Abstract
Anaerobic mono digestion usually suffers from several problems at high rates of organic load, which leads to a negative effect on the activity of methane producing bacteria, which leads to a decrease in biogas production. Therefore, it is important to find scientific alternatives to overcome these problems. In this study, the low efficiency of anaerobic mono digestion of kitchen waste was efficiently overcome by anaerobic co digestion of kitchen waste with cattle dung and poultry manure. The results indicated that anaerobic co digestion for kitchen waste with cattle dung (T4) has significantly increased the production of biogas more than anaerobic mono digestion for kitchen waste (T3). The obtained results showed that the produced biogas ranged from 17.68 to 30.95 L, and the highest production was observed from T1 (cattle manure and starter), followed by T4 (kitchen waste, cattle dung and starter) and the lowest production resulting from T2 (poultry manure and starter). The results also indicated that methane production ranged from 10.08 to 19.87 liters, and that T1 (cattle manure and starter) was more productive than T4 (kitchen waste, cattle dung and starter), and T4 outperformed other treatments in methane pro duction. Biogas and methane production rates were based on either total solid or volatile solid where, ranged between 136.53- 189.96 L/Kg consumed biogas and 77.84- 121.95 L/Kg consumed methane. Volatile fatty acids concentration was decreased after anaerobic fermentation process. Also, the pH values increased at the end of anaerobic digestion the values ranged between 7.65- 8.02. After anaerobic digestion, the total and faecal coliform count as well as Salmonella & Shigella were not discovered. The numbers of total bacterial count, aerobic cellulose decomposers and acid producers (aerobic and anaerobic) were decreased after anaerobic digestion. In contrast, the numbers of anaerobic cellulose decomposers were increased after anaerobic digestion.