Study On Chemical Action And Biological Action Of Manganese Sand On Manganese Removal From Groundwater

With the development of our society,various human activities have led to groundwater pollution.Groundwater often contains too much iron,manganese and ammonia nitrogen.Excessive iron,manganese and ammonia nitrogen can adversely affect the environment and humans.Therefore,the study of removing iron and manganese and ammonia nitrogen has important economic and social significance.This project used the groundwater in Acheng District of Harbin as the water source.The maturation process of different raw filter materials was studied.And then the differences in the ability of the filter column to remove contaminants were examined in the manner of biological inactivation and destruction of active membrane.Thus the biological and chemical actions in the manganese active membrane and the relationship between the two were compared,to deepen the understanding of the manganese removal mechanism.In order to study the differences in the maturation process of different raw materials,three kinds of filter materials?manganese sand,zeolite and quartz sand?were selected.Among them,the best manganese removal effect is the manganese sand filter column,followed by the zeolite filter column,and finally the quartz sand filter column.There was no significant difference in the manganese removal rate of the filter column after the active filter was matured.During the formation of the manganese active filter membrane,the organism was also constantly growing.In the process of ripening the filter material,not only the role of the organism existed,but also the role of chemistry.In order to study the manganese removal mechanism of manganese sand and the proportion of biological action,the experiment inhibited the biological action of the filter column by different sterilization methods.The manganese removal rate of the filter column was reduced after sterilization.After the filter material matured and stabilized again,the removal rate of the filter column manganese was about97%,which had a good manganese removal effect.After sterilization,the iron bacteria on the sand sample was less,and the biological effect was less.But filter column still had the ability of catalytic oxidation and manganese removal,which indicated that the manganese removal of the manganese active membrane was mainly the mechanism of chemical catalytic oxidation.In order to inhibit the chemical action of manganese sand in manganese removal,experiments were carried out by adding different concentrations of Fe²⁺solution.With the increase of Fe²⁺concentration,the more the removal rate of divalent manganese was reduced,the more the chemical action of the active filter membrane was reduced,and the longer the maturity of the filter material was.With the operation of the system,there was no significant change in the iron bacteria content before the filter material matured again,about 10⁴/cm³.This indicated that when the chemical catalytic oxidation of the active membrane was inhibited,the biooxidation by the iron bacteria was one of the contributors to the removal of divalent manganese in the groundwater.Comparing the biological and chemical effects of manganese-activated filter membranes of mature manganese sand,the following conclusion can be drawn:With the accumulation of manganese active membrane,the manganese removal mechanism of mature manganese active membrane is mainly chemical catalytic oxidation.