Anaerobic Decomposition and Voltage Produced by Selected Pesticides Using Microbial Fuel Cell Technology

Abstract

In this study, combined anaerobic and aerobic conditions were employed inside an air cathode double-chamber MFC, in an attempt to bio-remediate lambda-cyhalothrin, chlorpyrifos, and malathion in loam soil, tomato and cabbage surfaces. Conventional procedures were used to determine the proximate qualities of the tomato and cabbage. The colony-forming units were calculated using the conventional plate method. Optimization of variables (external resistance, microbe level, pesticide concentration, proximal matters, and operation pH) was performed as the current and voltage were monitored on an automated Arduino-based voltage and current sensor and a digital voltmeter. Pesticide concentrations were assessed by employing a GC-MS after QUECHERs extraction. The degradation levels were fitted into first, second, and third order decay equations and the collected information was modeled, simulated, then fitted applying linear, Gaussian, Boltzmann, as well as Lorentz models. The outcome demonstrated that the matrices' energy levels ranged from 292.37 Kcal/100g in tomatoes to 303.96 Kcal/100g in cabbage. The carbon content in tomatoes and cabbage were 47.13% and 47.45%, respectively, the bacterial count was observed to be 1.31 ± -0.05 x 106 cfu/g in tomato, 1.01 ±- 0.03 x105 cfu/g in cabbage, 3.01 ± 0.02x 109cfu/g in loam soil, and 3.15 ± 0.01 x 1010 cfu/ml in rumen fluid. The average potential difference and current in rumen fluid were 0.290 ± 0.057 V and 0.027 ± 0.008 mA, respectively. For chlorpyrifos, lambda-cyhalothrin, malathion, and pesticide mix, the produced potential difference varied between 0.227 and 0.551 V, 0.217 and 0.565 V, and 0.190 and 0.533 V respectively. Due to the strong microbial population feasting on the substrate, significant microbe concentration (1:2) was detected together with a high potential difference of 0.568 V and current (0.231 mA). Non-linear regression models showed closely fitting ranging from 0.9387 to 0.9997 coefficients. Therefore, the MFC system was able to both generate substantial electrical energy and degrade harmful pesticides in the environment. We recommend that mechanism of remediation be pursued by simultaneous monitoring on the GC-MS.