Trend in Research on Characterization, Environmental Impacts and Treatment of Oily Sludge: A Systematic Review

Abstract

Oily sludge is a hazardous material generated from the petroleum industry that has attracted increasing research interest. Although several review articles have dealt with specific subtopics focusing on the treatment of oily sludge based on selected references, no attempt has been made to demonstrate the research trend of oily sludge comprehensively and quantitatively. This study conducted a systematic review to analyze and evaluate all oily sludge-related journal articles retrieved from the Web of Science database. The results show that an increase in oily sludge-related research did not take place until recent years and the distribution of the researchers is geographically out of balance. Most oily sludge-related articles focused on treatment for harmfulness reduction or valorization with limited coverage of formation, characterization, and environmental impact assessment of oily sludge. Pyrolytic treatment has attracted increasing research attention in recent years. So far, the research findings have been largely based on laboratory-scale experiments with insufficient consideration of the cost-effectiveness of the proposed treatment methods. Although many methods have been proposed, few alone could satisfactorily achieve cost-effective treatment goals. To enable sustainable management of oily sludge on a global scale, efforts need to be made to fund more research projects, especially in the major oil-producing countries. Pilot-scale experiments using readily available and affordable materials should be encouraged for practical purposes. This will allow a sensible cost-benefit analysis of a proposed method/procedure for oily sludge treatment. To improve the treatment performance, combined methods are more desirable. To inform the smart selection of methods for the treatment of different oily sludge types, it is suggested to develop universally accepted evaluation systems for characterization and environmental risk of oily sludge.

Exploring the Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Production Potential of Total Petroleum Hydrocarbon Degrading Bacteria Using Oily Sludge Waste as Feedstock

“…Petroleum refineries, with a production capacity of 105,000 drums per day, produce approximately 50 tons of oily sludge per year . Globally, more than 1 × 10 7 tons of oily sludge is produced per year. − Alkane, cycloalkane, and polycyclic aromatic hydrocarbon (PAH) constitute the TPH fractions of oily sludge and impart toxicity to the surrounding environment, humans, and animals. ,− Moreover, seepage of oil from oily sludge stored in pits contaminates subsurface soil and aquifers . The Research Conservation and Recovery Act (RCRA) and the United States Environmental Protection Agency (USEPA) have considered such oily waste as hazardous waste. , There are several reports indicating the application of bioremediation approaches for treating oily sludge. ,− It would be preferable to recover some valuable byproducts along with their treatment.…”

Efficient Treatment of Oily Sludge via Fast Microwave-Assisted Pyrolysis, Followed by Thermal Plasma Vitrification

“…In the petroleum industry, a large amount of oily sludge is generated during the oil exploitation, storage, transportation, and refinery processes. Oily sludge usually exists as a complex semi-solid waste that is composed of water–oil emulsions mixed with solid particles [ 1 ]. In addition to the inorganic composition, which is similar to soil, the organic composition of oily sludge is mostly constituted of hydrocarbons, which are an oil resource.…”

Fast Detection of Heavy Metal Content in Fritillaria thunbergii by Laser-Induced Breakdown Spectroscopy with PSO-BP and SSA-BP Analysis

“…Compared with traditional analytical techniques, such as inductively coupled plasma mass spectrometry (ICP-MS) [7], atomic absorption spectrometry (AAS) [8], and inductively coupled plasma atomic emission spectrometry (ICP-ASE) [9], LIBS has many advantages, such as green spectrometry, a fast analysis speed, the elimination of the need for complex sample preparation, and multiple elemental measurements. LIBS has been widely used for quantitative and qualitative analyses in plant materials [10][11][12], animal tissues [13,14], mineral resources [15,16] and industrial applications [17]. Previous studies have provided a basis for the quantitative prediction of heavy metal content in Chinese medicine using LIBS.…”