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Low H 2 O 2 production, narrow adaptive pH range and slow Fe(II) regeneration on the cathode still limit efficiency of electro-Fenton (EF) and its application. Herein, we designed a bifunctional catalyst with FeS and Fe 3 O 4 nanoparticles dispersed on porous carbon (CFeS@C) using template of sodium alginate (SA)/FeSO 4 hydrogel mixed with carbon black (CB), which presented high H 2 O 2 generation efficiency and outstanding tetracycline degradation efficiency under wide pH ranges (3-8) with a low energy consumption of 19.6 kWh/kg total organic carbon (TOC). The introduction of CB created abundant oxygen vacancies in CFeS@C, promoting the oxygen adsorption and the electrochemical generation of H 2 O 2 , which further boosted the formation of •OH due to the interaction with Fe2+ on the cathode surface. Simultaneously, the reaction between the outer layer of FeS and Fe3+ not only accelerated iron cycling but also reduced the solution pH. It was verified that •OH and 1O 2 played a dominant role in organics degradation. The system maintained stability after 10 cycles and effectiveness in the treatment of pharmaceutical wastewater. This study would offer a new strategy to develop an efficient and durable bifunctional catalyst for heterogeneous EF system working in wide pH conditions for wastewater treatment. [Display omitted] • H 2 O 2 generation and multiple reactive species was achieved on FeS/Fe 3 O 4 @C as cathode. • The multi-layered reaction centers of O V , FeS and Fe 3 O 4 promoted pollutants removal. • Radical and non-radical oxidants were produced simultaneously on the cathode. • This system exhibited efficient degradation behavior in wider application pH. • It was promising and stable for removing various pollutants in water/wastewater. [ABSTRACT FROM AUTHOR]

Based on the natural air diffusion electrode (NADE) cathode, a solar-driven electrochemical integrated sewage treatment technology and equipment in a pilot scale was developed to treat dispersed rural wastewater. The non-aeration NADE had efficient and stable H 2 O 2 production performance, maintaining the H 2 O 2 output between 1474 and 1535 mg h−1 within 50 h with the current efficiency of 77.4%–80.6%. This electrochemical integrated wastewater treatment system was coupled with technologies such as dual-cathode electro-Fenton, peroxi-coagulation and photoelectro-Fenton, which effectively improved the conversion and utilization efficiency of H 2 O 2. It integrated Fenton-like oxidation, electro-oxidation and UV/H 2 O 2 , as well as Fe(OH) 3 -dominated flocculation, which could effectively remove various pollutants in wastewater. The integrated sewage treatment equipment (500 L d−1) realized the effective treatment of a rural decentralized domestic sewage, achieving simultaneous removal of chemical oxygen demand (COD), NH 3 –N, total phosphorus (TP) and bacteria. Driven by solar energy, its application feasibility, superiority and stability have been proved, providing theoretical and technical support for the efficient and low-consumption treatment of dispersed organic wastewater. [Display omitted] • Electrochemical integrated treatment equipment driven by solar energy is proposed. • The non-aeration NADE had efficient and stable H 2 O 2 production performance. • It integrates electro-oxidation, peroxi-coagulation and photoelectron-Fenton. • It has been successfully applied to the treatment of rural decentralized domestic sewage. • The pilot scale system exhibits good application feasibility, superiority and stability. [ABSTRACT FROM AUTHOR]

