Preparation Of Composite Modified Clay,Application Of That And Eichhornia Crassipes In The Repair Of Water

In recent years, the discharge of sewage of production and living to lakes and natural waters, the nutrient content of excessive accumulation, lake water eutrophication is becoming more and more serious phenomenon, algae bloom outbreaks frequently, and harmful aquatic common Microcystis aeruginosa of microcystin is a strong liver tumor promoter, pose a threat to human and ecological environment. So how to remove nutrients and prevent algae from and excessive growth in the water, microcystins release has become particularly important.In this study, we used two methods to remove phosphorus and algae directly in eutrophic waters. One was use composite modification of aluminium polychlorid and clay. The removal efficiency of phosphorus and algae, Microcystin release were discussed and its 20d long-term stagnation in the water, water soluble total nitrogen （DTN） and soluble total phosphorus （DTP）, microcystin （Microcystin-LR and Microcystin-RR） and chlorophyll a （Chl-a） concentration for safety analysis of water; the other was use Eichhornia crassipes and toxic Microcystis aeruginosa by the co-culture experiments, in order to provide the basis for discussing the influence of short-term intensive coexistence of Eichhornia crassipes and cyanobacteria in water,we researched the influence of physiological characteristics, cell structure of M. aeruginosa and different types of microcystins release and reduction under stress of E. crassipes.Our results indicated that:Removal rate of algae by PHAT could be up to 97.15% ±1.35%. It was significantly higher than that by PAC and AT+PAC.20 days long stay in the water, DTP is only the initial value of 5.3 ± 0.60%, Chl-a as the initial value of 1.7±0.70%, and microcystin content （MC-RR） for the natural decay of microcystins （MC-RR） 16.27± 0.91% in algal trearment. The results showed that composite modification of aluminium polychlorid and clay high removal efficiency phosphorus and algae. E. crassipes inhibited the growth of M. aeruginosa effectively and accelerate its death. E. crassipes damaged the SOD enzyme system of M. aeruginosa seriously. The SOD activity of co-cultured algal cells decreased to 2.67 ± 1.68U/protein after 6d, which resulted in the failure of the timely transformation of superoxide anion radical. The H₂O₂ level of algal cell was not increased significantly. Under the stress of E. crassipes for 4 days, cells of M. aeruginosa appeared to shrink, the thylakoid lamella structure was dissolved and the ATP level of algal cells declined rapidly. However, the release of Microcystin-LR and Microcystin-RR from M. aeruginosa due to the stress of E. crassipes was significantly lower than that due to natural decline. And the reduction of Microcystin-LR and Microcystin-RR in water under the influence of E. crassipes was significantly quicker than that under the process of natural decline.