Bio-membrane based on modified cellulose, lignin, and tannic acid for cation and oxyanion removal: Experimental and theoretical study

Two optimized methods, based on epoxy-amino reactivity of the Cellulose fibres (Cell) modified with diethylenetriamine (Cell‒DETA), (3-Glycidyloxypropyl)trimethoxysilane (Cell-Glymo), Lignin modified with epichlorohydrine (EL) and Tannic acid (TA), as an additional crosslinker, were developed for the production of the bio-renewable Cell-EL and Cell-EL-TA membranes. The influences of pH, contact time, adsorbent dose, and temperature on adsorption performances were studied by batch adsorption tests. The calculated capacities: 53.9, 99.9, 97.8 and 63.5, 115.8, 127.5 mg g−1 for Ni2+, Pb2+, Cr(VI) using Cell-EL and Cell-EL-TA, respectively, were obtained from Langmuir model fitting at 25 °C. The thermodynamic parameters indicated spontaneous and low endothermic processes. The results of the kinetic study, i.e. pseudo-second-order (PSO) and Weber-Morris (W-M), suggest an intra-particle diffusion as a rate-limiting step. The semi-empirical quantum chemical calculations aided the analysis of the non-specific and specific adsorbent/adsorbate interactions and their contribution to the overall bonding mechanism. Membrane utility was confirmed by performing a bed column study. In general, three main environmental issues of the present study, biodegradability of the used membrane, desorption efficiency, and development of the technology for the effective effluent water treatment and safe disposal of by-products highly conform to the demand of integrated environmental management system applicability in practice