BACKGROUND Although microalgae had been widely used in wastewater treatment, the treatment efficiency is affected by the carbon limitation of the carbon/nitrogen (C/N) ratio in wastewater. In the present study, the performance on nutrients removal and biomass production was investigated when Chlorococcum sp. GD was inoculated into non‐sterile municipal wastewater and cattle farm wastewater. RESULTS: Although wastewater had indigenous microalgae and bacteria, microalgae could grow and the growth of indigenous bacteria was inhibited when exogenous Chlorococcum sp. GD was inoculated into non‐sterile municipal wastewater and cattle farm wastewater. Nevertheless, both biomass production and nutrients removal were relatively low due to the low C/N ratio in both wastewaters. When sodium acetate was supplemented to both wastewaters in the late exponential growth stage, biomass production and nutrients removal were enhanced. Moreover, the lipid accumulation from microalgal cells grown in municipal wastewater and cattle farm wastewater were 33.2% and 20.9%, respectively. Linoleic and linolenic acids accounted for 47.64 to 56.41% of the total fatty acids, and were in great demand for dietary supplements and aquacultures. CONCLUSION: Chlorococcum sp. GD could be a potential candidate for bioremediation of both wastewaters. The exponential sodium acetate feeding would be an efficient approach for enhancing biomass production and nutrients removal efficiency from wastewater with a low C/N ratio. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

[Display omitted] • A multifunctional Janus solar evaporator was developed. • It exhibited synergic photocatalysis and solar-driven interfacial steam generation. • The JPMS presented effective desalination without the risk of salt accumulation. • Excellent water purification capacity. The expeditious advancement of solar-driven interfacial steam generation by utilizing renewable and free solar energy is a promising strategy for remedying the water crisis. However, salt accumulation on solar evaporators and organic pollutants increases in the remaining bulk water block its commercial potential for practical applications. Herein, a Janus solar evaporator was designed by using a commercialized melamine sponge as the matrix, followed by PDMS modification and deposition of Chinese ink, and TiO 2 nanoparticles. The Janus photothermal melamine sponge (JPMS) was designed with containing a hydrophobic salt resistance layer, and a composite photothermal and photocatalysis layer from top to bottom. The applicability of the developed JPMS was systematically investigated for water evaporation, photocatalytic degradation, desalination as well as wastewater treatment. The JPMS exhibits an evaporation rate of 1.49 kg m-2h−1 with a corresponding efficiency of 93.54% under 1 sun illumination. Notably, the JPMS also exhibits the high efficiency of synergic photocatalysis for organic pollutants and acquires an excellent salt rejection capability. Integration of SISG, photocatalytic, and salt resistance may be viewed as a prospective avenue for water purifying. [ABSTRACT FROM AUTHOR]

• A flow-through system based on the bifunctional cathode of Fe@BN-C/GF was developed. • The acceleration of the O 2 mass transfer promoted the stable production of 1O 2. • The SMT degradation was found not affected in the presence of inorganic salts and organic matter. • TOC removal in flow-through was 1.4 ∼ 2.4-folds that of the batch system under the pH 3 ∼ 11. • The TP, NH 3 -N and TOC in reverse osmosis concentrate could be simultaneously removed. To improve the mineralization efficiency of pollutants under wide pH ranges by self-sustained electrochemical advanced oxidation processes (EAOPs) without any reagent addition, a flow-through system based on the bifunctional cathode of B, N-doped carbon nanotubes embedded with nano-Fe0 particles that loaded on graphite felt (Fe@BN-C/GF) was developed. Dominant by 1O 2 oxidation, the sulfamethazine (SMT) degradation rate and TOC removal in this recirculated flow-through system were 2.6 ∼ 3.3-folds and 1.4 ∼ 2.4-folds that of the batch system under the pH ranges of 3 ∼ 11, respectively. The SMT degradation performance was found not affected in the presence of HCO 3 –, NO 3 –, Cl-, K+, or humic acid (HA). The Fe@BN-C/GF cathode had more potential to treat enlarged wastewater by 5-folds during 10 h operation, and the SMT and TOC removal was 99% and 70.31%, respectively. The total phosphorus (TP), ammonia nitrogen (NH 3 -N) and TOC in reverse osmosis concentrate and secondary wastewater effluent could be simultaneously removed to <0.01 mg L-1 and 8 mg L-1 by this flow-through system with a low electric energy consumption (EEC) of 0.022 and 0.18 kWh gTOC-1, respectively. This EAOPs based on the flow-through Fe@BN-C/GF cathode was self-sustained, and had very promising application prospect of high mineralization of pollutants even for low-conductivity wastewater. [ABSTRACT FROM AUTHOR]