Landfarming for Treatment and Disposal of Oily Wastes Originating in the South Petrochemical Complex

Abstract

Landfarming, a waste treatment system using biological degradation, has been very successfully used for the decomposition of oily sludges. This paper presents data on a project recently developed by COPESUL (Companhia Petroquimica do Sul) on implementation of this system as a solution for the disposal of oily sludges. The characteristics of this project are very different to those of other projects already operating in Brazil. It was due to the experience of these other projects that some modifications were introduced in the COPESUL project. The site chosen for disposal was divided into six parallel cells provided with internal roads to allow the easy access of equipment. The cells were made impermeable by means of a structure composed, from bottom to top, of: a layer of unsaturated natural clay with a minimum thickness of 3.60 m (with the top 15 cm compacted); a draining ballast, for safety purposes, which collects the liquid if this percolates through the top impermeable layer; an impermeable layer with a minimum thickness of 50 cm, obtained by compaction of the local clay; and a reactive layer, properly prepared to receive the sludge. The system is also provided with tanks to receive the waste to be treated and for storage of rainwater leachate which is collected and transported to SITEL (Integrated System for Treatment of Liquid Effluents) for treatment. Furthermore, a storage area for drums is provided for wastes delivered in this form. In addition to data on the project, the paper also gives details of the characteristics of the wastes, the monitoring plan, investment costs, and operating data.