Finding Chemical Pathways Toward the Valorization of Automobile-Service-Station Wastes

Abstract

Automobile-service-station wastes make for an acute environmental concern because they contain polyaromatic hydrocarbons, heavy metals, surfactants, and other harmful elements. An eco-friendly way to treat and take advantage of these wastes is embodied in the concept called "valorization". In the present work, valorization is described as a chemical process to remove solids from contaminated water and to stabilize oily sludge into a saponified product. Electrocoagulation and coagulation with aluminum were applied to separate oil-water emulsions and removed 99.7% of turbidity. Both coagulation processes obtained approximately 0.85 kg of treated water and 0.027 kg of dried oily sludge per kg of wastewater. A saponification process with dosages of 10% NaOH stabilized the dried oily sludge. In hopes of finding pathways to valorize wastes, chemical treatments with aluminum and NaOH obtained a product that can be used as a surfactant or as an energy source.Keywords: sludge, electrocoagulation, saponification, oil, wastewater