Study on the Removing Nitrogen and Phosphorus from Wastewater by Chlorella

目的]研究小球藻去除废水中氮磷的性能。方法]考察了初始氮磷浓度、氮磷比、光照条件和DH值等因素对去除效率的影响。结果]小球藻的氮磷去除率在初始氮磷浓度分别在55和7mg／L以下时接近100％．但初始氨氮浓度进一步升高至75mg/L以上时会导致氨氮去除率缓慢下降至90％。当氮磷比为5：1、10：1和25：1时．小球藻在4d内基本完全吸收水体中的氨氮；3种氮磷比下小球藻基本上7d内能完全去除水体中的磷。2种光照条件下（L/D为24h：0h和12h：12h1和初始氨氮浓度为30mg／L、总磷浓度为7mg／L时，小球藻的氮磷去除率基本都能达到100％。但L/D为24h：0h时的去除速率更快。小球藻去除氮磷的最适pH范围为7～8。结论]为利用生物治理污水及以后实现高效原生态的污水治理提供理论参考。

Study on the Removing Nitrogen and Phosphorus from Wastewater by Chlorella

Objective] The aim was to research Chlorella properties in removing ni- trogen and phosphorus from wastewater. Method] The effects of initial NH4＋-N and total P concentrations, N-to-P ratios, lightJdarkness ratios and pH on the removal of NH4＋-N and total P were evaluated. Result] The results showed that Chlorella al- most removed NH4＋-N and total P at 100% as initial concentrations of NH4＋-N and total P were no more than 55 and 7 mg/L, respectively, whereas the removal ratio of NH4＋-N decreased to 90% with initial NH4＋-N concentration coming up to 75 mg/L. With N-to-P ratios of 5：1, 10：1 and 25：1, Chlorella completely removed NH4＋-N within 4 d, while the removal ratio of total P reached almost 100% within 7 d, with different N-to-P ratios. With L./D ratios of 24 h： 0 h and 12 h： 12 h as well as the initial concentrations of NH4＋-N at 30 mg/L and total P at 7 mg/L, the removing ra- tio of NH4＋-N and total P almost achieved 100% by Chlorella, and the removing ra- tio under L/D ratio of 24 h：0 h proved much faster. The optimal pH range for Chlorella to remove NH4＋-N and total P was 7-8. Conclusion] The research pro- vides references for wastewater treatment in biological way and highly-efficient and environment-friendly treatment in future.