The Research On Microbial Removal Of Internal Nitrogen Pollution In Eutrophic Lake Sediments

The paper focused on a variety of microorganisms cultured in the nitrogen cycle to speed up the removal of nitrogen in water bodies, especially of nitrogen in the sediment, the main findings are as follows:(1) The isolation and purification of heterotrophic nitrifying bacteriaSeparated and purified19strains of different nitrification bacteria strains from Lion Rock soil in Huazhong Agricultural University campus and the paddy soil. Then used these strains for screening and rescreening in medium and simulation wastewater respectively. Chose the most effective strains like1strain number of A1-2of bacteria and1strain number of N3-5, then detect to use16SrRNA strains identification respectively for pneumonia Klebsiella’s bacteria(Klebsiella Pneumoniae) bacteria and dispersing Pan (Pantoea dispersa).(2) Physical and chemical factors’influence on nitrogen release from sediments and naturally denitrification ability①Aeration or artificially disturbance imposed on the model would enhance the release of ammonia nitrogen and total nitrogen from sediments②Temperature affected the ability of natural nitrogen simulation system, the higher the temperature was, the more the systems of natural nitrogen removed. This article focused on model’s naturally denitrification ability under10℃、20℃and30℃，the results showed as the temperature rises, the model’s naturally denitrification ability growed. The rate of TN removal during the system water was up to55%under30℃,28%and under10℃is28%within1week.(3) Effect of N cyclic sediments of complex microorganism on N removal①Comparative study on Y11、BHH、BH in the model of ammoniated ability, regarding the ammonia nitrogen and total nitrogen concentration in water of added value as the index, Bacillus pumilus Y11results displayed in this experimental simulation model shown strong ammoniated capacity, total nitrogen in water concentration peak is3.0mg/L, for twice than the control group1.5mg/L.②AT7ammonia-oxidizing bacteria and Y3-2of nitrite-oxidizing bacteria in model demonstrated significantly power to reduce ammonia-nitrogen, increase the concentration of nitrate-nitrogen, the concentration of ammonia was lower0.3mg/L, nitrate-nitrogen increased about1.0mg/L compared to the control.③DNF409denitrifiers in denitrification ability in the model had a relationship with sediment thickness. Separately in the sediment thickness was5cm、10cm.15cm of denitrification results: role of denitrifying bacteria has certain requirements for thickness of sediments,15cm group and10cm group’s sediment thickness were significantly better than the5cm group, but the differences are not obvious between10cm group and15cm group.④By adding laboratory filter of ammoniated bacteria, nitrification bacteria and anti-nitrification bacteria in different period, eliminate source nitrogen pigment pollution in the lake, results indicates that:in45days, experimental group total nitrogen (with end mud TN and water TN) removal rate reached41.1%, control group total nitrogen removal rate only14.2%, compare to the control group, experimental group’s total nitrogen rate is3times higher; experimental group’s average of nitrogen rate up to10.9mgN/L·d-1, control group average of nitrogen rate is only3.7mgN/L·d-1; experimental group end mud in the organic matter and alkaline nitrogen content from the initial decline33.247g/kg,238.0mg/kg respectively to the end of20.464g/kg,161.583mg/kg,25.337g/kg,184.33mg/kg significantly better than control groups. Organic matter in the sediments and alkaline nitrogen, total nitrogen extrusion rate up to38%,32%, respectively.This paper was about how to remove the nitrogen from eutrophic lake. Researches on physico-chemical factors, the natural of nitrogen ability of effect, investigation has N cycle bacteria their of role effect, eventually using composite N cycle microbial implementation to achieve the simulation system N effective removal, established the basic method of using microbial to remove nitrogen pigment in laboratory, finally lay the foundation for using microbial technology removal rich nutrition of Lake end mud within source N pigment pollution for actual application.