Due to the quenching of free radicals, high-salinity organic wastewater has become a pain point in the practical application of advanced oxidation processes (AOPs). In this work, a Poly (sodium 4-styrenesulfonate) (PSS) modified lanthanum ferrite and ceria composite (A-Ce/LaFe) was used to activate hydrogen peroxide (H2O2) for methylene blue (MB) degradation. The -SO3- in the PSS molecule brings about electrostatic interactions between the catalyst and environmental substances. The electrostatic repulsion forces anions (Cl-, HCO3-, etc.) to move away from the catalyst surface and prevent them from approaching and quenching free radicals. The electrostatic attraction causes a large number of cationic MB molecules to be adsorbed to the catalyst surface, thereby improving the local concentration and contact efficiency. In the typical high-salinity organic wastewaters (30000-70000 mg center dot L-1), A-Ce/LaFe achieves complete degradation of MB within 30 min, significantly superior to FeSO4 and ordinary perovskite. In addition to cationic pollutants, A-Ce/LaFe can effectively degrade electrically neutral pollutants in high-salinity organic wastewater. The synergistic effect of Fe2+/Fe3+ and Ce3+/Ce3+ electron transfer caused a large number of hydroxyl radicals generated by hydrogen peroxide decomposition became the dominant reactive oxygen species. This work has certain enlightening significance for high-salinity organic wastewater treatment by free radicals based AOPs.

A novel iron-carbon technique to enhance the production of medium-chain carboxylates (MCCs) from waste activated sludge (WAS) during anaerobic fermentation was proposed in this study. Results revealed that the maximal MCCs production (113.78mmol/L) and selectivity of MCCs were significantly enhanced by 30.50% and 144.48% respectively, at 20g/L iron-carbon. The optimal fermentation time was also shortened from 18 to 8 days. Mechanistic investigations disclosed that MCCs formation was significantly promoted by Fe2+, which was released from iron-carbon and assimilated by microorganisms. Further analysis showed that the solubilization (36.35%), hydrolysis (3.87%), and acidogenesis (33.47%) processes of WAS were promoted by iron-carbon, supplying more substrates (short-chain carboxylates (SCCs)) for the synthesis of MCCs. Iron-carbon enhanced the abundances of key microorganisms participating in the aforementioned bioprocesses, according to microbial community investigation. Additionally, the conductivity of sludge was improved by 127.84% with the addition of iron-carbon particles, thus improved the conditions for anaerobic biological activities.

Sulfate secondary pollution has always been an inherent problem of peroxymonosulfate-based advanced oxidation processes (PMS-AOPs). In this work, sulfate production is reduced from the source by increasing the PMS utilization rate. A three-dimensionally ordered macroporous perovskite composite material (3DCe@Fe) was synthesized to activate PMS for urotropine (URO) degradation under visible light. 3DCe@Fe shows strong adsorption capacity (When the initial concentration was 100 mg center dot L -1 , the URO adsorption removal rate reached 34.82 % within 30 min), the adsorption process increases the local concentration and shortens the diffusion path of reactive oxygen species (ROSs), thereby improving the contact efficiency and reducing ROSs quenching, ultimately improving the PMS utilization rate. When the PMS dosage was as low as 0.5 mmol center dot L -1 , the URO degradation rate and TOC removal rate still reached 93.25 % and 55.38 %, respectively. In addition, the oxygen vacancies on the catalyst surface trigger the formation of singlet oxygen ( 1 O 2 ), which has low reactivity with inorganic anions, thereby reducing the ineffective consumption of PMS in an environment containing multiple interfering substances. Therefore, in this work, a catalyst with high oxygen vacancy content and strong adsorption capacity was successfully developed, which provided ideas for the green and efficient operation of PMS-AOPs in actual wastewater treatment.

Even though regarded as one of the mainstream solutions for organic wastewater, the performance of advanced oxidation processes (AOPs) in high-salinity organic wastewater treatment has been widely questioned. Some common inorganic anions can weaken or even quench free radicals, resulting in a 41 +/- 9 % loss in reaction rate. In addition, due to the possible generation of toxic by-products represented by halides, direct contact of free radicals, organic pollutants and anions also brings additional environmental risks. Recently, researchers have found a fallback option-free radical pathways are being replaced by non-free radical pathways represented by singlet oxygen, but the efficiency decline and toxic byproducts seem difficult to completely avoid. In this work, the research progress on the application of AOPs in the treatment of high-salinity organic wastewater was reviewed. In addition, an idea based on the negatively charged catalyst was proposed, in which the anions will be driven away from the catalyst surface by electrostatic repulsion to avoid contact and quench the free radicals. This review is expected to provide guidance and new ideas for the treatment of high-salinity organic wastewater.

