复合混凝剂中Ca^(2+)对高溶解态磷坑塘水混凝效果的影响  

Effect of Ca^(2+) in compound coagulant on the coagulation effect of high dissolved phosphorus in pit water

作　　者：程紫微 王涛 郭忠 马龙 张俊 王玉飞 黄晨慧 徐慧[3] CHENG Ziwei;WANG Tao;GUO Zhong;MA Long;ZHANG Jun;WANG Yufei;HUANG Chenhui;XU Hui(Ningxia Great Wall Water Co.,LTD.,Yinchuan 750000,China;Yangtze River Delta Research Center for Eco-Environmental Sciences,Yiwu,Jinhua 321000,China;State Key Laboratory of Environmental Water Quality,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China)

机构地区：[1]宁夏长城水务有限责任公司,银川750000 [2]长三角(义乌)生态环境研究中心,金华321000 [3]中国科学院生态环境研究中心环境水质学国家重点实验室,北京100085

出　　处：《环境保护科学》2024年第1期87-95,147,共10页Environmental Protection Science

基　　金：国家自然科学基金委员会重点项目(52030003)。

摘　　要：文章以Ca^(2+)改性后的AlCl_(3)和PACl作为混凝剂进行混凝实验,通过出水浊度、余铝、总磷、絮体粒径及有机物组成等分析改性后混凝剂的作用机理,探讨混凝剂中存在的Ca^(2+)对高磷坑塘水混凝效果的影响机制。浊度去除方面,低投加量下Ca^(2+)可明显降低出水浊度。当投加量为0.10 mmol/L时,PACl出水浊度下降了33.52 NTU,AlCl_(3)出水浊度下降了28.72 NTU。余铝去除方面,当AlCl_(3)作混凝剂时,Ca^(2+)可以通过增加混凝剂的电中和能力来降低出水余铝浓度。溶解态磷去除方面,Ca^(2+)与磷酸根反应或通过压缩双电层和吸附电中和作用来增加溶解态磷的去除率。当投加量为0.20 mmol/L时,Ca^(2+)浓度为0.9 mmol/L,PACl溶解态磷去除率较未改性前提高16.1%。絮体粒径方面,Ca^(2+)可以促进颗粒之间脱稳凝聚,增加絮体粒径和分形维数,AlCl_(3)在0.20 mmol/L投加量下絮体粒径增加79μm。并且Ca^(2+)的加入使AlCl_(3)生成的絮体抗剪切能力更强,但是絮体受到破坏后更不容易恢复,使PACl形成絮体强度因子和恢复因子变大。有机物去除方面,Ca^(2+)可以提高有机物的去除率。对于0.20 mmol/L投加量,Ca^(2+)为0.06 mmol/L投加量条件下AlCl_(3)改性后混凝剂荧光响应值由1100降至800。Ca^(2+)modified AlCl_(3) and PACl were used as coagulants to carry out coagulation experiments.The mechanism of action of modified coagulants was analyzed through turbidity of effluent,residual aluminum,total phosphorus,floc particle size and organic composition,etc.,and the mechanism of the effect of Ca^(2+)in coagulants on the coagulation effect of high phosphorus pond water was discussed.In terms of turbidity removal,Ca^(2+)can significantly reduce effluent turbidity at low dosages.When the dosage was 0.10 mmol/L,the turbidity of PACl effluent decreased by 33.52 NTU,AlCl_(3),and 28.72 NTU.In terms of residual aluminum removal,when AlCl_(3) is used as a coagulant,Ca^(2+)can reduce the concentration of residual aluminum in the effluent by increasing the charge neutralization ability of the coagulant.In the aspect of dissolved phosphorus removal,Ca^(2+)reacts with phosphate or increases the removal rate of dissolved phosphorus by compressing an electric double layer and adsorption charge neutralization.When the dosage is 0.20 mmol/L,the removal rate of dissolved phosphorus is 16.1%higher than that before modification when the concentration of Ca^(2+)is 0.9 mmol/L,PACl.In terms of floc size,Ca^(2+)can promote unstable condensation between particles,increase floc size and fractal dimension,and increase floc size by 79μm when AlCl_(3) dosage is 0.20 mmol/L.The addition of Ca^(2+)makes the shearing resistance of the flocs formed by AlCl_(3) stronger,but it is more difficult to recover after the flocs are destroyed,which makes the strength factor and recovery factor of PACl flocs become larger.In terms of organic matter removal,Ca^(2+)can improve the removal rate of organic matter.For the dosage of 0.20 mmol/L and 0.06 mmol/L of Ca^(2+),the fluorescence response value of the coagulant modified by AlCl_(3) decreased from 1100 to 800.

关 键 词：混凝 高磷 CA^(2+) 复合混凝剂 

分 类 号：X703[环境科学与工程—环境工程]