Poly (3, 4-ethylenedioxythiophene) modified polyvinylidene fluoride membrane for visible photoelectrocatalysis and filtration

New directions on membranes for removal and degradation of emerging pollutants in aqueous systems

Emerging pollutants (EPs) refer to a group of non-regulated chemical or biological substances that have been recently introduced or detected in the environment. These pollutants tend to exhibit resistance to conventional treatment methods and can persist in the environment for prolonged periods, posing potential adverse effects on ecosystems and human health. As we enter a new era of managing these pollutants, membrane-based technologies hold significant promise in mitigating impact of EPs on the environment and safeguarding human health due to their high selectivity, efficiency, cost-effectiveness and capability for simultaneous separation and degradation. Moreover, these technologies continue to evolve rapidly with the development of new membrane materials and functionalities, advanced treatment strategies, and analyses for effectively treating EPs of more recent concerns. The objective of this review is to present the latest directions and advancements in membrane-based technologies for addressing EPs. By highlighting the progress in this field, we aim to share valuable perspectives with researchers and contribute to the development of future directions in sustainable treatments for EPs.

Ni-Fe oxide-PEDOT modified anode coupled with BAF treating ammonia and nitrite in recirculating seawater of aquaculture system

Efficient ammonia and nitrite removal in low nutrient recirculating seawater of recirculating aquaculture system (RAS) is critical for healthy cultivation. However, it is hard for conventional biological aerated filters (BAFs) to meet this demand under short hydraulic retention time (HRT). The electrooxidation-BAFs (E-BAFs) were constructed for efficient seawater treatment in a RAS of Sebastes schlegelii, with high activity anodic catalyst Ni-Fe oxide-PEDOT. Satisfactory ammonia removal (88.2% in E-BAFs, 33.7% higher than the control, stage 3) and nitrite removal (69.9 % in E-BAFs, 45.3% in the control) were achieved at HRT of 50 min. The proportion of nitrifying bacteria (Nitrospira, Nitrosomonas and Nitrosopumilus) and nitrification/denitrification genes (amoCAB, nxrAB, narGHI, et. al) were higher in E-BAFs than the control, suggesting better potential in functional bacteria enrichment. Aerobic colony number in RAS with E-BAFs was lower and specific growth rate (SGR) of Sebastes schlegelii (3.79%) was significantly higher, indicating a better culture effect.

Kinetics and thermodynamic studies of Methyl Orange removal by polyvinylidene fluoride-PEDOT mats

We report the preparation of poly(3,4-ethylene dioxythiophene) (PEDOT)-modified polyvinylidene fluoride electrospun fibers and their use as a novel adsorbent material for the removal of the anionic dye Methyl Orange (MO) from aqueous media. This novel adsorbent material can be used to selectively remove MO on a wide pH range (3.0-10.0), with a maximum capacity of 143.8 mg/g at pH 3.0. When used in a recirculating filtration system, the maximum absorption capacity was reached in a shorter time (20 min) than that observed for batch mode experiments (360 min). Based on the analyses of the kinetics and adsorption isotherm data, one can conclude that the predominant mechanism of interaction between the membrane and the dissolved dye molecules is electrostatic. Besides, considering the estimated values for the Gibbs energy, and entropy and enthalpy changes, it was established that the adsorption process is spontaneous and occurs in an endothermic manner. The good mechanical and environmental stability of these membranes allowed their use in at least 20 consecutive adsorption/desorption cycles, without significant loss of their characteristics. We suggest that the physical-chemical characteristics of PEDOT make these hybrid mats a promising adsorbent material for use in water remediation protocols and effluent treatment systems.