الفهرس 
Types of oily waste during processingOnly 14 pages are availabe for public view
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Abstract
Oily sludge is considered the most important resulted solid waste from crude oil storage tanks which are used for its storage. Consequently, that leads to crude oil losses in oily sludge leading to decrease the pumping amount from storage tanks and the possibility of corrosion, so the establishment bears the economic burden of that loss of crude oil. The establishment purges the sludge yearly by contracting with licensed stakeholders. Conventional way in oily sludge treatment methods (landfill and incineration) present various shortcomings, including high cost and need for specialized equipment and skilled personnel. Therefore, bioremediation by using different microbial communities provides a technique for cleaning up oily sludge totally or mostly by enhancing the natural biodegradation processes.
from the types of bioremediation: 1- Natural attenuation that relies on natural processes to clean up or attenuate pollutants in soil without addition of nutrients (such as sulfates and phosphates). 2- Bioaugmentation that depends on using the genetically engineered microorganisms or adding native microflora, which is preferred because these microorganisms have more ability for adaptation to particular pollutant than non-endogenous microorganisms.
The main aim of this study is to bioremediate for reduction of oily sludge in crude oil storage tanks.
The study was conducted by collecting and analysis of oily sludge samples from storage tank of Arab Petroleum Pipelines Company (Sumed Company) of Sidi Kerir and Ain Sukhna branches and soil samples polluted with oil spill from site. The oily sludge was bioremediated by four laboratory experiments to reach to the best bioremediation method. In first experiment, isolation of microorganisms from soil polluted with oil spill then used in bioremediation of oily sludge samples individually and oily sludge samples were bioremediated by known microorganisms with different inoculum amounts and at different time period for six months.
In second experiment, oily sludge samples were bioremediated by form of consortium (for the oily sludge from the establishment branches) of best biodegradable four strains with equal percentage (1:1:1:1) with different inoculum amounts and at different time period for two months. In third experiment, oily sludge samples from Sidi Kerir branch were mixed with polluted soil with oil spill for bioremediation in form of natural attenuation with different soil amount using three basins (B, D and C) for three months and the analysis was done weekly to assess bioremediation process. In fourth experiment, oily sludge samples from Sidi Kerir branch were mixed with polluted soil with oil spill with addition of used consortium in the laboratory trial for bioremediation in form of bioaugmentation for three months and the analysis was done weekly to assess bioremediation process.
The results of the study are summarized as follow:
First experiment:
Application of isolated Sulfur and Iron bacteria from polluted soil with crude oil in bioremediation of oily sludge as laboratory trial at different time period
The isolated Sulfur and Iron bacteria was used for bioremediation of 1% of oily sludge with different inoculum amounts and at different time periods, where by laboratory trial, Leptothrix group of iron bacteria was the most capable of total petroleum hydrocarbons biodegradation with percent 75% of 1% oily sludge with almost same percentage with any inoculum and at any time period.
Application of isolated and identified types of bacteria (M1, M7 and M10) from polluted soil with crude oil in bioremediation of oily sludge as laboratory trials at different time period
The isolated and identified types of bacteria (M1, M7 and M10) were used for bioremediation of 1% of oily sludge with different inoculum amounts and at different time periods, where the most advantageous isolated oily sludge-biodegradable microorganism was M10 (with 3ml inoculum after 9 days incubation period) that had 74% total petroleum hydrocarbons biodegradation rate of oily sludge but there was no detectable difference between biodegradation rate of M1 and M7.
Application of strain 48, Candida albicans and Pseudomonas aeruginosa in bioremediation of oily sludge as laboratory trials at different time period
Strain 48, Candida albicans and Pseudomonas aeruginosa were used, where Pseudomonas aeruginosa achieved the highest total petroleum hydrocarbons biodegradation rate 85.92% of 1% of oily sludge after 12 days incubation period which was followed by strain 48.
Second experiment:
Application a consortium of strains (48, M1.M7, M10) with equal ratio (1:1:1:1) in bioremediation of oily sludge as laboratory trials
A consortium of strains (48, M1.M7, M10) was applied for bioremediation of1% of oily sludge with different inoculum amounts and at different time periods, where it resulted in higher total petroleum hydrocarbons biodegradation rate of Ain Sukhna oily sludge than Sidi Kerir oily sludge up to 90% as cause of the high viscosity of Ain Sukhna oily sludge, and high water content of Sidi Kerir oily sludge.
