盐度对固定化曝气生物滤池中微生物的影响

在进水盐度为0～3%的范围内,固定化曝气生物滤池（BAF）处理人工合成采油废水的效果良好.在此基础上进一步研究盐度变化对该系统中微生物的影响,结果表明,当盐度小于1%时,载体上活体微生物数量不断上升,达1.3×10⁷ 个/cm³;当盐度上升到2%和3%时,活体微生物数量开始下降,细胞个体缩小、破裂,并随出水流失,经驯化后系统中微生物数量保持在1.1×10⁶ 个/cm³.在盐度为0.5%时,微生物脱氢酶活性(dehydrogenase activity,DHA）达最高,为14.4　μg/(mg·h),降解性能最好.微生物分泌的胞外多糖(extra cellular polysaccharide,ECP_c）起到了将微生物固定在载体上的作用,并在盐度为2%时达到最高209.9　μg/mg.载体上胞外多聚物(extra cellular polymers,ECP_s）和微生物质量随着系统运行而堆积,实验采用的FPUFS大孔载体（孔径为0.3～0.7　mm）可以有效地避免反应系统中由于微生物及其ECP_s累积而造成的堵塞现象,并且在高盐度的环境下提供良好的水、气、有机物的传质条件.

Effect of Salinity on Immobilized Microorganisms in Biological Aerated Filter (BAF)

Based on the satisfactory treatment effect of synthesized oil field wastewater with salinity of 0 - 3%, the salinity effect on the immobilized microorganism in the biological aerated filter (BAF) was further investigated. It was shown that the quantity of live microorganisms could rise to 1.3 x 10(7) per cm3 as the influent salinity was less than 1%, whereas it would decline to 1.1 x 10(6) per cm3 as the salinity increased to 2%, accompanied with the small and cracked cells running out in effluent in the domesticated system. Dehydrogenase activity (DHA) was the highest of 14.4 microg/(mg h) at salinity of 0.5%, which means the greatest degradation capability. And the extra cellular polysaccharide (ECP,) excreted by microorganisms to immobilize themselves on the carriers was the most of 209.9 microg/mg at the salinity of 2%. Although extra cellular polymers (ECP(s)) and microorganisms weight accumulated during the react system operation, the macro-pore diameter of patented FPUFS was from 0.3 to 0.7 mm, which could avoid the clog caused by the microorganisms and their ECP(s), and retained agreeable air and water condition for microorganisms under high salinity.