College of Petroleum Engineering, Xi'an Shiyou University, Xi'an, 710065, Shaanxi Province, China; Technology Center of High Energy Gas Fracturing, CNPC, Xi'an Shiyou University, Xi'an, 710065, Shaanxi Province, China.
College of Petroleum Engineering, Xi'an Shiyou University, Xi'an, 710065, Shaanxi Province, China.
J Environ Manage. 2018 Nov 15;226:163-168. doi: 10.1016/j.jenvman.2018.08.046. Epub 2018 Aug 13.
In this paper, fracturing flowback fluids were biologically treated by immobilized chlorella. The individual and interactive effects of three variables (sodium alginate concentration, CaCl concentration, and crosslinking time) on growth of immobilized algal were optimized by response surface methodology combined with Box-Behnken design. The results showed that the SA (sodium alginate) concentration most significantly affected algal density and treatment efficiency. The interaction between SA concentration and crosslinking time was weak, the interaction between CaCl concentration and crosslinking time was modest, while the interaction between SA concentration and CaCl concentration was significant. The immobilized chlorella performed the best when the SA concentration, CaCl concentration and crosslinking time were 2.42%, 2.69% and 16.76 h, respectively, and the COD removal rate of fracturing flowback fluids was significantly higher than that of the free algal (34.70% vs. 8.96%), indicating immobilization could improve growth and organics removal of chlorellas for processing fracturing flowback fluids.
本文采用固定化小球藻对压裂返排液进行生物处理。通过响应面法结合 Box-Behnken 设计优化了三种变量（海藻酸钠浓度、氯化钙浓度和交联时间）对固定化藻类生长的单独和交互作用。结果表明，SA（海藻酸钠）浓度对藻密度和处理效率的影响最大。SA 浓度和交联时间之间的相互作用较弱，CaCl 浓度和交联时间之间的相互作用适度，而 SA 浓度和 CaCl 浓度之间的相互作用显著。当 SA 浓度、CaCl 浓度和交联时间分别为 2.42%、2.69%和 16.76 h 时，固定化小球藻的效果最佳，压裂返排液的 COD 去除率明显高于游离藻（34.70%比 8.96%），表明固定化可以提高小球藻的生长和有机物去除能力，从而处理压裂返排液。
