Organochlorine Pesticides Residual And Distribution Characteristics In Water And Soil Medium

Organochlorine pesticides (OCPs) is regarded as the environmental priority controlpollutants publicly, which is also the typical durable organic pollutants with the characteristicsof refractory, half volatility, bioaccumulation and high-toxic, it is harmful to entironment andhuman healthy in a long-term.In this paper, HCHs residual in three typical soil was diagnosed and its distribution indifferent kinds of colloidal aqueous was studied. The results are as follows:(1) In Guan Zhong basin, the average residual quantity of HCHs in floodplain-silt is themost while in loess tableland-loess and loess first terrace-silly clay it is relatively less. Whichshows that the terrain and landform character affect the HCHs residual level..(2)The γ-HCH residual level is the highest in different soil with a probable reason ofusing of lindane.(3) The adsorption to HCHs of the three types of soil in Guan Zhong basin obeys thelaw of Henrry isothermal adsorption mode. And the adsorption ability of silly clay to HCHs islarger than floodplain-silt; the adsorption ability of loess is the least.(4) HCHs will distribute into colloidal quickly in a wave with colloidal. In a wave withhumic acid colloidal in balance,33.18%of HCHs will distribute in suspended phase,50.87%of HCHs distribute in colloidal phase, while15.68%of it distribute in true solution phase. Inthe wave with iron hydroxide colloidal in balance,17.39%of HCHs will distribute insuspended phase,54.9%of HCHs distribute in colloidal phase, while27.71%of it distributein true solution phase. In the wave with silica colloidal in balance,46.95%of HCHs willdistribute in suspended phase,35.09%of HCHs distribute in colloidal phase, while17.33%ofit distribute in true solution phase.(5) HCHs concentration in suspended phase shows rising trend as the colloidalconcentration in the wave with humic acid is increasing. HCHs concentration in suspendedphase is decreasing firstly and then increasing as the colloidal concentration in the wave withiron hydroxide is increasing, HCHs concentration in colloidal phase shows the opposite trendwith the the HCHs in suspended phase, HCHs concentration in true solution is in constant. In the wave with silica colloidal, the HCHs concentration in suspended phase, colloidal phaseand true solution phase tends to equilibrium slowly.(6) In the humic acid wave, The distribution percentage of HCHs in suspended phase,colloidal phase and true solution phase is HCHscolloidal phase＞HCHstrue solution＞HCHssuspendedphase, and in the iron hydroxide and silica wave, the distribution percentage of HCHssuspended phase, colloidal phase and true solution phase is HCHscolloidal phase＞HCHstruesolution＞HCHssuspended phase.