In this study, a matrix composite material of CdZnS and α-FeOOH on carbon cloth (CZS@FeOOH@CC) was prepared by a hydrothermal method , and was used for the degradation of As(III). The composite material has good photocatalytic activity of removing As(III) in the presence of oxalate. CZS@FeOOH@CC can completely degrade 10 mg/L As(III) within 10 min under visible light irradiation. The influence factors of CZS@FeOOH@CC composite material on catalytic oxidation of As(III) were also studied in the oxalate system. The photocatalytic oxidation efficiency of As(III) is affected by the oxalate concentration in the reaction system, and the atmosphere plays a major role in the degradation of As(III). Under visible light, oxalate first combines with Fe(III) on the surface of iron oxide to form Fe(III)-oxalate complex, and then the Fe(III)-oxalate composite is activated to produce·C 2 O 4 − . In the presence of oxygen, Fe(II) readily reacts with O 2 and oxidizes to Fe(III). The introduction of CdZnS promoted the separation of interfacial electron holes, and accelerated the REDOX cycle of Fe(II)/Fe(III). This study provides a feasible and simple method for accelerating the catalytic removal of heavy metals from wastewater by iron-based materials.
Shi Lin,Zhan Cetao,Bai Wenjing,Wang Wei,Yuan Shoujun,Hu Zhen-Hu
Arsanilic acid ( p -ASA), an organoarsenic additive found in livestock wastewater, can release toxic inorganic arsenic into the environment. While bioelectrochemical systems have proven effective in decomposing organoarsenics, managing the resulting inorganic arsenic remains a challenge. This study demonstrated the feasibility of a two-stage bioelectrochemical process designed to facilitate p -ASA degradation and in situ recover inorganic arsenic from contaminated livestock wastewater. It consisted of two sequential stages: (I) anodic stimulation for p -ASA degradation and (II) reversing electrode polarities for the cathodic reduction of inorganic arsenic. In Stage I, the anode significantly enhanced the degradation of p -ASA, resulting in 18 μg/L of As(III) and 700 μg/L of As(V) released into the bulk solution. In Stage II, the cathode further reduced the As(III) and As(V) to 8.9 and 35.5 μg/L, respectively, through the synergistic action of the cathode and suspended microbes. The inorganic arsenic was recovered as a layer of As(V)-O on the cathode. Microbial analysis indicated that Alcaligenes was responsible for the degradation of p -ASA, while Anaerobacillus and Desulfitibacter played key roles in reducing As(V) and As(III) on the cathode, respectively. This study provided a promising alternative approach for the removal of organoarsenics and in situ recovery of inorganic arsenic from organoarsenic-bearing wastewater.
危险品化学品经营许可证（带存储）