Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, PA 15261, United States.
Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, PA 15261, United States; Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, IN 46556, United States.
Sci Total Environ. 2019 May 20;666:1161-1168. doi: 10.1016/j.scitotenv.2019.02.056. Epub 2019 Feb 14.
Water generated by hydraulic fracturing for the production of oil and gas, commonly termed 'produced water', may contain residual organic compounds from the fracturing process or the subsurface formation. Biological treatment is a potential technology to remove residual organic compounds in produced water. Biocides are often added to both fracturing fluids and produced water to limit undesirable microbiological activity, and glutaraldehyde is the most commonly used biocide in hydraulic fracturing. Residual biocides in produced water can limit biological treatment efficiency. We evaluated the effect of glutaraldehyde on the biodegradation of five of the most commonly reported organic compounds in hydraulic fracturing fluids in an engineered biofilm treatment. Our results demonstrated that glutaraldehyde delays biological organic compound removal by introducing a biodegradation lag phase. In addition, the effects of glutaraldehyde were more pronounced for more rapidly degraded compounds. Finally, the presence of glutaraldehyde did not decrease microbial abundance nor drive microbial community structure, suggesting that observed effects were due to altered microbial activity. These results highlight the necessity to consider co-contaminant interactions during treatment of complex waste streams where residual biocide may be present.
用于石油和天然气生产的水力压裂产生的水，通常称为“产出水”，可能含有压裂过程或地下地层中残留的有机化合物。生物处理是去除产出水中残留有机化合物的一种潜在技术。杀菌剂通常添加到压裂液和产出水中，以限制不良的微生物活动，戊二醛是水力压裂中最常用的杀菌剂。产出水中残留的杀菌剂会限制生物处理效率。我们评估了戊二醛对工程生物膜处理中五种水力压裂液中最常见报告的有机化合物的生物降解的影响。我们的结果表明，戊二醛通过引入生物降解滞后期来延迟生物有机化合物的去除。此外，戊二醛对降解速度较快的化合物的影响更为显著。最后，戊二醛的存在并没有降低微生物丰度，也没有改变微生物群落结构，这表明观察到的影响是由于微生物活性的改变。这些结果强调了在处理可能存在残留杀菌剂的复杂废水时，需要考虑共污染物相互作用的必要性。
