Selectively recovering rare earth elements with carboxyl immobilized metal-organic framework from ammonium-rich wastewater.

The material with high adsorption capacity and selectivity is essential for recovering rare earth elements (REE) from ammonium (NH-N)-rich wastewater. Although the emerging metal-organic framework (MOF) has gained intensive attention in REE recovery, there are scientific difficulties unsolved regarding restricted adsorption capacity and selectivity, hindering its extensive engineering applications. In this work, a diethylenetriamine pentaacetic (DTPA)-modified MOF material (MIL-101(Cr)-NH-DTPA) was prepared through an amidation reaction.

Electrochemical reductive removal of trichloroacetic acids by a three-dimensional binderless carbon nanotubes/ CoP/Co foam electrode: Performance and mechanism.

Numerous chlorinated disinfection by-products (DBPs) are produced during the chlorination disinfection of water. Among them, chloroacetic acids (CAAs) are of great concern due to their potential human carcinogenicity. In this study, effective electrocatalytic dechlorination of trichloroacetic acids (TCAA), a typical CAAs, was achieved in the electrochemical system with the three-dimensional (3D) self-supported CoP on cobalt foam modified by carbon nanotubes (CNT/CoP/CF) as the cathode.

Electrochemically selective ammonium recovery from wastewater via coupling hydrogen bonding and charge storage.

Electrochemical ammonium (NH) storage (EAS) has been established as an efficient technology for NH recovery from wastewater. However, there are scientific difficulties unsolved regarding low storage capacity and selectivity, restricting its extensive engineering applications. In this work, electrochemically selective NH recovery from wastewater was achieved by coupling hydrogen bonding and charge storage with self-assembled bi-layer composite electrode (GO/VO).

Evaluating the role of salinity in enhanced biogas production from two-stage anaerobic digestion of food waste by zero-valent iron.

Salts including NaCl are the most common food flavoring agents so they are often accumulated in food waste (FW) and have potential impact on anaerobic digestion (AD) of FW. In this study, the enhanced biogas production from two-stage anaerobic digestion (TSAD) of FW by microscale zero-valent iron (ZVI) under different salinity (3, 6, 9, and 15 g NaCl/L) was evaluated. Under salinity stress, ZVI becomes a continue-release electron donor due to the enhanced corrosion and dissolution effect and the slow-down surface passivation, further improving the performance of TSAD.

Electrocatalytic reduction of nitrate by carbon encapsulated Cu-Fe electroactive nanocatalysts on Ni foam.

Electrocatalytic denitrification is an attractive and effective method for complete elimination of nitrate (NO). However, its application is limited by the activity and stability of the electrocatalyst. In this work, a novel bimetallic electrode was synthesized, in which N-doped graphitized carbon sealed with Cu and Fe nanoparticles and immobilized them on nickel foam (CuFe NPs@NC/NF) without any chemical binder.

Achieving high-performance electrocatalytic reduction of nitrate by N-rich carbon-encapsulated Ni-Cu bimetallic nanoparticles supported nickel foam electrode.

The cathode with low-energy consumption and long-term stability is pivotal to achieve the conversion of nitrate (NO) to nitrogen (N) by electrocatalytic denitrification. Herein, a binder-free electrode was synthesized by directly immobilizing N-doped graphitized carbon layer-encapsulated NiCu bimetallic nanoparticles on nickel foam (NF) (NiCu@N-C/NF) and served as the cathode for electrocatalytic NO reduction. Morphological characterization indicated that Ni and Cu nanoparticles were encapsulated by the N-doped graphitized carbon layer and well-dispersed on the surface of NF.

Sulfide enhances the Fe(II)/Fe(III) cycle in Fe(III)-peroxymonosulfate system for rapid removal of organic contaminants: Treatment efficiency, kinetics and mechanism.

The activation of peroxymonosulfate (PMS) by Fe(II) or Fe(III) for environmental decontamination is severely limited by the low conversion rate from Fe(III) to Fe(II). Here, we found that this puzzling problem could virtually be solved by introducing trace amounts of S. With the addition of 0.

Zirconium-modified biochar as the efficient adsorbent for low-concentration phosphate: performance and mechanism.

