Work

Acclimation of sludge-derived biofilms for effective removal of emerging contaminants: Impacts of inoculum source and carbon supplementation

Year: 2025

Type: article

Abstract: Contaminants of emerging concern (CECs) have gathered significant public attention due to their widespread occurrence, high persistence, and increasing exposure potential. In this study, we used polyethylene biocarriers for acclimating biofilms from singular or combined activated sludges collected from three wastewater treatment plants (R, P, and L) over 5 month-long cycles. The acclimated biofilms achieved an average removal rate at 0.333, 0.313, and 0.185 week -1 for N, N-diethyl-meta-toluamide (DEET), sulfamethoxazole (SMX), and carbamazepine (CBZ), respectively, when external carbon was supplemented, which were significantly higher ( p < 0.05) than biofilms that did not receive external carbons. Metabolite screening revealed SMX transformation through ipso -hydroxylation and acetyl conjugation, while CBZ degradation could be initiated by epoxidation. Significant but slower degradation rates (0.024∼0.031 week -1 ) were observed for aminotriazole (AMT), lidocaine (LDC), and trimethoprim (TMP), whereas atrazine (ATZ) exhibited minimal removal, highlighting its high recalcitrance. Biofilms acclimated from individual R and P sludges, with external carbon supplementation, attained the greatest removal efficiencies for 7 CECs. Multivariate statistical correlations ( p < 0.05) identified potential degraders, including Sphingomonas and Zoogolea for AMT, Labrys and Koazkia for CBZ, and Asprobacter , unclassified Cyclobacteriaceae ( ELB16–189 ) and Bryobacteraceae ( Fen-178 ) for LDC. Abundance distribution of potential degraders among biofilms revealed that Sludge R favored the enrichment of key degraders for AMT, CBZ and LDC, while Sludge P was more conducive to acclimating CBZ degraders. This study advances our understanding of strategies in biofilm acclimation to improve CEC removal and provides insights into degradation pathways and associated microbial communities for future research. • Enhanced CEC removal achieved with biofilms from optimized sludge inocula. • External carbon supplementation significantly boosted biofilm-mediated CEC degradation. • SMX was transformed via ipso-hydroxylation and acetyl conjugation. • Decomposition of CBZ could be initiated by epoxidation. • Potential CEC degraders were identified via statistical correlations.

Source: Journal of Hazardous Materials

DOI: 10.1016/j.jhazmat.2025.138235

Authors: Chao Li, Liang Zhu, Lisa Axe, Mengyan Li

Institutions: New Jersey Institute of Technology, Zhejiang University

Language: English

Topic: Pharmaceutical and Antibiotic Environmental Impacts

Subfield: Pollution

Field: Environmental Science

Domain: Physical Sciences

SDGs: Clean water and sanitation, Responsible consumption and production, Good health and well-being

Open Access status: hybrid

Estimated APC paid: $4,340