Bioremediation of Oil Sludge in Shengli Oilfield

Abstract

Large quantity of dehydrated oil sludge, generated in the disposal process of oil-containing sewage in Shengli oilfield, needs to be rendered harmless to human and to the environment. Bioremediation has been accepted as an important method for the treatment of oil sludge by employing indigenous or extraneous microbial flora. The bioremediation of a dehydrated oil sludge of 960 m 3 in volume was carried out in a prepared bed in Binyi oil-containing sewage disposal station, Shengli oil fields, China. Four different treatments were made to study the impact of certain process parameters on the bioremediation efficiency. Of the oil contaminants, 52.75% was degraded within 160 days when treated in a greenhouse, while the oil contaminations decreased by only 15.46% in the untreated sludge. The variations of the physical and chemical properties of oil sludge, the amount and the functional diversity of microorganisms in sludge were characterized. The results indicated that the water-holding capacity of oil sludge, the amount and the metabolism functional diversity of microorganisms in sludge in the three treatments increased markedly compared with the control.

Remediation of Oily Waste using Soil Organic Nutrient Stimulant

“…This was carried out based on the principles of biostimulation, bioaugmentation and composting [8,10,11]. The soil-goat dung nutrient stimulant treatment and control were set up in triplicates using transparent, sterile small sized buckets with perforated lids.…”

“…The first tenfold dilution was made using 10g of the oily waste sample in 90ml of diluent. The dilution were shaken and further serial ten-fold dilutions made up to 10- 8 . The isolation and enumeration of hydrocarbon utilizing microorganisms were done by vapour-phase transfer method as described by [13,14,15], Aliquots (0.1ml) of appropriate dilutions (10 ) of oily waste samples were inoculated onto mineral salt medium (MSM) using the surface spreading technique.…”

“…It can be achieved in situ or ex situ through biostimulation, bioaugmentation achieved by land filling, land farming, use of bioreactor, composting or vermiculture [4,7] The cost of treating waste generated from industrial activities is often high, thus most industrial waste are not treated before disposal into the environment. Bioremediation is an efficient, economic and alternative to physicochemical treatment of waste generated from the oil industry [8]. Microorganisms are able to use the total petroleum hydrocarbons of the crude oil as source of carbon and energy and break them down to simpler non-toxic compounds such as carbon (iv) oxide and water [7].…”

Biological degradation of oil sludge: A review of the current state of development

“…In recent years, most refineries treat oil sludge using conventional methods which includes; physical treatment (storage, landfilling, combustion and incineration in a rotary kiln, lime stabilization, stabilization and solidification) (Wright and Noordhius, 1991;Karamalidis and Voudrias, 2001;Bhattacharyy and Shekdar, 2003;Radetski et al, 2006;Beech et al, 2009;Liu et al, 2010), chemical treatment (oxidative thermal treatment, treatment with fly-ash, pyrolysis treatment and solvent extraction) (Bonnier et al, 1980;Atlas, 1984;Taiwo and Otolorin, 2009) and biological treatment (landfarming, bio-reactor treatment and composting) (Pereira-Neta, 1987;Piotrowski, 1991;Lees, 1996;Singh et al, 2001;Hejazi et al, 2003;Mahmoud, 2004;De-qing et al, 2007;Srinivasarao et al, 2011;Udotong et al, 2011;Besalatpour et al, 2011). Most of the physical and chemical methods require expensive equipments and high energy to treat the oil sludge.…”

“…Such options should be able to take care of the limitations of the previous methods while improving oil sludge bioremediation. Therefore, composting process which involves the careful control and addition of nutrients, watering, tilling, addition of suitable microbial flora and bulking agents (wood-chips or hay) were considered an alternative option to improve the bioremediation of oil sludge (De-qing et al, 2007). The process leads to the production of carbon dioxide, water, minerals and stabilized organic matter (Pereira-Neta, 1987).…”