Enhancing Bioremediation of Oily Waste by Bioaugmentation Method

Abstract

Abstract Total E&P Indonesie (TEPI) has an ongoing bioremediation facility located in Senipah which is called IPOC (Industrial Process of Oily waste Composting). IPOC started its first phase in 2001 using drill cutting and contaminated soil with initial Total Petroleum Hydrocarbon (TPH) content maximal 15000 mg/kg, and currently it is being used to treat oily waste from production activities such as produced sand and sludge from emulsion treatment with initial TPH around 40000–60000 mg/kg using composting method. A study program has been developed to accelerate bioremediation process through the use of more selective microorganisms with identified capability to degrade hydrocarbon. The use of this technique are key strategy to minimize operating time and cost per unit of volume of oily waste to reach end point TPH criteria (10000 mg/kg) within less than 8 months as regulated. This paper presents the results of treatability tests designed for enhancing bioremediation process. Introduction Oil and gas production activities in TEPI generate hydrocarbon contaminated waste such as produced sand entrained in desander units at well platforms, sludge from vessel and tank cleaning, and residual solid decanter from emulsion treatment facility. These types of waste are categorized as hazardous waste and needs to be managed and treated properly according to prevailing regulations. Bioremediation using natural biological activity to degrade hydrocarbon is among the most useful and cost-effective method that is used for managing these types of waste. Initiated as pilot project in 2001, IPOC has been used to compost drill cuttings and aged contaminated soil to reach end result of around 10000 mg/kg TPH content within 365 days, with removal rate of 65% - 75% (Chaineau, 2003). After demonstration of the successful pilot scale to authorities, the company has decided to enlarge the bioremediation facility to be used in industrial scale. Starting from 2006, IPOC has been used in industrial scale as licensed facility for biotreatment of hydrocarbon contaminated waste from oil and gas production activities of the company. The evaluation of implementation of bioremediation process in IPOC after 4 years of implementation in industrial scale has resulted in decision to perform further study to optimize the hydrocarbon biodegradation process using bioaugmentation method, i.e. by addition of isolated and cultured microorganisms capable of biodegrading or transforming hydrocarbons to the treated media in order to achieve cost-savings and accelerate bioremediation. A treatability study was conducted to evaluate the efficiency of cultured microorganisms to stimulate bioremediation of hydrocarbon contaminated waste. The microorganism had been isolated from the hydrocarbon contaminated waste. The rate of degradation of petroleum hydrocarbons by the indigenous microorganism and in the presence of cultured microorganism was assessed with the addition of bio-surfactant and various type of bulking agents for a period of about 70 days in laboratory. Indonesian Regulation for Treatment of Oily Waste and Contaminated Soil According to the Ministry of Environment Decree No. 128 Year 2003 (MoE Decree No.128/2003) about Technical Guideline and Requirement for Biological Treatment of Oily Waste and Contaminated Soil, the treatment of oily waste can be conducted with biological method as one of several treatment options. Several allowed biological methods in treating oily wastes are landfarming, biopile, and composting. The technical guideline for biological treatment of oily waste and composting covers the technical requirement, analysis of treatment process, end criteria of treatment process, handling of treatment result, and monitoring and control of treatment result. All of those technical requirements are further specified in permit of biological treatment which shall be validated prior the beginning of treatment process.