Our study could be indicative of mitigation protocols that can be used to alleviate membrane fouling on ceramic membranes during oily wastewater treatment.

Efficient one-pot synthesis of magnetic MIL-100(Fe) using nitric acid without additional Fe ion addition and adsorption behavior of charged organic compounds.

Metal organic frameworks (MOFs) are attracting attention as high-performance adsorbents because of their high specific surface area and porosity. In particular, magnetic MIL-100(Fe) has the both characteristics of Fe3O4 and MIL-100(Fe), which are magnetic characteristics, high specific surface area and open metal sites. However, multiple synthetic steps are required for synthesis of magnetic MOF, and there is limitation that the residual organic linker and unreacted Fe center ions can be discharged, and they cause water pollution. In this study, magnetic MIL-100(Fe) was synthesized within 4 h without the addition of Fe ions by using nitric acid for the surface modification of Fe3O4. Magnetic MIL-100(Fe) was confirmed through XRD, FTIR, and TEM surface analysis, and the optimal conditions for nitric acid addition were selected through magnetization measurements and BET analysis of synthesized magnetic MIL-100(Fe). Thereafter, adsorption evaluation was performed using MB and MO, which are representative cationic and anionic dyes, respectively. The pseudo-second-order Langmuir model showed a relatively high correlation compared to the other models. This shows that the adsorption mechanism depends on both the amount of adsorbent and adsorbate, and Fe3O4 modification with nitric acid does not cause any change in the adsorption mechanism. In the case of adsorption selectivity between the MB and MO, removal rates of 93.27% and 58.73% were obtained, respectively. The above results can contribute to the simplification of the manufacturing of magnetic metal organic frameworks for removing ionic organic compounds and the minimization of water pollution in the manufacturing process.

Ionic fluid as a novel cleaning agent for the control of irreversible fouling in reverse osmosis membrane processes.

While a variety of chemical cleaning strategies has been studied to control fouling in membrane-based water treatment processes, the removal of irreversible foulants strongly bound on membrane surfaces has not been successful. In this study, we firstly investigated the diluted aqueous solutions of ionic fluid (IF, 1-ethyl-3-methylimidazolium acetate) as a cleaning agent for three model organic foulants (humic acid, HA; bovine serum albumin, BSA; sodium alginate, SA). The real-time monitoring of cleaning progress by optical coherence tomography (OCT) showed that fouling layer was dramatically swelled by introducing IF solution and removed by shear force exerted during cleaning. This phenomenon was induced due to the pre-existing interactions between organic foulants were weakened by the intrusion of IF into the fouling layer, which was analyzed by the measurement of adhesion forces using atomic force microscopy (AFM). In the experiments with model foulants and wastewater effluent, IF was added to alkaline cleaning agents (NaOH) to verify the applicability to be supplemented in commercial cleaning agents, and resulted in the significantly enhanced control of irreversible membrane fouling. Implication of utilizing recyclable IF with negligible volatility is that environmental effects of membrane cleaning solutions could be minimized by decreasing usage of cleaning chemicals, while increasing the cleaning efficiency.

Prediction of forward osmosis membrane engineering factors using artificial intelligence approach.

Currently, forward osmosis (FO) is widely studied for wastewater treatment and reuse. However, there are still challenges which need to be addressed for the application of the FO on a commercial scale. In the meantime, with a strong capability to solve the complicated nonlinear relationships and to examine of the relations between multiple variables, artificial intelligence (AI) technique could be a viable tool to improve FO system performance to make it more applicable. This study aims to develop an AI-based model for supporting early control and making decision in the FO membrane system. The results show that the artificial neural networks model is extremely suitable for prediction of water flux, membrane fouling, and removal efficiencies. The most appropriate input dataset for the model was proposed, in which organic matters, sodium ion, and calcium ion concentrations played a vital role in all predictions. The best model architecture was suggested with an optimal hidden layers (2-4 layers), and neurons (10-15 neurons). The developed models for membrane fouling show strong correlation between experimental and predicted data (with R2 values for prediction of membrane fouling porosity, thickness, roughness, and density were 0.85, 0.97, 0.97, and 0.98, respectively). The prediction of water flux presented a high R2 and low root mean square error (RMSE) of 0.92 and 0.9 L m-2.h-1, respectively. Prediction of the contaminant removal exhibits a relatively high correlation between the observed and predicted data with R2 values of 0.87 and RMSE values of below 2.7%. The developed models are expected to create a breakthrough in the control and enhancement in a novel FO membrane process used for wastewater treatment by providing us with actionable insights to produce fit-for-future systems in the context of sustainable development.

Possibility assessment of ultrafiltration membrane pre-treatment efficiency for brackish water reverse osmosis-based wastewater reuse: Lab and demonstration.

