Both -SO3H and -OH oxygen-containing groups were contained in the molecular structure of sodium lignosulfonate (LS). Thus, in this work, LS modified zero-valent iron (LS-ZVIbm) was prepared by ball-milling to activate peroxymonosulfate (PMS) at neutral pH for sulfamethazine (SMT) degradation. The LS-ZVIbm/PMS process dramatically improved the removal of SMT by removing 96.5 % of SMT within 5 min compared to the ZVIbm/PMS process, which only removed 17.8 % of SMT. In addition, the LS-ZVIbm/PMS system reduced the amount of ZVI and PMS by more than 90 %. Inorganic ions and natural organisms had little effect on SMT degradation in this system and the system was well adapted to pH variations, so it also had good SMT removal effect in natural water bodies. Unfortunately, the current reuse rate of LS-ZVIbm was low and needed to be further improved. Characterization by SEM, XPS, FTIR and DFT calculations substantiated that the modification by LS ball-milling improved the catalytic activity of ZVI, thus enhancing PMS activation for antibiotics removal. The main pathways for the production of multiple reactive substances and their roles in SMT removal were elucidated by EPR tests, free radical quenching experiments and quantitative assays. center dot OH, SO4 center dot-, 1O2, O2 center dot-, and Fe (IV) reactive substances were participated in SMT removal and center dot OH was dominated. In brief, present study presents a promising antibiotic treatment based on modified ZVI.

Due to the low cost and abundant reserves of transition metals, there is an urgent need for the design and fabrication of transition metal electrocatalysts for hydrogen evolution reaction (HER) in order to facilitate hydrogen production. In this study, we present a self-supported needle-grass shaped Zn-Co composition on porous Nickel foam (NF) through typical hydrothermal synthesis. The Zn-Co/NF electrodes exhibit highly efficient HER performance in 1.0 M KOH alkaline solution. Specifically, the ZC (1:4)/NF catalyst requires only 98 mV overpotential at a current density of 50 mA cm− 2 due to the synergistic effect between the Zn-Co composition and Ni layers. Furthermore, stability tests reveal that after 1000 continuous cycles with a scan rate of 20 mV s− 1, there is only slight change observed in the LSV curves of ZC (1:4)/NF catalysts. This work provides a novel strategy for designing and fabricating efficient HER electrocatalysts.

Zero-valent iron (ZVI) is a widely employed material for environmental remediation due to its capability to effectively degrade or reduce various pollutants. The enhancement of its reactivity and applicability can be achieved through chemical surface modification. Chemical surface modification involves introducing specific chemical functional groups onto the surface of ZVI, altering its surface chemical properties and structural morphology. This article provides an overview of the advancements made in four commonly used chemical modifications of ZVI, namely ZVI sulfide, ZVI silicide, ZVI oxalate, and ZVI phosphate. The review examines the impacts of these four different modified compounds on the surface structure and reactivity of ZVI, as well as elucidates the mechanisms by which modified ZVI interacts with and removes pollutants. Furthermore, the article discusses the prospects and challenges associated with modified ZVI, offering valuable insights for future research and the application of environmental remediation technologies.

In this work, boron (B) was used to promote Fe3 + /peracetic acid (Fe3 + /PAA) for the degradation of sulfamethazine (SMT). An SMT degradation efficiency of 9.1% was observed in the Fe3 + /PAA system over 60 min, which was significantly increased to 99.3% in the B/Fe3 + /PAA system over 10 min. The B/Fe3 + /PAA process also exhibited superior resistance to natural substances, excellent adaptability to different harmful substances, and good removal of antibiotics in natural fresh water samples. The mechanism of action of boron for Fe3+ reduction was determined using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) spectroscopy, density functional theory (DFT) calculations, and electrochemical tests. The dominant role of center dot OH was confirmed using quenching experiments, electron spin resonance (EPR) spectroscopy, and quantitative tests. Organic radicals (R-O center dot) and Fe(IV) also significantly contribute to the removal of SMT. DFT calculations on the reaction between Fe2+ and the PAA were conducted to further determine the contribution from center dot OH, R-O center dot, and Fe(IV) from the perspective of thermodynamics and the reaction pathways. Different boron dosages, Fe3+ dosages, and initial pH values were also investigated in the B/Fe3 + /PAA system to study their effect of SMT removal and the production of the reactive species. Fe(IV) production determined the kR-O center dot+ Fe(IV) value suggesting that Fe(IV) may play a more important role than R-O center dot. A comparison of the results with other processes has also proved that the procedure described in this study (B/Fe3 + /PAA) is an effective method for the degradation of antibiotics.(c) 2023 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.