Third experiment:
Pilot study of natural attenuation as land farming with different amounts of soil
It was verified that the amount and height of soil is a very effective factor. where basin D (with 2.3kg soil with height 3.3cm) after three weeks, was proved that it was the best in comparing with basin C (with 1.7kg soil with height 2.6cm) and basin B (with 3.12kg soil with height 5cm). The optimum condition in basin D was after three weeks, where physical parameters (PH, water content, and water holding capacity, 8.56, 11.51% and 73.93% respectively) were within acceptable range in comparison with referenced optimum condition (6-9.5, 10-20% and 25-85% respectively).
For chemical parameters (oil and grease, and total petroleum hydrocarbon 175.95ppm ”56.67%”, and 181.7 ”90%” respectively) were within acceptable limits (20 to 60% reduction in a period of 3 to 6 weeks for oil &grease and total petroleum hydrocarbons) where the target parameter (total petroleum hydrocarbons) biodegrade to 90% and nutrients ratios(C:P= 127.92:1 and N:P=7.62:1) were close to optimum condition (C:P=120:1 and N:P=10:1). For biological parameters, total viable bacteria were 5695±1 CFU, iron and sulfur bacteria were disappeared. Therefore, the aid of microbial degradation process eliminated oily sludge by having enzyme systems to degrade hydrocarbons, and because of the existence of high water infiltration in the soil and higher fertility level.
Fourth experiment:
Pilot study of bioaugmentation as land farming
Bioaugmentation (enhanced applied bioremediation) as land farming of oily sludge by land farming achieved 99.18% removal of total petroleum hydrocarbons so; in comparing with natural attenuation 97.84% , bioaugmentation was a method that could be considered to initiate the treatment of oily sludge in large scale. The experiment showed that the treated soil was less toxic and marked decreases in its total petroleum hydrocarbon.
Based on the findings of the study, it was concluded that cleaning up of total hydrocarbons is a real environmental problem. Therefore, it was observed that bioremediation of total hydrocarbons can lead to reduce its amount as a environmental pollutant with both natural attenuation and bioaugmentation. It was found that the bioaugmentation achieved better biodegradation rate of hydrocarbon relatively than natural attenuation and in shorter time period. Those had the less cost in comparing with other options such as incineration and leading to healthy environment and consequently to safe public health.
Recommendations
The following recommendations are suggested bases on results of the study to be applied in large scale.
• Using heating system by heat exchanger to prevent the accumulation of oily sludge and with of mixers inside storage tanks.
• Selecting biodegradation way of oily sludge is by land treatment with treatment site determination and target sludge characterization and bioremediation.
• The soil within the land farm is a very important parameter; it should be arranged into windrows of not more than 0.5 meters height. The base (lining) should be constructed with a gentle slope (between approximately 2 and 10º) and thickness of 0.3 meters to prevent the leakage of the leachate to ground water.
• For environmental evaluation and monitoring of land farming by main parameter analysis such as: PH, total petroleum hydrocarbons, acute toxicity, toxicity of leachate, moisture levels and most probable number (MPN) bacterial counts.
• Try to put environmental criteria for judging land farming treatment to achieve site-specific remediation objectives within a time frame.
• Further studies:
- Study the application of consortium, different isolates, bacteria and yeast in pilot and field studies of crude oil tank to study their effect in bioremediation of oily sludge with the same conditions of field tank, especially iron bacteria due to high amount of iron which is one of main causes of oily sludge formation.
- Study the impact of increasing the concentration of consortium used in bioaugmentation with different inoculums concentrations to achieved higher biodegradation rate of total petroleum hydrocarbon.
- Study the addition of biosurfactant with bacteria in bioremediation process as an aid for the bacteria in biodegradation process. Biosurfactants have been studied for use in reducing the viscosity of heavy oils. Biosurfactants produced by biological resources, such as microbes and plants, are a structurally diverse group of surface-active compound spread by microorganisms. Biosurfactants have several advantages over chemical surfactants, such as lower toxicity, higher biodegradability, and better environmental compatibility.
- Study the environmental impact assessment of the bioremediation with estimating the economic benefits from bioremediation to resulted oily sludge from crude oil storage tanks.