Calcium lignosulfonate is a common anionic surfactant. In this study, calcium lignosulfonate (SL) was employed to modified chalcopyrite surface and promote chalcopyrite bioleaching. The bioleaching experiments revealed that in the absence of SL, the bioleaching rate of chalcopyrite was slower at the initial stage, and it was accelerated after a period of 12 days. Conversely, when SL was introduced during the bioleaching process, the bioleaching rate of chalcopyrite was a significant acceleration within the first 6 days. After the introduction of SL, the bioleach rate of chalcopyrite was about 3 times faster in the first 12 days. This highlights the effect of SL on expediting the bioleaching efficiency of chalcopyrite. Mechanism research indicates that after the introduction of SL, the adsorption energy of bacteria on mineral surface decreased from -2.71 to -4.37 mJ/m 2 , the adhesion of bacterial was promoted. Further analysis through scanning electron microscopy, electrochemical analysis, and Xray photoelectron spectroscopy demonstrates that after SL modification, the structure of jarosite on the chalcopyrite leaching residues became denser, and the relative content of Fe (III) and S (VI) was increased from 56.4 % and 84.6% to 65.4% and 91.5%, respectively. These alterations are highly conducive to electron transfer processes and chalcopyrite oxidation.

As one of the ideal peroxymonosulfate (PMS) activators, perovskites exhibit high activity and stability. In this work, our research group reviewed the research progress of perovskites as PMS activators. Firstly, the activation mechanism is described, which mainly involves the radical pathways based on the redox of metal ions and the non-radical pathways based on oxygen vacancies. Then, as the focus, the strengthening strategies for perovskites, including morphological engineering, interface engineering and electronic modulation, etc. were summarized. In addition, we also pay attention to some of the latest research in this field, such as tailored properties perovskites and sustainability. Finally, the development direction of perovskites as PMS activators was prospected. This paper is expected to provide a reference for the application of perovskite/PMS system in actual wastewater treatment.

Owing to higher biochemical reaction rates and biogas production, the thermophilic anaerobic system might have more advantages than mesophilic one for treating organic wastewater. However, it is not clear that how the COD/SO42- ratio affect the performance of thermophilic anaerobic system. Therefore, a thermophilic anaerobic reactor was constructed to investigate the influence of COD/SO42- ratio on treating sulfate-rich wastewater. The chemical oxygen demand (COD) removal efficiency, sulfate removal efficiency and methane production were above 90 %, 75 % and 400 mL/d at COD/SO42- higher than 2.0, respectively. The proportion of electrons flowing to the methane-producing archaea (MPA) was higher than 50 %. At the COD/SO42- ratio between 0.5 and 2.0, the COD removal and the methane production decreased, whereas the sulfate removal was enhanced and the proportion of electrons flowing to the sulfate-reducing bacteria (SRB) increased to higher than 50 %. As the COD/ SO42- ratio decreased, the thermophilic anaerobic system gradually changed from methane production to sulfate reduction, similar to the mesophilic anaerobic system. However, the COD removal, methane production and sulfate tolerance were higher in the thermophilic anaerobic system. The dominant genus of MPA was Methanosaeta, Methanothermobacter and Candidatus_Methanomethylicus. The dominant genus of SRB was Thermodesulfovibrio, which might contribute to the higher degree of sulfuric acid tolerance in the thermophilic anaerobic process compared to the mesophilic one.

The chain elongation bioprocess for the production of medium -chain carboxylates (MCCs) is promising for resource recovery from organic wastes. In this study, the microbiome development and metabolic interactions in chain elongation system with 10% granular activated carbon (GAC, size between 1.5-2 mm) were investigated. The bioreactor achieved an electron recovery rate over 70%, and the carbon distribution towards caproate was over 64%. Additionally, the microbial community structure shifted and chain elongation microbiome rapidly acclimated from traditional anaerobic fermentation consortia. The taxonomic composition shifted in favor of MCCs production by enriching the key microbes associated with caproate production. Caproate-producing Clostridium (75% abundance) and proteolytic Proteiniphilum remarkably predominated in the microbial community. Further metagenomics analysis recovered genome bins of Clostridium kluyveri, Clostrium indolis, Clostridium aminovalericum and Proteiniclasticum ruminis, which together represented the majority of the microbial community. Among them, the complete ethanol -acetate fermentation for caproate production via the reversed beta-oxidation pathway (RBO) and fatty acid biosynthesis (FAB) pathway were fully recovered, suggesting that both the pathways contributed to MCCs formation. Further metabolic pathways analysis suggested that microbial metabolic exchanges between chain elongator and symbiotic bacteria, such as cross -feeding of acetate and acetylCoA, is vital to shape a robust microbial ecosystem.

