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Did you know? How thermal desorption technology uses high temperatures to separate harmful substances in soil?
With the accelerated pace of industrialization, the problem of soil pollution is becoming increasingly serious. In particular, the damaging impact of petroleum pollutants on the land environment cannot be ignored. Among many environmental remediation technologies, low-temperature thermal desorption (LTTD) technology has attracted much attention due to its high efficiency and reusability. This article explores how this technology works, its scope of applications, and its importance.
What is low-temperature thermal desorption technology?
Low-temperature thermal desorption is a technology that uses thermal energy to separate contaminants in soil, especially petroleum hydrocarbons. This technology can be applied to excavated soil to evaporate and desorb harmful substances inside it by raising the temperature of the soil. Although LTTD is not specifically designed to decompose organic matter, in some cases, high temperature operating conditions may cause partial or complete decomposition of organic matter.
LTTD processing flow
When using LTTD technology, the excavated soil is first screened to remove items larger than two inches in diameter. The soil is then heated to a sufficient temperature, usually between 300 and 1,000 degrees Fahrenheit, depending on the nature of the contaminants that need to be removed. The high temperature of the soil will cause the oily components to volatilize, and the gases will then be directed to the secondary treatment unit for subsequent treatment through afterburners or other treatment facilities.
The treated soil can be returned to the original site, used as landfill cover, or even mixed into asphalt for secondary use.
Application scope and effectiveness
LTTD has a good removal effect on petroleum products such as gasoline, aviation fuel, diesel and lubricants. This technology can be adapted to different types of soil, whether it is coarse-grained or fine-grained soil, and can achieve good results through different pretreatments. However, the operation of this technology needs to be tested according to local and national regulations to ensure the feasibility of the treatment plan.
Operation principles and design
Low temperature thermal desorption systems can be divided into fixed facilities and mobile units. Most systems use different configurations and designs, such as rotary dryers, thermal spirals, and conveyor ovens. When designing, it is important to consider the nature of the contaminants and the economics of the system. Not only that, but you also need to pay attention to environmental permit requirements and operational monitoring.
In stationary facilities, contaminated soil will be transported to multiple machines for treatment, while mobile units can operate directly at the contaminated site, providing greater flexibility.
Necessity of gas treatment system
LTTD systems also need to be equipped with effective gas treatment facilities to remove particulate matter, organic vapors and carbon monoxide from emissions. Gas treatment usually uses a combination of dust removal equipment, post-burners and activated carbon to avoid harmful gases from polluting the atmosphere.
Economic considerations
As one of the environmental remediation options, the economics of LTTD often depends on the characteristics of the specific site, such as the volume of contaminated soil, the type of pollutants, etc. Construction costs, equipment transportation distance and site used all affect the overall cost.
Conclusion
In the face of the increasingly serious soil pollution problem, the implementation of low-temperature thermal desorption technology can not only quickly and effectively treat pollutants, but also provide an important opportunity for environmental protection. As technology advances, its application in environmental remediation will probably become more widespread, but are there any deeper challenges and opportunities behind this that we should think deeply about?
