Nitrification is an important step to affect nitrogen removal in biological treatment processes. 生物脱氮系统中，硝化作用好坏是影响脱氮工艺效率的重要步骤。
Biological technology of denitrification and phosphorus removal has been focused on in wastewater treatment field in recent years. 生物脱氮除磷技术一直是污水处理领域所关注的重点。
