农用城市污泥二硝基甲苯在蕹菜-水稻土-渗漏水系统中的分布特征研究

在水稻土中施用城市污泥和化肥盆栽蕹菜，应用GC/MS技术对蕹菜植株、土壤和渗漏水中2,4-二硝基甲苯(2,4-DNT)和2,6-二硝基甲苯(2,6-DNT)进行分析。结果表明，各处理蕹菜植株中2,4-DNT和2,6-DNT在各处理植株中的含量分别为0.035～0.307 mg/kg和0.007～0.392 mg/kg；土壤中的含量分别为0.015～0.146 mg/kg和未检出～0.285 mg/kg；渗漏水中的含量分别低于0.10 mg/L和未检出。施肥（包括化肥、污泥、污泥＋化肥）可能导致蕹菜植株和土壤中2,6-DNT的累积，2,4-DNT的情况较复杂。施肥也可能导致水体2,4-二硝基甲苯污染。不同处理的土壤-植株-渗漏水系统中2,4-DNT和2,6-DNT的含量分布特征不同。化肥中2,4-DNT的生物有效性明显高于2,6-DNT，施用化肥提高了污泥中2,4-DNT的生物有效性，降低了2,6-DNT的生物有效性，使2,4-DNT更易被蕹菜吸收积累，2,6-DNT更趋于分布在土壤中。

Distribution features of dinitrotoluene in Ipomoea aquatic-soil-leachate system for agricultural use of municipal sludge

Ipomoea aquatic was potted in paddy soil applied with municipal sludge and chemical fertilizer, and 2,4-dinitrotoluene and 2,6-dinitrotoluene in plant, soil and leachate were determined by GC/MS to investgate distribution features of dinitrotoluene in Ipomoea aquatic-soil-leachate system. Results show that the concentrations of 2,4-dinitrotoluene and 2,6-dinitrotoluene range from 0.035 mg/kg to 0.307 mg/kg and from 0.007 mg/kg to 0.392 mg/kg in Ipomoea aquatic, respectively, and from 0.015 mg/kg to 0.146 mg/kg and from below detection limit to 0.285 mg/kg in soil respectively. The concentrations of 2,4-dinitrotoluene and 2,6-dinitrotoluene in leachate were less than 0.10 mg/L and below detection limit respectively. Both municipal sludge and chemical fertilizer resulted in accumulation of 2,6-dinitrotoluene in Ipomoea aquatic and soil, and the accumulation of 2,4-dinitrotoluene in leachate as well as 2,4-dinitrotoluene in chemical fertilizer were much more bioavailable than 2,6-dinitrotoluene. Biolavailabilities of 2,4-dinitrotoluene and 2,6-dinitrotoluene in municipal sludge were both affected by applying chemical fertilizer to promote the former while inhibit the latter, which increased the uptake of 2,4-dinitrotoluene by plant and accumulation of 2,6-dinitrotoluene in soil.