In this experiment, C3N5 was synthesized by pyrolysis of 3-amino-1,2,4 triazole material, and then 1% Co-C3N5, 3% Co-C3N5, 5% Co-C3N5, 7% Co-C3N5, and 9% Co-C3N5 were synthesized by varying the mass ratio of cobalt chloride to C3N5 by stirring and ultrasonic shaking. SEM, XPS, and XRD tests were performed on the synthesized materials. The experimental results showed that Co atoms were successfully doped into C3N5. The electrocatalytic reduction experiments were performed to evaluate their NH3 yields and electrochemical properties. The results showed that the ammonia yield obtained by the electrolysis of the 9% Co-C3N5 catalyst as the working electrode in a mixed electrolytic solution of 0.1 mol/L KNO3 and 0.1 mol/L KOH for 1 h at a potential of −1.0 V vs. RHE was 0.633 ± 0.02 mmol∙h−1∙mgcat−1, and the Faraday efficiency was 65.98 ± 2.14%; under the same experimental conditions, the ammonia production rate and Faraday efficiency of the C3N5 catalyst were 0.049 mmol∙h−1∙mgcat−1 and 16.41%, respectively, and the ammonia production rate of the C3N5 catalyst was nearly 13-fold worse than the 9% Co-C3N5, which suggests that Co can improve the Faraday efficiency and ammonia yield of the electrocatalytic reduction of NO3−. This is due to the strong synergistic effect between the cobalt and C3N5 components, with C3N5 providing abundant and homogeneous sites for nitrogen coordination and the Co-N species present in the material being highly efficient active sites. The slight change in current density after five trials of 9% Co-C3N5 and the decrease in ammonia yield by about 12% in five repetitions of the experiment indicate that 9% Co-C3N5 can be recycled and work stably in electrocatalytic reactions and has good application prospects.

In recent years, dye wastewater caused serious effects on environmental ecology and human health. Thus, in the present study, hydroxylamine (HA) was used to improve the Fe3O4/H2O2 process for removing the typical dye pollutant (tartrazine). Only 2.8% tartrazine could be removed in Fe3O4/H2O2 system within 60 min at the reaction of 1 g/L Fe3O4, 1 mM H2O2, and pH 4 while 97.5% tartrazine could be removed within 20 min after adding 1 mM HA into the Fe3O4/H2O2 system. Compared with Fe3O4/H2O2 system, the removal rate for removing tartrazine in Fe3O4-HA/H2O2 system could enhance more than 100 times. Electron paramagnetic resonance tests (EPR), radical quenching experiments and quantitative determination demonstrated that center dot OH was the major reactive species for removing tartrazine in Fe3O4-HA/H2O2 system and center dot OH produced concentration in Fe3O4-HA/H2O2 system was also much higher than that in Fe3O4/H2O2 system. The key factors affecting tartrazine removal in Fe3O4-HA/H2O2 system were also conducted. The optimal HA dosage, Fe3O4 dosage, and H2O2 dosage was 1 mM, 1 g/L and 1 mM. The optimal initial pH in Fe3O4-HA/H2O2 system was 3, but compared with Fe3O4/H2O2 system, the tatrazine removal efficiency could significantly improve under any initial pH condition. Fe3O4-HA/H2O2 process had strong adaptability to inorganic ions and good applicability to different pollutants. Fe3O4-HA/H2O2 process also exhibited good recycle ability for tartrazine removal. Overall, Fe3O4HA/H2O2 process is an effective and good practical applicability approach for dye wastewater treatment.

