001. Wenyan Liang, Guozhi Luo, Hongxin Tan, Niannian Ma, Nan Zhang, Li Li. College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China. Efficiency of biofloc technology in suspended growth reactors treating aquacultural solid under intermittent aeration. Aquacultural Engineering, 59, 2014, Pages: 41- 47.

Aquacultural solid waste from a recirculation aquaculture system was used as a substrate to produce heterotrophic bacteria in suspended growth reactors. The efficiency of nitrogen recycling under intermittent aeration (IA, 0.5-h aeration/0.5-h non aeration) and continuous aeration (CA) strategy was investigated. The nitrogen dynamics, biochemical composition of biofloc and efficiency of nitrification/denitrification/ammonium assimilation of biofloc were determined. No significant differences were observed in the nitrogen recycling rate, crude protein and polysaccharides contents of biofloc between the IA and CA reactors. The energy used for intermittent aeration was almost one half of that for continuous aeration. IA strategy (0.5-h aeration/0.5-h non aeration) appears to be more effective to produce biofloc in aquaculture solid waste in reactors than CA strategy.

Keywords: Heterotrophic nitrogen assimilation; Intermittent aeration; Aquaculture solid waste; Biofloc technology

002. Yanbin Zhu, Shan Li, Dengxin Li, Chunyan Liu and Fang Ma. School of Environment Science and Engineering, Donghua University, Shanghai 201620, China. Bioflocculation behaviours of microbial communities in water treatment. Water Science and Technology, 69(4), 2014, Page: 694 - 702.

We studied the flocculation behaviours of microbial communities in 21 soil, wastewater and activated sludge samples to clarify the effects of culture medium types on flocculation ability and screening efficiency, and to analyze diverse functions and microbial compositions. The bioflocculants produced by 33% of the microbial communities had flocculating efficiencies higher than 90%. Six out of the eight microbial communities with efficiencies over 94% were screened from the culture medium using dibutyl phthalate (DBP) as the carbon source. BF-BCT, which was derived from the Chinese cabbage soil sample, had the highest flocculating efficiency (99.6%), species diversity and uniformity. Nine highly efficient strains were separated and purified from seven different microbial communities, indicating that flocculating microorganisms are widely distributed in ecosystems. The 16S rRNA gene testing shows that the eight bacterial and the one fungal strains are common soil microorganisms. The flocculating abilities of BB11 (Sphingobacterium multivorum) and SE3 (Galactomyces geotrichum) have never been reported hitherto. Six strains, including the most flocculating-active TB13 and JB17, were screened from the culture medium using DBP as the sole carbon source. In particular, we compared the performance of culture media and analyzed analogous microbial communities with a Biolog automatic micro-analysis system for the first time.

Keywords: biofloculation; dibutyl phthalate; microbial community; water treatment