Abstract: Based on the internal ecological restoration mechanism of ammonia nitrogen polluted groundwater, we studied the purification characteristics of ammonia nitrogen polluted groundwater by using indigenous nitrogen bacteria in groundwater loaded by scoria,  an ecologically safe natural mineral material. The results show that the biomass of indigenous nitrogen bacteria loaded by scoria is about 2.12×10⁷ per gram. The loading material can effectively remove hydrochemical factors while removing ammonia nitrogen from groundwater. The ammonia nitrogen removal rate is 83.39%~98.84%. The removal capacity of hydrochemical factors from large to small is Fe²⁺,HCO^-₃,Ca²⁺,Mn²⁺,CO^2-₃,SO^2-₄,S^2-,Mg²⁺,  in which Fe²⁺,Mn²⁺,S^2-,SO^2-4 promote ammonia nitrogen purification to a certain extent,  and CO^2-₃,HCO^-₃,Ca²⁺,Mg²⁺ inhibit ammonia nitrogen purification. The microstructure of the loading material becomes smooth after purification,  and the small protrusions are covered. The research results provide an experimental  basis for the research and development of internal ecological regulation and restoration technology of nitrogen polluted underground.

Key words:  ammonia nitrogen polluted groundwater; , scoria; , nitrogen bacteria; , loading material; , purify