Experimental Study On Removal Of Iron And Manganese From Groundwater By Microalgae

Groundwater is an important part of natural water resources and occurs in underground rock voids.In recent years,the impact of human life and production activities on groundwater has become more and more obvious,and the health of residents whose are the main source of groundwater supply has been threatened,which has attracted extensive attention from the government and the whole society.Therefore,the study of groundwater environment has a very important practical significance.In this paper,the excess elements Fe and Mn in the groundwater of Sunan Mining Area in Huaibei Coalfield,Anhui Province are taken as the research object,and the relevant theories of microbiology and environmental science are used to study the removal of Fe and Mn by microalgae,including three parts:superiority micro-effect screening experiment,optimization experiment of environmental conditions for removing Fe and Mn and application experiment of removing Fe and Mn by microalgae in groundwater.The main results are as follows:(1)The growth trend of different microalgae is different:Microcystis aeruginosa>Chlorella pyrenoidosa>Scenedesmus obliquus>Anabaena flos-aquae;The pH value of algae solution will gradually increases gradually in the growth process of different microalgae,and finally stabilize at pH=10;Different microalgae have good removal effects on Fe and Mn in water,but from the effect of the fourth day,the removal efficiency of Fe and Mn by Microcystis Aeruginosa is the best,which can be used as the dominant microalgae to remove Fe and Mn from groundwater.(2)The results of single factor experiment and orthogonal experiment show that the longer the illumination time,the more the initial dosage and the higher the initial pH value,the better the growth of Microcystis aeruginosa and the higher the removal rate of Fe and Mn in water.The results of orthogonal experiment showed that the order of factors affecting microalgae growth and removal of Fe and Mn in water was initial dosage>illumination time>initial pH value.(3)Excessive Fe and Mn in groundwater in Sunan mining area are common,with the exceeding rates of 66.15%and 38.46%respectively,which are mainly related to the geological background of the study area and the supergene environment of the mining area(such as coal mine solid waste dumping site and mine water discharge,etc.).(4)Microcystis aeruginosa can grow normally in underground water,and can remove Fe and Mn well,which achieves the expected effect in application experiment.At the same time,it is found that Microcystis aeruginosa can also remove trace element Cu well.(5)Through the study,it was found that there was cation exchange phenomenon in the adsorption of Fe and Mn by Microcystis aeruginosa in the experiment,and the adsorption of algae was the main reason for the reduction of metal elements,and other effects such as precipitation could not be ruled out.Figure[36]table[13]reference[128]...