Reactive oxygen species (ROSs) in Fenton process are of great importance in treating contaminants in wastewater. It is crucial to understand their chemical properties, formation, and reaction mechanisms with contaminants. This review summarizes the reactive oxygen species in Fenton process, including hydroxyl radical (•OH), superoxide radical (O2•−), singlet oxygen (1O2), hydroperoxyl radical (HO2•), and high-valent iron. •OH shows a trend to react with chemistry groups with abundant electrons through H-atom abstraction, radical adduct formation and single electron transfer. Electron transfer is discovered to be an important pathway when 1O2 degrades organic pollutants. Ring-opening and β-scission are proposed to be the possible ways of 1O2 to certain contaminants. Proton abstraction, nucleophilic substitution, and single electron transfer were proposed to explain how O2•− degrade pollutants. As the conjugated acid of O2•−, radical adduct formation and H-atom abstraction are reported for the reaction mechanisms of hydroperoxyl radical. High-valent iron in Fenton, namely Fe(IV), reacts with certain pollutants via single- or two-electron transfer. This review is important for researchers to understand the ROSs produced in Fenton and how they react with pollutants.

In this research, a BiOI/C3N5 heterostructure was synthesized using a solvothermal technique to prevent the recombination of photoexcited electrons and holes. The morphology, structure, and mechanism of the material were investigated using x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), x-ray photoelectron spectroscopy (XPS), ultraviolet–visible diffuse reflectance spectroscopy (UV–Vis DRS), energy-dispersive x-ray spectroscopy (EDS), electron paramagnetic resonance (EPR), and photoluminescence (PL) spectroscopy, among other tests. The photocatalytic performance of the heterostructure was evaluated through the degradation of tetracycline hydrochloride (TCH). Results showed that compared to C3N5 and BiOI alone, the formation of the heterostructure significantly enhanced the photocatalytic efficiency, achieving 1.5 times the degradation efficiency of pure C3N5 and twice that of BiOI. Under optimal conditions, the composite material degraded nearly 90

Background: Nowadays, antibiotic pollution is increasingly serious and posing a huge threat to ecology and human health. Therefore, it is vital to find effective approaches to remove antibiotics. Methods: In this study, boron (B) was adopted to accelerate the surface and solution Fe2+ recycle in Fe3O4/ peracetic acid (PAA) system, which showed excellent performance for antibiotics removal. Significant findings: According the XPS analysis and experiments detection, both recycle of surface and solution Fe2+ could be enhanced in the presence of boron in Fe3O4/PAA system. 74.0% sulfamethazine (SMT) could be removed within 60 min in Fe3O4/PAA system while 93.4% could be removed within only 20 min in B/Fe3O4/ PAA system and the value of k in B/Fe3O4/PAA system (0.136 min-1) was also much higher than that in Fe3O4/ PAA system (0.028 min-1). The effect of boron, Fe3O4, PAA dosage and initial pH on removing SMT in Fe3O4/ PAA system were also conducted. Quenching experiments and EPR experiments demonstrated that 'OH, organic radicals (R-O') and Fe(IV) exhibited 63.1%, 17.3%, and 16.2% role in removing SMT, respectively. Possible SMT degradation pathway and the toxicity of transformation products were analyzed. B/Fe3O4/PAA exhibited superior resistance to inorganic ions and nature organic matters, good recycle ability, excellent adaptability to various pollutants, and efficient performance for antibiotics removal in natural fresh water.

The composite cathode materials xLiMnPO4-Li3V2(PO4)3/C (x = 1, 2) are prepared from Mn2V2O7 and MnV2O6 precursors with a simple solid-state method. XRD results show that the composites consist of orthorhombic LiMnPO4 and monoclinic Li3V2(PO4)3 phases, without any other impurity phases. The average particle size and agglomeration degree of the materials are reduced with Li3V2(PO4)3 compounded into LiMnPO4. Electrochemical performance tests manifest that the specific discharge capacities of xLiMnPO4-Li3V2(PO4)3/C (x = 1, 2) at various C-rates are much higher than those of LiMnPO4/C. The discharge profiles of both composites contain three voltage plateaus of 3.62, 3.68 and -4.05 V. Especially, 2LiMnPO4-Li3V2(PO4)3/C delivers the first specific ca-pacity of 159.6, 133.5 and 112.2 mAh/g at 0.1C, 2C and 5C, respectively, and exhibits excellent cyclic stability.

