煤化工反渗透浓水的高效降解菌株筛选、鉴定及应用研究

一般煤化工废水经过多级氧化处理后，反渗透淡水回用、浓水经蒸发产生难处理的“危废”，有机物的存在对“危废”循环利用有显著制约作用。以煤化工反渗透浓水为底物（TOC为233.4 mg/L，TDS为50.9 g/L，BOD₅/COD仅为0.05），从不同菌源中筛选得到9株高效耐盐菌，经16S rDNA测序表明，这些菌株属于假单胞菌属、芽孢杆菌属及嗜盐单胞菌属。将9株耐盐菌配制成复合耐盐菌剂连续式运行处理实际废水，有机物去除率可达30%，为进一步提高去除率，经臭氧氧化预处理，有机物去除率可提高至40%，达到国内外较先进水平。根据气质联用分析，臭氧氧化预处理会破坏废水中环状物质的结构，提高复合耐盐菌剂对难降解有机物的去除效果。本研究为煤化工反渗透浓水中有机物的生物降解提供了可行性方案。

Isolation,identification and application of highly efficient halotolerant strains for coal chemical reverse osmosis concentrate treatment

Coal chemical industry plays an important role in national economy of China. Currently, coal chemical wastewater is usually treated by chemical oxidation and biochemical oxidation to remove the organic matter, followed by reverse osmosis (RO) to get the recycled fresh water. The concentrate is subsequently evaporated, while the generated mixture of salts and organic matter belongs to hazardous waste, which is costly to be treated and not environmentally friendly. With the increasing requirements of environmental protection, fractional crystallization has been developed to solve this problem. However, organic matter significantly inhibits salt crystallization. Consequently, there is considerable interest in removing the organic matter of coal chemical RO concentrate efficiently and economically. The cost of advanced oxidation treatment is higher, while it is hard to conduct microbiological treatment in such wastewater since it is weak in high salinity and concentrated toxic compounds. In the work reported here, coal chemical RO concentrate contained 50.9 g/L of TDS and 233.4 mg/L of TOC (total organic carbon) with BOD₅/COD of 0.05. Nine halotolerant bacteria strains were successfully isolated from different sludge and soil, which belonged to Pseudomonas sp., Bacillus sp., and Halomonas sp.by16S rDNA identification. Meanwhile, the research has studied physiological and biochemical characteristics of these nine strains. The results showed that the strains can grow well at 0—15% salinity. Ozone oxidation pretreatment and halotolerant bacteria preparation (mixture of nine strains) treatment was used to treat the wastewater. After one month's continuous operation, the TOC removal ratio reached 40%, reflecting an advanced level compared to the previous study. According to GC-MS (gas chromatography-mass spectrometer) analysis, ozone oxidation can destroy the cyclic structure of organic matter and improve the TOC removal ratio of subsequent halotolerant bacteria preparation. This work provided an effective approach to degrade coal chemical reverse osmosis concentrate by microbial method.