Development of suitable leachate recirculation process for anaerobic organic waste stabilization

Abstract

At present, only a few researches on leachate recirculation to enhance organic waste stabilization with biogas maximization were found. Attempts to enhance the system were by controlling environmental factors such as pH and nutrients that were not adequate for organic waste stabilization enhancement. Moreover, previous works of leachate recirculation development were only the guidelines to be employed with a lot of uncertainty since all of those guidelines did not concern to the degradable phase and food input through leachate recirculation so that the overloading or lower loading employment often occurred in anaerobic organic waste degradation system. The purpose of this research was to define the optimum degradation from various leachate VFA loading input, to study the relationship between daily VFA loading input and daily methane production output on anaerobic organic waste degradation, and to define duration to reach optimum anaerobic organic waste degradation period from VFA loading input development. The experiment was set as 4 bioreactors capable of running organic waste degradation. In addition, these bioreactors accepted VFA loading input to specify suitable VFA loading input for optimizing anaerobic organic waste degradation. Moreover, daily VFA loading input, leachate VFA concentration, COD, temperature, pH, ORP, alkalinity, nutrients and methane gas output were analyzed to define essential criteria on anaerobic organic waste degradation system. Finally, the result from the experiment was used to develop the correlation model between daily VFA loading input and methane gas output. The result showed that the methane gas production was the highest for the daily 9,800 mg VFA loading input as indicated from the cumulative gas were 7,267 ml, 9,046 ml, 10,712 ml and 11,170 ml in reactor 1, 2, 3 and 4 with 1,225 mg, 2450 mg, 4,900 mg and 9,800 mg daily volatile fatty acids loading, respectively. The faster anaerobic stabilization during acid phase contributed to higher methane production could be occurred with the attempt of high leachate volatile fatty acid loading bioreactor.