Achieving advanced treatment of phosphorus (P) to prevent water eutrophication and meet increasingly stringent wastewater discharge standard is an important goal of water management. In this study, a low-cost, high-efficiency phosphate adsorbent zirconium-modified biochar (ZrBC) was successfully synthesized through co-precipitation method, in which the biochar was prepared from the pyrolysis of peanut shell powder. ZrBC exhibited strong adsorption ability to low-concentration phosphate (< 1 mg·L) in water, and the phosphate removal reached 100% at the investigated dosage range (0.

Peroxymonosulfate (PMS) activation by mackinawite for the degradation of organic pollutants: Underappreciated role of dissolved sulfur derivatives.

The internal Fe/Fe cycle is important for peroxymonosulfate (PMS) activation by iron-based materials to produce the reactive oxidative species (ROS) for the breakdown of organic contaminants. Previous studies have focused on the contribution of heterogeneous sulfur species to the Fe/Fe cycle such as lattice S(-II) and surface SO of iron sulfides. In this study, we found that the dissolved S(-II) from mackinawite (FeS) had a substantial contribution to the Fe/Fe cycle.

2D/2D FeNi-layered double hydroxide/bimetal-MOFs nanosheets for enhanced photo-Fenton degradation of antibiotics: Performance and synergetic degradation mechanism.

The photo-Fenton system exhibits great potential in environmental remediation. However, photo-Fenton process suffers from slow reaction kinetics, which is caused by the low yield of available charge carriers and active radicals. In this work, the 2D/2D FeNi-layered double hydroxide/bimetal-organic frameworks nanosheets (FeNi-LDH/BMNSs) photocatalyst was fabricated via an in-situ semi-sacrificial template strategy.

[Enhancement Effects and Mechanisms of Microscale Zero Valent Iron on the Performance of Anaerobic Co-digestion of Waste Activated Sludge and Food Waste].

Focusing on low biogas yields in the anaerobic co-digestion of waste activated sludge and food waste, the enhancing effects and mechanisms of microscale zero valent iron (mZVI) on anaerobic co-digestion was investigated. The results indicated that the addition of mZVI enhanced the methanogenesis stage of co-digestion but had no significant effect on the solubilization, hydrolysis, and acidification stages. With a dosage of 10 g·L mZVI, the cumulative methane yield (based on VS) within 15 days reached 238.

Highly selective electrochemical nitrate reduction using copper phosphide self-supported copper foam electrode: Performance, mechanism, and application.

A highly active and selective electrode is essential in electrochemical denitrification. Although the emerging Cu-based electrode has attracted intensive attentions in electrochemical NO reduction, the issues such as restricted activity and selectivity are still unresolved. In our work, a binder-free composite electrode (CuP/CF) was first prepared by direct growth of copper phosphide on copper foam and then applied to electrochemical NO reduction.

Efficient degradation of bisphenol A via peroxydisulfate activation using in-situ N-doped carbon nanoparticles: Structure-function relationship and reaction mechanism.

A novel in-situ N-doped carbon nanoparticles (NCNs) was prepared through direct pyrolysis of N-rich polyaniline (PANI) without using external N-containing precursor and the as-prepared materials were employed as metal-free peroxydisulfate (PDS) activator for bisphenol A (BPA) degradation. The catalyst derived from PANI carbonization at 900 °C (NCNs-9) displayed the excellent catalytic activity to activate PDS, resulting in 96.0% BPA degradation efficiency within 20 min.

Electro-assisted autohydrogenotrophic reduction of perchlorate and microbial community in a dual-chamber biofilm-electrode reactor.

The electro-assisted autohydrogenotrophic reduction of perchlorate (ClO) was investigated in a dual-chamber biofilm-electrode reactor (BER), in which the microbial community was inoculated from natural sediments. To avoid the effect of extreme pH and direct electron transfer on perchlorate reduction, a novel cathode configuration was designed. The pH of the cathode compartment was successfully controlled in the range of 7.

Enhanced anaerobic co-digestion of waste activated sludge and food waste by sulfidated microscale zerovalent iron: Insights in direct interspecies electron transfer mechanism.

