改性粘土对球形棕囊藻(Phaeocystis globosa)和东海原甲藻(Prorocentrum donghaiense)的去除作用

摘要

Removing harmful algae blooms (HABs) with modified clay is an effective and widely applied method.In present study,we determined removal efficiencies for Phaeocystis globosa and Prorocentrum donghaiense with six different aluminum-modified clays,and analyzed the effects of zeta potential,pH of modified clay suspension,and the size of clay particles on the removal efficiencies.The results show that the removal efficiencies of the six modified clays for different HABs species are very different.Among the six experimental aluminum dosages,some are effective to Prorocentrum donghaiense,and some other to Phaeocystis globosa.In addition,to apply different dosage that specific and selective to an alga,pH should be considered and controlled in a sensitive water area.The removal efficiencies of six aluminum-modified clays improved gradually with the increasing concentration of modified clay and aluminum ion.To achieve a high removal efficiency,decreasing the pH of modified clay suspension,enhancing the surface positive charge,and selecting an appropriate clay particle size are recommended.This study provides a reference for the control and mitigation of HABs in emergency.%利用改性粘土去除藻华生物是目前有害藻华应急处置最常用的方法.本文研究了六种铝盐改性粘土(PAC-MC、PAFC-MC、PAFCs-MC、AC-MC、AS-MC、PAS-MC)对藻华生物球形棕囊藻(Phaeocystis globosa)、东海原甲藻(Prorocentrum donghaiense)的去除效率,考察了悬浮液pH、改性粘土颗粒表面电位及粒径分布等因子对去除效率的影响.结果显示:不同赤潮生物由于生物特征不同,其去除效率存在较大差异,PAC-MC、PAFC-MC、PAFCs-MC对东海原甲藻有较高的去除效率,但对于球形棕囊藻去除能力较差;AC-MC、AS-MC、PAS-MC对两种藻华生物均有较好的去除效果,但对水体酸碱扰动较大,在pH敏感水域应注意用量;对于同一种改性粘土,提高铝离子含量、增加改性粘土浓度有利于除藻效率的提升;自絮凝程度越低、表面正电性越强(或负电性越弱)、悬浮液pH值越低的改性粘土,除藻能力越强.本研究进一步为改性粘土应急处置有害藻华提供了参考.