Wu, Xiaojuan, Zhang, Liyuan, Zhang, Bo, Zheng, Yongbiao, Liu, Yonghong, Hou, Bo  ORCID: https://orcid.org/0000-0001-9918-8223 and Wang, Ning
2026.
Interface-oriented PANI-Fe3O4 modification of PU carriers improves biofilm formation and resilience in MBBRs.
Journal of Environmental Chemical Engineering
14
(4)
, 123348.
10.1016/j.jece.2026.123348
|
Preview |
PDF
- Accepted Post-Print Version
Available under License Creative Commons Attribution. Download (1MB) | Preview |
Abstract
Moving bed biofilm reactors (MBBRs) rely on rapid microbial attachment and stable biofilm activity on suspended carriers. However, pristine polymeric carriers often show limited initial bio-affinity, and mature biofilms may lose stability under hydraulic or loading disturbances. Here, a porous polyurethane carrier modified with polyaniline and iron components (PU-P/F) was developed to regulate the carrier–biofilm interface and improve biofilm formation and resilience. The modification shifted the carrier zeta potential from −6.98 mV (PU) to + 5.96 mV (PU-P/F), accelerating early microbial attachment and increasing Day-2 biofilm biomass to 2127.5 mg/L, compared with ∼1500 mg/L on PU. When influent COD increased to ∼600 mg/L, COD removal in the PU reactor declined to 80.1%, whereas the PU-P/F reactor maintained stable performance. Under steady operation, PU-P/F achieved higher COD removal (92.5%) and improved nitrogen removal, with ammonium conversion of 97.61% and total nitrogen removal efficiency of 95.4%. The maximum nitrogen removal rate reached 0.182 kg N/(m³·d) under short-HRT conditions. Nitrogen balance analysis and ex-situ denitrification assays indicated that PU-P/F enhanced both nitrification and denitrification, with a denitrification rate 2.5 times higher than that of PU. The modified carrier supported a protein-rich EPS matrix, which, together with stable Fe3O4 incorporation and low iron leaching, may have contributed to improved biofilm cohesion. These results demonstrate that PU-P/F enables stable, high-rate MBBR operation under intensified conditions.
| Item Type: | Article |
|---|---|
| Date Type: | Publication |
| Status: | Published |
| Schools: | Schools > Physics and Astronomy |
| Additional Information: | RRS policy applied |
| Publisher: | Elsevier |
| ISSN: | 2213-3437 |
| Date of First Compliant Deposit: | 3 June 2026 |
| Date of Acceptance: | 26 May 2026 |
| Last Modified: | 18 Aug 2026 08:45 |
| URI: | https://orca.cardiff.ac.uk/id/eprint/187392 |
Actions (repository staff only)
 |
Edit Item |
Altmetric
Altmetric