利用废弃铁刨花去除污水中的磷

Reuse of Waste Iron Shavings for Phosphorus Removal from Sewage

采用废弃铁刨花作为填料去除污水中的磷酸盐,以解决污水处理出水TP浓度不达标的问题。当铁刨花填料试验系统的水力停留时间(HRT)为2.8 h时,在初始运行阶段(20 d)TP去除率超过90%;运行50 d内,TP去除率均在85%以上。单位质量铁刨花对TP的平均去除速率为70mg/(kg·d)。通过气水冲洗可去除填料表面的沉积物,维持除磷效果,酸洗则可解决长期运行中填料表面沉积问题。通过对沉积物进行XRD和XRF分析,推断铁刨花的除磷机理为:在铁碳微电解作用和氧化作用下生成FePO_(4)沉淀,同时也生成了具有较大比表面积的FeOOH以促进磷的吸附,从而达到高效除磷效果。

Waste iron shavings were reused as fillers to remove phosphate in sewage to solve the problem of effluent TP exceeding the discharge standard in sewage treatment plants.When the hydraulic retention time(HRT)of the iron shaving filter system was 2.8 h,the TP removal rate was over 90%at the initial operation stage(20 days)and over 85% in 50 days of operation.The average removal efficiency of TP by iron shavings was 70 mg/(kg·d).Air-water washing could remove the surface sediments and maintain the phosphorus removal efficiency.Acid cleaning could remove almost all sediments on the surface of the fillers in long-term operation.The sediments were analyzed by XRD and XRF,and the TP removal mechanism by iron shavings was inferred as follows:FePO_(4) precipitation was generated through iron-carbon micro-electrolysis and oxidation,and FeOOH with large specific surface area was also generated to promote phosphorus adsorption,thus achieving efficient phosphorus removal.