Removal of hardness from circulating cooling water of power plant by electrocoagulation
LIU Siqi1,2,, LI Yibing1,,, CAO Di2, ZHANG Juanjuan2, HUI Shaohua1,2, ZHU Haiyang1,2, CAO Hongkun1, LI Kuan3, LI Wulin3, MAO Ran2, ZHAO Xu2, 1.School of Civil and Transportation, Hebei University of Technology, Tianjin 300401, China 2.State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China 3.Jiangsu Jingyuan Environmental Protection Co. Ltd., Nantong 226000, China
Abstract:The removal of Ca2+ and Mg2+ from circulating cooling water of power plant by electrocoagulation with the sacrificial aluminum anodes was studied in this work. The effects of current density, electrolysis time, initial pH and number of anodes on hardness removal in the electrocoagulation process were investigated. The results showed that the increase of current density and the extension of electrolysis time were benefit for the removal of Ca2+ and Mg2+. At the current density of 10 mA·cm?2 and the electrolysis time of 90 minutes, the removal efficiencies of Ca2+, Mg2+ and hardness were 93.5%, 95.8% and 94.6%, respectively. Compared with neutral and acidic conditions, alkaline condition was more benefit for the removal of Ca2+ and Mg2+. At the initial pH=10, the removal efficiencies of Ca2+, Mg2+ and hardness were 85.4%, 97.7% and 93.5%, respectively. With the increase of the number of anodes, the removal efficiencies of Ca2+ and hardness increased. The addition of sodium carbonate was also benefit for the removal of Ca2+ and hardness. The above results provide a reference and basis for further increasing the removal efficiency of hardness by electrocoagulation. Key words:electrocoagulation/ Ca2+/ Mg2+/ total hardness/ circulating cooling water.
图1电絮凝反应装置 Figure1.Experimental device used in the electrocoagulation process
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1.School of Civil and Transportation, Hebei University of Technology, Tianjin 300401, China 2.State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China 3.Jiangsu Jingyuan Environmental Protection Co. Ltd., Nantong 226000, China Received Date: 2019-06-12 Accepted Date: 2019-08-13 Available Online: 2020-05-06 Keywords:electrocoagulation/ Ca2+/ Mg2+/ total hardness/ circulating cooling water Abstract:The removal of Ca2+ and Mg2+ from circulating cooling water of power plant by electrocoagulation with the sacrificial aluminum anodes was studied in this work. The effects of current density, electrolysis time, initial pH and number of anodes on hardness removal in the electrocoagulation process were investigated. The results showed that the increase of current density and the extension of electrolysis time were benefit for the removal of Ca2+ and Mg2+. At the current density of 10 mA·cm?2 and the electrolysis time of 90 minutes, the removal efficiencies of Ca2+, Mg2+ and hardness were 93.5%, 95.8% and 94.6%, respectively. Compared with neutral and acidic conditions, alkaline condition was more benefit for the removal of Ca2+ and Mg2+. At the initial pH=10, the removal efficiencies of Ca2+, Mg2+ and hardness were 85.4%, 97.7% and 93.5%, respectively. With the increase of the number of anodes, the removal efficiencies of Ca2+ and hardness increased. The addition of sodium carbonate was also benefit for the removal of Ca2+ and hardness. The above results provide a reference and basis for further increasing the removal efficiency of hardness by electrocoagulation.