• 상하수도학회지
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• 제24권4호
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• pp.395-406
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• 2010

In this study, anaerobic digestion, electro-oxidation and electro-fenton oxidation processes were investigated to reduce oily refinery sludge. Anaerobic digestion process was not suitable for oily activated sludge reduction because of characteristics itself and, as experimental results revealed, reduction efficiency was low for electro-oxidation process. However, 40% total suspended solid reduction of oily activated sludge was obtained by electro-fenton oxidation process, operating at pH=1, 0.5 A and $Fe^{2+}$:$H_2O_2$ ratio = 1:30. In addition, higher reduction efficiency was obtained as reaction time was increased (30, 60, 90, 120 min) despite of low $H_2O_2$ concentration. From the results, it has been investigated that electro-fenton oxidation is efficient process for oily activated sludge reduction.

• 해양환경안전학회지
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• 제6권1호
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• pp.57-67
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• 2000

All crude oil carries a little of water, sand, and mineral sediment molecules tightly bounded with hydrocarbons. The result is the gradual precipitation of these heavier elements into thick, granular petroleum by products known as crude oil sludge. The oily sludges in ship tanks and in storage facilities have to be treated efficiently in order to keep the security and the capacity of storage facilities, to protect a serious environmental pollution, and to retrieve lost resource. The oily sludge treatment system should be designed to satisfy requirements mentioned in safe work condition. As a basic study, in this paper, an oily sludge treatment system by ultrasonic waves was proposed. Then, the features of ultrasonic energy and recovery of sludge with ultrasonic waves are investigated by experiments. As results, we found that ultrasonic waves are a new energy to flow oil sludge environment-friendly in safe work condition. In addition, it was shown that ultrasonic energy is more efficient than thermal energy in treating oil sludge, and that the volume of wastes for disposal is reduced remarkably.

• 대한화학회지
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• 제55권5호
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• pp.842-845
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• 2011

Wet air oxidation (WAO) of oily sludge was carried out using $Fe^{3+}$ as catalyst, placed in a 0.5 L batch autoclave in the temperature range of $250-330^{\circ}C$. Experiments were conducted to investigate the effects of temperature, the initial COD, reaction time, concentration of catalyst and $O_2$ excess (OE) on the oxidation of the oily sludge. The results showed that in the WAO 88.4% COD was achieved after 9 min reaction at temperature of $330^{\circ}C$, OE of 0.8 and the initial COD of 20000 mg/L. Temperature was found to have a significant impact on the oxidation of oily sludge. Adding a catalyst significantly improved the COD removal. Homogenous catalyst, $Fe^{3+}$, showed effective removal for pollutants. COD removal was 99.7% in the catalytic wet air oxidation (CWAO) over $Fe^{3+}$ catalyst. The results proved that the CWAO was an effective pretreatment method for the oily sludge.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권5호
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• pp.41-46
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• 2015

Three types of experiments, based on the physical properties of oily sludge landfilled soil, were conducted to recover total petroleum hydrocarbons (TPH) from the soil. These experiments included gravity separation, solvent extraction using water, and air floatation. The oil portion was not easily separated from the wet (raw) soil because water molecules aggregate the soil particles, despite the fact that the soil was sandy. However, the drying and grinding processes destroyed the aggregates, causing the TPH recovery to increase to approximately 60% when air floatation was used. The drying process decreased the specific gravity of the soil sample, thereby enhancing the overall recovery of TPH from the soil. Although thermal desorption and/or incineration are common choices for heavily dumped sites, physical separation can recover the oil portion instead of simply removing it.

• Environmental Engineering Research
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• 제20권4호
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• pp.392-396
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• 2015

This work aims to investigate the oily wastewater treatment by the electrocoagulation-flotation (ECF) and propose a mathematical model for the efficiency prediction. Cutting oil was used to prepare the synthetic oily wastewater with submicron droplet sizes. The chemical coagulation by aluminium sulfate was firstly tested following by the electrocoagulation-flotation with aluminium electrodes. Both processes gave the effective treatment performance with the efficiencies higher than 90%. However, the ECF consumed less aluminium dosage as well as produced less sludge, which were its advantage on the chemical coagulation. The performance of the ECF was found to be affected by the current density, oil concentration, and reaction time according to the analysis by the design of experiment (DOE). Finally, the prediction model was proposed by two approaches, including linear and logarithm function. The latter model gave more accuracy prediction results in terms of treatment efficiency and duration in the lag and stable stages.

• 한국미생물·생명공학회지
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• 제48권4호
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• pp.515-524
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• 2020

With the increasing demand for enzymes in industrial applications there is a growing need to easily produce industrially important microbial enzymes. This study was carried out to screen the indigenous refinery bacterial isolates for their production of two industrially important enzymes i.e. lipase and protease. A total of 15 bacterial strains were isolated using Soil Extract Agar media from the oil-contaminated environment and one was shown to produce high quality lipase and protease enzymes. The culture conditions (culture duration, temperature, source of nitrogen, carbon, and pH) were optimized to produce the optimum amount of both the lipase (37.6 ± 0.2 Uml-1) and the protease (41 ± 0.4 Uml-1) from this isolate. Productivity of both enzymes was shown to be maximized at pH 7.5 in a medium containing yeast extract and peptone as nitrogen sources and sucrose and galactose as carbon sources when incubated at 35 ± 1℃ for 48 h. Bacterial strain SAB06 was identified as Bacillus licheniformis (MT250345) based on biochemical, morphological, and molecular characteristics. Further studies are required to evaluate and optimize the purification and characterization of these enzymes before they can be recommended for industrial or environmental applications.

• 유기물자원화
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• 제21권4호
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• pp.33-43
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• 2013

해양에서 발생하는 해양폐기물의 효율적인 관리와 해양오염방제시스템에 대한 진일보한 전략수립이 필요하다. 2011년에 발생한 해양오염사고 건수는 총 287건이며, 유출량은 369 kL로 나타났으며 이는 전년 대비 각각 13%, 39%가 감소하였다. 해양물질별 5년 평균량을 살펴보면, 오일 유출량 310.5 kL(중유 106.0 kL, 경유 178.9 kL, 선저폐수 22.3 kL, 기타유 7.7 kL)이고, 폐기물 62.3톤, 위험유해물질(HNS) 510.6 kL로 나타났다. 2011년도 폐기물 종류별 해양배출은 총 투기된 양은 3,972 $m^3$이고, 가축분뇨 795 $m^3$(20%), 폐수 1,431 $m^3$(36%), 하수슬러지 887 $m^3$(22%), 폐수슬러지 813 $m^3$(21%), 분뇨 5 $m^3$(0.1%), 기타 41 $m^3$(0.9%)로 나타났다. 해양폐기물의 개념을 보다 명확히 할 필요가 있다. 유해화학물질관리에 따른 통합사고관리체계를 구축해야 한다. 해안오염을 제거하기 위하여 방제책임자가 활용 할 수 있는 한국형 해안방제시스템의 필요하다. 해상방제와 마찬가지로 해안방제도 단계적 대응체제 구축이 필요하다.