Journal of Water Process Engineering 38 (2020) 101569 Available online 26 August 2020 2214-7144/© 2020 Elsevier Ltd. All rights reserved. Biopolymer (gum arabic) incorporation in waste polyvinylchloride membrane for the enhancement of hydrophilicity and natural organic matter removal in water Mohammed Modu Aji, Soundararajan Narendren, Mihir Kumar Purkait, Vimal Katiyar * Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India A R T I C L E INFO Keywords: Waste polyvinyl chloride Gum arabic Hydrophilicity Natural organic matter Biopolymer Membrane ABSTRACT The utilization of waste polyvinyl chloride (PVC) as a membrane substrate and its hydrophilicity enhancement by incorporation of a sustainable biopolymer, gum arabic (GA) for natural organic matter (NOM) removal in water, was studied in this research. Phase transformation method was used for membrane preparation by varying the percentage of GA. Interactions between waste PVC and GA at different loadings (1–5 wt. %) were analyzed using various analytical techniques for morphology and evaluation studies. Field emission scanning electron micro- scopy, thermogravimetric analysis, Fourier transforms infrared spectroscopy, equilibrium water content, contact angle, porosity, water fux, and compaction factor were assessed. Furthermore, the assessment of NOM removal from water was also studied. It was found that blending of waste PVC with GA enhanced its hydrophilicity by 25%, improved its water permeation from 51 to 98 L/m 2 h, with a fux recovery ratio of around 80%, and a rejection of around 96%. The onset degradation temperature was also improved by ~30 ◦ C and the mechanical strength was enhanced by ~ 1.2 MPa. The present study depicts the outcome of the incorporation of GA as a green alternative additive for enhancing the performance of waste PVC based membranes in water treatment applications. 1. Introduction Surface water is assiduously contaminated by natural organic matter (NOM) from various sources like the chemical, microbiological, anthropogenic, and phytochemical transformation of fora and fauna [1, 2]. NOM are those complex heterogeneous organic substances resulting from terrestrial and marine origins that affect the quality, purity, appearance, and other physicochemical parameters of water [2,3]. These problems are generally compounded when the water source is purifed by a conventional method. During chlorination for drinking water treatment, the complex substances can react and produce health-threatening compounds like trihalomethanes (THMs) [4,5]. Humic acid (HA) is a category of NOM which exists in surface and river water. The presence of HA in water can result in bad odor, color alter- ation, absorption of metals, and an increase in turbidity and microbial activities [1,6]. Therefore, HA has to be removed to produce safe water for public utility. Coagulation is one of the traditional methods of NOM removal but coagulants have to be purchased repeatedly to sustain the process [5]. Moreover, HA may combine with coagulants to hinder the overall process and generate sludge that requires additional removal [4, 7]. Adsorption is another established technique that can remove NOM from water. However, the adsorbent is required to be regenerated and separated from the water system every time [4]. Similarly, ion exchange is another viable method for the removal of NOM. Nevertheless, this requires resin and resin revival, the handling of which involves addi- tional operational and disposal costs [8]. Likewise, during chlorination, the phenolic hydroxyl moiety of the HA may react with the disinfectant (chlorine) and produce trihalomethanes [1,3]. Membrane fltration has proven to be an effcient process for NOM removal to make water usable [9]. However, the major challenge of this separation process is its high cost and membrane fouling [3,8,10]. This article is focused on the preparation of low cost hydrophilic membranes to address the above discussed challenges. The application of the prepared membrane was confrmed by applying it for NOM removal from synthetic wastewater. Waste plastic was used to reduce membrane cost and to protect the environment as well. The pressure poised by waste plastic on the envi- ronment is enormous. Suitable discarding of post-consumer plastic is a challenge [11]. To manage this challenge, many waste management and * Corresponding author. E-mail address: vkatiyar@iitg.ac.in (V. Katiyar). Contents lists available at ScienceDirect Journal of Water Process Engineering journal homepage: www.elsevier.com/locate/jwpe https://doi.org/10.1016/j.jwpe.2020.101569 Received 1 June 2020; Received in revised form 28 July 2020; Accepted 29 July 2020