Physicochemical Remediation

Incineration and soil washing are typical physicochemical soil remediation processes applied to munitions-contaminated soils. In the incineration treatment, the contaminated soil material is burned at 800-1000°C, but this is should be performed at a special plant that ensures that the exhaust fumes are detoxified. Hence, the process itself is very expensive, even ignoring the additional costs of excavation and transportation of the soil material, as incineration is an offsite process. This decontamination is, however, very successful, although the soil material is biologically dead and the texture is destroyed. Soil washing, too, is mostly performed offsite. The contaminated soil material is usually crushed and then washed. To ensure that the contaminants are passed from the soil material to the washing solution, either acids, bases, tensides, organic solvents or physical methods like kinetic energy are used. The contaminants remain in the fine-grain fraction, which must be separated, dried and disposed. Advantages are its relatively low cost compared to incineration, the rapidity of the process, and the preservation of the soil texture. The applicability of the process depends on the characteristics of the toxicant as well as those of the soil material. Good conditions are provided by soluble substances and sandy and gravelly soil materials. Excavation and physical removal of the soil is perhaps the oldest remediation method for contaminated soil. The advantages of excavation include the complete removal of the contaminants and the relatively rapid clean up of a contaminated site (Wood 1997). Disadvantages include the fact that the contaminants are simply moved to a different place, where they must be monitored; the risk of spreading contaminated soil and dust particles during the removal and transportation of contaminated soil; and the relatively high cost. Excavation can be the most expensive option when large amounts of soil must be removed or disposal as hazardous or toxic waste is required.

Stabilizing the heavy metals in the soil is another useful method of minimizing the bioavailability of heavy metals onsite, and has many advantages over excavation. One way of stabilizing heavy metals consists of adding chemicals to the soil that cause the formation of minerals that contain the heavy metals in a form that is not easily absorbed by plants, animals, or people. This method is called in situ fixation or stabilization, and it does not disrupt the environment or generate hazardous wastes. Instead, the heavy metal combines with the added chemical to create a less toxic compound. The heavy metal remains in the soil, but in a form that is much less harmful. One example of the in situ fixation of heavy metals involves adding phosphate fertilizer as a soil amendment to soil that has high amounts of the heavy metal lead. Chemical reactions between the phosphate and the lead cause a mineral called lead pyromorphite to form. Lead pyromorphite and similar minerals called heavy metal phosphates are extremely insoluble in water (Lambert et al. 1997). This has two beneficial effects. The minerals (and the heavy metals) cannot be easily spread by water to pollute streams, lakes, or other groundwater. Also, the heavy metal phosphates are less likely to enter the food chain by being absorbed into plants or animals that may eat soil particles. This method is relatively rapid and takes about the same amount of time as excavation.

Body Detox Made Easy

Body Detox Made Easy

What exactly is a detox routine? Basically a detox routine is an all-natural method of cleansing yourbr body by giving it the time and conditions it needs to rebuild and heal from the damages of daily life and the foods you eat and other substances you intake. There are many different types of known detox routines.

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