CNPC Research Institute of Safety and Environmental Technology, Beijing 102206, China; State Key Laboratory of Petroleum Pollution Control, Beijing 102206, China.
CNPC Research Institute of Safety and Environmental Technology, Beijing 102206, China; State Key Laboratory of Petroleum Pollution Control, Beijing 102206, China.
Sci Total Environ. 2021 Nov 10;794:148436. doi: 10.1016/j.scitotenv.2021.148436. Epub 2021 Jun 17.
Shale gas drilling wastewater is a challenging waste stream generated in gas industries. It is a mixture of different organic and inorganic compounds. Treatment of this complex wastewater relies on a suitable technology for the removal of small suspended particles and dissolved elements. This study employed electrocoagulation (EC) as an efficient method for shale gas drilling wastewater pretreatment. The optimum operating conditions for turbidity, TOC, and Ca removal were determined using a response surface methodology (RSM). The chloride (Cl) removal and residual iron of effluent in the EC process were also tested and evaluated. Based on the analysis of variance (ANOVA), the coefficient of determination (R) was calculated and found to be above 0.86 for all the responses. The maximum removal efficiencies were found to be around 98.3%, 78.5%, and 56.5% for turbidity, TOC, and Ca removal under the optimum conditions, respectively. In order to treat drilling wastewater by EC process both efficiently and economically, the following operating parameters are recommended: 318 A/m for current density, 20 min for reaction time and 4.4 for initial pH. A total operation cost of 0.80 US$/m was estimated under these conditions.
页岩气钻井废水是天然气工业中产生的一种具有挑战性的废水。它是不同有机和无机化合物的混合物。处理这种复杂的废水依赖于适当的技术来去除小悬浮颗粒和溶解元素。本研究采用电絮凝（EC）作为预处理页岩气钻井废水的有效方法。使用响应面法（RSM）确定浊度、TOC 和 Ca 去除的最佳操作条件。还测试和评估了 EC 过程中废水中的氯化物（Cl）去除率和残留铁。根据方差分析（ANOVA），计算得出所有响应的确定系数（R）均高于 0.86。在最佳条件下，浊度、TOC 和 Ca 的去除率最高分别达到约 98.3%、78.5%和 56.5%。为了高效、经济地用电凝聚工艺处理钻井废水，建议采用以下操作参数：电流密度 318 A/m、反应时间 20 min 和初始 pH 值 4.4。在此条件下，估计总运行成本为 0.80 美元/m。
