Browsing by Author "Wang, Pin"

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    Removal of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) by coagulation: influence of coagulant and dosing conditions
    (Elsevier, 2025-03-01) Wang, Pin; An, Guangyu; Carra, Irene; Hassard, Francis; Campo Moreno, Pablo; Sakar, Hacer; Jodkowska, Monika; Wang, Dongsheng; Jefferson, Bruce; Chu, Wenhai; Jarvis, Peter
    Per- and polyfluoroalkyl substances (PFAS) pose significant risks to the environment and human health. Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) are two of the most frequently detected PFAS in the environment. In most surface water drinking water treatment works (WTW), coagulation is the first processes exposed to a range of contaminants, including PFAS. While not designed to be a process for removal of micropollutants, it is important to understand the fate of PFAS in coagulation processes, intended or otherwise, to determine whether water treatment sludge can be a significant sink for this group of micropollutants. This work advances understanding of PFAS removal in coagulation processes by comparing the removal of PFOA and PFOS by four metal coagulants (Zr, Zn, Fe, and Al) from real water matrices. The coagulant performance followed the order Al > Fe > Zr > Zn. Al was taken forward for further evaluation, with significant removal of PFAS (>15 % for PFOA and > 30 % for PFOS) being observed when the pH<5.5 and the dose was > 5 mg Al·L-1. The adsorption of PFOA and PFOS onto flocs through hydrophobic interaction was the primary removal route. The impacts of background matrix on the mechanisms of coagulation for PFAS were explored using five organic compounds. Macromolecular organic compounds contributed to an increase in removal due to the sorption of PFAS and subsequent removal of the organic-PFAS aggregate during coagulation. Low molecular weight organic matter inhibited the removal of PFAS due to the ineffective removal of these compounds during coagulation.
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    Simultaneous removal of organic micropollutants and metals from water by a multifunctional β-cyclodextrin polymer-supported-polyaniline composite
    (Elsevier, 2024-02-15) Wang, Pin; An, Guangyu; Jarvis, Peter; Liu, Wen; ShunkeDing, Shunke; Qu, Ruixin; Li, Zhanghan; Ye, Cheng; Chu, Wenhai
    The occurrence of diverse pollutants in water resources across the globe, including organic micropollutants and heavy metals, has challenged the efficacy of many existing water treatment processes. Various materials and media have been developed for removal of these compounds, but few have the capacity to remove multiple contaminants which are typically present in real water sources. Here we report on a novel sorbent (PANI@PCDP) for the simultaneous removal of organic micropollutants and heavy metals during a single process. Cr(VI) and bisphenol A (BPA) were selected as target pollutants due to their frequent occurrence in aquatic environments and the significant health risks they pose. PANI@PCDP exhibited a high level of performance for removal of BPA and total Cr at pH 6 for initial concentrations of 0.5–100 mg/L for Cr(VI) and 0.228–22.8 mg/L for BPA. Up to 98 % Cr was removed at pH 6 through the adsorption and reduction of Cr(VI), followed by the sequestration of the generated Cr(III). In addition, BPA could be captured by PANI@PCDP at an adsorption rate of 1.4 × 10-1 g mg−1 min−1 as a result of the fast formation of complexes with the media. When the PANI@PCDP media was tested on a wider variety of emerging organic micropollutants (including chlorinated aromatic compounds, simple aromatics, and pharmaceuticals) good removal was observed. Such performance benefits arise from the integration of porous β-cyclodextrin polymers with polyaniline, which provides the PANI@PCDP with multiple binding sites for contaminant removal. In addition, the PANI@PCDP can be regenerated at least five times without loss in performance using a facile procedure, providing evidence for its practical application in water treatment.