With economic development and population growth, phosphorus pollution in wastewater has increasingly caused severe environmental problems such as eutrophication. Thus, efficient phosphorus removal from wastewater is crucial for maintaining aquatic environmental health and sustainable water resource development. Conventional chemical/electrochemical technologies for phosphorus removal have advantages of high efficiency and mature processes but are limited by difficult chemical dosage control and secondary pollution risks. Capacitive deionization (CDI) technologies have shown significant application potential in phosphorus-containing wastewater treatment for its environmentally friendly traits of no chemical dosing and electrode renewability. This paper systematically reviews the application of CDI and its derivatives such as membrane capacitive deionization (MCDI), flow capacitive deionization (FCDI), and hybrid capacitive deionization (HCDI) for phosphorus removal. Based on electric double-layer theory, CDI removes phosphorus through reversible electrosorption. Phosphate species migrate toward the positively polarized electrode during adsorption and are released by short-circuiting or reversing the electrode polarity during regeneration. Its performance is mainly governed by electrode materials, device configuration, and operating parameters such as voltage, pH, and electrode spacing. In summary, CDI and its derivatives exhibit remarkable technological innovation and application potential in wastewater phosphorus removal.

The recombination of electrons and holes in the semiconductor photocatalyst seriously affects the hydrogen production efficiency in photocatalytic water splitting. The appearance of S-scheme heterojunction can greatly reduce the recombination rate. In order to enrich this type of photocatalyst, the performance of metal-free g-C3N4/g-C3N4(P) heterostructure is studied theoretically. The negative adhesion energy proves the stability of the heterostructure. Research on PDOS, projected band structures, charge transfer, band edge positions and photocatalytic mechanism shows more clearly and comprehensively that this g-C3N4/g-C3N4(P) heterostructure is S-scheme with high redox ability. The near-zero ∆GH* of free energy change in HER process indicates that this g-C3N4/g-C3N4(P) heterostructure should have good HER performance. This work enriches the photocatalyst types and provides a theoretical support for the experimental study of corresponding photocatalysts.

The two-electron water oxidation reaction (WOR) is a promising approach for hydrogen peroxide production, which have many advantages over two-electron oxygen reduction reaction and traditional anthraquinone process. However, the WOR are ordinarily prone to proceed in four-electron path which ends in molecular oxygen production for most water oxidation scenarios. Developing high selective 2 electron WOR catalyst is needed. In this research, a group of fluorine and antimony doped sin dioxide coated titanium electrodes (Ti/SnO2-Sb-F) were synthesized to study the effect of fluorine doping on hydrogen peroxide production through WOR. The hydrogen peroxide production on Ti/SnO2-Sb-F-2 can reached 10.34 mu mol & sdot;cm-1 & sdot;min-1 with a faradic efficiency of 30.13 % in sodium carbonate electrolyte solution. The production rate was 2.12 times higher than that of Ti/ SnO2-Sb-F-0 without fluorine doping. Electrochemical characterization revealed that fluorine doping improved the conductivity of SnO2 and resulted in high electrochemical activity for WOR. Theoretical calculation manifested fluorine doping makes WOR more energetically favorable toward hydrogen peroxide production. This paper provides a substantial approach for selection and synthesis of effective catalyst for 2 e-WOR.

Valorizing waste vinasse into Fe-doped multifunctional biochar offers an efficient route to boost peroxymonosulfate (PMS) activation and improve wastewater purification. In this study, a magnetic porous Fe-doped vinasse biochar (FVB700) was synthesized via co-pyrolysis of vinasse and ferrous oxalate. The obtained material exhibited a synergistic effect between adsorption and PMS catalytic activation for efficient bisphenol A (BPA) removal. Specifically, FVB700, with primary iron species (Fe0, Fe3C, and Fe3O4), rapidly adsorbed BPA through monolayer chemisorption, and the adsorbed BPA was subsequently degraded via PMS activation. Quenching experiments and EPR analysis identified singlet oxygen (1O2) as the dominant nonradical species responsible for BPA degradation in the FVB700/PMS system. Density functional theory analysis revealed Fe3C as the main catalytic center, anchoring PMS via its terminal -SO4 oxygen and reacting with another adsorbed HSO5- to generate 1O2. The FVB700/PMS system retained high performance across a wide pH range (4-11), resisted common water matrix interferents (Cl-, NO3-, HCO3-, H2PO4-, and humic acid), and achieved 78.9 %-90.2 % BPA removal in actual water bodies (tap water, groundwater, and pharmaceutical wastewater). Moreover, in a continuous-flow fixed-bed reactor, it maintained over 90 % BPA removal for 8 days, underscoring its long-term stability and practical applicability. Degradation pathway analysis and ECOSAR prediction showed detoxification of BPA into low-hazard intermediates. This study presents an eco-friendly, "waste-to-resource" strategy that integrates Fe-doping with an adsorption-oxidation synergy for the sustainable and efficient remediation of organic contaminants in water.

