湖泊科学2017，Vol.29Issue(2)：343-350,8.DOI:10.18307/2017.0210
PAC改性粘土处理蓝藻水华对水环境的影响
Impacts of PAC modified clay applied in the control of cyanobacteria bloom and left in wa-ter on water environment
摘要
Abstract
It has become an important measure for emergency treatment of cyanobacteria by using modified clays to control algal blooms in coastal regions and aquaculture water. However, there is less research focusing on the security risks led by toxic algae which were attached on the modified clay and left in the water. In this paper, PAC modified clay was selected for simulation experi-ments.The effects of applying the modified clay on the structure of cyanobacteria attached on the PAC modified clay, release and re-duction of nutrients and microcystins, and the amounts of other functional bacteria ( nitrifying-denitrifying bacteria) were investiga-ted. The results showed that algae removal rate of modified clay applied in the slightly blooming water was 96.04%±0.99%. There was not a significant difference of algae removal rate inslightly blooming water and severely blooming water. Application of the modi-fied clay effectively controlled the concentration of cyanobacteria in water for a long time. Transmission electron microscopy experi-ments revealed that cyanobacterial cell membrane became incomplete and the regular lamella structure was damaged after the cya-nobacteria being settled with modified clay for 4 days. With the damage of cyanobacteria attached on PAC modified clay, the con-tent of dissoloved total nitrogen in water increased rapidly, while the content of dissoloved total phosphorus could be maintained at a low concentration for a long time. With the application of PAC modified clay in water, the total bacteria number in the water was in agreement with that of the blank control, while the number of nitrifying-denitrifying bacteria decreased significantly. The releasing risks of microcystins after loading the modified clay mainly happened in the severely blooming water. The application of PAC modi-fied clays in severely blooming water resulted in an accelerating release of MC-LR and MC-RR. The peak value of MC-LR and MC-RR amounts were 1.69±0.09 times and 2.04±0.09 times larger than that in control case,respectively. But the time of MC-LR a-mount reaching to the safety limit(<1 μg/L) was shortened for about 8 days, compared to the control case. In addition, the appli-cation of PAC modified clay in water did not lead to excessive concentrations of Al3+ and Cl-.关键词
PAC改性粘土/蓝藻水华/营养盐释放/藻毒素释放/硝化、反硝化细菌Key words
PAC modified clay/cyanobacteria bloom/nutrients release/microcystins release/nitrifying-denitrifying bacteria引用本文复制引用
周庆,杨小杰,韩士群..PAC改性粘土处理蓝藻水华对水环境的影响[J].湖泊科学,2017,29(2):343-350,8.基金项目
国家水体污染控制与治理科技重大专项(2012ZX07103-002)和江苏省自然科学基金项目(BK20130730)联合资助. （2012ZX07103-002）
