Application of solar greenhouse energy for night-soil sludge and yard waste co-composting process enhancement.

This study investigates the feasibility of the co-composting process of night-soil sludge and yard waste using the solar greenhouse reactor to reduce the composting time. Changes in physicochemical and biological properties were monitored during the co-composting processes: solar greenhouse composting with natural ventilation and static pile composting with natural ventilation. Furthermore, the biodegradation of organic matter was evaluated. The physicochemical analysis showed that the solar greenhouse composting could significantly expedite a rising temperature to the thermophilic temperature range within the first day of the composting process and maintain the thermophilic phase for at least 7 days. On the other hand, the static pile composting treatment could not reach the thermophilic stage. Moreover, the solar greenhouse composting system could enhance the composting process during the first two weeks, as evidenced by higher accumulated temperature integration (145.00 °C), organic matter reduction (7.60 %), and OM reduction rate constant (k, 0.0243 k day-1 , R2=0.84), and the GI value (130.29 %). Twenty-eight days of composting are sufficient to produce compost that meets Thai agricultural standards and is free of Salmonella typhi. The results concluded the success of the thermophilic composting using the solar greenhouse reactor for enhancing the biodegradation of organic matter, thus, reducing the composting process time.