Bio-electrocatalytic remediation of hydrocarbons contaminated soil with integrated natural attenuation and chemical oxidant. (October 2021)

• Record Type: Journal Article
• Authors: Chandrasekhar, K.; Velvizhi, G.; Venkata Mohan, S.
• Is Part Of: Chemosphere. Volume 280(2021)
• Publication Date: 2021-10
• Subjects: Polycyclic aromatic hydrocarbons (PAH) -- Bio-electrochemical treatment system -- Bio-stimulation -- Microbial Fuel Cell (MFC) -- Soil bioremediation.; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2021.130649
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: The present study aimed to assess the possibility of integrating natural attenuation (NA) and chemical oxidation (O) with the bio-electrocatalytic remediation (BET) process to remediate petroleum hydrocarbons contaminated soil. Six different reactors were operated, wherein in the first reactor was a NA system, and the second condition to the NA was supplemented with a chemical oxidant (NAO). These systems were compared with BET systems which were differentiated based on the position and distance between the electrodes. The study was performed by considering NA as a common condition in all the six different reactors viz., NA, NAO, NA + BET with 0.5 cm space amid electrodes (BETH-0.5 ), NAO + BET with 0.5 cm space amid electrodes (BETOH-0.5 ), NAO + BET with 1.0 cm space amid electrodes (BETOH-1 .0 ), and NAO + BET with vertical electrodes at 1.0 cm distance (BETOV-1 .0 ). The highest total petroleum hydrocarbons (TPH) degradation efficiency was observed with BETOH-0.5 (67 ± 0.8%) followed by BETOH-1.0 (62 ± 0.6%), BETH-0.5 (60%), BETOV-1.0 (56 ± 0.5%), NAO (46.6%), and NA (27.7%). In NA, the indigenous microorganisms remediate the organic contaminants. In the NAO system, KMnO4 actively breakdown the carbon-carbon double bond functional group. Further, in BETOH-0.5, an anodophilic bacteria enriched around the electrode reported enhanced treatment efficiency along with a maximum of 260 mV (1.65 mA). BET systems integrated with chemical oxidation processes were much more effective in the TPH removal process than an individual process. The BET method adopted here thus provides a good opportunity for bio-electrocatalytic remediation of TPH and resource recovery in the form of bioelectricity. Graphical abstract: Image 1 Highlights: The present study infers that additional strategies in the natural attenuation will enhance soil bioremediation. The integrated natural attenuation showed an 18% (oxidant) and 33% (BET) increment in TPH removal efficiency. Less distance amid the electrode assembly achieved significant remediation of higher ring PAHs. The self-induced bio-potential nature of BET reported effective performance over other conditions. An integrated BET method provides an excellent opportunity for enhanced TPH removal and resource recovery.