Carbon mineralization of sewage sludge and fly ash

Abstract

In this study, it was aimed to determine stabilization degrees of important wastes those both used as amendment and disposed as waste. Because, the stabilization degree of the wastes are important for the prediction of the degradation pattern of the organics, the adequate supplement of essential nutrients to the plants, the nutrient release pattern and the organic matter application time. For this aim, sewage sludge and fly ash were selected and their carbon mineralization rates were determined. The wastes were added to the soil at various amounts (Reactor 1 with soil and sewage sludge, Reactor 2 with soil, sewage sludge and 5% fly ash, Reactor 3 with soil, sewage sludge and 10% fly ash and Reactor 4 with soil and fly ash), and incubated at 22 o C. The carbon mineralization followed two steps with a rapid and slower step. The degradation patterns were similar to each other during the incubation period, especially at the second step. It was seen that the ash added could avert the degradation of the organics in the sewage sludge and the outflow of CO 2 -C. During the incubation period, the lowest CO 2 -C outflow was mostly seen in the reactor that the ash was added as a percentage of 10. During step two, the maximum CO 2 -C outflows were seen in the reactor with ash alone. It could be said that ash with sewage sludge gives rise to less CO 2 -C outflow than being alone in the soil. Analysis of variance (ANOVA) was used to determine if significant differences existed among the reactors used. The model used confirmed that significant differences existed between reactors used (F=14.68, P<0.05).