ELECTRICITY PRODUCTION FROM FOOD WASTE LEACHATE USING DOUBLE CHAMBER MICROBIAL FUEL CELL

This study was aimed at evaluating the performance of non-aerated and aerated double chamber microbial fuel cells from food waste leachate. The value of open circuit voltage (OCV) and close circuit voltage (CCV) were taken to analyze power density and current density of both confi gurations. Two double chamber microbial fuel cells (MFC) with diff erent confi gurations were developed to produce electricity from food waste leachate and studied for 30 days. Anode and catode were made by uncoated carbon felt and graphite rod. Food waste and water were incubated inside a reactor. After 30 days, the electricity production characteristics between the two confi gurations were obtained. Both confi gurations reached the same maximum power density and maximum current density but the aerated MFC showed higher performance of maximum open-circuit voltage (OCV), average power density, and current density than nonaerated MFC. The results show that the supplying continuous dissolved air in the cathode chamber resulted in higher voltage, higher average power density, and higher average current density in double chamber microbial fuel cell.


INTRODUCTION
Food wastes are the largest component in municipal waste of urban area (Levis & Barlaz, 2011) and it has the potential to produce energy. Most food wastes, generated from communities, restaurants and food factories, and end up in the landfi ll without any sustainable treatment. In fact, food waste can be used as a useful source of energy (Li, Cheng, Selvam, & Wong, 2013).
Nevertheless, the waste characteristics infl uence the selection of technology and waste management including how to convert the waste into a valuable form of energy (Sudibyo et al., 2017). Considering Indonesia as the developing country and the 4 th most populous country in the world, understanding of a proper technology to manage the food wastes is essentially needed.
One type of food wastes is in liquid form, often called as the leachate. It is addressed by a complex structure and high pollutant (Levis & Barlaz, 2011). Food leachate is formed from the hydrolysis or acidogenic stage of the anaerobic process of microorganisms that are rich of volatile fatty acids (Xu, Lam, Karthikeyan, & Wong, 2011). Moreover, leachate can be obtained from food waste that contains many organic elements (Kang, Shin, & Park, 2002) such as NH 4 + -N, heavy metals, organic and inorganic chlorine, salt, etc.
Heavy pollutants from leachate can also contaminate water sources (Rikame, Mungray, & Mungray, 2012). It adversely aff ects the health of the ecosystem.
A microbial fuel cell (MFC) is a bioelectrochemical system that can convert chemical energy to electrical energy contained in an organic substrate directly (Li, Ka, & Wong, 2013) and it can be used as a solution to treat leachate food waste. MFC is one of the electrochemical technology to treat leachate and can produce clean energy (Rikame et al., 2012). It is eff ective to generate energy and decreases organic matter in leachate (Choi & Ahn, 2015). There are two After that, an electrical energy is resulted and fi nally water is produced as the waste product. Since the waste product is harmless, MFC is an environmentally friendly method to produce power and a viable alternative for leachate treatment.
In principle, food waste leachate can be used as a substrate to produce electricity using MFC. One of the food waste products is acidic food waste leachate. Using aerated double chamber MFC, it could produce more electricity than using non-aerated one from acidogenic food waste leachate (Rikame et al., 2012). It was also reported by Greenman, Galvez, Giusti, and Ieropoulos (2009)

RESEARCH METHOD
The food waste that containing fruit and vegetable wastes was collected and incubated inside an anaerobic reactor, illustrated in Figure 1.
The reactor had a single inlet on the top to insert food waste and water and single outlet in the bottom to collect the leachate.
A fi lter was located in the reactor bottom (prior to the outlet) to result pure leachate.
The food waste was submerged in the water for more than 30 days inside the reactor to produce proper leachate. After that, leachate was collected from the reactor outlet.
The two laboratory-scale double chamber MFC were used in this study.