Chemical characteristics of the industrial wastewater sludge, degradation of the sludge in soil and CO2 generation and changes of nitrogen in soil treated with the sludge were investigated. The results obtained were summarized as follows:
1. Degradation rate of the sludge in soil was 26% at natural temperature, and 33% at incubation temperature at 12 weeks after treatment.
2. T-C, T-N and the C/N ratio of sludge in soil was 16.0%, 0.63% and 26, respectively, at natural temperature, and 15.0%, 0.65% and 23, respectively, at incubation temperature at 12 weeks after treatment.
3. Camulative CO2 generation in soil treated with 1%, 3% and 5% of sludge was 284, 440 and 512 ㎎/100g, respectively, at natural temperature, and 440, 558 g and 654 ㎎/100 g, respectively, at incubation temperature at 12 weeks after treatment.
4. Changes of inorganic nitrogen in soil treated with 1%, 3% and 5% of sludge were 7.8, 12.8 and 16.3 ㎎/100g, respectively, at incubation temperature at 12 weeks after treatment. Mineralization ratio of organic nitrogen in soil treated with 1%, 3% and 5% of sludge was 10.7%, 13.6% and 15.2%, respectively, at incubation temperature at 12 weeks after treatment.
5. Changes of pH in soil treated with 1%, 3% and 5% of Industrial wastewater sludge were in the range of 6.7∼7.5 at natural temperature, and 6.1∼7.9 at incubation temperature at 12 weeks after treatment.