Jeffery Layton Ullman

Membrane technology has received great attention in the desalination and water treatment sectors over the last few decades. However, membrane fouling remains a critical issue that affects membrane performance, a phenomenon common in membrane bioreactors (MBRs). This major drawback can be overcome by the preparation of antifouling membranes using an electrospinning technique that generates a hydrophilic modification of membranes. In this study, nanocomposite polyvinylidene fluoride (PVDF) and cellulose acetate (CA) polymer was fabricated to mitigate membrane fouling. Surface and mechanical characterization of the electrospun membrane was performed to assess morphology, chemical composition, and hydrophilic/hydrophobic properties. Anti-fouling performance of the composite PVDF/CA membrane was evaluated versus a neat PVDF membrane through bench-scale experiments. The PVDF/CA nanofiber membrane displayed a more hydrophilic nature, demonstrated by a lower water contact angle (101° vs. 115°) and increased wastewater flux (190 L/m²·h. vs. 160 L/m²·h), although the composite membrane demonstrated lower tensile strength (2.0 ± 0.1 MPa vs. 1.7 ± 0.1 MPa). The new material demonstrated greater anti-fouling performance compared to the neat PVDF membrane. Results suggest that this nanofiber material shows promise as an enhanced antifouling membrane that can overcome membrane fouling limitations.

Reverse osmosis and microfiltration are two membrane-based separation techniques that have gained popularity over the past few decades. A fundamental barrier to improving the overall efficiency of membrane separation is membrane fouling. The accumulation of foulants causes a reduction in permeate flux, a loss of selectivity and permeability, and a reduction in the membrane’s lifespan. Numerous chemical and physical surface changes have been studied to enhance membrane antifouling properties. Additionally, research has concentrated on creating membranes that use cutting-edge materials to improve their antifouling capability. This paper focuses on a wide-ranging and thorough analyses of the different types of fouling during wastewater treatment based on current research results regarding fouling control strategy and the potential of new methods for wastewater treatment. It is a further step forward for the evaluation of mitigation measures for emerging membrane fouling problems.

Eucalyptus wood is made up of lignocellulosic material; this lignocellulosic material contains two types of biopolymers, i.e., carbohydrate and aromatic polymers. In this study, this lignocellulosic material was used to prepare biochar. Three biochar, i.e., laboratory-based (B1), barrel-based (B2), and brick kiln-biochar (B3), were used for fluoride and arsenic removal from aqueous solution. Barrel-based biochar was prepared by using the two-barrel method’s alteration. The highest fluoride removal (99%) was attained at pH 2 in the presence of B1, while in the presence of B2 and B3, maximum fluoride removal was 90% and 45.7%, respectively. At pH 10, the maximum arsenic removal in the presence of B1, B2, and B3 was 96%, 94%, and 93%, respectively. The surface characteristics obtained by Fourier-transform infrared spectroscopy (FTIR) showed the presence of carbonyl group (C-O), and alkene (C=C) functional groups on all the three studied biochars. Isotherm studies showed that the adsorption was monolayered (all the adsorbed molecules were in contact with the surface layer of the adsorbent) as the Langmuir isotherm model best fits the obtained data. Adsorption kinetics was also performed. The R² value supports the pseudo-second-order kinetics, which means that chemisorption was involved in adsorbing fluoride and arsenic. It is concluded that B1 gives maximum removal for both fluoride (99%) and arsenic (96%). The study shows that lignocellulose-based biochar can be used for arsenic and fluoride removal from water.