Oil removal from runoff with natural sorbing filter fillers.

The aim of this paper was to investigate the ability of Lithuanian sheep wool waste and reeds (Phragmites australis) to absorb oil from runoff when it flows through filters filled with these materials. The third material that was analysed, the synthetic sorbent Fibroil, was chosen for comparing the results. The laboratory experiments were performed in several stages, with the following being filtrated: tap water with a diesel admixture, road runoff contaminated with oils, and also suspended solids. The significance of this work is due to the high runoff filtering rate (∼10 m/h) and high oil concentrations in the runoff (50-230 mg/L) used in the experiment. In these cases the use of sorbents is limited. Wool waste and reed (Phragmites australis) fillers are quite efficient (98-99%) in oil removal from runoff at a 10 m/h filtering rate. However, wool fillers clog up quickly. Reeds of the genus Phragmites australis are a natural source for the production of oil sorbents. The results obtained in this experimental work can be used in the design of equipment for the treatment of oil-contaminated runoff from gas stations as well as sullage from roads and tunnels.