微藻-细菌处理油田采出水与生活污水的效能

Efficiency of Microalgae-bacteria Treatment of Oilfield Produced Water and Domestic Sewage

李 冉 李 彤 王亮亮 赵 进 潘 杰

LI Ran LI Tong WANG Liangliang ZHAO Jin PAN Jie

油田采出水污染物浓度高，缺少生物生长需要的N、P等元素，而生活污水富含N、P，但排放波动大，单独处理成本高。为提高油田污水的生物处理效率，降低处理成本，将模拟油田采出水与模拟生活污水混合用于微藻-细菌共生培养，考察采出水与生活污水不同体积混合比（1∶3、1∶5、1∶15、1∶35）对生物生长和营养物去除的影响。其中，微藻为普通蛋白核小球藻，菌种由酵母菌、乳酸菌、硝化菌、枯草芽孢菌等组成。结果表明，随着培养时间的延长，不同比例采出水/生活污水混合液的生物量、藻密度、菌密度和叶绿素基本呈增长趋势。微藻-细菌在采出水/生活污水混合比为1∶3的混合液中的生长情况最好，培养7 d后的总生物量为0.55 g/L，其中藻密度为0.23 g/L，菌密度为0.32 g/L。高比例采出水/生活污水混合液有利于藻类的生长。在采出水/生活污水混合比为1∶3的水样中培育7 d后藻叶绿素a的含量最高，达 649.27 μg/mg；在混合比为1∶5的水样中藻叶绿素b的含量最高，达821.23 μg/mg。在营养物去除方面，高混合比的污水更有利于微藻-细菌吸收营养物。当采出水/生活污水混合比为1∶3时，有机物和氨氮去除率最高，化学需氧量（COD）去除率为 65%，氨氮去除率为 37%；采出水与生活污水混合比为1∶5的水样对总磷的去除效果最好，去除率为70%。将油田采出水和生活污水按适当体积比混合，可以促进藻-菌生长，提高生物处理效率。

Oilfield produced water has a high concentration of pollutants and lacks elements such as N and P needed for biological growth. Domestic sewage is rich in N and P，but the discharge fluctuates greatly，and the cost of separate treatment is high. In order to improve the biological treatment efficiency and reduce the treatment cost of oilfield sewage，the simulated oilfield produced water was mixed with the simulated domestic sewage for microalgae-bacteria symbiosis culture，and then the effects of different volume mixing ratios of produced water and domestic sewage（1∶3，1∶5，1∶15，1∶35）on the growth of organisms and the removal of nutrients were investigated. The microalgae was Chlorella vulgaris，while the strains were composed of Saccharomyces cerevisiae，Lactobacillus，Nitrobacter and Bacillus subtilis. The results showed that the biomass，algal density，bacterial density and chlorophyll of different ratios of produced water/domestic sewage mixtures basically presented an increasing trend with the increase of incubation time. Microalgae-bacteria grew best in the produced water/domestic sewage mixture with a mixing ratio of 1∶3. The total biomass was 0.55 g/L after 7 d of incubation，of which the algal density was 0.23 g/L and the bacterial density was 0.32 g/L. The high ratio of produced water/domestic sewage mixture was favorable for the growth of algae. The highest content of algal chlorophyll a was 649.27 μg/mg after 7 d of incubation in the produced water/domestic sewage mixing ratio of 1∶3，while the highest content of algal chlorophyll b was 821.23 μg/mg in the mixing ratio of 1∶5. In the aspect of nutrient removal，the sewage with a high mixing ratio was more favorable for the nutrient absorption by microalgae-bacteria. The highest removal rates of organic matter and ammonia-nitrogen were obtained when the mixing ratio of produced water and domestic sewage was 1∶3. Meanwhile， the removal rate of chemical oxygen demand（COD）was 65%，and that of ammonia-nitrogen was 37%. The water sample with a mixing ratio of produced water and domestic sewage of 1∶5 had the best removal of total phosphorus，with a removal rate of 70%. Mixing oilfield produced water and domestic sewage in appropriate volume ratio could promote the growth of algae-bacteria and improve the efficiency of biological treatment.

10.19346/j.cnki.1000-4092.2025.01.020