Effects Of Percarbamide On Soil Physico-Chemical Properties And Organic Pollutant Degradation

Percarbamide is an important chemical product and a new fertilizer, widely using in foreign, but just beginning in china. In order to evaluate the effects of percarbamide on the physico-chemical properties of soils and the potential degradation efficiency of organic contamination, the changes of pH, volatilization of Ammonia, percarbamide-N transformation, active Al and other trace elements, and the growth of maize in 3 acidic soils and 3 alkali soils were studied by indoor incubation test; Also the degradation efficiency of two nonionic surfactants (Triton X-100 and Tween80) and two chlorhydrocarbons(trichloromethane TCM, and perchloroethylene PCE ) by percarbamide in one soil was investigated. The results show that:1. Effects of acidity and alkalinity of soils on percarbamide hydrolysis is relative to its concentration. At 25 °C, the changes of pH in acidic soils increased quickly, while the changes of pH in alkali soils increased first, then fell, rose again, with the increasing concentrations of applied percarbamide. The time-course experiment revealed that the increase of soil pH was short-term, a subsequently slow drop after reached their maximum in 6 soils, and pH of 3 alkali soils fell less than original ones after 2 weeks.2. Ammonia volatilization intensity followed the changes of soil pH: rose to maximum, and then fell between 3 acidic soils and 3 alkali soils with different maximum and different time. The maximum of ammonia volatilization intensity in 3 acidic soils and 3 alkali soils was the 7th day and the 3rd day respectively; the initial ammonia volatilization intensity from percarbamide was higher than that from urea in 6 soils, while the total ammonia volatilization quantity of urea peroxide were less than urea in 3 acidic soils, and were little higher than urea in 3 alkali soils. The order of intensity and amounts of ammonia volatilization of percarbamide was similar to...