The enhancement of zerovalent iron (ZVI) on anaerobic digestion (AD) has been proved, but there are still some problems that constrain the large-scale application of ZVI, such as the destruction of cell membrane and the inhibition of methanogenesis led by rapid H accumulation. Aiming at these problems, sulfidated microscale zerovalent iron (S-mZVI) was employed to evaluate its effect on anaerobic co-digestion (AcoD) of waste activated sludge (WAS) and food waste (FW). Experimental results showed that S-mZVI promoted the direct interspecies electron transfer (DIET) between specific bacteria and methanogens, resulting in higher methane yield.

Electrochemical Cr(VI) removal from aqueous media using titanium as anode: Simultaneous indirect electrochemical reduction of Cr(VI) and in-situ precipitation of Cr(III).

In this work, a novel method for complete Cr(Ⅵ) removal was achieved in a single-chamber cell with titanium (Ti) as anode via simultaneous indirect electro-reduction of Cr(Ⅵ) and in-situ precipitation of Cr(Ⅲ). The Cr(Ⅵ) and total Cr removal, and electric energy consumption were optimized as a function of electrochemical reactor, current density, initial Cr(Ⅵ) and chloride (Cl) concentration, and initial solution pH. The maximum Cr(Ⅵ) and total Cr removal efficiency reached 80.

Catalytic degradation of ciprofloxacin by a visible-light-assisted peroxymonosulfate activation system: Performance and mechanism.

Peroxymonosulfate (PMS) is extensively used as an oxidant to develop the sulfate radical-based advanced oxidation processes in the decontamination of organic pollutants and various PMS activation methods have been explored. Visible-light-assisted PMS activation to construct a Fenton-like process has shown a great potential for pollution control. In our work, BiVO nanosheets were prepared using a hydrothermal process and used to activate PMS under visible light.

Heterogeneous activation of persulfate by Ag doped BiFeO composites for tetracycline degradation.

Persulfate (PS) activation have been extensively considered as a promising technology for removing recalcitrant pollutants, due to their production of radicals with superior oxidation reactivity. However, a catalyst with high reactive and convenient recovery for PS activation still remains to be developed. In this work, the silver-doped bismuth ferrite (Ag-BiFeO, x = 0.

Influence of low voltage electric field stimulation on hydrogen generation from anaerobic digestion of waste activated sludge.

Low voltage electric field is an important stimulation condition for biochemical metabolic of microorganism. But few literatures were available related to the effect of low voltage electric field on hydrogen production from anaerobic digestion of waste activated sludge (WAS). This study aims to explore such influencing thus carried a series experiments under 35 ± 1 °C and pH 7.

The inhibitory effect of thiosulfinate on volatile fatty acid and hydrogen production from anaerobic co-fermentation of food waste and waste activated sludge.

Thiosulfinate, a nature antibiotic, existed in all parts of Allium thereby accumulating in kitchen waste vastly. However, few literatures were available related to its influence on volatile fatty acids (VFA) and hydrogen production when kitchen waste digestion technology was applied. This study aimed to explore the inhibitory effect and the relevant mechanism.

Synergistic adsorption and electrocatalytic reduction of bromate by Pd/N-doped loofah sponge-derived biochar electrode.

In this work, a novel Pd/N-doped loofah sponge-derived biochar (Pd/NLSBC) material with three-dimensional (3D) network structure was prepared through the carbonization-impregnation method and applied as cathode for electrocatalytic bromate removal. The N-doped biochar not only increased the adsorption capacity of electrode, but also facilitated electron transfer, subsequently resulting in the high electrocatalytic activity for bromate removal. The results indicated higher bromate adsorption capacity of Pd/NLSBC electrode was favorable to the electrocatalytic bromate removal.

Biological perchlorate reduction: which electron donor we can choose?

Biological reduction is an effective method for removal of perchlorate (ClO), where perchlorate is transformed into chloride by perchlorate-reducing bacteria (PRB). An external electron donor is required for autotrophic and heterotrophic reduction of perchlorate. Therefore, plenty of suitable electron donors including organic (e.