1, incineration
Incineration is a method of fully oxidizing oily sludge in the incinerator at high temperature in the presence of excessive air and auxiliary fuel, with the purpose of minimizing the residue of toxic and harmful substances and inhibiting the generation of new pollutants. Incineration has been widely used in the treatment of oily sludge in large refineries, and it is recommended by HJ 607-2011Technical Specification for Pollution Control of Waste Mineral Oil Recovery.
2. Curing method
Solidification treatment of oily sludge is a technology to fix or contain oily sludge in inert solidification matrix by physical and chemical methods to form solidified products with good mechanical properties, impermeability and leaching resistance. Commonly used curing agents are cement and fly ash. The solidified oily sludge can be used as building materials, such as building subgrade base, and its compressive strength and tensile strength should meet the standard requirements of cement stabilized macadam subgrade base in JTJ 057-94 Test Code for Stabilized Materials of Inorganic Binders in Highway Engineering and JTJ 034—2000 Technical Code for Construction of Highway Pavement Base.
3. Biological treatment
Under aerobic conditions, biological treatment technology utilizes microorganisms to metabolize PHCs as carbon source in oily sludge and convert them into CO2 and H2O. At present, the main biological treatment technologies are in-situ tillage, composting, biological mud and biological enhancement. In-situ culture and composting both use natural microorganisms in soil to naturally degrade PHCs in oily sludge, so it is difficult to control the types and activities of microorganisms, and they occupy a large area, are greatly affected by natural conditions such as rainfall and temperature, and may also pollute soil and groundwater, so they are rarely used in practice. Both biological sludge process and biological enhancement process transform PHCs in oily sludge into low toxic intermediates (such as organic acids and aldehydes) by inoculating microorganisms, and finally into CO2 and H2O. The key is to screen efficient PHCs degrading bacteria.