It is a great challenge for effective treatment of shale gas produced water (SGPW), a typical industrial wastewater with complex composition. Single forward osmosis (FO) or membrane distillation (MD) process has been widely used for desalination of SGPW, with membrane fouling not well addressed. Fertilizer draw solution (DS) with high osmotic pressure is less likely to cause FO fouling and can be used for irrigation.
View Article and Find Full Text PDFLow pressure membrane takes a great role in hydraulic fracturing wastewater (HFW), while membrane fouling is a critical issue for the stable operation of microfiltration (MF). This study focused on fouling mitigation by sodium percarbonate (SPC) oxidation, activated by ultraviolet (UV) and ferrous ion (Fe(II)). The higher the concentration of oxidizer, the better the anti-fouling performance of MF membrane.
View Article and Find Full Text PDFSubstantial volumes of hazardous shale gas produced water (SGPW) generated in unconventional natural gas exploration. Membrane distillation (MD) is a promising approach for SGPW desalination, while membrane fouling, wetting, and permeate deterioration restrict MD application. The integration of gravity-driven membrane (GDM) with MD process was proposed to improve MD performance, and different pretreatment methods (i.
View Article and Find Full Text PDFMembrane distillation (MD) offers promise for recycling shale gas produced water (SGPW), while membrane fouling is still a major obstacle in standalone MD. Herein, sodium percarbonate (SPC) oxidation was proposed as MD pretreatment, and the performance of the single MD, SPC-MD hybrid process and Fe(II)/SPC-MD hybrid process for SGPW treatment were systematically evaluated. Results showed that compared to raw SGPW, the application of SPC and Fe(II)/SPC led to the decrease of the fluorescent organics by 28.
View Article and Find Full Text PDFMembrane electrochemical reactor (MER) shows superiority to electrochemical oxidation (EO) in high salinity organic wastewater (HSOW) treatment, but requirement of proton exchange membranes (PEM) increases investment and maintenance cost. In this work, the feasibility of using low-cost pressure-driven membranes as the separation membrane in MER system was systematically investigated. Commonly used pressure-driven membranes, including loose membranes such as microfiltration (MF) and ultrafiltration (UF), as well as dense membranes like nanofiltration (NF) and reverse osmosis (RO), were employed in the study.
View Article and Find Full Text PDFThe scaling-induced wetting phenomenon seriously affects the application of membrane distillation (MD) technology in hypersaline wastewater treatment. Unlike the large amount of researches on membrane scaling and membrane wetting, scaling-induced wetting is not sufficiently studied. In this work, the current research evolvement of scaling-induced wetting in MD was systematically summarized.
View Article and Find Full Text PDFPolycyclic aromatic hydrocarbons (PAHs) with their carcinogenic, teratogenic, and mutagenic effects can cause great damage to the ecosystem and public health when present in water. With bioremediation, PAH contamination in water environment can be greatly reduced in an eco-friendly manner. It has thus become the research focus for many environmental scientists.
View Article and Find Full Text PDFTreatment of recalcitrant landfill leachate (LFL) induces huge energy consumption and carbon emissions due to its complex composition. Although membrane distillation (MD) exhibits good potential in LFL treatment with waste heat utilization, membrane fouling and ammonia rejection are still the major problems encountered that hinder its application. Herein, membrane electrochemical reactor (MER) was coupled with MD for simultaneous membrane fouling control and resource recovery.
View Article and Find Full Text PDFDesulfurization wastewater in coal-fired power plants (CFPPs) is a great environmental challenge. This study aimed at the current status and future research trends of desulfurization wastewater by bibliometric analysis. The desulfurization wastewater featured with high sulfate (8000 mg/L), chlorite (8505 mg/L), magnesium (2882 mg/L) and calcium (969 mg/L) but low sodium (801.
View Article and Find Full Text PDFThe development of high efficient photocatalysts for antibiotics contamination in water remains a severe challenge. In this study, a novel step-scheme (S-scheme) photocatalytic heterojunction nanocomposites were fabricated from integrating AgCl nanoparticles on the MIL-100(Fe) octahedron surface through facile multi-stage stirring strategy. The S-scheme heterojunction structure in AgCl/MIL-100(Fe) (AM) nanocomposite provided a more rational utilization of electrons (e) and holes (h), accelerated the carrier transport at the junction interface, and enhanced the overall photocatalytic performance of nanomaterials.
View Article and Find Full Text PDFUltrafiltration is an environmentally friendly water treatment technology, but membrane fouling significantly impacts membrane performance and service life. Photocatalytic modification of membrane is regarded as an effective way for membrane fouling control. In this study, graphite oxide (GO), AgPO and AgPO-GO nanomaterials were applied in polyvinylidene fluoride (PVDF) ultrafiltration membranes modification, and the membranes was denoted as P-GO, P-AgP and P-AgP@GO, respectively.
View Article and Find Full Text PDFEffective extraction of useful resources from high-salinity textile wastewater is a critical pathway for sustainable wastewater management. In this study, an integrated loose nanofiltration-electrodialysis process was explored for simultaneous recovery of dyes, NaCl and pure water from high-salinity textile wastewater, thus closing the material loop and minimizing waste emission. Specifically, a loose nanofiltration membrane (molecular weight cutoff of ~800 Da) was proposed to fractionate the dye and NaCl in the high-salinity textile wastewater.
