Enhanced Hexavalent Chromium Treatment in Constructed Wetland-Microbial Fuel Cell

Abstract

Mining is the major source of heavy metal pollution, and hexavalent chromium Cr(VI) is one of the most significant concerns among non-essential heavy metals. Cr (VI) can accumulate in the food chain or in the body, leading to chronic damage. Constructed Wetlands are a type of engineered wetlands that mimics natural wetlands and is involved in wastewater treatment. By integrating microbial fuel cells into a constructed wetland, the performance of CW can be enhanced while also producing bioelectricity. In this study, a constructed wetland-Microbial fuel cell (CW-MFC) was investigated for its ability to treat hexavalent chromium removal from synthetic wastewater and bioelectricity production. The CW-MFC was operated at varying concentrations (25-100 mg/l) and a hydraulic retention time of 48h. The study found that the system achieved nearly complete degradation (99 ± 0.002%) of Cr (VI) and removed 85-87 % of COD, a measure of organic pollutants. Moreover, the system produced preferable electricity generation (103 ± 0.002 V). To confirm the performance of the system, SEM-EDX analysis of Canna sps will be conducted to assess the extent of chromium accumulation. Additionally, microbial diversity profiling will observe the complete microbial diversity present in the system, and different enzyme activities will be observed to evaluate the effect of chromium on the microbes. This exploratory study will suggest that the CW-MFC system has the potential to treat wastewater while producing renewable energy.