With the aim of addressing the difficult problem of biodegradable organic nitrogen in biochemical effluent of a printing and dyeing industrial park, the combined ozonation-sequencing batch biofilm reactor (O-SBBR) process was used for advanced treatment. The influencing factors and degradation kinetics were analyzed; quenching experiments were carried out; and the types of free radicals, succinate dehydrogenase activity, and denitrification function genes were determined. The results showed that the suitable ozonation condition was pH 8.
View Article and Find Full Text PDFCryptosporidium infection is a serious threat for HIV/AIDS patients, causing severe diarrhea and even death. The overall prevalence of Cryptosporidium in HIV/AIDS patients was calculated as approximately 8.69% (7,799/89,724), with higher prevalence observed in individuals with diarrhea, individuals with low CD4 T-lymphocyte counts, and antiretroviral therapy-naïve individuals.
View Article and Find Full Text PDFThis study systematically explored the effect of humic acid (HA) (as model of natural organic matter) on the kinetics, products and transformation pathway of triclosan (TCS) by laccase-catalyzed oxidation. It was found that TCS could be effectively transformed by laccase-catalysis, with the apparent second-order rate constant being 0.056 U mL min.
View Article and Find Full Text PDFA method based on ultrasound-assisted liquid-liquid extraction and high-performance liquid chromatography has been optimized for the determination of six polybrominated diphenyl ether congeners. The optimal condition relevant to the extraction was first investigated, more than 98.7 ± 0.
View Article and Find Full Text PDFThe successful application of co-immobilized aerobic-anaerobic biomass under limited aeration in wastewater treatment systems would eliminate the problems associated with the intermediates mono-chlorophenol (MCP) and di-chlorophenol(DCP) accumulations. With low initial pentachlorophenol (PCP) concentration, all PCP could be completely removed under oxygen-limited strict anaerobic conditions, and the removal efficiencies with different initial headspace oxygen percentage (IHOP) were not obviously different from each other. While at high initial PCP concentration, under strictly anaerobic conditions PCP and their intermediates were clearly higher than that under other conditions, and produced obvious accumulation, the highest PCP reduction was achieved by the system receiving 30 IHOP, oxygen-limited system also exhibited lower residual TOC concentration and lower concentration of metabolic intermediates MCP and DCP.
View Article and Find Full Text PDFCultivation of aerobic granular sludge for pentachlorophenol (PCP) degradation under microaerobic condition (DO concentration was controlled at 0.2-0.7 mg/L) was studied in this paper.
View Article and Find Full Text PDFDegradation of 2,4,6-trichlorophenol (TCP) with co-immobilizing anaerobic granular sludge and isolated aerobic bacterial species was studied in coupled anaerobic/aerobic integrated reactors. The synergism of aerobes and anaerobes within co-immobilized granule might facilitate degrading the TCP and exchange of anaerobic metabolites 4-CP, which promoted system organic removal efficiency and recovered from organic shock-loads more quickly. The biomass specific activities experiment further confirmed that strict anaerobes be not affected over the course of this experiment by the presence of an oxic environment, aerobic activity predominated in the outer co-immobilized granule layers, while the interior was characterized by anaerobic activity.
View Article and Find Full Text PDF