The Research Of Temporary Romoval Of Microcystis In Urban Landscape Water In Case Of Emergency

As increasing human activities has generated great effects on aquatic ecosystem,the eutrophication of cyanobacterial blooms is becoming more and more prominent.Algae’s excessive breeding could lead a series of problems, such as water qualitydeterioration, destruction of the structure and function of original ecological system.Algal toxins could do great damage to aquatic animals and plants, even humansurrounding the polluted waters. As far as eutrophication problem mainly causes bycyanobacterial blooms, it is needed not only to begin from incentives-the control ofnitrogen and phosphorus in water, but also to consider the control of eutrophication ofthe development process-inhibiting the growth of algae breeding or killing algae, butalso to give sufficient attention to both the improve water conditions of the slow flowwater bodies and simultaneous implement of other multi-pronged approaches. But mostof current technologies such as controlling nitrogen and phosphorus, killing orinhibiting the growth of algae, all achieves effect from only some one aspect, and couldnot solve the fundamental problem. This study proposed modification and coordinationof some materials with good effects to remove algae, so as to achieve not only theremove of algae, but also simultaneous reduction of nitrogen, phosphorus and organicmatter in algae fluid.This thesis selected the most common Microcystis aeruginosa of pure algae as theresearch object. Using inorganic flocculant PAC, organic flocculant chitosan and thesynergistic of this two, LaCl3modified zeolite and diatomite, and these two kinds of modified clay and flocculant collaborative, to investigate the functional materials’effects respectively on the removal of Microcystis aeruginosa，and the impact of TN,TPand organic matter in the algae fluid. Microscope observation was carried out on thefallout to study settlement form the treated algal cells. Finally, resuspension experimentwas conducted to the materials’ function to resettle algae after resuspension resultedfrom external interference.The research results showed:(1)Two kinds of flocculants synergistic is better than to remove algae in theseparate dose. Separate two kinds of flocculants dose has certain effects in reducingsoluble microbial metabolites and aromatic removal of proteinⅡof algal liquid, and twokinds of flocculants together on organic matter removal efficiency is higher than singledose. For the purpose of this study to remove DOM of the supernatant fluid, the bestproportion of two kinds of flocculants is0.5mg/L chitosan and5mg/L PAC.(2)Zeolite and diatomite were both modified respectively with acid and LaCl3.When dose is5g/L, the diatomite remove algae rate increase to85.1%from1.9%unmodified, the removal rate of TP increase from12.3%to70.3%. Zeolite remove algaerate increase to72.3%from2.9%unmodified, the removal rate of TP increase from8.8%to60.3%.(3) Modified clay and flocculating agent together with the increment of dose, algalcell removal rate improve, and under the same additive amount of modified diatomiteremoval rate is higher than the modified zeolite. PAC with modified clay has betterremoval effect on TP, and coordination PAC with modified diatomite presented a muchhigher TP removal efficiency than that of PAC coordinated with modified zeolite.(4) When Stirring intensity is20rpm, flocs formed by flocculants are alreadysuspended again. algae flocs treated respectively with modified diatomite and modifiedzeolite under40rpm stir both appear resuspension. For modified clay with PACtogether, modified diatomite treated algae start resuspension under60rpm, while algaliquid treated using modified zeolite appear resuspension under80rpm. Chitosan withmodified clay has the strongest ability to against resuspension. alga deposition treatedwith modified diatomite and modified zeolite are both at100rpm to resuspension.