Biological Treatment Of Drilling Waste

Abstract

Abstract Off shore operators are now faced with more stringent forthcoming regulations regarding waste discharge. Several aspects are to be taken into account when considering waste disposal in the sea; among them, the total amount of COD and the toxicity. While, in many regards, the problem caused by the processing fluids toxicity has been addressed, the elimination of residual COD from the waste is yet to be solved. Biodegradation of drilling waste is one of the major routes taken by third party contracters to address the reduction of COD in sea-discharged cuttings. This report describes a technique specifically developed to enhance drilling waste biodegradation under selected conditions. The suggested treatment involved biological catalysts used in conjunction with or prior to the biodegradation. We demonstrated that the considered environment-compatible substitute for oil-based mud could be more efficiently biodegraded if an enzymatic pretreatment was carried out prior to or during the actual biodegradation. The biodegradation rate, expressed as CO2 evolvement, was significantly higher in lipase-treated cultures. In addition, we demonstrated that this treatment was applicable to substrates in emulsion, suspension, or adsorbed on solid. P. 71