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Many studies have shown that both Chironomid larvae and Microcystis aeruginosa would form disinfection byproducts (DBPs) under chlorination or chloramination. However, in the natural state, Microcystis aeruginosa and Chironomid larvae exist together. DBPs of chlorination between Chironomid larvae and Microcystis aeruginosa were widely assumed to be "black box." This study focused on effects of Microcystis aeruginosa on DBP formation during the chlorination of Chironomid larvae metabolites. Results of the study suggest that the presence of Microcystis aeruginosa not only influences the concentration of DBPs from Chironomid larvae metabolism, but also changes the trend of individual DBPs. Results suggest that Microcystis aeruginosa may change the trend of chloropicrin (TCNM), and Microcystis aeruginosa may promote TCM, 1,1-DCP, 1,1,1-TCP, and TCNM formation, while inhibiting the accumulation of DCAA and TCAA. Results illustrate the mechanism of Microcystis aeruginosa participating in DBP formation during chlorination of Chironomid larvae. [ABSTRACT FROM AUTHOR]

The emission of nitric oxide (NO) to the atmosphere is a major environmental problem. To abate NO emission from the industrial flue gas, a rotating drum biofilter (RDB) was developed for the denitrifying removal of NO. After the start-up period, the RDB could effectively remove NO from the waste gas and the denitrifying removal efficiency could reach 85%. After the addition of CuII(EDTA) to the nutrients, the removal efficiency could increase to 99.1%. To improve the understanding of the relationship between the composition of bacterial population and the performance of the RDB, a denaturing gradient gel electrophoresis (DGGE) of polymerase chain reaction-amplified genes coding for 16S rRNA was used to analyze and determine the changes in bacterial communities in the RDB. Results showed that there was a slight change in microbial diversity after the addition of CuII(EDTA) to the nutrient solution, which led to an increase in NO removal efficiency. Eight major bands of 16S rRNA gene fragments obtained from the DGGE gels of biofilm samples were further purified, reamplified, cloned, and sequenced. Phylogenetic analysis identified sixteen types of micro-organisms in the RDB. Sequences of these fragments were compared with those listed in the database of the GeneBank (National Center for Biotechnology Information). Gene analysis of 16S rRNA showed that the major populations were Clostridium sp., β-proteobacterium, γ-proteobacterium, and Cytophaga-Flexibacteria-Bacteroides (CFB) groups. In addition, it was concluded that denitrification was caused by the organism with DNA represented by bands labelled G-5, G-6, and G-8. G-5 was related to a γ-proteobacterium, whereas those labeled G-6 and G-8 were related to a β-proteobacterium. [ABSTRACT FROM AUTHOR]