Phosphorylated Bacterial Cellulose-Poly(vinyl alcohol) Membrane for Organic Pollutant Removal.

A bacterial cellulose (BC)/poly(vinyl alcohol) (PVA) composite membrane was phosphorylated using a diammonium phosphate (DAP) solution to increase its capability to remove organic pollutants from wastewater. The bacterial cellulose was extracted from nata de coco waste, and the formation of a composite membrane was achieved by casting aqueous mixtures that, in addition to the BC, contain 3% w/w PVA relative to the BC. The membranes thus made were subsequently phosphorylated to increase the surface charge density and thereby the adsorption capacity of the membrane. The concentration of DAP was varied from 0.05 to 0.3 M to vary the charge density of the membrane. Using methylene blue (MB) as a model pollutant, it is shown that phosphorylation increases the MB adsorption capacity from 2.9 to 20.3 mg/g and leads to multilayer adsorption behaviors. Recyclability experiments confirm the high reusability of the membranes over 5 cycles and demonstrate a high removal efficiency of over 90%.