外源渗透保护剂对活性污泥耐盐能力的影响

EFFECT OF EXOGENOUS OSMPROTECTANTS ON THE SALINITY TOLERANCE OF ACTIVATED SLUDGE

高盐分是导致很多工业废水生物处理效率下降的主要因素之一。探讨在生物处理系统中添加渗透保护剂提高活性污泥耐盐能力的可行性。结果表明:添加海藻糖、谷氨酸、甜菜碱和钾离子能提供有效的渗透保护作用,减轻盐分对污泥降解活性的抑制,其中以甜菜碱的渗透保护效果最好。对于未经盐分驯化的非耐盐污泥,当NaCl质量分数为3%时,添加20 mg/L的甜菜碱可使其耗氧速率从9.5 mg/h提高到29.5 mg/h;对于经过盐分驯化的耐盐污泥,当NaCl质量分数为6%时,添加50 mg/L的甜菜碱可使其耗氧速率从10.5 mg/h提高到24.9 mg/h。当生物处理系统受到瞬时盐分冲击时,活性污泥中的微生物细胞可以快速吸收添加的甜菜碱而平衡外界渗透压,从而缩短活性污泥对高盐环境的适应期,减轻盐分对活性污泥的毒害。

Hypersaline wastewater, generated by many industrial activities, is difficult to treat through conventional biological processes due to high salinity. In this article, the feasibility of enhancement of exogenously supplied betaine on the salinity tolerance of the activated sludge was studied. The results indicated that many osmprotectants, such as trehalose, glutamate, betaine and potassium ion, could provide osmprotection for the activated sludge under high salinity. And betalne was the optimum osmprotectant. Adding 20 mg/L betaine was sufficient to confer good osmprotection to salt-sensitive sludge under 3% sodium chloride, the oxygen uptake rate was raised from 9.5 mg/h to 29.5 mg/h. And 50 mg/L betaine was sufficient to confer good osmprotection to salt-tolerant sludge under 6% sodium chloride, the oxygen uptake rate was raised from 10. 5 mg/h to 24. 9 mg/h. Under salt stress, betaine could be absorbed into the microbial ceils to balance the extracellular osmolality and thus alleviated the repression of high salinity to the activity of the activated sludge.