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Ultrasound (US) was introduced into a persulfate (PS) / zero-valent copper (ZVC) system for the degradation of bisphenol AF (BPAF). In this system, ZVC worked as a catalyst to activate PS. Compared with the PS/ZVC process, the degradation rate of BPAF in the PS/ZVC/US system raised significantly from 59.8% to 97.0% due to a synergistic interaction between sonolysis and a heterogeneous reaction. When ultrasound was 120 W at 20 kHz and initial BPAF concentration was 20 mol/L, the BPAF could be completely removed after a 60-min reaction with 0.5 g/L ZVC, 1 mM PS. According to kinetics research, the decomposition of BPAF in a PS/ZVC/US system could be separated into two stages with a demarcation point after about 20 min of reaction via pseudo-first-order rate constants (). A Quantitative analytical k obs modeling for the study of main radicals was established, and the result indicated was the predominant radical in acidic conditions and both •OH and SO •-4 SO •-4 were the predominant radicals in relative basic conditions. Moreover, the effects of initial persulfate dosage, initial BPAF concentration, and coexisting inorganic anions on BPAF degradation were evaluated. A high-accuracy mass spectrometer was used to study the oxidation process and potential activities were deduced. Finally, the possible reaction mechanisms in the PS/ZVC/US system is proposed that the surface heterogeneous catalysis was the key step to activate PS. This work will promote the understanding of the utilization of ZVC in advanced oxidation and also the key role of in activating PS. Cu +

Iron (hydro)oxides, including poorly crystalline ferrihydrite and the more crystalline forms, hematite and magnetite, play an important role in the biogeochemical cycling of arsenic in aquatic environments. In this study, adsorption and oxidation experiments for As(III) were performed on ferrihydrite, hematite, and magnetite, respectively. The results showed that the three iron (hydro)oxides acted as a catalyst for the oxidation of As(III) in the presence of oxygen. The variation in the oxidation states of As(III) on iron (hydro)oxides were confirmed by X-ray Absorption Near-Edge Structure (XANES) spectra. Adsorption kinetics of As(III) followed a pseudo-second-order equation in the three iron (hydro)oxides systems. Oxidation of As(III) on the three iron (hydro)oxides was observed by the determination of total As(V) concentration. The pseudo-first-order equations satisfactorily described the oxidation kinetics data. The oxidation rate constants in the different iron (hydro)oxide systems followed the order: hematite > ferrihydrite > magnetite, that is, 0.0111, 0.0021, and 0.0009 h-1, respectively.

By taking the fillings from the wastewater treatment reactor of a practically stable operation of the BAF, it is to test the lipid phosphorus biomass both in the bio-film and floc in the fillings, and active changing laws of microbes. The experiments show that BAF sewage treatment results from the joint action of bio-film and biological floc. The experiments provide theoretical foundations for the operating mechanism of BAF, packing height and the optimization of backwash time. Due to its high efficiency, energy saving, small area, easy operation and management, Biological Aerated Filter (BAF) technology has become a research focus[1] of a biological wastewater treatment technology in recent years. BAF process is characterized of a lot of filler in the activated sludge, besides the bio-film on the fillings. This sludge contains active living organisms, shed bio-film, suspended matters from the raw sewage and other adsorptions from the wastewater. They are collectively referred to as biological floc. When oxidating and decomposing organic matters in the sewage, it intercepts and adsorb sunken substances. Throughout BAF operation process, it is as irreplaceable as the bio-film.

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