Low-Cost Electrode Modification to Upgrade the Bioelectrocatalytic Oxidation of Tannery Wastewater Using Acclimated Activated Sludge

Abstract

Effective and eco-friendly technologies are required for the treatment of tannery wastewater as its biological toxicity and large volume leads toground water pollution. Hydrophobic (unmodified carbon felt) and hydrophilic modified carbon felt with Linde Type A zeolite (LTA zeolite) and bentonite were examined for their effects on bacterial attachment, current generation, and tannery wastewater treatment efficiency. Chronoamperometry and cyclic voltammetry confirmed the higher electron transfer obtained with modified anodes. Maximum current densities of 24.5 and 27.9 A/m² were provided with LTA zeolite and bentonite-modified anodes, respectively, while the unmodified carbon felt gave a maximum current density of 16.9 A/m². Compared with hydrophobic unmodified carbon felt, hydrophilic modified electrodes increased the exploitation of the internal surface area of the 3D structure of the carbon felt by the electroactive biofilm. The study revealed 93.8 ± 1.7% and 96.3 ± 2.1% of chemical oxygen demand (COD) reduction for LTA zeolite and bentonite, respectively. Simultaneous chromium removal was achieved with values of 94.6 ± 3.6 and 97.5 ± 2.2 for LTA zeolite and bentonite, respectively. This study shows the potential approach of carbon felt clay modification for the efficient tannery wastewater treatment using bioelectrochemicals systems (BESs) accompanied with high current recovery.

Allochthonous and Autochthonous Halothermotolerant Bioanodes From Hypersaline Sediment and Textile Wastewater: A Promising Microbial Electrochemical Process for Energy Recovery Coupled With Real Textile Wastewater Treatment

“…Tenacious, resistant, and exoelectrogenic microorganisms used in bioelectrochemical systems (BES) can perform the dual function of degrading pollutants and recovering in the form of electrical energy, the energy resulting from the oxidation of these pollutants. Indeed, previous studies reported that exoelectrogenic populations have favorably demonstrated an added value for the treatment of recalcitrant pollutants, such as azo dyes, petroleum hydrocarbon, and heavy metals (Adelaja et al, 2015 ; Choudhury et al, 2017 ; Monzon et al, 2017 ; Grattieri and Minteer, 2018 ; Vijay et al, 2018 ; Askri et al, 2019 ; Elabed et al, 2019a , b ).…”

Remediation of Potential Toxic Elements from Wastes and Soils: Analysis and Energy Prospects

“…Zeolites are effective for purifying water and gases [51][52][53]. There are numerous works on their production using coal ash [54][55][56][57][58].…”

Tunisian hypersaline sediments to set up suitable halotolerant microbial bioanodes for electrostimulated biodegradation of thiabendazole

“…Tough, resilient, and exoelectrogenic microorganisms from extreme environments (Cherif et al, 2017;Ben Abdallah et al, 2018;Askri et al, 2019) used as inoculums in microbial electrochemical systems could fulfill the double function of degrading the TBZ and recovering the energy resulting from its oxidation, or at least directly follow its fate in solution by measuring the specific current of its oxidation. Previous studies have demonstrated that exoelectrogenic populations have favorably contributed to the treatment of recalcitrant pollutants, such as azo dyes, heavy metals, and petroleum hydrocarbons (Grattieri and Minteer, 2018;Vijay et al, 2018;Elabed et al, 2019;Askri et al, 2020). Askri et al (2020) demonstrated the high performance of microbial bioanodes enriched from bacterial communities of Tunisian extreme environment saline sediments and real textile wastewater for degrading dyes at 91 ± 3% and recovering electric current streams up to 12.5 ± 0.2 A/m 2 .…”