| Tongzhou District Huoxian corn demonstration field is used for the study. Farmland soil adsorption/desorption characteristics of nitrogen and nitrogen pollution of groundwater are studied. A large number of related data is collected, collated and analyzed in the study area. With indoor static experiment is used, soil adsorption and desorption of ammonium nitrate and the characteristics and influencing factors were studied. Combining the local soil nitrate nitrogen and ammonium nitrogen adsorption/ desorption of the law. Local agricultural activities on groundwater nitrogen pollution of the actual contribution is clearly explained. The results showed that:Soil nitrate maximum adsorption rate is 34.89% to 36.78% and the maximum desorption rate is 65.14% to 69.73%. Soil ammonium maximum adsorption rate of 64.67% to 67.67%, and the maximum desorption rate is 43.67% to 45.45%. Two dynamic equations on soil adsorption/desorption and soil nitrate nitrogen ammonium nitrogen adsorption kinetics fits better. Elovich equation on soil ammonium nitrogen desorption kinetics fits better. Langmiur equation on soil nitrate nitrogen and ammonium nitrogen adsorption thermodynamic process fitting better. Annual groundwater nitrate fertilizer caused the contribution to 1.37% and the contribution of ammonium nitrogen goes 1.52%. Combination of soil particle size, pH and the amount of adsorbent under conditions of soil nitrate and the law of the ammonium nitrogen adsorption isotherms, recommendations and measures are made. |
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