洛克沙胂在土壤柱中的淋溶迁移

畜禽粪便中残留的兽药进入土壤后的移动性是评价其淋溶能力(对地下水的污染风险)的重要信息.通过土壤柱稳定流实验,考察了不同淋溶剂、粪浸液等对洛克沙胂在不同深度(0～20、20～50、50～80 cm)灰潮土中的迁移行为影响.结果表明,水、0.01mol·L~(-1) CaCl_2、0.01 mol·L~(-1) EDTA-Na2淋溶剂,对不同深度土壤柱中洛克沙胂的淋溶穿透曲线(BTCs)呈现不同程度的不对称性,在不同深度土壤柱中对洛克沙胂的淋出率分别为:水为92.3%～97.1%,0.01 mol·L~(-1) CaCl_2为71.0%～84.9%,0.01 mol·EDTA-Na_2为75.4%～91.2%;土壤柱先用粪浸液通过后,洛克沙胂的穿透曲线峰时间均有不同程度的提前,淋出率均有增加,在不同深度土壤柱中的淋出率分别为:水为96.4%～110.4%,0.01 mol·L~(-1) CaCl_2为94.5%～106.8%,0.01 mol·L~(-1) EDTA-Na_2为90.8%～103.2%.说明洛克沙胂随粪便进入土壤后可较快地淋溶迁移,可进入地表水和地下水中,对水环境质量的影响较大.

Leaching of Roxarsone in Soil Columns

The transport behavior of veterinarial drugs residue in animal manure into soils is essential for evaluating the potential ability leaching to groundwater. Roxarsone, a animal feed additive widely used for growth stimulation, run into soil with the fertilizer of animal manure. The transport characteristic of roxarsone in soil was investigated by leaching experiment in soil columns. The transport proportion of roxarsone to various depth Grayfluvo-aquicsoils leached by water, 0.01 mol·L~(-1) CaCl_2, 0.01 mol·L~(-1) EDTA-Na_2 were determined using soil column experiment. Effect of water-extract of chicken manure on leaching of roxarsone in different depth soils was also studied. Results showed all measured breakthrough curves (BTCs) of roxarsone exhibited extent of asymmetry with sharp adsorption and slow desorption fronts leaching by water, 0.01 mol·L~(-1) CaCl_2、0.01 mol·L~(-1) EDTA-Na_2. Comparing the dose of roxarsone to soil column, the leaching rate in different depth soils was 92.3%～97.1% by water, 71.0%～84.9% by 0.01 mol·L~(-1) CaCl_2, 75.4%～91.2% by 0.01 mol·L~(-1) EDTA-Na_2 respectively. When the water-extract of chicken manure was firstly through these soil columns, the peak time of BTCs was all shortened and the content of roxarsone leached from soil was all increased, with leaching rate 96.4%～110.4% by water, 94.5%～106.8% by 0.01 mol·L~(-1) CaCl_2, 90.8%～103.2% by 0.01 mol·L~(-1) EDTA-Na_2. It was came to a conclusion that roxarsone into soil with the manure application could be fastly leached into groundwater from different depth soils, being a risk to water environment.