Control Technology Of Nitrogen And Phosphorus Non-point Source Pollution With Biochar

With increase inputs of nitrogen, phosphorus fertilizer in agricultural production,nitrogen and phosphorus has constantly accumulated in soil. Excess nitrogen, phosphorusimported surface water, leading to increase surface water eutrophication. Through adsorptiontest and soil column leaching test, the effect of bamboo charcoal on nitrogen and phosphorusmigration and on inhibition of leaching loss of nitrogen and phosphorus in red soil werestudied to seek biochar control technology of nitrogen and phosphorus non-point sourcepollution in acidic red soil.First of all, through adsorption kinetics experiments, adsorption isotherm experiments andthe factors influencing adsorption experiments, the characteristics and influencing factors ofadsorption of bamboo charcoal to ammoniacal nitrogen, nitrate nitrogen and phosphorus werestudied. The results showed:1.The removal rate of ammoniacal nitrogen,nitrate nitrogen and phosphorus increasedwith the decrease of the particle size.2.The removal rate of ammoniacal nitrogen,nitrate nitrogen and phosphorus increasedwith the increase of the inputs.3.With the increase of temperature, the removal rate of phosphorus first increased andthen decreased, the removal rate of ammoniacal nitrogen decreased slowly, the removal rateof nitrate nitrogen first decreased and then increased.4.With the increase of pH, the removal rate of phosphorus decreased,the removal rate ofammoniacal nitrogen increased, the removal rate of nitrate nitrogen first increased and thendecreased.Then, taking red soil in Hunan area as an example through soil column leachingexperiments, the effects of bamboo charcoal inputs in different amount (0%,1%,3%and7%)on the inhibition of leaching loss of ammoniacal nitrogen, nitrate nitrogen and phosphorus inthe soil were studied. The results showed:1.Bamboo charcoal was demonstrated to alleviate ammonia nitrogen, nitrate andphosphorus leaching loss significantly. With the increase in the amount of bamboo charcoalinputs, ammonia nitrogen, nitrate and phosphorus cumulative leaching reduced.2. The inhibition effect of bamboo charcoal among ammonia nitrogen, nitrate nitrogenand phosphorus is some different. In the actual control process, while alleviating ammonianitrogen, nitrate and phosphorus leaching, and considering the cost factors,3%(w/w) ratio ofbamboo charcoal to soil is reasonable.Bamboo charcoal can fixed leaching easily nitrogen, phosphorus in the soil. It not onlyinhibits nitrogen, phosphorus leaching in soil, reduces the occurrence of eutrophication,butalso keeps the red soil fertility, improves the utilization of fertilizer. It is a win-win move toenvironment and agriculture.