Full-scale operation of a tubular ultrafiltration system in the treatment of oily waste.

摘要

An aluminum company in West Virginia uses an oil-water (metal working fluid) in their rolling mill process for lubrication. In the past, the company collected the oily-waste into two lined waste ponds with a combined holding capacity of 5 million gallons. Separation of the oil-water mixture occurred as emulsifiers in the metal working fluid broke down. Free oil was skimmed resulting in a pond effluent, which contained 0.2 to 1.0% oil. Pond effluent was sprayed on a treatment field and the remaining oil was degraded naturally. The daily flow to the spray fields averaged 80,000 gallons. In 1993, concerns about direct land treatment of the waste surfaced, due to new groundwater regulations issued by the West Virginia Department of Environmental Protection. As a result, the company investigated alternatives for oily-waste treatment. The technologies studied were as follows: chemical addition dissolved air flotation (CA-DAF), biological aerated filter, tubular and rotary ultrafiltration (UF), land application, and constructed wetlands. The primary pollutant of concern was oil/grease (O/G). Separation of the free oil in a single three million-gallon pond was selected as primary treatment. Tublar ultrafiltration was chosen as the secondary treatment process. Tubular UF was selected to treat the remaining water phase or pond effluent. Permeate from the tubular UF is sent to a hybrid constructed wetlands for polishing. Residual from the tubular UF is treated using high-shear rotary Ultrafiltration (HSR-UF). HSR-UF is able to concentrate oily-waste to ∼70% oil. The residual from the HSR-UF was to be disposed of off site.