Improving the Performance of Constructed Wetland Microbial Fuel Cell (CW- MFC) for Wastewater Treatment and Electricity Generation

Yussur D Abdulwahab,Talib Abbas,Alaa Mohammed

doi:10.21123/bsj.2021.18.1.0007

Yussur D Abdulwahab, Talib Abbas + Show 1 more

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https://doi.org/10.21123/bsj.2021.18.1.0007

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Abstract

The current study deals with the performance of constructed wetland (CW) incorporating a microbial fuel cell (MFC) for wastewater treatment and electricity generation. The whole unit is referred to as CW-MFC. This technique involves two treatments; the first is an aerobic treatment which occurs in the upper layer of the system (cathode section) and the second is anaerobic biological treatment in the lower layer of the system (anode section). Two types of electrode material were tested; stainless steel and graphite. Three configurations for electrodes arrangement CW-MFC were used. In the first unit of CW-MFC, the anode was graphite plate (GPa) and cathode was also graphite plate (GPc), in the second CW-MFC unit, the anode was stainless steel mesh (SSMa) and the cathode was a couple of stainless steel plain (SSPc). The anode in the third CW-MFC unit was stainless steel mesh (SSMa) and the cathode was graphite plate (GPc). It was found that the maximum performance for electricity generation (9 mW/m3) was obtained in the unit with stainless steel mesh as anode and graphite plate as cathode. After 10 days of operation, the best result for COD removal (70%) was obtained in the unit with stainless steel mesh as anode and stainless steel plain as cathode. The effect of temperature was also investigated. The performance of unit operation for electricity generation was tested at three values of temperature; 30, 35 and 40oC. The best result was obtained at 40oC, at which the current density obtained was 80 mA/m3. A culture of Algae could grow in the unit in order to supply the cathodic region with oxygen.

Highlights

Water is an important and critical resource required for industrial processes, food production, energy generation among other applications
The aim of this work is to examine the performance of constructed wetlands (CW)-microbial fuel cell (MFC) for wastewater treatment (COD removal) and electricity generation using electrodes made of grid stainless steel and compare it with another types of electrodes using plain stainless steel and graphite electrodes
In the second constructed wetland microbial fuel cell (CW-MFC) unit, the anode was stainless steel mesh (SSMa) while the cathode was a couple of stainless steel plain (SSPc) and the unit is referred to as (SSMa-SSPcCW-MFC)

Summary

Introduction

Water is an important and critical resource required for industrial processes, food production, energy generation among other applications. The availability and quality of water is extremely affected by climate changes [1]. For this reason, wastewater could be treated and used as wash water or for reuse in green areas [2]. Physical and biological technologies are normally used for wastewater treatment These technologies are featured with considerable power consumption and relatively high cost. One of the extensive biological technologies which takes more attentions by the researchers is constructed wetlands (CW). It has been considered environment friendly and the most cost-effective technology used for this purpose [3]. The reactions that occur in two zones aerobic and anaerobic can be utilized for the implementation of microbial fuel cells (MFCs)

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