Biosorption assessment of emerging contaminants onto acidogenic and methanogenic biofilm reactors: Influence of lipophilic and electrostatic interactions

Author(s)

Carneiro, Rodrigo B. ; Takeda, Paula Y. ; Dias, Maria E. S. ; Nogueira, Elis W. ; Zaiat, Marcelo ; Santos-Neto, Alvaro J.

• Document type: Journal article
• Source: JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING; v. 13, n. 2, p. 13-pg., 2025-04-01.

Abstract

This study assessed the biosorption mechanisms of eight target emerging contaminants (ECs) in two anaerobic fixed-bed biofilm reactors (FBBR), one acidogenic (AcFBBR) and one methanogenic (MtFBBR), by depicting the lipophilicity (logK(ow) / logD(ow)), electrostatic interactions with biofilm and solid-water distribution coefficient (K-D) of each compound at varied pH levels. Hydrophilic compounds (e.g., sulfamethoxazole - SMX, and paracetamol - PCT) showed low biosorption, while lipophilic compounds (e.g., diclofenac - DCF, and ibuprofen - IBU) were highly detected on biofilm, especially in acidic conditions. DCF and IBU displayed the highest biosorption, significantly impacted by lipophilicity and electrostatic interactions with biofilm. In contrast, carbamazepine biosorption was unaffected by pH shifts. Mass balance analysis revealed biodegradation as the primary removal mechanism, with biosorption accounting for less than 5 % of removal in most cases, except for DCF under acidic conditions, with biosorption reaching 23 %. Hydrophilic compounds like SMX and PCT achieved high biodegradability (BD > 80 %), while recalcitrant compounds like DCF, despite high biosorption, resisted to biodegradation mechanism (BD < 30 %), likely due to chlorine atoms in its molecular structure. The pH proved to be a key factor in the biosorption of DCF on the biofilm, increasing the K-D from 702 to 5950 L kg(-1)TSS, with a significant increase in BS from 4 % to 23 %, with a reduction in pH from 5.5 to 4.2. The study underscored the association between pH and the properties of emerging contaminants to determine their fate during anaerobic digestion. (AU)

• FAPESP's process: 19/22532-0 - Anaerobic biotransformation of emerging organic micropollutants in a two-phase (acidogenic-methanogenic) treatment system treating domestic wastewater
• Grantee: Rodrigo Braz Carneiro
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 23/10489-9 - Decentralized treatment of hospital wastewater in two-phase anaerobic bioreactors: evaluation of antibiotic removal
• Grantee: Elis Watanabe Nogueira
• Support Opportunities: Scholarships in Brazil - Support Program for Fixating Young Doctors
• FAPESP's process: 17/02147-0 - Single drop chromatography and its coupling to mass spectrometry: instrumental strategies, development of materials, automation and analytical applications
• Grantee: Fernando Mauro Lanças
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 22/10615-1 - Consolidation of the biorefinery concept applied to the biological treatment of wastewater and solid wastes
• Grantee: Marcelo Zaiat
• Support Opportunities: Research Projects - Thematic Grants