This study comprehensively investigates the effects of annealing on the structural, electrochemical properties and passivation film characteristics of Ti20Zr20Hf20Be20Ni20 (at

The layered material hexagonal boron nitride nano-sheets (BNNSs) have similar exotic properties like graphite and have been extensively used in thermal coating, automotive industry and many other applications. However, it is still a challenge to find a green and environmentally friendly method for BNNSs preparation from hexagonal boron nitride (h-BN). This research reported a liquid phase stripping method to prepare BNNSs by using low eutectic solvent (DES) as dispersion, which consists of choline chloride as hydrogen bond acceptor and triethanolamine as hydrogen bond donor. h-BN was exfoliated by ultrasonic method to obtain few layers of BNNSs. The structure and morphology of BNNSs were characterized by Raman spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and atomic force microscopy. The results show that BNNSs are successfully peeled by liquid-phase ultrasonic method with DES as dispersion. The size of the peeled BNNSs was small, and the thickness was only 1.2 nm. The hydroxylation product of the BNNSs can reach adsorption capacities of 286.51 mg/g for Rhodamine B and 147.46 mg/g for Cango red, which were respectively 1.22 and 1.50 times of those for BNNSs. The preparation method for BNNSs was simple and without secondary pollution. The hydroxylation modification for BNNSs was successful to improve its adsorption capacity.

Efficient removal of chemical oxygen demand (COD) and ammonium-N (NH4+-N) is the key issue for treatment of old landfill leachate. In this study, a peroxodisulfate assisted electro-oxidation and electro-coagulation coupled system (POCS) adopting Ti/SnO2–Sb2O3/TiO2 and Fe dual-anode was constructed for synergistic removal of COD and NH4+-N in old landfill leachate. Laboratory experiment results showed that with current density of 20 mA cm−2, initial pH value of 8.0 and peroxodisulfate (PDS) concentration of 60 mM, the POCS system can reach removal efficiencies of 84.2% for COD and 39.8% for NH4+-N. The POCS effectively reduced the complexity of macromolecular organics and avoided the need to add acid or base to adjust pH value. The residual NH4+-N could be effectively recovered through struvite precipitation with a 93.8% purity of the precipitate.

Fluorine is an essential trace element for human skeletal and teeth health, while excess intake of fluoride induces many kinds of diseases. The national standard for fluoride concentration in drinking water quality in China is less than 1.0 mg L-1. -1 . Developing effective and environmental friendly approach to remove fluoride from water especially with high fluoride concentration in low cost is quite necessary. Herein, fluoride removal by MgO modified sucrose-derived porous carbon composite (MPCC) in batch and fixed-bed column systems was studied. The maximum fluoride adsorption capacity of MPCC was 26.6 mg g -1 at 25 degree celsius. Common anions Cl-,- , SO42-and 4 2- and NO3- 3- showed negligible effect on fluoride removal, while a negative impact was observed with co-existence of HCO3-. 3- . The fluoride adsorption kinetic was well fitted with Langmuir adsorption model and the adsorption mechanism was ion exchange reaction between-OH and F-.- . The fluoride concentration can be successfully lowered down to the acceptable level of environmental standard for high concentration influent fluoride. The MPCC composite exhibited excellent regeneration performance, endowing it as promising adsorbent for re- mediation water with fluoride pollution.

目前,全膜工艺是全量处理垃圾渗滤液的主要工艺,但其运营成本较高,开发运营成本低的无膜全量处理工艺具有积极意义.文章以江苏某生活垃圾填埋场老龄渗滤液为研究对象,采用Fen-ton+生化脱氮+电氧化组合工艺,对经两级AO生物处理后的MBR产水进行中试研究.结果表明,组合工艺对COD、氨氮和总氮具有很好的去除效果,处理后的主要水质指标满足《生活垃圾填埋场污染控制标准》(GB 16889-2008),水处理费用为34.3 元/m3,明显低于全膜处理法的成本.

