Decontamination of water polluted with oil through the use of tanned solid wastes

Sorption by natural organic substrates, inorganic materials or synthetic fibers is one of the most popular methods used for the separation of oily wastes from contaminated water. In this work, the ability of chrome shavings (CS) and of buffing dusts of crust leather (BDCL) to remove motor oils and oily wastes from demineralised water and natural seawater has been studied. Tannery solid wastes are formed mainly by proteins and have a highly organized structure in the form of fibers ( Φ: 100 nm). These wastes have a high oil sorption capacity. Tanned solid wastes are capable of absorbing many times their weight in oil (6.5-7.6 and 12.8-14.5 g/g dry substrate, respectively, for ground CS and BDCL). The sorption capacity depends strongly of sorbent nature. The removal of oils from the water surface is a quasi-instantaneous process. After use, the saturated waste floats and can be removed in an efficient and easy manner. The results look fairly promising as to possibilities of using tanned wastes to remove oils from industrial effluents and from contaminated coastal areas.