Evaluation of Stability and Maturity during Tobacco Industrial Solid Waste Composting

We studied the changes of physicochemical and biological properties in order to evaluate the stability and maturity of the composting process during the forced-aeration composting process of tobacco industry wastes. Composting was carried out using two methods, i.e. waste tobacco leaves mixed with 15% waste tobacco stems (bioreactor A) and the addition of 30% waste tobacco stems (bioreactor B). The results showed that two composting all maintained the temperature exceeding 55°C for more than 3days. Compared with treatment B, the time of reach high temperature in the treatment A was shorted by 1 day and the sustaining time of high temperature extended by 3 days. The final electrical conductivity in compost A did not exceed the limit value of 3.00ms/cm-1for stable compost. The final germination index in composting A and B were 111% and 85% respectively, which suggested a higher stability in composting A than B.