Electricity generation from anaerobic sludge and cassava wastewater subjected to pretreatment methods using microbial fuel cell

In this study, batch production of electricity using anaerobic sludge from a beverage factory subjected to heat pretreatment at 105°C for 90 minutes was investigated. Cassava wastewater with a COD value of 32,000 mg/L subjected to pretreatment with (i) sonication and (ii) α-amylase (enzyme) was used as a substrate. Experiments were conducted in a double chamber microbial fuel cell separated by a Proton Exchange Membrane (PEM) to study the amount of electricity produced. Methylene blue was used as electron mediator while the phosphate buffer saline solution acted as electrolyte. The value of voltage (mV) and current (mA) were measured every 30 minutes during the first 24 hours and hourly measurements were performed afterwards for a total of 10 days. The power outputs were calculated based on the obtained measurements. The average maximum power output was obtained from cassava wastewater subjected to pretreatment with α-amylase and was 9861 mW as compared to untreated with 7159 mW. Apart from electricity production, the COD removal efficiency by microorganisms for cassava wastewater with α-amylase was 56% and that for untreated was 42%. Higher COD removal rate and power outputs were obtained for both pretreatment methods compared to the control. This shows that cassava wastewater can be a suitable substrate for electricity generation.