Effect of sewage sludge mixing ratio on composting of TNT-contaminated soil

초록

The effect of sewage sludge as an organic amendment on the composting of TNT (2,4,6-trinitrotoluene)-contaminated soil was estimated. The mixing ratios of contaminated soil to sewage sludge were chosen to be 1:0 (soil alone), 1:0.5, 1:1.5, and 0:1 (sludge alone) on a wet weight basis. During 45 days of composting, ca. 80 similar to 85% of 1300 mg-TNT/kg was degraded in all mixing experiments of sewage sludge, whereas only ca. 20% of TNT was degraded in soil alone. For the 1:0.5 and 1:1.5 contaminated soil-to-sewage sludge ratios, the first-order degradation rates were 0.0356/day and 0.0403/day, compared to 0.0050/day for soil alone. Sludge addition was effective in accelerating the biodegradation of TNT. The mixing ratio of 1:0.5 contaminated soil to sludge is recommended for the composting of TNT-contaminated soils, considering the elevated treatment cost of adding the organic amendments or bulking agents.

키워드