The process of nanofiltration purification of water from various organic pollutants was examined. Cellophane film made from cheap natural raw materials was used as a membrane. The model substances targeted for removal were dyes (Safranin O, Orange II, and Remazol Brilliant Blue R, each differing in molecular weight, chemical composition, and charge) and ceftriaxone. The obtained cellophane permeability to water was 0.145 kg/(m2∙h∙atm). Cellophane membranes were found to be effective in retaining dissolved anionic substances containing acid groups. When Orange II and Remazol Brilliant Blue R were removed from the water, the retention coefficients were 97 ± 2 and 99 ± 1%, respectively. For the cationic dye Safranin O, the retention coefficient values were negative, –7 ± 3%. At the same time, ceftriaxone had the retention coefficient of only 41 ± 5%, which can be attributed to a combination of factors, such as its high affinity for cellophane and steric restrictions.