Preparation Of Modified Microbial Flocculant FCZJ-15 And Study On Treatment Of Wastewater Containing Fluoride

Chronic fluorosis can cause a series of health problems.The toxic effect of excessive fluoride absorption on plants is also very serious.With the migration and enrichment of fluorine,it will produce a series of environmental problems,which ultimately threaten human health.Therefore,it is of great significance for the treatment of wastewater containing fluoride.At present,there are many disadvantages in the widely used fluoride removal technology.It is still a blank in China to study the application of microbial flocculant in the treatment of fluoride removal.The application of microbial flocculant in the process of fluoride removal can not only improve the shortcomings of the existing fluoride removal technology,but also broaden the application scope of microbial flocculants.The purpose of this paper is to develop a new type of flocculant with high efficiency and good effect on the degradation of FCZJ-15.The selection of modifier,the concentration of modifier,the adding time of modifier,the temperature of co culture,the initial pH,the effect of Mg²⁺,the optimum culture time and so on were studied,in order to get the optimal culture conditions.Under this condition,the modified flocculant producing strain CZJ-15 was obtained.Flocculant FCZJ-15 was produced by fermentation of flocculant producing strain CZJ-15.The wastewater containing fluoride was treated by FCZJ-15.On the basis of these experiment,a synergistic flocculation model was established.The flocculation mechanism of FCZJ-15 and aluminum salt was analyzed by FTIR,SEM and Zeta potential measurement.The following results are obtained:?1?The optimum conditions for the modification of CZJ-15 were as follows:pH=6.38,Time=84h,[Al3+]=0.85g/L,[Mg3+]=0.6g/LTemp=34.2??2?Flocculant FCZJ-15 is not suitable for the treatment of fluoride separately,but FCZJ-15 is suitable for the treatment of waste water containing fluoride with aluminum salt The addition of FCZJ-15 was better than the first addition of AlCl3·6H2O.Mixture ratio:[FCZJ-15]:[AlCl3 6H2O]=16:9?mass ratio?.?3?The fluorine removal efficiency can reach more than 95%when pH=7.14 is controlled by fluoride removal.?4?The surface groups of flocculant FCZJ-15 are amide group,carboxyl group and hydroxyl group.The surface groups of flocculant FCZJ-15 are amide group,carboxyl group and hydroxyl group.?5?Under the electron microscope,the main structure of the flocculant FCZJ-15 is loose,and the pore diameter is larger,and the adsorption site is more,which is beneficial to the flocculation reaction.?6?In the process of fluoride removal,the flocculation of FCZJ-15 is mainly based on the neutralization of electricity and ion complexation,and the structure of four hydroxyl alumina promotes the flocculation process.?7?Has a great potential application in fluorine modified microbial flocculant FCZJ-15 in high fluoride area,greatly reduces the use amount of aluminum salt.Aluminum salt consumption is only about half of the original amount of use,greatly reduces the formation of aluminum salt pollution two possible.It's a kind of environmental friendly flocculant.