湖泊富营养化是当今严重的环境问题之一,导致这一问题的本质原因是氮、磷的过量输入导致初级生产力的增加.当外源磷得到控制后,控制湖泊中内源磷的释放成为解决湖泊富营养化问题的重点.传统控制内源磷释放的方法有多种,如铝盐、铁盐混凝沉淀法,底泥覆盖法等,这些方法可能产生磷的重新释放、二次污染等问题.锁磷剂对控制内源磷的释放表现出明显优势,具有控磷效果好、无污染、无生态风险等特点,具有广阔的应用前景.本文对最新的锁磷剂研究及应用进展进行概述,以期为控制湖泊内源磷释放提供参考.

Nitrogen-doped carbons (N/Cs) have been widely studied and manifested excellent catalytic performance for oxygen reduction reaction (ORR) for fuel cell systems. However, to date, controversies remain in the  unambiguous identification of the active sites in N/Cs. In the present study, ORR test was conducted on three N/Cs in O2-saturated 0.1 M KOH aqueous solution, where apparent graphitic N contents linearly correlated ORR activity was observed. Theoretical calculations demonstrated graphitic N doping exhibited smaller Gibbs free-energy change than that of pyridinic N doping for ORR and the pyridinic N leads to more chance of proceeding with 2 e- ORR, which were consistent with the experiment results. These results provide suggestion that graphitic N plays a key role for ORR activity offered by N/Cs. This work may pave a generic avenue to determine active sites in heteroatom-doped carbons and can be exploited for rational design and engineering of effective carbon-based catalysts.

在非晶合金中添加第二相制备非晶合金复合材料能够有效地解决非晶合金室温脆性的问题,但第二相的引入对非晶基体高温变形行为造成的影响尚不明确.本研究在Zr55Cu30Al10Ni5非晶合金中添加两种不同的陶瓷颗粒Al2O3和Si3N4,通过放电等离子烧结法制备了一系列不同体积分数的陶瓷颗粒增强Zr基非晶合金复合材料.通过进行高温压缩试验,并建立多颗粒随机分布模型进行数值模拟,对其高温变形行为进行了系统性研究.结果表明,在421℃时,两种复合材料都表现为应力过冲后应变硬化;在441℃时,Al2O3增强的复合材料表现为屈服后应变硬化,对于SisN4增强复合材料,当第二相体积分数小于25％时表现为屈服后应变硬化,当第二相体积分数大于25％时材料却表现为应力过冲后应变硬化.两种非晶合金复合材料的高温变形行为差异与增强相形貌以及增强相颗粒团聚行为导致的第二相分布不均匀有关.

In this study, fluoride removal from water body was studied by applying the MgO/sucrose (MgO/suc) composite in batch and fixed-bed column systems. The MgO/suc was characterized by SEM, XRD, and FTIR. The impacts of various operating parameters including bed mass, flow rate, fluoride concentration, influent temperature, and influent pH were explored in fixed-bed column system, and the investigation on the effects of co-existing anions showed that a detrimental impact on the removal efficiency of fluoride was observed with HCO3−. Moreover, the adsorption process was fitted well by pseudo-second-order and Langmuir models. Thermodynamics results exhibited that fluoride adsorption onto MgO/suc was a spontaneous exothermic process. Besides, Thomas and Yan models were employed to fit the obtained data, and Yan model displayed the best agreement with the breakthrough curves (BTCs), and the mass transfer of fluoride was controlled by multiple diffusion steps. According to these obtained results, we concluded that fluoride adsorption might be primarily obtained through the chemisorption and hydrogen bonding. Thus the MgO/suc composite is a promising adsorbent for the remediation of fluoride in wastewater.

This paper theoretically studies the photocatalytic performance of g-C3N4 self codoped with C–N pair using first-principles. Calculations show that the system with a N2–C1 pair been replaced is the most stable structure. The difference in PDOS after codoping results from the neutral 2p orbital energy difference between the substitution and original atoms, as well as the change in interaction among all atoms after codoping. The band gap can be reduced by 0.41 eV through self C–N codoping. The visible light absorption ability is obviously enhanced through codoping. Both the CBM and VBM of g-C3N4 after codoping are still enough to meet the redox potentials for splitting water. In general, the g-C3N4 self codoped with C and N should have good performance as photocatalyst in water splitting process.

