污水生物处理工艺对重金属离子的去除特性分析

Removal characteristics of heavy metals in two urban wastewater treatment plants

以福州市A、B两座污水处理厂为研究对象,Mn、Fe、Ni、As、Cr为检测项目,对各重金属元素的去除特性与去除机制进行分析讨论.研究结果表明：①两座污水处理厂进水重金属离子污染情况不严重,仅Mn、Fe含量略高,可能与福州地区环境背景有关;②以A/O工艺作为生物单元的A污水处理厂对重金属离子的去除率在49.3％ （Mn）至93.1％ （Fe）之间,以CASS工艺为主的B污水处理厂去除率整体上劣于A污水处理厂,各重金属离子的去除率在28.5％ （Mn）至88.2％ （Fe）之间;③在城市污水生物处理过程中,重金属去除主要依赖于生物单元,物理单元的去除作用不显著;④预测两座污水处理厂对各重金属离子的去除能力为0.03～18.10kg·d-1.

The removal characteristics of five heavy metals （Mn, Fe, Ni, Cr and As） in two urban wastewater treatment plants called A and B in Fuzhou were studied. The results showed： （1） the influents of these two wastewater treatment plants weren＇ t seriously polluted by heavy metal except for Mn and Fe, which may be resulted from the environmental background of Fuzhou ; （2） A takes A/O process as the biological unit, the removal effciencies for these heavy metals of the whole process ranged from 49.3% for Mn to 93.1% for Fe. B utilizes CASS process for secondary treatment, which yielded lower removal effciencies than A/O process that ranging from 28.5% for Mn to 88.2% for Fe; （3） during the treatment process of urban wastewater, the removal of heavy metals mainly depended on biological unit, while the physical unit had no or little removal effect to heavy metals; （4） the removal capacities for heavy metals of these two wastewater treatment plants were calculated respectively, ran- ging from O. 03 to 18.10 kg · d-1.