[Environmental behavior in wetland soil of organic chlorine from pulp bleaching wastewater]

The adsorption equilibrium and leaching characteristics of organic chlorine on soils were studied by mean of soil column method using bleaching water in laboratory condition. Soil samples were also collected from the wetland that irrigated with pulp wastewater from one to three years, and analyzed for the distributing characteristics of organic chlorine in soils. The results showed that measured equilibrium isotherms for absorbable organic chlorine (AOCl) in the soils were of Freundlich type with the adsorption constant 7.3410 in the soils without irrigated and 4.9501 irrigated for 2 years. The nonlinear constants were 0.5024 and 0.6108, respectively. The AOCl was detected in the leachate, it was found that most of the AOCl was adsorbed by the soils, especially topsoil. The average contents of extractable organic chlorine (EOCl) were 4.48 microg/g, 10.35 microg/g and 10.07 microg/g in the topsoil irrigated for la, 2a and 3a respectively, which had increased distinctly compared with the background value.