两种典型污水处理工艺中痕量重金属迁移规律研究

Investigation of the Migration Law of Trace Heavy Metal in Two Typical Sewage Treatment Processes

为揭示城市污水中痕量重金属在污水生物处理过程中的迁移和去除规律,笔者以福州市两个典型的污水处理厂为研究对象,研究了污水处理过程中Ni、Cu、Cd、Hg、Pb 5种痕量重金属的含量、分布、迁移和去除规律。结果表明:1两污水处理厂进水中各重金属指标含量均较低,出水均能达到GB 18918—2002一级B标准;2污水处理厂Ⅰ所采用的CASS工艺对Ni、Cd、Hg、Pb的去除率分别为49.00%、3.13%、59.46%、9.69%,总去除率大小顺序为Hg>Ni>Pb>Cd;3污水处理厂Ⅱ所采用的A/O工艺对Ni、Cu、Cd、Pb的去除率分别为53.02%、38.24%、82.96%、75.63%,总去除率大小顺序为Cd>Pb>Ni>Cu,相比CASS工艺,去除效果较好;4CASS工艺每日可处理Ni、Cd、Hg、Pb的质量分别为0.160 5、0.001 0、0.022 0、0.012 5 kg;A/O工艺每日可处理Ni、Cu、Cd、Pb的质量分别为0.172 5、0.078 8、0.075 0、0.583 5 kg,日处理能力较高。

Two typical sewage treatment plants in Fuzhou were selected as the research object for reveal the migration and removal law of the trace heavy metals in biological sewage treatment process, in which the content, distribution, mi- gration and removal law of five kinds of trace heavy metals include Ni, Cu, Cd, Hg and Pb were investigated. The results showed that ： 1 ） The heavy metals index value of the influent water of two plants were relatively small, and the effluent were reached the grade B of the China national water quality standard（GB 18918-2002） ; 2） The heavy metals removal efficiency of Ni ,Cd,Hg and Pb were as follows ：49.00 % ,3.13 % ,59.46 % ,9.69 % by used of CASS process in plant I , and the order of the removal rate is Hg〉Ni〉Pb〉Cd. The CASS process was invalid for removal of Cu ; 3） The A/O process used in plant l] got another result,the heavy metals removal ef ciency of Ni,Cu, Cd and Ph were as follows： 53.02 %, 38.24 %, 82.96 %, 75.63 %, and the order of the removal rate is Cd〉Pb〉Ni〉Cu, which was more effective than the CASS process, but was invalid for removal of Hg; 4） The daily treatment capacities of Ni, Cd, Hg and Pb by CASS process were 0.160 5,0.O01 0,0.022 0 and 0.012 5 kg,respeetively; for A/O process, they could achieve 0.172 5,0.078 8, 0.075 0 and 0.583 5 kg, respectively,which was higher than the CASS process.