Characteristics Of Adsorption And Desorption On Browl Coal And Peat And The Effects Of Humic Acid Fertilizer

Fertilizer is very important in agriculture. But now, low N use efficiencyand high environmental risk of chemical N fertilizer are worldwide concern,which may be overcomed by using new slow-release fertilizers. So, the studyon slow release fertilizer has very important practice meanings to theproduction in agriculture and forestry, etc. The brown coal is a kind ofimportant raw material of the fertilizer and its reserves in our country are up tomore than 130 billion tons. Simulative experiments, potted experiments andfield experiments are used to study the effects of N,P,K concentration,equilibrium time and pH value on the adsorption of humic acid extracted fromShanxi brown coal and its absorptive regularity. The effect of the ratio of peatto brown coal on the adsorption of N,P,K was studied too. Humic acidfertilizer was manufactured through the adsorption characteristic. At the sametime, we studied the N,P,K release characteristic and regularity and the effectof this humic acid fertilizer on the quality and output of spinach. Purpose ofthis research was offering basic data for the production of humic acidslow-release fertilizers, the main result are as follows:1. The effects of various kinds inorganic acid on the content, cation exchangecapacity and optics nature of humic acid in brown coal was studied .Theresults showed that the content and the optics nature was not affected byPhosphoric acid and Hydrochloric acid treatment ,but the cation exchangecapacity can be increased to some extent .The content of humic acid can beincreased by 25 per by suitable for intensity Nitric acid, The cation exchangecapacity can be greatly increased and the optics characteristic was greatlychanged .The best condition would be different to different brown coal.2. With the increase of NH4 concentration, adsorption capacity of NH4 + +increased. The adsorption of NH4 on humic acid could be well described by +Freundlich equation and its kinetics adsorption fit Elovich equations best.Under the condition of pH lower than 7.04, pH increase of medium was ofgreat advantage of NH4 adsorption and could improve the velocity of +adsorption reaction. Under the condition of pH lower than 4.03, physicaladsorption was the dominant. However, under the condition of 4.03