Ultrafiltration (UF) membranes are considered a pre-treatment for brackish water reverse osmosis (BWRO) membranes because of the high rejection rate of particulates and the productivity of the final water quantity. This study presents the performance and membrane surface property analysis of UF membranes for commercial membrane manufacturers, and their structural strength and chemical resistance were evaluated. Moreover, the pilot-scale UF-BWRO process was operated for two months using real wastewater based on the results of this study. Although the overall properties were similar, the poly (ether-sulfone) UF membrane showed higher tensile strength than the polyvinylidene difluoride and polyacrylonitrile UF membranes. The UF membrane showed a high removal rate of particulates (over 90%) but low rejection rate of organic compounds, such as humic acid and sodium alginate (below 30%). After exposure to high concentrations of chemicals, the contact angle of the membranes was reduced by approximately 15% compared to that of the virgin membranes. In addition, despite the exposure to low-and high-concentration chemicals, UF membranes were relatively stable in terms of tensile strength. During the operation period of the pilot-scale UF-RO process, the UF membrane showed a high turbidity removal of over 93%, and the UF-BWRO process presented a high salt rejection of over 92%. The UF membrane showed potential for the pre-treatment of BWRO membranes.

Recovery of volatile fatty acids using forward osmosis: Influence of solution chemistry, temperature, and membrane orientation.

This study investigates the suitability of forward osmosis (FO) for recovery of volatile fatty acids (VFAs) from anaerobic digesters (ADs) and identifies the conditions favorable for commercially viable maximum recovery of VFAs. The recovery efficiency of VFAs is evaluated using a polyamide (PA)-based thin-film composite (TFC) membrane. The pH (3, 5, 7, and 9), temperature (20 °C and 40 °C), and membrane orientation (active-layer [AL]-facing FS and AL facingDS) were changed, and water flux, reverse salt flux (RSF), rejection rate, and concentration factor (CF) were evaluated for five VFAs. The water flux and RSF were higher at a higher pH, temperature and in AL-DS mode. A low rejection rate of 23-36% and a CF of 0.20-1.90 were observed at a pH below the pKa due to the solubility of molecular VFAs, while rejection rates was 80-97% and concentration increase by 1 to 4.8-fold at a pH above the pKa values were achieved due to deprotonation of VFAs and changes in membrane surface charges. With an equal increase in temperature of FS and DS from 20 to 40 °C, the rejection rate decreased by almost 20%. While with a transmembrane temperature change, a decrease in rejection rate of 20% was observed compared with baseline experiments due to decreases in viscosity and high diffusivity. In AL-DS mode, VFAs were rejected at a rate of almost 20% lower than that in AL-FS mode due to internal concentration polarization and membrane properties. These findings provide useful information on the factors that can influence optimal recovery rates of VFAs.

Fate, elimination, and simulation of low-molecular-weight micropollutants in an integrated activated carbon-fertiliser drawn osmotic membrane bioreactor.

This study investigated the behaviour and simulation of low-molecular-weight (low-MW) micropollutants (MPs) in a powdered activated carbon (PAC)-assisted fertiliser-drawn OMBR. 10% increase in water recovery and two times thinner fouling layer were observed in OMBR with addition of 100 mg-PAC/g-MLSS. This amount of PAC also boosted the richness and diversity in microbial community (Chao1 and Shannon index increased 1.5 times). Nearly 100% low-MW MPs were eliminated in PAC-OMBR, while 2-80% was achieved with traditional OMBR. This reduced the pathway of low-MW MPs into diluted fertiliser from 47% to < 1% of the total influent mass. Hydrophilicity played the crucial role in the removal of low-MW MPs, especially acetaminophen and nonylphenol. Neural network was suitable for the simulation of MP behaviour with high accuracy (R = 0.98, RMSE = 4.7%). The findings support safer and cleaner use of the diluted fertiliser and promote a cost-effective tool for real-time analysis of MP behaviour.

Fertilizer draw solution index in osmotic membrane bioreactor for simultaneous wastewater treatment and sustainable agriculture.

This study investigated the feasibility of applying a novel protocol for constructing a fertilizer draw solution (DS) index used in osmotic membrane bioreactor (OMBR) for simultaneous wastewater treatment and sustainable fertigation. The results indicated that system performance (i.e., water flux, reverse salt flux, contaminant removal) varied critically under different fertilizers. In which, the highest water recovery (∼60%) was observed with potassium chloride (KCl), whereas the lowest value (∼20%) was observed with ammonium nitrate (NH4NO3), which corresponded to the highest reverse salt flux. With all fertilizers, the membrane fouling layer thickness was in the range of 15.7-45.7 µm. The foulant were mostly irreversible and hydrophilic, with protein and polysaccharides were the dominant compounds. NH4NO3 and NH4H2PO4 (MAP) fertilizers caused the highest and lowest fouling resistances, respectively. Based on the matrix of performance aspects, the very first DSI was constructed for the assessment of fertilizer suitability. Principal component analysis (PCA) showed that fouling resistance played a pivotal role in the total variation of the system. The multi-criteria decision analysis (MCDA) suggested MAP as the most appropriate fertilizer with the highest fertilizer DS index (0.90), followed by KH2PO4 (0.67), KCl (0.65), NaNO3 (0.58), and NH4NO3 (0.16). A numerical simulation using an artificial intelligence-based technique revealed that MAP is also capable of maintaining high performance during long-term operations.