| In recent years, with economic development, many of our lakes and reservoirs are serious eutrophication and algal blooms outbreaks frequently, which not only bring serious damage to the aquatic environment but also endanger human health and cause enormous economic losses. Therefore, to explore new and cost-effective methods to control water bloom will have important scientific significance and application foreqround.Quaternary cationic surfactant is a special class of material with amphiphilic structure, which could be ionized with the positively charged in the water. Therefore, the quarternary ammonium salt cationic surfactants can be used for surface modification of natural minerals, so that the surface properties of natural minerals could be changed from hydrophilic into hydrophobic, by which we could enhance their ability of natural minerals to remove algae. The the main types of lake water bloom of Microcystis aeruginosa (Microcystisae; FACHB-942) is selected as the main object of the study which is suppled by Scenedesmus, we also use the cheap and easy natural sediment as vehicle to remove the algae. Quaternary ammonium cationic surfactants is used to change the surface characteristics of the natural sediment to improve the removal capacity of the algae. First of all, after consulting a large number of related literature, the most representative quaternary ammonium cationic surfactants of three different structure that has a better effection in removing alage were screen out initial to make the surface modification of natural sediment. The results show that modified sediment obtained by the three quaternary ammonium cationic surfactant of different structure have some role in the removal of Microcystis aeruginosa, and removal efficiency was connect with the molecular structure of the modifier,as is that the Single-chain structure of cetyltrimethylammonium bromide (CTAB) is better.than the double-stranded structure of poly vinyl dialkyl quaternary ammonium salt (DPQAC) and the ring of poly diallyldimethylammonium chloride Ammonium (PDMDAAC). Natural sediment modified by CTAB have a very good efficiency on the removal of Microcystis aeruginosa and cells, which indicate the sediment modified by CTAB has a capacity of broad applicability on the algae removal. The removal rate of Microcystis aeruginosa was about75%and the removal rate of Scenedesmus algal was about80%24h later when the loading was0.04g/g and the amount was5g/L, and that the rate can reach above96%48h later. In addition, the particle size of the modification sediment. preparation temperature, aging time, pH, and the initial density of algae has a significant impact on the alage removal rate. Sedimentation kinetic experiment was made by the using of spectrophotometer, the factors of the removal of Microcystis aeruginosa by sediment modified was experied (the amount of load and system of pH value), we also studied their respective effection of algae removal.Then a modifier that has the best results on removing algae was selected to make a depth exploration, and studied the efficiency and influencing factors of the kinds of modification of sediment on the removal of Microcystis aeruginosa. Finally, combined with the existing literature, we studied the mechanism of organic modification on the removal of algae and the flocculation kinetics of these sediment on the basis of the experiment, so as to provide the theoretical basis abuout the follow-up study of the removal of the algae bloom by organic modification of sediment.Thus, the surface organic modification of sediment algae as a new agent has a good efficiency on the algae removal along with a broad development and application. |
PDF Full Text Request