As one of the important microorganisms in the mining area, the role of iron-sulfur oxidizing microorganisms in antimony (element symbolized as Sb) migration and transformation in mining environments has been largely neglected for a long time. Therefore, the processes of the typical iron-sulfur oxidizing bacterium Acidithiobacillus ferrooxidans (A. ferrooxidans) and pyrite interaction coupled with the migration and transformation of Sb were investigated in this paper. The bio-oxidation process of pyrite by A. ferrooxidans not only accelerates the oxidation rate of Sb(III) to Sb(V) (62.93% of 10 mg·L-1 within 4 hours), but also promotes the adsorption and precipitation of Sb (32.89 % of 10 mg·L-1 within 96 hours), and changes in the dosage of minerals, Sb concentration, and pH value affect the conversion of Sb. The characterization results show that the interaction between A. ferrooxidans and pyrite produces a variety of reactive species, such as H2O2 and •OH, resulting in the oxidation of Sb(III). In addition, A. ferrooxidans mediates the formation of stereotyped iron-sulfur secondary minerals that can act as a major driver of Sb (especially Sb(V)) adsorption or co-precipitation. This study contributes to the further understanding of the diversified biogeochemical processes of iron-sulfur oxidizing bacteria-iron-sulfur minerals-toxic metals in mining environments and provides ideas for the development of in-situ treatment technologies for Sb.

Ammonium sulfate [(NH4)2SO4] is an effective activator of malachite sulfidization flotation. In this work, we explored the effects of ammonium ion (NH4+) and copper ion (Cu2+) on malachite sulfidization flotation and investigated the underlying mechanism. Flotation experiments demonstrated that NH4+ can not only eliminate the negative effects of Cu2+, but also work together with Cu2+ to further promote malachite sulfidization flotation in a certain concentration range. Zeta potential, SEM-EDS, and X-ray photoelectron spectroscopy analysis results indicated that the single Cu2+ weakened the oxidation of S (II) species on the malachite surface and reduced the formation of sulfides. In the presence of NH4+, Cu2+ did not inhibit the formation of sulfides on malachite surface but worked with NH4+ to promote it. Aqueous speciation calculation and adsorption test revealed that NH4+ and Cu2+ interacted to form Cu (II)-NH3 complexes, which reacts with S (II) species to form a copper sulfide substance that is more easily adsorbed on the malachite surface than the copper sulfide colloid formed by the reaction between Cu2+ and S (II) species. This leads to the improvement of surface sulfidization.

The treatment of emerging pollutants has become a challenging and multidisciplinary subject. Advanced oxidation processes based on persulfate are a strategic opportunity to address this issue, with research into catalysts and catalytic processes being the focus of this process. In this work, flower-like cobalt sulfide (F-CoS) particles acted as catalysts in peroxymonosulfate (PMS) activation for degrading an organic pollutant, sulfamethoxazole (SMX). The results indicated that F-CoS/PMS combined system performed excellently, with SMX being completely oxidized within 10 min. And the system exhibited superior resistance to environmental factors (e.g. pH and anions). Radicals quenching and electron paramagnetic resonance (EPR) analyses indicated that non-radical pathways based on high-valent cobalt-oxo (Co(IV)) species and 1O2 take a dominant position in SMX degradation, instead of SO4 & BULL; and & BULL;OH. Electrochemical, in-situ Raman and density functional theory (DFT) calculations revealed that PMS interacts with Co sites on the F-CoS surface, and then electronic transfer processes occurred, in which PMS acts as an electron acceptor to produce Co(IV) species and as an electron donor to produce 1O2. This study not only implies a method with great potential application in organic wastewater treatment but also contributes to further comprehending the heterogeneous activation process and catalytic mechanism of PMS.

