Improving bioelectricity generation and COD removal of sewage sludge in microbial desalination cell

Abstract

Improving wastewater treatment process and water desalination are two important solutions for increasing the available supply of fresh water. Microbial desalination cells (MDCs) with common electrolytes display relatively low organic matter removal and high cost. In this study, sewage sludge was used as the substrate in the Microbial desalination cell (MDC) under three different initial salt concentrations (5, 20 and 35 g.L) and the maximum salt removal rates of 50.6%, 64% and 69.6% were obtained under batch condition, respectively. The MDC also produced the maximum power density of 47.1 W m and the averaged chemical oxygen demand (COD) removal of 58.2 ± 0.89% when the initial COD was 6610 ± 83 mg L. Employing treated sludge as catholyte enhanced COD removal and power density to 87.3% and 54.4 W m, respectively, with counterbalancing pH variation in treated effluent. These promising results showed, for the first time, that the excess sewage sludge obtained from biological wastewater treatment plants could be successfully used as anolyte and catholyte in MDC, achieving organic matter biodegradation along with salt removal and energy production. In addition, using treated sludge as catholyte will improve the performance of MDC and introduce a more effective method for both sludge treatment and desalination.

Microbial fuel cell‐enhanced electrokinetic process for remediation of chromium from marine sediments

“…When a stable performance was observed in voltage generation during the open‐circuit mode, the polarization curves (Figure 3) and power density variation (Figure 4) were plotted with changing applied external resistance from 50 k to 10 Ω stepwise in 20‐min intervals. The maximum power density was measured by applying different external resistance via a resistance box 29,31,44 . For ensuring the validity of the obtained results, the reactors operated at least twice under different external resistance.…”

“…The sediment solution pH was measured using a pH meter (WA‐2017SD, Lutron, Taiwan) every day. The polarization and power density curves were determined and plotted according to Watson et al 44 by changing the applied external resistors from 50 k to 10 Ω (resistor box) over 20 min intervals 29,31,44 . This procedure was performed to achieve the highest power density and internal resistance of the reactor 45…”

“…Solar energy, as well as microbial fuel cells (MFCs), have been considered as effective methods to be combined with EKR 22,24‐27 . Among these approaches, MFC as a nascent applied science in wastewater treatment, clean water production, 28‐30 and green energy generation, 30,31 have been proposed in recent years. The previous studies findings have shown the high potential of MFC in producing renewable and low‐cost energy sources 32‐34 .…”

Energy Productivity Analysis of Industrial Wastewater Treatment Plants: A Data Envelopment Analysis Approach

“…So far the wastewater demonstrating specialists have concentrated on displaying the emanating wastewater qualities, while the understood energy angles have gotten next to no consideration. After work, power is the biggest working expense related to wastewater treatment with 25-40% of the aggregate [19]. In the most widely recognized kind of WWTP, the actuated muck plant, around half of this energy is utilized for air circulation purposes [16,20].…”

“…The measure of energy required for operations fluctuates broadly among individual WWTPs relying upon emanating attributes, treatment innovation, required gushing quality, and plant estimate [19]. Furthermore, for all WWTP sizes, the vast majority of the energy is expended in natural treatment.…”