The Research Of Aerobic Compost Maturity Indicators Of Bailonggang Sludge

In this paper, the extensive research on compost maturity at home and abroad was investigated; it is found that so far there is no unified standard of judgment in compost maturity. This paper puts forward an idea that considers the heat of combustion value as an indicator to judge compost maturity.Composting experiment was carried out and indicators such as temperature, moisture, pH, Conductivity (EC), volatile solids (VS), solid total carbon (TC), and aerobic rate of samples were measuredas well as the heat of combustion value. The results indicate that the heat of combustion value changes regularly during composting, and may well reflect the maturity of the composting. The correlation analysis of heat of combustion value with other traditional indicators revealed that the heat of combustion value as an indicator to judge compost maturity has some representative.However, above method can only reflect on the whole composting process. To find a more detailed and accurate method to indicate material changes during composting, thermogravimetric analysis was proposed.The study of thermogravimetric analysis consists of two parts. Firstly, combustion and pyrolysis analysis were carried out on the raw material for composting respectively, and found that there are mainly organic weight loss, which occurred at 200 ℃ ～690 ℃, both in combustion and pyrolysis. From weight loss rate (DTG) curve it can be seen that organic weightlessness stage can be divided into two parts, 200℃~400℃ and 400℃~690℃ respectively. According to the theory that thermal analysis of the higher temperature, the more stable the structure of substances are, the organic matters desorbed at different temperature were defined as easily biodegradable organics and refractory organics seperately. Also on the combustion and pyrolysis DTG curves, analysis found that pyrolysis is more sensitive; therefore pyrolysis is more suitable for composting study. Secondly, another composting experiment was carried out and indicators were measured as...