This work presents a novel chitosan coated magnetite/rhodochrosite composites prepared by thermal reduction method were used to efficient remove Cr(VI) from aqueous solution. A series characterization including XPS, XRD, FTIR, SEM, TEM and electrochemical measurement were used to investigate the characterization of pre-pared materials. SEM and TEM results show that the chitosan carbon (Ch-BC) firmly coated the thermally modified rhodochrosite and magnetite, and composites prepared at 900 degrees C can further improve its specific surface area. The removal of Cr(VI) by MaRh@Ch-500, MaRh@Ch-700 and MaRh@Ch-900 are all highly pH dependent. At pH 5, MaRh@Ch-500 showed the best Cr(VI) removal capacity than others, which is 13.4, 18.1 and 9.9 times of natural magnetite, rhodochrosite and Ch-BC, respectively. Additionally, maximum adsorption capacity for MaRh@Ch-500 fitted by Langmuir model was 104.5 mg/g at pH 2, 30 degrees C. Electrochemical analysis confirmed that based on coated of Ch-BC, the MaRh@Ch-500 presented stronger redox activity, lower resistance and stronger electrical conductivity than others, which is more favorable to electron transfer. XPS results show that nearly 92.33 % Cr(VI) was converted to CrxFe1-x(OH)3/Cr2O3 and loaden on the surface of MaRh@Ch-500. Our results provide theoretical support for the development of efficient treatment of Cr(VI) polluted water.

复杂难处理的氧化铜矿具有氧化率高、结合率高、矿物组成复杂等特点.孔雀石是一种典型氧化铜矿,其在矿浆中会与水的偶极子相互吸引形而成定向排列的水化膜,不利于浮选.孔雀石在硫化浮选过程中,其表面形成的硫化面积小、硫化物不稳定且易脱落.本文对硫酸铵增强硫化效果进行了系统研究,研究发现铵盐对氧化铜矿表面的硫化具有明显的促进作用,且能有效地提高孔雀石硫化浮选回收率.对溶液中S元素组分分析发现,在孔雀石浮选的最佳浮选pH范围内,HS?为主要的含硫组分,推测HS?是孔雀石硫化的主要物质.Zeta电位结果表明:硫酸铵的加入能促进HS?/S2?等负离子在矿物表面吸附.原子力显微镜(AFM)测试分析表明,硫酸铵提高了孔雀石表面硫化物的稳定性.X射线光电子能谱(XPS)研究表明,硫化过程是硫离子与矿物表面的铜离子发生氧化还原反应过程,硫酸铵的加入能促进这一氧化还原反应的进行,提高硫化效率.基于硫酸铵促进活化硫化浮选机理的研究,形成了先硫后氧?深度活化氧化铜矿异步浮选新工艺,并且成功地应用于华刚矿业的生产实践,大幅提高氧化铜矿浮选回收率.

In view of the strong hydrophilicity of malachite, the sulfidation performance of conventional sulphidizing re-agent sodium sulfide on malachite is not satisfactory. In this work, we discussed the effect of tetraamminecopper (II) complex pretreatment on the sulfidation and flotation behavior of malachite. The performance was evaluated by micro-flotation experiments. The flotation results showed that a better flotation recovery can be obtained with a molar concentration of tetraamminecopper (II) sulfate of only one-twentieth of the conventional activator (NH4)2SO4, all else being equal. Scanning Electron Microscope with Energy Dispersive Spectrometer (SEM-EDS) shows that the weight percentage of S and Cu on the surface of the sulfidized malachite increased significantly in the present of [Cu(NH3)4]2+. The FTIR and Raman results showed that sulfur ions could be chemisorbed on the surface of malachite and form a layer of copper-sulfide species. X-ray photoelectron spectroscopy (XPS) further confirmed the actual existence of the sulfide layer, which consists of monosulfide (S2-), disulfide(S22-) and polysulfide (Sn2-). The presence of the activator [Cu(NH3)4]2+ can significantly increase the formation of disulfide and polysulfide on the surface of malachite, thereby promoting the subsequent interfacial adsorption of xanthate.

Widespread hexavalent chromium (Cr (VI)) in the environment has become a worldwide problem, and economical and efficient treatment is urgently needed. In this paper, the treatment method of Cr (VI) by microorganisms and iron minerals (pyrite and magnetite) under anaerobic conditions was investigated. Furthermore, the influence of Cr (VI) on the microbial community structure was explored. The reduction test demonstrated that the removal rate of Cr (VI) in a single biological group was 54.96%; however, in the pyrite and biological groups and magnetite and biological groups, the removal rates of Cr (VI) increased to 83.06% and 78.23%, respectively. Microorganisms and iron minerals work together to produce a better removal effect on the removal rate of Cr (VI). Mechanistic studies have found that in the process of Cr (VI) reduction, a passivation layer is formed on the surface of the mineral that hinders the progress of the reaction. The addition of bacteria can reduce the negative impact of the passivation layer. At the same time, iron minerals have better electron-receiving and -conducting ability and can be used as electron carriers for bacteria to reduce Cr (VI). In addition, iron minerals and the disappearance of Cr (VI) will change the structure of the community and affect the expression of its functions, which is more conducive to reducing Cr (VI). This work sheds new light on the treatment of heavy metal pollution and the understanding of the synergistic reduction mechanism of Cr (VI).

