土壤中三卤甲烷(THMs)前驱物质流出的规律

通过室内模拟淋溶实验,初步探讨了以三卤甲烷生成潜能(THMFP)为指标的土壤三卤甲烷前驱物质的流出规律.结果显示:土壤淋出液中THMFP的浓度与土壤性质特别是土壤中腐殖质含量、组成与卤代活性,模拟雨水的酸度及累积淋溶量等有关.土壤中所含腐殖质的量越大、腐殖质的卤代活性越高且溶解迁移能力越强,则淋出液中THMFP的浓度越大;酸度最低(pH3.0)的模拟雨水淋洗下,淋出液中THMFP的浓度最低;模拟雨水的pH值愈低,土壤THMFP愈易流出;本实验条件下,淋出液中THMFP的浓度随累积淋溶量的增大呈下降趋势.

Outflows of Trihalomethane Precursors from Soils

Outflows of trihalomethane formation potential (THMFPs) which was chosen as an index of the amount and reactivity with chlorine of THMs precursors from soils were studied with soil column experiment. The results indicated that factors influencing THMFP concentrations of leacheates were the physicochemical properties of soils, especially contents, composition and reactivities with chlorine of humic substances, the pH value of feed solution and cumulative leaching volume. The THMFP concentrations of leachates rose with increases in amounts of humic substances with high solubility as well as reactivity with chlorine. The effluents of soil samples contained the lowest THMFP concentrations under the feed solution of the lowest pH value (pH 3.0). THMFPs appeared to more easily flow out from soils with the feed solution of lower pH value, which was properly due to the increases in solubility of humic substances under the lower pH value conditions. In most cases, THMFP concentrations of leachates showed decline with the increase of cumulative leaching volumes of feed solution.