堆肥化处理TNT红水污染土壤

Composting Soils Contaminated by TNT Red Water

DNTS[二硝基甲苯磺酸盐,主要包括2,4-DNT-3-SO3-(2,4-二硝基甲苯-3-磺酸盐)和2,4-DNT-5-SO3-(2,4-二硝基甲苯-5-磺酸盐]是TNT(2,4,6-三硝基甲苯)红水污染土壤中主要污染物质,为研究堆肥化对土壤中DNTS的降解效果,采用有机废物堆肥方法,探讨堆肥化对TNT红水污染土壤中DNTS降解的可行性,以及温度、含水率和pH变化对降解效果的影响.结果表明,有机废物堆肥能处理TNT红水污染土壤,在堆肥60 d内,5个堆肥体系(猪粪+木屑、猪粪+麦壳、污泥+木屑、污泥+麦壳和马粪+木屑)对2,4-DNT-3-SO3-的降解率为65.5%~88.4%,对2,4-DNT-5-SO3-的降解率为60.9%~100%.在第4天各堆肥体系的高温阶段(29.7~53.6℃),5个堆肥化体系中2,4-DNT-3-SO3-总量的49.5%~67.3%被降解,说明各堆体的中温-高温阶段对有机物的降解起重要作用.堆体含水率随堆肥时间的延长呈下降趋势,在堆肥第8天,外源补水至体系含水率为50%,猪粪+麦壳体系对2,4-DNT-3-SO3-的降解率从70.2%增至88.4%,说明适当的外源补水可提高2,4-DNT-3-SO3-的降解率.5个堆肥体系中pH均呈初期上升、后期下降并趋于稳定的趋势,但在整个堆肥过程中,堆体pH始终保持在7.3~8.3之间.研究显示,5个堆肥体系中猪粪+麦壳体系对DNTS的降解率最高,分别为88.4%和100%.

Dinitrotoluenesulfonates（2,4-dinitrotoluene-3-sulfonate and 2,4-dinitrotoluene-5-sulfonate） are the main pollutants of soils contaminated by TNT red water from explosives factories. The present study assessed the effectiveness of composting with organic waste to degrade dinitrotoluenesulfonates,as well as the effects of the changes in moisture,temperature and pH during the composting process. The obtained results revealed that the degradation rates in five composting systems（i.e.,pig manure＋sawdust,pig manure＋rice chaff,sewage sludge＋ sawdust,sewage sludge ＋ rice chaff,and horse manure ＋ sawdust） were 65. 5%-88. 4% for 2,4-dinitrotoluene-3-sulfonate and60. 9%-100% for 2,4-dinitrotoluene-5-sulfonate during the 60-day composting. More than 49. 5% of dinitrotoluenesulfonates were degraded in the thermophilic period（29. 7-53. 6 ℃） in the fourth day. The moisture contents of the five composting systems declined during the composting process,and supplementing water to 50% in the eighteenth day caused an increase from 70. 2% to 88. 4% in the degradation rate of 2,4-dinitrotoluene-3-sulfonate（pig manure ＋ rice chaff）. The pH of the five composting systems increased initially,decreased subsequently and stabilized finally. The results showed that organic waste composting can treat soil polluted by TNT red water. The pig manure＋sawdust system had the highest degradation rate among the five studied composting systems,representing degradation rates of88. 4% and 100% for 2,4-dinitrotoluene-3-sulfonate and2,4-dinitrotoluene-5-sulfonate,respectively.