We have carried out the first systematic study of the effects of visible light on the homogenous dynamics in the bromate-sulfite-ferrocyanide (BSF) reaction. Under flow conditions, the reaction system displayed photoinduction and photoinhibition behavior, and the oscillatory period decreased with the increase of light intensity, which is due to the fact that light irradiation mainly enhanced the negative process and affected the positive feedback. The light effect on positive and negative feedback is studied by analyzing the period length of pH increasing and decreasing in detail. With the increase of light intensity, the period length of pH increasing decreases monotonically, while the period length of pH decreasing changes nonmonotonically. These results suggest that light could be used as a powerful tool to control homogenous dynamics. Results obtained from numerical simulations are in good agreement with experimental data.

Many drugs adjust and/or control the spatiotemporal dynamics of periodic processes such as heartbeat, neuronal signaling and metabolism, often by interacting with proteins or oligopeptides. Here we use a quasi-biocompatible, non-equilibrium pH oscillatory system as a biomimetic biological clock to study the effect of pH-responsive peptides on rhythm dynamics. The added peptides generate feedback that can lengthen or shorten the oscillatory period during which the peptides alternate between random coil and coiled-coil conformations. This modulation of a chemical clock supports the notion that short peptide reagents may have utility as drugs to regulate human body clocks.

Sulfidization xanthate flotation remains the most promising method for the beneficiation of malachite. In this study, L-arginine (LA) was first used to modify the malachite surface and improve the efficiency of sulfidization flotation. The performance of LA was evaluated by the flotation experiments. The mechanism of interaction between LA and the malachite surface was investigated by adsorption experiments, zeta potential measurements, scanning electron microscopy (SEM-EDS) and X-ray photoelectron spectroscopy (XPS) analysis. Flotation experiments showed that LA had a significantly promoting effect on malachite sulfidization flotation. Adsorption experiments and SEM-EDS results indicated that LA improved the adsorption of S (II) species into the malachite surface and promoted the formation of sulfides. This finding was further confirmed by the XPS analysis. The XPS measurements results determined that S (II) species reacted with Cu (II) on the malachite surface and form polysulfides, adding LA promoted the reaction. The zeta potential measurements showed that LA increased the positive electrical properties of the mineral surface, which was conducive to S (II) species adsorption and the sulfidization reaction. This work sheds new light on the development of sulfidization activation.

A combination depressant SHI was composed of sodium sulfite (Na2SO3) and sulfonated lignin (SL) in a 5:1 M ratio. In this study, SHI and sodium silicate (Na2SiO3) were employed to inhibit the floatability of galena, and the synergies between agents was explored. Micro-flotation results shown that after 2.4 x 10(-4) mol/L SHI was added, the recovery of galena and fine-galena declined by 53% and 36%, respectively. SHI exhibited excellent depressing efficiency toward galena. In the presence of Na2SiO3, the inhibitory effect of SHI was more obvious. Zeta potential measurements indicates that SHI and Na2SiO3 altered the potential of galena surface through chemical reaction or adsorption action. The X-ray photoelectron spectroscopy results demonstrate that Na2SiO3 in the SHI were reacted with Pb ions on the galena surface and formed PbSO3, the SL was adsorbed by the galena surface through hydrogen bonding. In parallel, Na2SiO3 interacted with the mineral surface by generating PbSiO3. The addition of inhibitors increased the oxidation rate of the galena surface, thereby reducing the adsorption of collectors. Density functional theory simulations shown that Na2SiO3 reduced the bonding energy between the galena surfaces and Na2SiO3, and improved the stability of adsorption.

针对孔雀石矿物亲水性强,常规硫化剂硫化作用后表面硫化膜不稳定的现状,开发出铜铵络合物作为强化硫化钠硫化作用的活化剂.试验结果表明:铜铵络合物在碱性条件下的主要作用成分为Cu(NH3)42+,该成分可起到与硫酸铵相似的活化效果,促使孔雀石表面覆盖的硫化物更均匀更致密,进而达到促进孔雀石表面疏水的效果.铜铵络合物应用于西藏玉龙氧化铜矿浮选过程时,在原矿含Cu 4.47％ 的条件下,经2粗2精2扫闭路浮选试验获得了氧化铜浮选精矿含铜24.14％、铜回收率82.15％的较好指标.