Performance and Morphology Evaluation of Thin Film Composite Polyacrylonitrile/Polyamide Nanofiltration Membranes Considering the Reaction Time

Novel Fenton process of Co-catalyst Co9S8 quantum dots for highly efficient removal of organic pollutants

Advanced oxidation processes (AOPs) have been widely accepted as an efficient and promising strategy for treating organic pollutants, is mainly dominated by hydroxyl radicals (•OH); however, its further practical application has been hindered by its low decomposition rate of H₂O₂. Hence, for the first time, we propose an eco-friendly and facile synthesis methodology synthesize water-soluble Co₉S₈ quantum dots (QDs) derived from commercial cobalt disulfide (CoS₂), which can serve as excellent co-catalysts to dramatically enhance the decomposition rate of H₂O₂. It is demonstrated that the conversion rate of H₂O₂ into •OH is ca. 80.02% promoted by Co₉S₈ QDs, whereas the conventional Fenton process is ca. 34.9%. The result shows that unsaturated edged S atoms on the surface of Co₉S₈ play a pivotal role in this enhancement, where the number of protons will react with sulfur atoms to form H₂S and expose reductive metallic active sites to accelerate the Fe³⁺/Fe²⁺ conversion. In addition, to tackle the issue for difficult recovery of liquid quantum dots, the magnetic Co₉S₈ QDs/Fe₃O₄ nanoparticles are particularly synthesized, which show excellent performance for degradation of 20 mg/L Rhodamine B (RhB). Moreover, the TOC degradation rate can remain stable at 80% even after five cycles. It is expected that this work will provide a new pathway of thinking in the Fenton process and impulse the usage of liquid quantum dots in practical AOPs application.

Progress of Interfacial Polymerization Techniques for Polyamide Thin Film (Nano)Composite Membrane Fabrication: A Comprehensive Review

In this paper, we review various novel/modified interfacial polymerization (IP) techniques for the fabrication of polyamide (PA) thin film composite (TFC)/thin film nanocomposite (TFN) membranes in both pressure-driven and osmotically driven separation processes. Although conventional IP technique is the dominant technology for the fabrication of commercial nanofiltration (NF) and reverse osmosis (RO) membranes, it is plagued with issues of low membrane permeability, relatively thick PA layer and susceptibility to fouling, which limit the performance. Over the past decade, we have seen a significant growth in scientific publications related to the novel/modified IP techniques used in fabricating advanced PA-TFC/TFN membranes for various water applications. Novel/modified IP lab-scale studies have consistently, so far, yielded promising results compared to membranes made by conventional IP technique, in terms of better filtration efficiency (increased permeability without compensating solute rejection), improved chemical properties (crosslinking degree), reduced surface roughness and the perfect embedment of nanomaterials within selective layers. Furthermore, several new IP techniques can precisely control the thickness of the PA layer at sub-10 nm and significantly reduce the usage of chemicals. Despite the substantial improvements, these novel IP approaches have downsides that hinder their extensive implementation both at the lab-scale and in manufacturing environments. Herein, this review offers valuable insights into the development of effective IP techniques in the fabrication of TFC/TFN membrane for enhanced water separation.