高熵合金由于其独特的多主元原子组成,具有与一般合金不同的微观结构和优异性能,是一种优良的结构工程材料.研究发现,不同于传统合金材料,随着温度的降低,高熵合金普遍保持优良的物理和力学性能,部分性能甚至还得到了提高,这使得高熵合金成为一种潜在的可应用于极端低温环境中的低温材料.低温处理作为热处理的延伸,在钢铁和有色金属中获得了广泛应用,近期研究发现低温处理对高熵合金同样具有效果.本文综述了高熵合金低温条件下的物理和力学性能变化,揭示了深冷处理及结合热处理和加工工艺的低温处理对高熵合金性能的作用机制,总结了高熵合金低温下获得优异性能的原理,以及低温处理对高熵合金组织结构的影响,并对高熵合金低温性能和低温处理的未来研究方向进行展望.

Electro-Fenton (EF) has shown great advantages in the effecient degradation of recalcitrant organic pollutants through in situ generation of & BULL;OH, and the main limitations on system performance are the efficiencies of H2O2 activation and Fe2+ regeneration. In this research, a triple-cathode EF system with a microbial fuel cell (MFC) cathode for the acceleration of Fe2+ regeneration, a gas diffusion electrode for H2O2 production and a stainless steel mesh (SSM) for electro-activation of H2O2 was designed for efficient degradation of organic pollutants. The triple-cathode EF exhibited improved removal rate for recalcitrant organic pollutants with an average electricity consumption of 18.2 kWh Kg(-1) TOC for Rhodamine B degradation, and the dosage of Fe2+ could be reduced to 0.1 mM due to better utilization of H2O2 and inhibition of parasitic reactions. Electrochemical characterization and theoretical calculation revealed that both one-electron reduction and H*-mediated activation contributed to the electro-activation of H2O2 on SSM. This work demonstrates a novel construction and feasible approach for efficient EF with low cost.

The corrosion behavior of TiZrHfBeCu(Ni) high-entropy bulk metallic glasses (HE-BMGs) has been investigated. The TiZrHfBeCu(Ni) HE-BMGs exhibited high corrosion resistance in 3.5 wt. % NaCl solution because of accumulation of ZrO2 and TiO2 in the passive film. Ni promoted increases of the ZrO2, TiO2, and HfO2 contents and a decrease of the BeO content, which improved the HE-BMG corrosion behavior. Compared with Zr41.2Ti13.8Ni10Cu12.5Be22.5 BMG, the high-entropy effect of HE-BMGs can significantly reduce the atomic mobility, which inhibits outward migration of Cu, reduces the kinetics of the dissolution reaction, and inhibits inward erosion by Cl−, thereby improving the corrosion performance.

