Study Of Adsorption Characteristics And Impacts On Groundwater Quality Of Ammonium Nitrogen And Phosphorus In The Downstream Dry Farmlands Of Liaohe River

The paper studies the soil of the dry farmlands in the downstream plain of LiaoheRiver via site sampling and laboratory test. It identifies the adsorption dynamics processand influencing factors of ammonium nitrogen and phosphorus by laboratoryexperiments and predicts their impacts on ground water environment through leachingamount estimation. The main findings are summarized as follows: Soil adsorptiontowards ammonium nitrogen and phosphorus is a composite dynamic process. Fastadsorption of ammonium nitrogen occurs within1minute, and the maximum adsorptionrate is493mg·kg^-1·min^-1which accords with second-order dynamic equation. Thecontent of clay with diameter smaller than0.005mm、pH value and the content oforganic matter have positive correlations with the equilibrium adsorption of ammoniumnitrogen. Fast adsorption of phosphorus occurs within0.5hour, and the maximumadsorption rate is499mg·kg^-1·h^-1which accords with double constant equation andparabolic diffusion equation. The content of organic matter and the content of physicalclay in partial alkaline soil with diameter smaller than0.01mm have positivecorrelations with the equilibrium adsorption of phosphorus. The results of leachingamounts show Damintun region, which possesses a higher leaching amount of bothelements, causes potential dangers to the groundwater quality. While Liujianfang region,who’s leaching amount is the smallest, affects groundwater quality the least.