Coupled Adsorption and Biodegradation of Trichloroethylene on Biochar from Pine Wood Wastes: A Combined Approach for a Sustainable Bioremediation Strategy

Abstract

Towards chlorinated solvents, the effectiveness of the remediation strategy can be improved by combining a biological approach (e.g., anaerobic reductive dechlorination) with chemical/physical treatments (e.g., adsorption). A coupled adsorption and biodegradation (CAB) process for trichloroethylene (TCE) removal is proposed in a biofilm–biochar reactor (BBR) to assess whether biochar from pine wood (PWB) can support a dechlorinating biofilm by combining the TCE (100 µM) adsorption. The BBR operated for eight months in parallel with a biofilm reactor (BR)—no PWB (biological process alone), and with an abiotic biochar reactor (ABR)—no dechlorinating biofilm (only an adsorption mechanism). Two flow rates were investigated. Compared to the BR, which resulted in a TCE removal of 86.9 ± 11.9% and 78.73 ± 19.79%, the BBR demonstrated that PWB effectively adsorbs TCE and slows down the release of its intermediates. The elimination of TCE was quantitative, with 99.61 ± 0.79% and 99.87 ± 0.51% TCE removal. Interestingly, the biomarker of the reductive dechlorination process, Dehalococcoides mccartyi, was found in the BRR (9.2 × 105 16S rRNA gene copies/g), together with the specific genes tceA, bvcA, and vcrA (8.16 × 106, 1.28 × 105, and 8.01 × 103 gene copies/g, respectively). This study suggests the feasibility of biochar to support the reductive dechlorination of D. mccartyi, opening new frontiers for field-scale applications.

Recent advances and trends of trichloroethylene biodegradation: A critical review

“…Recently, commercial polyhydroxy butyrate combined with pine biochar improved the bioreductive dechlorination of TCE (approximately 80 mg/day) from aqueous solutions in a new reactor setup and small pilot scale ( Rossi et al, 2022a ). In a subsequent study, they confirmed that biofilm-biochar reactor was able to remove more than 99% of 100 μM TCE, and that Dehalococcoides mccartyi and tceA , bvcA , and vcrA genes played significant roles in TCE biodegradation ( Rossi et al, 2022b ). Furthermore, the addition of biochar supported nanoscale iron sulfide composite (CMC-FeS@biochar) followed by Corynebacterium variabile HRJ4 achieved 99% of TCE (10 mg/L) removal, and acetylene was the main product of the chemical process, whereas ethylene was the main product of the biological process ( Lyu et al, 2018 ).…”

“…Biochar-microorganism collaboration can promote the biodegradation of TCE (Figure 5C; Liu et al, 2021;Rossi et al, 2022b). The advantages include: (1) the adsorption of TCE on biochar can create a low-toxic environment for microorganisms;…”

“…Therefore, more efforts should be devoted to exploring the actual mechanisms of anaerobic reductive dechlorination. Overall, pceA , tceA (TCE to DCE), tceA , dceA , vcrA , bvcA (cis-DCE to VC), and tceA , vcrA , bvcA (VC to ethene) are crucial RDases involved in TCE reductive dechlorination process ( Figure 2B ; Ise et al, 2011 ; Popat and Deshusses, 2011 ; Dugat-Bony et al, 2012 ; Zinder, 2016 ; Dolinova et al, 2017 ; Mao et al, 2019 ; Yan et al, 2021 ; Rossi et al, 2022b ). Furthermore, the recently discovered new strain Dehalococcoides mccartyi NIT01 contains 19 rdhA genes (including NIT01 - rdhA7 and rdhA13 ), which are basically the same as the encoded vcrA and pceA ( Asai et al, 2022 ).…”

“…Biochar-microorganism collaboration can promote the biodegradation of TCE ( Figure 5C ; Liu et al, 2021 ; Rossi et al, 2022b ). The advantages include: (1) the adsorption of TCE on biochar can create a low-toxic environment for microorganisms; (2) the multi-layer porous structure of biochar can provide a habitat for microorganisms; (3) biochar can promote the biodegradation of TCE by stimulating the metabolic activity of functional anaerobic microorganisms ( Aktaş et al, 2012 ; Liu et al, 2021 ).…”

Synthetic and Natural Surfactants for Potential Application in Mobilization of Organic Contaminants: Characterization and Batch Study

“…To achieve a maximum adsorption condition, far superior to any soil, the carbonaceous reference sorbent material pine wood biochar (PWB, Plößberg bei Tirschenreuth, Germany) was selected. Previous studies have shown that this material has a high adsorption capacity due to its high organic carbon content and remarkable surface development, making it an alternative to activated carbon [48,49]. A series of isothermal batch experiments with PWB/contaminant/surfactant were conducted at room temperature (23 ± 2 • C) and pressure in 20 mL batch reactors (VWR International glass vials, Milan, Italy), using different amounts of sorbent material (10, 20, 50, 80, 100, and 200 mg), and 50 mg L -1 of contaminant solution.…”