The efficient removal of complexed heavy metals (HMs) from alkaline electroless plating wastewater is still challenging. A polyamine-grafted chitosan-wood flour-based composite (ACS-AWF) was optimally synthesized. Its adsorption behavior toward Ni(II) in simulated pyrophosphate (PP, the main complextant)-Ni plating wastewater and underlying mechanisms were examined. PP considerably promoted Ni(II) adsorption by up to 108.1%, and the enhancement tolerated excess PP or other substances. Ni(II) adsorption by ACS-AWF was 1.38-similar to 10 times that of several commercial HM-favored resins in the same complexed system. According to the liquid solute species tracking, solid chemical characterizations (eg. synchrotron radiation X-ray adsorption spectroscopy), and theoretical calculations, it was found that Ni(II), primarily as NiP2O72-, could be captured by charge-assistant coordination with the surface polyamine. Then, the coadsorption of PP altered the interface properties via both electrostatic shielding and bridging effect, enhancing Ni(II)-amine coordination efficiency. A dinuclear multilayer coordination structure [-amine-Ni-PP-Ni-amine-] was proposed as the dominant Ni(II) binding mode in the presence of PP. Ni(II) and PP could be sequentially desorbed from ACS-AWF using gradient elution with >95.5% Ni(II) purity. ACS-AWF was then stably reused in five cycles (capacity loss <10%). These results may guide adsorbent design and application in HM purification and recycling from complexed wastewater.

Zero-valent iron/peroxymonosulfate (Fe0/PMS) has been considered as a promising approach for wastewater treatment. Anions and cations are widely present in wastewater and have significant effects on the performance of the Fe0/PMS system for wastewater treatment. Thus, in the present study, tartrazine was selected as the target model; SO42−, NO3−, HCO3−, and Cl− were selected as representative anions and Ca2+, Cu2+, Mg2+, and Mn2+ were chosen as representative cations. The effect of these anions and cations on tartrazine removal and major radicals in the Fe0/PMS were systematically investigated. The presence of a certain concentration of SO42− and Cl− had positive, NO3− had negative, and HCO3− had negligible effects on tartrazine removal in the Fe0/PMS system. SO42− and HCO3− had a small effect on the contribution proportion of reduction, SO4•− and •OH; a certain concentration of Cl− could enhance the contribution proportion of •OH; and NO3− would decrease the contribution proportion of SO4•− and •OH. A certain concentration of each of Ca2+, Cu2+, Mg2+, and Mn2+ could enhance the tartrazine removal in the Fe0/PMS system. Ca2+, Cu2+, and Mg2+ had no effect of the contribution of reduction, SO4•− and •OH, while a certain concentration of Mn2+ could enhance the contribution proportion of SO4•−. These results can provide some references for the Fe0/PMS system to treat actual wastewater containing anions and cations.

High-temperature nitrogen (N) doping boosts the activity of biochars for peroxymonosulfate (PMS) activation, but the N heat loss causes the unsatisfactory catalytic efficiency. Improving the surface area for obtaining the high exposure of N sites is a promising solution. Herein, a soft template-KHCO3 etching strategy is used to synthesize the N-doped porous bowl-like carbon (NPBC) with ultrahigh external surface area (1610.8 m2 g-1). The bowl-like structure eliminates inert bulk interior and allows unobstructed mass transfer of reactants onto both outer and inner surfaces, while the large pore channels by KHCO3 etching further improves the exposure degree of limited N sites. Although NPBC has only 0.43% N content, 93.1% of bisphenol A (BPA) is removed within 1 min through the electron-transfer pathway by fully utilizing the N active centers, and the kinetic rate constant (k) reaches 5.29 min-1, exceeding reported values by 2-270 times. Moreover, the NPBC/PMS system possesses excellent applicability for various organics and conditions, effectively mineralizes BPA and reduces effluent biotoxicity. A quantitative index W representing N exposure degree is first proposed and shows high linearity with the k values of BPA degradation (R2=0.992, 0 <W<3750 m2 g-1%-1), proving the critical role of W in determining catalytic efficiency.

