Biological Manganese Stabilization And Removal Processing With The Analysis Of The Microbial Community Structure

The manganese removal technology for groundwater is guided by the theory of "biological manganese fixation and manganese removal",and also opens up a precedent for engineering practice.We improve the traditional secondary treatment process into the "water weak aeration + primary biological filter" process,which is the application of bio-filter layer to remove groundwater in the typical process of iron and manganese and has been widely used,While the water quality is better than the national standard.A shortcut that was an efficient and very economical solution was found to solve a problem that has plagued mankind over half a century for removing manganese from groundwater.The actual experience of the actual operation of the water plant shows that where there is a higher concentration of ferrous ions in the filter,where there will be a greater extension in the biofilter filter layer for the iron and manganese layer of the same culture cycle.The normal culture cycle will be more than 5 to 6 month's time,and the performance of the stable operation of the biofilter after maturation is poor;In addition,a certain concentration of ammonia nitrogen present in the groundwater will inhibit the biological filter culture.It is must be considered firstly to remove ammonia nitrogen completely,and then remove the groundwater manganese ions completely.In this study,the removal mechanism of manganese ions in biogas removal and removal of manganese in groundwater with high iron and high manganese and ammonia nitrogen was studied to explore the microbes that played a key role in the removal of manganese ions.and its community structure was analyzed in order to better guide and apply to engineering practice.According to the previous study on the redox relationship of the interaction between iron and manganese ions in the removal process of iron and manganese in the biofilter,it was found that there was a complicated redox reaction between the iron and manganese ions in the biofilter layer.And the groundwater quality of the situation is closely related to the groundwater Fe²⁺.When the concentration of Fe²⁺ is higher than 3mg / L,it will provide electron donor for the reduction of manganese oxide with higher valence state,leading to the precipitation of divalent manganese ions,and then destroy the biofilm structure which has been formed in the biological filter,and thus affect the water quality.only when the vast majority of ferrous ions in the upper part of the biofilter was oxidized after removal,a highly efficient and solid biological manganeselayer in the lower part of the biofilter was formed then.that is to say,the iron-manganese ions are removed in the same filter,but are removed at different layers of the filter.The groundwater source of the target water plant studied in this paper is the water quality of high iron and high manganese containing ammonia nitrogen.Most of the iron is removed from the upper part of the biofilter and accompanied by weaker manganese removal.The manganese ion is in the middle and lower part of the filter.To remove this,it requires the thickness of the filter layer maintained within a certain range to ensure the realization of the above functions.According to the discovery of the destruction of high concentration of iron and manganese filter layer in the high-iron type,the damage model of the removal of manganese biofilter in the case of high iron water quality was put forward.In the use of single-layer filter for biological manganese filter layer of the culture process,the backwash filter after the mixing layer will cause part of the manganese biofilm and water in the source of high concentrations of ferrous ions in direct contact to suffer damage to delay the removal of manganese biological Membrane accumulation,then delay the culture cycle.In this paper,the idea of using the double-layer filter for the rapid start-up of the biological manganese filter was shown.The experimental results showed that the Fe²⁺ is 15 mg / L and the Mn²⁺ is 1.5mg / L,and the mature period of ferro-manganese bio-layer purification was shortened to 2 months.The demand of oxygen dissolved in ammonia-containing groundwater in the process of biological purification is great.Under the experimental water quality conditions(Fe²⁺ is about 15mg/L,Mn²⁺ is about 1.5mg/L,NH4+-N is about 1mg/L),To achieve the same level of iron and manganese ammonia nitrogen purification of the same layer,the dissolved oxygen in the water needs to be controlled at 7.5mg/L or more.Dissolved oxygen mainly consumed in the upper part of the filter layer of ferrous metals,ammonia and other reducing substances in the oxidation of the middle and lower part of the biological manganese filter layer can get enough surplus dissolved oxygen is the key factor in the success of manganese filter.According to the content of ammonia nitrogen in groundwater,it is necessary to fully consider the aeration process and the whole process in the process of biological purification.Under the condition of experimental water quality,weak water aeration?DO about 4 5mg / L?can not meet the water purification?DO about 8.5 11 mg / L?;when the ammonia nitrogen content increased again,limited by the water saturation of oxygen saturation,raw water once oxygenated will not be able to meet the needs of purification,the use of water,And then twice aeration and oxygenation of the two-stage series filter and continuous aeration oxygenated aeration biological filtration was retried.The key of the rapid start-up of bio-manganese filter of nitrogen-containing groundwater is the rapid accumulation of nitrifying bacteria.The experiment of circulating culture of biological filter column is carried out.The results show that the cycle culture accelerates the accumulation of nitrifying bacteria and the addition of manganese bacteria,The start-up period of the bio-purification filter layer of the ammonia-containing groundwater was reduced to 20 days.A strain of 14 strains of pure manganese oxide was obtained.And the colony morphology and morphology of the cells were observed.There are four dominant bacteria in the upper layer of the biofilter,namely Propionibacterinm,Nitrosomonas,Prevotella,Methylophilace,Nitrospira,unclassified?close to 50%?in the middle and lower layers of the biofilter,others?not classified?,lower Delftia,Acinetobacter,Burkholderia,Ochrobactrum,Gemmatimonadace,Saprospirace,unclassified,others more,where Ochrobactrum is the only genus of the lower layer.The aeration system of Songbei Waterworks in Harbin has been transformed two times and the stable operation of the first grade treatment process has been realized,and the effluent index is superior to the national standard.The second phase of Songbei Waterworks has been successfully started and operated steadily.In the whole process of Biological Manganese Removal and manganese removal,under the premise of not adding any kind of agent,the purification of high iron and high manganese in the typical northern cold region and the underground water quality containing ammonia nitrogen caused by non-point source pollution is realized,which is another successful application of the Biological Manganese Removal Process.