人工湿地野茭白对酸性重金属废水的处理效能研究

Study on the Treatment Efficiency of Wild Zizania on Acidic Heavy Metal Wastewater in Constructed Wetland

[目的]为利用人工湿地处理酸性重金属废水提供理论依据。[方法]通过盆栽试验,研究了人工湿地种植野茭白对酸性含铁、锰、总铬等重金属废水的处理效果。[结果]在试验时间内(7d),低浓度(铁≤800mg/L、锰≤524.8mg/L、总铬≤40mg/L)重金属废水的pH值由2上升到7左右;废水中铁、锰、总铬的浓度分别下降到5.0、5.0、1.5mg/L,达到污水综合排放标准。而当废水中重金属浓度较高时,需延长处理时间。重金属浓度较低时,湿地系统对铁、锰、总铬的去除率分别达到98.4%,81.2%和99.5%以上。[结论]人工湿地种植野茭白可不同程度降低废水中重金属的含量,实现工业废水的达标排放。

[Objective] The study aimed to supply theoretical basis for treating acidic heavy metal wastewater with constructed wetland. [Method] Through potting experiments,the treating effect of planting wild Zizania in constructed wetland on acidic heavy metal wastewater containing iron,manganese and total chromium and so on was studied. [Result] During experimental period （7 d）,the pH value of heavy metal wastewater at low concn. （iron≤800 mg/L,manganese≤524.8 mg/L and total chromium≤40 mg/L） was increased from 2 to be around 7; the concn. of iron,manganese and total chromium in wastewater were decreased to 5.0,5.0 and 1.5 mg/L resp.,which reached the comprehensive standard for wastewater emission. When the heavy metal concn. in wastewater was higher,the treating time needed to be extended. When the heavy metal concn. in wastewater was lower,the removal rates of wetland system on iron,manganese and total chromium reached above 98.4%,81.2% and 99.5% resp. [Conclusion] Planting wild Zizania in constructed wetland could decrease heavy metal content in wastewater to different degrees and realize the standard-satisfied emission of industrial wastewater.