基质对人工湿地脱氮除磷效果影响研究

构建了粉煤灰+石灰石混合基质床人工湿地处理养殖废水,并与石灰石单一基质床相比较,结果表明,粉煤灰是一种磷吸附能力很强的基质,在人工湿地中填充粉煤灰和石灰石组成的混合基质可以明显提高磷去除效率,而且粉煤灰还可以作为碱源供应碱而有利于氮的去除;磷素在人工湿地中的主要去除机理是基质吸附,因此加大基质填充深度增加基质填充量可以明显提高磷的去除;而氨氮的主要去除机理为硝化/反硝化反应,湿地内部溶解氧是限制其去除的关键因素,因此增加基质填充高度虽然能增强反硝化作用,但不能增加复氧而强化硝化作用,故对氨氮的去除影响很小。

Study of the Effect of Substrata on Removing Nitrogen and Phosphorus in Constructed Wetland

Constructed wetland treatment of wastewater is conducted by mixed substrata bed of fuel ash plus limestone and its effect is compared with simple substratum bed of limestone.The results show that fuel ash is a strong matrix for absorbing phosphorus,that mixed substrata in constructed wetland stuffed with fuel ash and lime stone can obviously enhance efficiency for removing phosphorus while fuel ash can be used as alkali supply for nitrogen removal,and that the main phosphorus removal mechanism in constructed wetland is substrata adsorption,so increasing the amount of matrix by raising packing depth can significantly improve the removal effect of phosphorus.Because the main ammonia nitrogen removal mechanism is nitrification-denitrification,dissolved oxygen in constructed wetland is the key factor to restrict ammonia nitrogen removal,although raising packing height of the matrix can reinforce denitrification,the oxygen supply can not be increased to consolidate nitrification,thus,it has little effect on ammonia nitrogen removal.