Abstract
The process of dry anaerobic digestion (DAD) is an effective economic and environmentally friendly method due to its features such as reducing the volume of waste, destroying pathogens, consuming less energy, and producing biogas rich in energy and fertilizer. This study was conducted on a pilot scale with a reactor volume of 24 L in 30 days for three ratios of C/N: 30, 25, and 20 separately using a mixture of activated sludge and plant waste. During the process, the temperature, pH, and ratio of C/N were measured at certain times, and the percentage of gases produced by the Gas chromatography (GC) device was also measured. The results were compared with the National standard of Iran (Compost, Physical, and Chemical Specifications) at the end of the process. The results showed that the average volume of biogas produced in ratios of C/N: 30, 25, 20 is 1.7, 2.5, and 1.5 L. d(-1), respectively. The results showed that in the C/N ratio of 20, and 25, the amount of, C/N ratio and NO(3) are in the range the standard of class 1, and the amount of Phosphorus pentoxide (P(2)O(5)) is in the range the standard of class 2. The results showed that the average microbial parameters in ratios of C/N: 30, 25, and 20 are lower than the national standard of Iran. The dry digester is an efficient method in waste treatment, methane gas production, and quality fertilizer close to the national standard of Iran.