1. Measurement and Control Division, Council for Mineral Technology (MINTEK), Private Bag X3015, Randburg, Johannesburg 2125, South Africa
2. Institute for Nanotechnology and Water Sustainability, College of Science Engineering and Technology, UNISA Science Campus, University of South Africa, Roodepoort, Johannesburg 1710, South Africa
3. Department of Chemistry, University of Eswatini, P/Bag 4 Kwaluseni Campus, Kwaluseni 0004, Eswatini
4. State Key Laboratory of Separation Membranes and Membrane Process, National Center for International Joint Research on Membrane Science and Technology, Tianjin 300387, China