"Feasibility Study of Potential Use of Pulp and Paper Mill Fly Ash as a Co-Composting Material"

The fly ash waste from local pulp and paper industry was mixed with municipal sewage sludge (bio solids) as a co-composting material to investigate the feasibility of applying carbon-enriched fly ash in improving the quality of bio solids generated from water treatment facility. Parallel experiments were conducted under the same composting conditions, only in one of which the fly ash was added. The other without adding fly ash was used as a control. The composting parameters, including pH, moisture content and carbon to nitrogen ratio, electrical conductivity and germination index, of the parallel experiments were monitored for 30 days. Meanwhile, the microbial activity, an important indicator of compost maturity, was examined through plate counting. Free PAHs in the compost system was also measured to investigate the degree of biodegradation in the composting system. The results of parallel experiments were compared to evaluate the feasibility of using ash as a stabilizer.