Effects of heavy metal ions Cu^(2+)/Pb^(2+)/Zn^(2+)on kinetic rate constants of struvite crystallization  

作　　者：Guangyuan Chen Tong Zhou Meng Zhang Zhongxiang Ding Zhikun Zhou Yuanhui Ji Haiying Tang Changsong Wang 

机构地区：[1]State Key Laboratory of Materials-Oriented Chemical Engineering,Nanjing Tech University,Nanjing 211816,China [2]Jiangsu Province Hi-Tech Key Laboratory for Biomedical Research,School of Chemistry and Chemical Engineering,Southeast University,Nanjing 211189,China [3]Qinghai Salt Lake Yuantong Potash Fertilizer Co.,Ltd.,Golmud 816000,China

出　　处：《Chinese Journal of Chemical Engineering》2023年第5期10-16,共7页中国化学工程学报（英文版）

基　　金：financial support from the National Natural Science Foundation of China (21838004);Priority Academic Program Development of Jiangsu Higher Education Institutions (PPZY2015A044);Top-notch Academic Programs Project of Jiangsu Higher Education Institution (TAPP)。

摘　　要：Struvite(MAP)crystallization technology is widely used to treat ammonia nitrogen in waste effluents of its simple operation and good removal efficiency.However,the presence of heavy metal ions in the waste effluents causes problems such as slow crystallization rate and small crystal size,limiting the recovery rate and economic value of the MAP.The present study was conducted to investigate the effects of concentrations of three heavy metal ions(Cu^(2+),Zn^(2+),and Pb^(2+))on the crystal morphology,crystal size,average growth rate,and crystallization kinetics of MAP.A relationship was established between the kinetic rate constant Ktcalculated by the chemical gradient model and the concentrations of heavy metal ions.The results showed that low concentrations of heavy metal ions in the solution created pits on the MAP surface,and high level of heavy metal ions generated flocs on the MAP surface,which were composed of metal hydroxides,thus inhibiting crystal growth.The crystal size,average growth rate,MAP crystallization rate,and kinetic rate constant Ktdecreased with the increase in heavy metal ion concentration.Moreover,the Ktdemonstrated a linear relationship with the heavy metal concentration ln(C/C~*),which provided a reference for the optimization of the MAP crystallization process in the presence of heavy metal ions.

关 键 词：STRUVITE CRYSTALLIZATION Heavy metal ions KINETICS Kinetic modeling Kinetic rate constant 

分 类 号：X703[环境科学与工程—环境工程] O643.1[理学—物理化学]