摘要
针对某小城镇污水处理厂混合进水浓度高的问题,本研究探讨了磁混凝技术在典型小城镇混合污水处理厂提质增效与技术升级改造中的适用性,结果表明,优化的混凝条件为:pH=7,PAC和PAM投加量分别为600 mg·L^(-1)和4 mg·L^(-1),慢搅速率为30 r·min^(-1).三维荧光光谱耦合区域面积积分法(FRI)和平行因子法(PARAFAC)的分析结果表明,污水中溶解性有机物(DOM)以色氨酸类、酪氨酸类及富里酸类3种组分为主,内源性特征明显.磁种可显著提升混凝效果,优化的磁种投加量为400 mg·L^(-1),浊度和COD去除率分别为99.7%和82%.在磁混凝过程中,磁种作为絮体形成的核心并促进絮体生长,可显著提升絮体的比重、密实度与沉降性能,进而强化固液分离效率,沉降时间缩短为1/6.同时,密实度的增加和微磁场的作用可进一步提升絮体颗粒间的结合力,强化水力冲击下混凝过程的稳定性.因此,与传统混凝工艺相比,磁混凝技术在典型小城镇污水处理提质增效中具有较高的应用潜能.
In consider of the high concentration of mixed sewage,this work evaluates the potential of magnetic coagulation technology in technical upgrading and reconstruction and the quality improvement in typical wastewater treatment plants in small towns of China.The optimized pH,PAC and PAM dosage,and slow stirring rate were 7600 and 4 mg·L^(-1),30 r·min^(-1),respectively.It is found that main DOMs in mixed sewage were tryptophan,tyrosine and fulvic acid by three-dimensional fluorescence spectrum coupled with fluorescence region integral(FRI)and parallel factor analysis(PARAFAC)method,which showed significant endogenous property.The magnetic seed significantly improve the coagulation efficiency with an optimal dosage of 400 mg·L^(-1),and the removal efficiency of turbidity and COD were 99.7%and 82%,respectively.It was found that the magnetic seeds acted as the nucleus during flocs formation and promote their growth,then the specific gravity,compactness and settleability of flocs were significantly enhanced.As a result,the solid-liquid separation efficiency is strengthened and the settling time can be shortened to 1/6.Moreover,the increased compactness and the micro magnetic field of the magnetic seeds could further improve the binding force between magnetic flocs,thus strengthen the stability of coagulation process under high hydraulic conditions.Therefore,magnetic coagulation showed significant potential in the treating mixed sewage in typical small towns and the technical upgrading and reconstruction of sewage treatment plants.
作者
张淳
徐东耀
康赛
李晨璐
郑利兵
魏源送
ZHANG Chun;XU Dongyao;KANG Sai;LI Chenlu;ZHENG Libing;WEI Yuansong(Laboratory of Water Pollution Control Technology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085;China University of Mining and Technology,Beijing 100085;State Key Joint Laboratory of Environment Simulation and Pollution Control,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085)
出处
《环境科学学报》
CAS
CSCD
北大核心
2022年第7期268-278,共11页
Acta Scientiae Circumstantiae
基金
国家水体污染控制与治理科技重大专项(No.2017ZX07102)
中国-斯里兰卡水技术研究与示范联合中心项目。