View Article and Find Full Text PDFIn this work, a recyclable self-floating A-GUN-coated (Ag/AgCl@g-CN@UIO-66(NH)-coated) foam was fabricated for effective inactivation of Microcystis aeruginosa (M. aeruginosa) under visible light. The floating photocatalyst was able to inactivate 98% of M.
View Article and Find Full Text PDFThis study proposed a cation-regulation strategy based on metal ion removal coupled Na-regulation for enhancing anaerobic fermentation of waste activated sludge. The optimal treatment condition was: cation-exchange resin dosage of 1.75 g/g SS for 1-day treatment, followed by Na-enhanced anaerobic fermentation at NaCl concentration of 20 g/L.
View Article and Find Full Text PDFThough sulfamethoxazole (SMX) degradation at the low or medium concentration (SMX< 30 mg/L) has been reported in the microbial fuel cell (MFC), further exploration is still urgently required to investigate how the high concentration of SMX affect the anode biofilm formation. In this study, the degradation mechanism of SMX and the response of microbial community to SMX at different initial concentrations (0, 0.5, 5 and 50 mg/L) were investigated in MFCs.
View Article and Find Full Text PDFA novel plasmonic Ag/AgCl@LaFeO (ALFO) photocatalyst was successfully synthesized by a simple in-situ synthesis method with enhanced photocatalytic activity under visible light for harmful algal blooms (HABs) control. The structure, morphology, chemical states, optical and electrochemical properties of the photocatalyst were systematically investigated using a series of characterization methods. Compared with pure LaFeO and Ag/AgCl, ALFO-20% owned a higher light absorption capacity and lower electron-hole recombined rate.
View Article and Find Full Text PDFHydrophobic membranes used in membrane distillation (MD) systems are often subject to wetting during long-term operation. Thus, it is of great importance to fully understand factors that influence the wettability of hydrophobic membranes and their impact on the overall separation efficiency that can be achieved in MD systems. This Critical Review summarizes both fundamental and applied aspects of membrane wetting with particular emphasis on interfacial interaction between the membrane and solutes in the feed solution.
View Article and Find Full Text PDFAntibiotic contamination is increasing scrutinized recently. In this work, the Ag-AgCl/WO/g-CN (AWC) nanocomposites were successfully synthesized using a two-step process involving electrostatic self-assembly and in-situ deposition for trimethoprim (TMP) degradation. The as-prepared photocatalysts were investigated and characterized by XRD, FTIR, XPS, TGA, SEM, TEM, UV-vis, PL and EIS.
View Article and Find Full Text PDFPrevious studies have demonstrated that sludge hydrolysis and short-chain fatty acids (SCFAs) production were improved through NaCl assistant anaerobic fermentation. However, the effect of NaCl concentrations on hydrolase activity and microbial community structure was rarely reported. In this study, it was found that α-glucosidase activity and some carbohydrate-degrading bacteria were inhibited in NaCl tests, owing to their vulnerability to high NaCl concentration.
View Article and Find Full Text PDFIn this work, a novel Ag/AgCl@g-CN@UIO-66(NH) heterojunction was constructed for photocatalytic inactivation of Microcystis aeruginosa (M. aeruginosa) under visible light. The photocatalyst was synthesized by a facile method and characterized by XRD, SEM, TEM, BET, XPS, FT-IR, UV-vis DRS, PL and EIS.
View Article and Find Full Text PDFSolar energy is considered one of the most promising energy sources for the degradation of pollutants in the water treatments. An innovative solar photo-thermochemical system involving peroxydisulfate (PDS) as an oxidant and xenon lamp as a solar irradiation light source was applied with hopes to degrade organic matters and alleviate the ultrafiltration (UF) membrane fouling when treating the real surface water. Moreover, heat-activated PDS pretreatment was used as a comparison to explore the respective proportions of solar light and heating effects, finding that solar light effect dominated the activation of PDS to degrade natural organic matters (NOMs) when the reaction temperature was below 50 °C and they both contributed to the production of free radicals at the temperature of >50 °C.
View Article and Find Full Text PDFThis study reported a "treating waste by waste" strategy to dispose waste activated sludge (WAS), i.e. reverse osmosis (RO) brine-enhanced anaerobic fermentation.
View Article and Find Full Text PDFThe frequent harmful algae blooms (HABs) in eutrophic waters pose serious threats to the water environment and health of human beings and animals. In this study, a new type of photocatalytic coating was prepared by loading AgCO-N:GO (AGON) on the polyurethane sponge modified by silica sol via a dip coating method for the photocatalytic inactivation of Microcystis aeruginosa (M. aeruginosa) and degradation of Microcystin-LR (MC-LR).
View Article and Find Full Text PDFThis study reported the NaCl-enhanced anaerobic fermentation with cation-exchange resin regeneration waste liquid (CRWL) as alternative NaCl source for waste activated sludge (WAS) disposal and carbon recovery. Through 4-day CRWL-enhanced anaerobic fermentation at Na concentration of 0.34 mol/L, the Na-caused sludge disintegration triggered numerous release of dissolved organic matters (DOMs), i.
View Article and Find Full Text PDFThis study developed an economical approach for enhancing short-chain fatty acids (SCFAs) production from waste activated sludge (WAS) by NaCl assistant anaerobic fermentation. With NaCl addition at 20 g/L, sludge disintegration with extracellular polymeric substance (EPS) disruption and cell lysis were induced owing to the attack of osmotic pressure, which facilitated WAS solubilization with release of biodegradable organic matters. The SCOD sharply increased to 4092 mg/L (SCOD/TCOD = 23.
View Article and Find Full Text PDF