接触氧化-水生蔬菜湿地联合处理太湖蓝藻沼液

Combined process of biological contact oxidation and aquatic vegetable wetland for algae anaerobically digested effluent treatment

针对太湖蓝藻厌氧发酵后沼液高碳高氮磷的特性,研究接触氧化-水生蔬菜湿地组合工艺处理太湖蓝藻厌氧发酵沼液的效果和作用机理。结果表明:接触氧化池为后续的水生蔬菜湿地减轻处理负荷,组合工艺出水中平均化学需氧量ρ(COD)<50 mg/L、氨氮质量浓度ρ(NH3-N)<1.5 mg/L、总氮质量浓度ρ(TN)<5.9 mg/L、总磷质量浓度ρ(TP)<0.5 mg/L,达到《城镇污水处理厂污染物排放标准》(GB 18918—2002)一级A排放标准。组合工艺能够有效去除太湖蓝藻厌氧发酵沼液有机污染物,接触氧化池的生化处理对烷烃类污染物、芳烃及杂环类化合物均有良好的去除效果;通过电镜发现:空心菜根系有巨大的表面积为拦截颗粒物和微生物的富集提供便利。组合工艺出水中的微囊藻毒素质量浓度低于0.3μg/L。接触氧化池和水生蔬菜湿地富集的大量微生物协同降解藻毒素是其去除的主要原因。

The effect and mechanism of a contact oxidation and aquatic vegetable wetland process were studied to treat the Anaerobically Digested Effluent of Algae of Taihu Lake with high carbon, nitrogen, and phosphorus. The results show that the contact oxidation tank reduces the inlet load of the subsequent aquatic vegetables wetland, and the chemical oxygen demand p（COD）, ammonia nitrogen p（NI-I3-N）, total nitrogen p（TN）, and total phosphorus p（TP） of the average effluent of the combined process are less than 50, 1.5, 5.9 and 0.5 mg/L, respectively, which all achieve the first standard of GB 18918-2002. GC-MS analysis results demonstrate that organic pollutants of the slurry can be removed effectively during the combined process, biochemical treatment of the contact oxidation tank has a good performance in dealing with alkane pollutants, aromatic hydrocarbons and heterocyclicthe compounds. Observed by SEM, it is found that ipomoea aquatica roots have huge surface area for the enrichment of microorganisms and the interception of organic matters. The content of microcystins in the effluent is below 0.3 μg/L after the combined process. The synergistic degradation of the enriched microbes in contact oxidation and aquatic vegetable wetland is the main reason for microcystins removal.