重度污染源汇入湖泊综合治理工程的实践

Comprehensive Treatment of a Lake with Input of Severe Pollution Source

为探索出一套有效的重度污染源汇入湖泊治理技术体系,创新性应用"污染源前处理+湖体水生态系统构建"综合技术体系于工程实践,采用修建初期雨水调蓄池、生活污水截流进污水厂、污水厂尾水人工湿地提标、湖体构建水生态系统等措施对海口市某湖泊进行综合治理,并从化学及生物指标等方面进行全面评价。实践结果表明,前处理工程使外源污染负荷得到极大降低,可为后续生态修复创造条件,直排污水通过污水厂处理后,氨氮和总磷浓度分别降低了63.55%和84.2%,尾水经过人工湿地处理后氨氮浓度降低了59.5%,CODMn浓度降低了74.5%。水生态系统构建2个月后,水体清澈见底,主要水质指标明显优于治理前,3个月后水生态系统持续稳定,水体溶解氧浓度逐渐上升,氨氮浓度持续下降,总磷浓度也有一定程度的降低,浮游动物生物量及种类显著增加,实现了污染湖泊治理的目标。此外,配合应急措施构建的水生态系统能在雨季一定雨污溢流后保持较稳定状态,具备一定抵抗外界干扰的能力。

Comprehensive technical system of“contamination source pretreatment and lake water ecosystem construction”was innovatively applied in engineering practice to explore a set of effective heavy polluted lake governance technology system.A series of comprehensive treatment measures such as construction of initial rainwater storage tank,sewage interception into wastewater treatment plant,treatment of tail water by constructed wetland and construction of water ecosystem were used in a lake in Haikou City,and the treatment effect was comprehensively evaluated from chemical and biological indicators.The pretreatment projects greatly reduced the external pollution load and created conditions for the subsequent ecological restoration.After the direct discharged wastewater was treated by the wastewater treatment plant,the concentration of NH3-N and TP was reduced by 63.55%and 84.2%,respectively.The concentration of NH3-N and CODMn in tail water decreased by 59.5%and 74.5%after treated by constructed wetland.After 2 months of water ecosystem construction,the water was clear,and the main water quality indicators were significantly better than those before treatment.After three months,the water ecosystem continued to be stable,DO gradually increased,NH3-N concentration continued to decrease,TP concentration also decreased to a certain extent,and the zooplankton biomass and species increased significantly,indicating that the lake governance goal was achieved.In addition,the water ecosystem built with emergency measures could maintain a relatively stable state after receiving a certain amount of rainwater and sewage overflow in wet season,and had a certain ability to resist external disturbances.