High-entropy bulk metallic glasses (HE-BMGs) are alloys that contain five or more principal elements in equal or near-equal atomic ratios. HE-BMGs have the composition of a high-entropy alloy (HEA), structure of a bulk metallic glass, and satisfy the thermodynamic, kinetic, and structural conditions for amorphous formation. They have excellent comprehensive properties and potential as structural and functional materials. This paper summarizes the composition design, crystallization behaviors and the physical, mechanical, and thermal stability properties of Zr-Ti containing HE-BMGs. The phase formation rules for HEAs can be used to determine compositions region for bulk glass formation. However, the developed HE-BMGs have poor glass-forming ability (GFA) compared with other BMGs in the same system. In order to obtain HE-BMGs with high GFA, attempts have been made to design near-equiatomic HE-BMGs. An effective strategy for developing HE-BMGs with high GFA is to replace elements in the HE-BMGs at equal atomic ratios. This strategy has enabled the preparation of a Ti20Zr20Hf20Be(Cu7.5Ni12.5) high-entropy amorphous alloy with a critical diameter of 30 mm. New near-equiatomic HE-BMGs with high GFA can also be obtained by similar element substitution based on selected ternary alloys. Because of the high-entropy effect, the crystallization behaviors of HE-BMGs differ from those of other BMGs in the same/similar alloy systems. The non-isothermal crystallization of Zr-Ti containing HE-BMGs involves multistage crystallization, and the nucleation rate decreases with increasing crystallization degree. Zr-Ti containing HE-BMGs have higher activation energies than Vit-1, which means better thermodynamic stabilities. In addition to having a high-entropy effect, near equatomic Zr-Ti containing HE-BMGs are affected by a single principal element. For example, the nucleation rate of Zr31Ti27Be26Cu10Ni6 increases gradually during the initial stage of crystallization; this is consistent with the behavior of Zr-based metallic glass. At the next stage, high entropy effect plays the major role. In other words, the effect induced by single principal elements has a stronger influence on the crystallization process of the near equiatomic Zr-Ti containing HE-BMGs. In terms of mechanical properties, a Zr-Ti containing HE-BMG has high strength, i.e., close to the theoretical prediction, high corrosion and wear resistance, and room-temperature brittleness. The room-temperature plasticity of the Zr-Ti containing HE-BMGs can be obviously improved by adjusting the composition, surface coating, cryogenic cycling treatment and cryothermal cycling treatment. Because of the high-entropy effects and sluggish diffusion effect due to the complexity of the ingredients, HE-BMGs have high creep resistance and corrosion resistance and give high thermal oxidation performances. The macroscopic deformation behaviors of the HE-BMGs show significant temperature and strain rate dependence. At the temperature of hot-embossing process, it was found that Zr-Ti containing HE-BMGs possess a relatively poor thermoplastic formability, especially under the reduced mould size to tens micrometers. Ultrasonic loading is an effective measure to conspicuously enhance the thermoplastic formability of Zr-Ti containing HE-BMGs. There are some expected goals that have not been reached in research on Zr-Ti containing HE-BMGs. At present, the alloy design strategies are mainly applicable to single-element, binary and ternary amorphous alloys. Multi-principal-element amorphous alloys have no appropriate measures for design. The compatibility of tensile ductility and high strength of HE-BMGs is still an overarching goal. New techniques such as machine learning and high throughput can be used to identify compositions with excellent properties. With the development and use of new experimental apparatus, the influence of a higher number of elements on the structures and properties of Zr-Ti HE-BMGs will able to be verified more accurately. In terms of hot-embossing process, the problem of the high viscosities of Zr-Ti HE-BMGs at their formation temperature needs to resolve by process optimization.

The electrogeneration of H2O2 and electro-regeneration of ferrous are conflicting matters in electro-Fenton system. In this research, the degradation of Rhodamine B, methyl orange (MO) and 4-chlorophenol (4-CP) was investigated using a novel dual-cathode microbial fuel cell (MFC) electro-Fenton (EF) hybrid system. An air-cathode of an EF system was used for H2O2 electrogeneration and a carbon felt cathode of a MFC was used to accelerate Fe2+ regeneration. Synergistic improvement of MFC power generation and the degradation of the above refractory organics through EF reaction was achieved. The EF air-cathode was fabricated by adopting activated carbon/graphite powder mixture and PVDF binder, which showed higher H2O2 generation but slower Fe3+ reduction rate than MFC carbon felt cathode. The Rhodamine B removal rate constant and mineralization current efficiency of the MFC coupled EF were 64% and 42% higher than that of uncoupled EF, respectively. The MFC-EF coupled system also exhibited significantly higher removal efficiency for MO and 4-CP than that of un-coupled EF system. Moreover, the power density of MFC was greatly enhanced by coupling EF due to higher Fe3+/Fe2+ redox potential than oxygen reduction.

Modification of exoelectrogens with conjugated polymers is an efficient strategy to improve extracellular electron transfer (EET) from individual cells to electrode. However, due to the hydrophobic nature of conductive polymers, improving cell-electrode adhesion needs to be addressed. In this research, we report the modification of Shewanella oneidensis MR-1 by successively in situ coating individual cells with polypyrrole (PPy) and adhesive polydopamine (PDA). The PPy-PDA modified cells display improved conductivity and adhesion. We employ PPy-PDA modified cells as anode in microbial fuel cells (MFCs) and find that electm-activity of anode is greatly improved as direct EET is improved, and riboflavin secretion which is conducive to indirect EET is enhanced. The maximum power density of MFCs employing PPy-PDA modified cells is 11.8 and 4.8 higher than that of PPy modified and unmodified cells, respectively. Our results indicate this in situ modification of exoelectrogens with PPY-PDA offers a facile and promising strategy for performance improvement of MFCs.