工厂化循环水海水养殖尾水反硝化研究

Study on nitrogen removal from industrial recirculating mariculture tail water

工厂化海水养殖尾水的大量排放不仅危害受纳水体环境,而且威胁人类健康。基于工厂化循环水养殖尾水高氧、低碳、高硝酸盐氮的特征,建立反硝化生物脱氮滤池,重点探究其碳源补充量和脱氮性能。结果表明,反硝化所需COD/N略高,否则硝酸盐氮去除率低,且亚硝酸盐氮出现积累。当COD/N为5∶1时,硝酸盐氮和总氮的去除率均在80%以上。磷酸盐的去除效率几乎不受COD/N比率的影响,但磷去除负荷相对较高,能够满足实际尾水除磷要求。因此,反硝化滤池可用于海水养殖尾水深度脱氮、除磷,实现养殖尾水达标排放或零排放。

The discharge of large amounts of wastewater from factory mariculture not only harms the nearshore environment,but also threatens humans health.Based on the characteristics of high dissolved oxygen,low organic carbon and high nitrate nitrogen in the tail water of factory recirculating aquaculture,a denitrification filter was established,focusing on the carbon source supplement and nitrogen removal performance.Results showed that the COD/N ratio needed for denitrification was slightly higher,otherwise the removal rate of nitrate was low and nitrite accumulated.When the COD/N ratio reached at 5∶1,the removal rates of nitrate and total nitrogen were above 80%.The phosphorus removal efficiency was almost not affected by COD/N ratio,but the phosphorus removal load was relatively high,which could meet the actual phosphorus removal in tail water.Therefore,denitrification filter can be used for deep nitrogen and phosphorus removal in mariculture tail water to achieve standard discharge or zero discharge of wastewater.