Remediation technologies biological

This is an ex situ, slurry-phase, biological remediation technology that treats soils contaminated with organics, particularly polycyclic aromatic hydrocarbons (PAHs) with four or greater rings. 

Various soil remediation techniques such as incineration, soil washing, or biological soil treatment were applied in the past, but the microbiological degradation of TNT-contaminated soils is considered to be the most favorable technique as far as costs are concerned [414]. The following is a summary of these TNT remediation technologies ... 

For the site of the trickling pond, a site-specific strategy for the remediation was established. Flighly contaminated hot spots were excavated to protect the groundwater. The applied biological treatment technology was tested in pilot scale on site. A feasibility study was done for the estimation of remediation time and TNT reduction which can be achieved by biological transformation. 

On the basis of the feasibility studies, an in situ technology was applied for the biological remediation of TNT and its transformation products. Microbiological transformation of TNT in the soil was stimulated by the addition of a carbon source and iron particles. The amount of additive was 51/m molasses and 5kg/m iron particles. Thus for the treatment of the whole 2,000m site, there was a requirement for lOm molasses and lOt iron. The addition of molasses and a subsequent mechanical tillage to a... 

Liquid-phase adsorption using GAC is one of the most widely used remediation technologies. The major disadvantage of this approach is that it simply transfers contaminants from one phase to another, and further treatment or disposal of the receiving phase is typically required. Biological treatment has the potential to completely destroy contaminants, and it is generally... 

Hydrocarbon Environmental Recovery Systems bioremediation response advancement technologies (BRAT) are biological remediation products for treatment of organic contaminants in soil or water. According to the vendor this technology has been applied full scale at a number... 

The Simplot Anaerobic Biological Remediation (SABRE ) process is a patented, ex situ technology used to treat soils contaminated with nitroaromatic compounds. Researchers isolated a selection of anaerobic bacteria based on their ability to degrade nitroaromatic compounds with the total destruction of intermediate compounds by the completion of treatment. These bacteria are the basis of the SABRE process. 

According to the vendor, this commercially available technology can also enhance biological remediation. 

The process produces no air emissions. Because this is an aqueous-based technology, neither NO, nor SO is produced. The delivery system is closed so no volatilization of toxic organic compounds occurs. The electron beam can be used efficiently and effectively as pretreatment for biological remediation. The electron beam can break complex organic compounds, making them suitable for microbiological degradation. 

Biological processes offer interesting opportunities for remediation of groundwater contaminated with MTBE/TBA. Up to now, mainly lab-scale simulation of ex situ and in situ remediation technologies have been described, while reports of applications in the field are still limited, especially in Europe. A growing number of field data are expected the coming years. 

The efficient removal or permanent immobilization of metals achieved by current techniques such as physical extraction, chemical leaching, and vitrification results in both soil structure and fertility detriment. On the other hand, remediation technologies based on biological systems (bioremediation and phytoremediation) seem to be sound processes that enhance the natural response of soil to heavy metal contamination. In these cases, the slow rates of heavy metal removal in soil are strong drawbacks to scaling up the processes for technological applications. 

Existing soil treatments offering solutions for most pollutants include physical, chemical, thermal, and biological techniques. Most physical treatment processes remove pollutants from the soil-water complex for further treatment or disposal in a more concentrated form. There are, however, some pollutants that are difficult to remove using conventional remediation technologies. Some of them are not only persistent or toxic but also have low solubility and strong adsorption to soil surfaces and organic matter in low-permeability clayey soils [5]. 

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