摘要
后置化学除磷工艺是实现城市污水处理厂出水总磷(TP)达到地表水IV类标准的经济有效方法。选择合适的除磷剂和助凝剂,以及优化运行参数是保证深度除磷的重要因素。选取聚合氯化铝(PAC),聚合硫酸铁(PFS)和聚合硅酸铝铁(PSAF)作为除磷剂,磁粉和聚丙烯酰胺(PAM)作为助凝剂,利用实际污水处理厂二沉池出水,在不同组合方式和投加量条件下,分析出水中溶解态TP(DTP)和颗粒态TP(PTP)浓度特征,采用正交试验优化深度化学除磷工艺。结果表明,单独采用除磷剂时,PFS对TP去除效果优于PSAF和PAC,投加量为40 mg/L时即可满足出水TP含量小于0.3 mg/L的要求。以PSAF为除磷剂时,PAM和磁粉为助凝剂可以促进除磷剂PSAF对TP的去除效果,减少除磷剂的使用。通过对化学除磷工艺出水的颗粒物粒径分析,发现微粒径的PTP是高标准出水中TP的主要存在形态,优化后置化学除磷条件形成较大TP颗粒粒径,以促进微粒径PTP的重力分离或采用过滤截留分离含磷微絮体是实现深度除磷的技术关键。
The post chemical phosphorus removal process is an economic and effective method to achieve the total phosphorus(TP)in the effluent of municipal wastewater treatment plants to reach class IV standards for surface water.Choosing proper phosphorus remover and coagulant,as well as optimizing operation parameters are important factors to ensure the advanced phosphorus removal.Using polymerized aluminum chloride(PAC),polymerized ferric sulfate(PFS)and polysilicate aluminium ferric(PSAF)as phosphorus removers,magnetic powder and polyacrylamide(PAM)as coagulants,and the concentration characteristics of dissolved TP(DTP)and particulate TP(PTP)in water were analyzed under different combinations and dosage conditions using the effluent from the secondary sedimentation tank of actual wastewater treatment plant,and the advanced chemical phosphorus removal process was optimized by orthogonal experiment.Results showed that PFS was more effective than PSAF and PAC in removing TP when phosphorus remover was used alone,and the dosage of 40 mg/L could meet the requirement of effluent TP less than 0.3 mg/L.When PSAF is used as phosphorus remover,PAM and magnetic powder as coagulant can promote the removal effect of TP then reduce the use of phosphorus remover.Through the study of distribution characteristics of particulate phosphorus and particle size,it is revealed that PTP is the main existing form of TP in high standard effluent.Optimization of post chemical phosphorus removal conditions to form larger TP particle size and to promote the gravity separation of particle size PTP or the use of filtration to retain the separation of phosphorus-containing microflocs is the key technology to achieve advanced chemical phosphorus removal.
作者
彭五庆
李彭
蔡浩东
刘玉学
何义亮
PENG Wuqing;LI Peng;CAI Haodong;LIU Yuxue;HE Yiliang(School of Environmental Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;School of Ecology and Environment,Anhui Normal University,Wuhu 241000,China;School of Environment and Municipal Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)
出处
《净水技术》
CAS
2022年第2期68-74,共7页
Water Purification Technology
基金
水体污染控制与治理科技重大专项(2017ZX07202-001)。
关键词
深度化学除磷
聚合硅酸铝铁
地表水Ⅳ类
颗粒态TP(PTP)
粒径分布
advanced chemical phosphorus removal
PSAF
surface water of grade Ⅳ
particulate total phosphorus(PTP)
particulate distribution
