壳聚糖载铜灭藻剂对Chlorella pyrenoidosa的去除

Removal of Chlorella Pyrenoidosa by copper-chitosan algaecide

针对直接投放CuSO4灭藻易致水体Cu2+局部偏高的事实,以壳聚糖作载体合成缓释性的壳聚糖载铜灭藻剂(Copper-Chitosan Algaecide,CCA),研究其对蛋白核小球藻的灭藻效应.结果表明,CCA能有效控制蛋白核小球藻的生长,其最佳施用时间为蛋白核小球藻的迟缓期,且随着灭藻剂用量增加,灭藻率增大.对于富营养化水体,CCA的96h-EC50为13.2mg·L-1,其推荐剂量为10～30mg·L-1,施用2d后,灭藻率达到80%以上,此时残铜量降为0.38mg·L-1.CCA灭藻剂是通过释放Cu2+和改变pH值来实现对藻类生长的抑制,其释放Cu可分解为24h前的一级动力学过程和24h后的Elovich两级过程,并可持续抑藻15d以上.

A copper-containing algaecide（CCA） was prepared by using chitosan as the carrier material and then we investigated its effect on the removal of Chlorella pyrenoidosa.The results showed that the CCA could clearly suppress the growth of Chlorella pyrenoidosa.The optimal application time of algaecide was during the lag phase of Chlorella pyrenoidosa,and the algae removal increased with increasing CCA dosage.The 96h-EC50 of CCA was 13.2 mg · L-1 for Chlorella pyrenoidosa and an effective dosage of 10~30 mg · L-1 is recommended for eutrophied water bodies.The rate of algae removal could reach over 80% two days after application of the recommended dosage of CCA,while the residual Cu2＋ concentration was decreased to 0.38 mg · L-1.The release of Cu2＋ and change in water pH associated with CCA application were the main algae removal mechanisms.The first-order and Elovich-second-order equation could be used to describe the release dynamics of Cu2＋ from CCA for the initial 24 hrs and the subsequent period,respectively.The effective duration of CCA application was over 15 d.