Jianliang Xue

The cathode of the microbial electrochemical systems (MESs) can continuously provide electrons to drive microbial or electrode-based reduction reactions for pollutant degradation. Cathode material is a key factor influencing the efficiency of MESs in wastewater treatment. Carbon-based materials have attracted widespread attention due to their property tunability and low toxicity. This review focuses on enhancing the performance of MESs for wastewater treatment through the modification of carbon-based cathodes. It summarizes common modification strategies for carbon-based cathode materials and evaluates their application performance in both abiotic and biotic cathode systems. The results indicate that the modification of carbon-based cathodes significantly improves the wastewater treatment efficiency of MESs. Moreover, this review discusses the current limitations, noting that most studies remain at the laboratory stage, and proposes future research directions for practical implementation. Overall, carbon‑based cathode modification is a promising strategy to advance MESs toward practical wastewater treatment and resource recovery.

In the context of global energy demands, the efficient demulsification of highly stable heavy crude oil emulsions remains a critical challenge. This study systematically investigated the demulsification mechanisms of two demulsifiers (P1# and P2#) through multi-dimensional characterisation and performance evaluation. The results indicated that asphaltenes and resins can strengthen the oil–water interfacial film and stabilise the emulsion due to their unique structural properties. FTIR and ¹HNMR analyses showed that both demulsifiers contained polar groups and alkyl chains; however, P1# exhibited higher viscosity and lower surface tension, which favored its rapid adsorption at the interface. Demulsification tests at 60 °C demonstrated that P1# achieved superior efficiency (92.44% demulsification efficiency (DE) in 120 min versus 82.31% for P2#), attributable to its enhanced ability to displace asphaltene/resin at the oil-water interface. Turbiscan stability analysis and microscopic observations confirmed that P1#-treated emulsions underwent faster droplet coalescence and significant interfacial film disruption. Mechanistic studies indicated that the demulsifiers competitively adsorb at the interface, thereby weakening film cohesion through steric hindrance and charge redistribution. XRD and FTIR analyses suggested that interactions between the demulsifier and the asphaltene/resin increased interlayer spacing and reduced crystallinity. Zeta potential and interfacial tension measurements further highlighted P1#’s ability to neutralize negative charges (from −14.52 mV to +8.3 mV) and reduce the IFT (from 28.5 mN/m to 12.1 mN/m), thereby promoting droplet aggregation. This study helps elucidate the mechanism of emulsion phase transition induced by demulsifiers and provides theoretical support for improving the demulsification efficiency of crude oil emulsions.

BACKGROUND: Acid mine drainage (AMD) is a major environmental threat in mining areas due to its strong acidity, high concentrations of sulfate, and heavy metals. Utilizing sulfate‐reducing bacteria (SRB) to reduce SO₄²⁻ and remove heavy metals is a promising and economical AMD treatment. However, AMD lacks sufficient electron donors for sulfate reduction. Banana peel fermentation broth, containing various small‐molecule organic acids, is an effective alternative carbon source for SRB, promoting the use of agricultural waste in environmental remediation. This study aims to investigate the impact of adding banana peel fermentation broth to the bioreactor on pollutant removal performance and analyze its effect on the microbial community structure.RESULTS: The bioreactor utilising banana peel fermentation broth as an electron donor, demonstrated the effective removal of various pollutants, including sulfate (55.7%), Cu²⁺ (90.74%), Mn²⁺ (70.77%), Fe²⁺ (81.28%) and Cd²⁺ (100.00%), with an average reduction of 74.20% in chemical oxygen demand (COD). Sulfate reduction resulted in an increase in pH from 5.5 to 7.9. Microbial community structure analysis revealed that the primary genera involved in sulfate reduction were Desulfurispora and Desulfovibrio, while Delftia contributes to the immobilization of heavy metals. Additionally, the key genera responsible for fermentation to produce small molecule acids were Leptolinea and Sedimentibacter. In symbiosis with SRB, they play a crucial role in the removal efficiency of metals and sulfate.CONCLUSION: The overall sulfate and heavy metals removal efficiency was found to be satisfactory after 30 days of continuous reactor operation. There was a notable increase in microbial abundance and community diversity within the reactor. Therefore, banana peel fermentation broth is a promising alternative organic carbon source in acid mine drainage(AMD) treatment. © 2025 Society of Chemical Industry (SCI).

With the rapid development of nanotechnology, nanomaterials have been widely utilized in many industries and daily life applications due to their unique properties. However, their potential release and the human health/environmental consequences have raised public concern greatly. In this study, we compared the toxic effects of AgNPs and AgNO₃ on Skeletonema costatum in 10, 100, and 500 μg·L⁻¹ Ag treatments. In all the AgNP exposure experiments, cell membrane damage and growth inhibition occurred. However, the cellular damage only obviously appears on exposure to a high concentration of AgNO₃. The antioxidant enzyme (SOD and CAT) activities and lipid peroxidation in Skeletonema costatum were also induced significantly in the AgNP treatments. In addition, the percentage of Ag release in seawater increased with the increase in AgNP concentrations (13%, 32% for 100 and 500 μg·L⁻¹ AgNPs). Thus, the biotoxic effects of AgNPs were found to be due to a combination of the solubilization of particles into toxic metal ions and the nature of the nanoparticles. It was worth noting that the induction of oxidative stress and damage to the cell membrane comprised the dominant mechanism of toxicity for AgNPs. Therefore, the behavior of nanometals in seawater affects the biotoxic effect on the phytoplankton. These results shed light on the biological toxicity of nanometals and their possible toxicity mechanism.