碱性锌酸盐型锌镍合金因其优异的综合性能已成为业界的研究热点,综述了近年来的工艺进展.碱性锌酸盐型镀液体系通常以NiSO4、ZnO等做主盐,强碱(NaOH)作导电盐,具有分散能力好、易钝化处理、对设备腐蚀小等优点,但也存在镀液电流效率低,过程控制参数多,生产废水难处理等缺点.今后研究的核心问题在于寻找更好的镀液配方,开发更优异的络合剂及添加剂种类,从而保证镀件稳定光亮的同时,降低生产成本及废液处理难度.

络合废水中重金属与有机酸之间交互影响,导致常规方式分离重金属难度高、效果差,因此其处理成为近年来重金属污染控制热点与难点.文章在调研大量重金属-有机酸络合废水处理前沿技术的基础上,对沉淀、吸附、铁置换/还原以及高级氧化等重金属-有机酸络合废水处理技术进行了回顾与总结,并分析了其优缺点及优化方向.指出可实现络合废水中COD高效去除及重金属同步回收,不产生二次污染的高效低耗新技术是今后此类废水处理的主要难点和发展重点.

A combination of hydrothermal treatment and FeSO4/Ca(ClO)2 oxidation was developed to enhance the dewatering performance of sludge. First, capillary suction time (CST), specific resistance to filterability (SRF), and water content (Wc) are used to evaluate the sludge dewaterability. The effect of the hydrothermal temperature, the concentration and the molar ratio of FeSO4 and Ca(ClO)2 on the sludge dewatering performance was examined to determine the optimal conditions. Furthermore, the mechanism of the degradation of EPS in sludge was studied using density functional theory (DFT), e.g., electrostatic potential (ESP) analysis, bond order analysis, and bond dissociation enthalpy (BDE) analysis. The results show that the sludge dewaterability was significantly improved with the combined method. The floc structure and the oxygen-containing groups of EPS in sludge are the key reasons for its hydrophilicity and high water content. The combined method can enhance sludge dewatering by breaking the floc structure and removing oxygen functional groups, which is a promising technology for sludge dewatering.

A combined advanced treatment technology of'biological contact oxidation + magnetic resins + chelate resins' based on resins adsorption was employed to treat electroplating wastewater in a Jiangsu company.The practical operation results showed that,the effluent quality could reach the GB 21900-2008 Figure 3 standard and GB 3838-2002 Ⅲ class water standard,and the mass concentration of total Cu and Ni was less than 0.1mg/L,and COD was less than 20 mg/L.Meanwhile,the comprehensive toxicity ofwastewater could reach EPA833-B-94-002 toxicity limits requirements (chronic toxicity was less than 1TUc,and acute toxicity was less than 0.3TUa).

The high-salinity organic wastewater from industrial production process is complex and refractory, and it cannot be effectively treated by a single treatment technology. The research progress of main treatment technologies for high-salinity organic wastewater was reviewed. Moreover, project cases were also analyzed. It was pointed out that process integration was the development direction of high-salinity organic wastewater treatment. For instance,the integrated process of pretreatment and evaporation or incineration was employed to realize the recycling of salt and water in wastewater.

电镀废水是典型复合污染废水,其中重金属离子、表面活性剂、络合剂等多种污染物共存.本文选取电镀工艺中常用的添加剂十二烷基苯磺酸钠(SDBS)以及络合剂柠檬酸钠(CA)为研究对象,使用自主研发的新型磁性强碱树脂NDMP对有机酸吸附动力学、吸附等温线进行了研究,同时考察了溶液条件(pH值、重金属等)对吸附的影响.研究表明,NDMP树脂对2种有机酸的吸附等温线均符合Langmuir模型,说明有机酸在树脂上的吸附是单层吸附,303K下NDMP对SDBS和CA的最大吸附量Q0分别为2.97mmol/g和0.959mmol/g.通过研究Cu(Ⅱ)与SDBS和CA复合组分在树脂上的吸附行为,结果表明,NDMP能同时吸附CA-Cu(Ⅱ)的复合组分,且随着pH值的升高吸附量增大,当pH＞3时,CA-Cu(Ⅱ)组分中Cu(Ⅱ)主要以[Cu(Ⅱ)-Citrate]-实现与CA在树脂上的共吸附.