Environmental remediation using green technologies

Business News | 22 Sep |

The term environmental remediation refers to a broad range of technological processes to ensure the elimination of contamination, pollution, and exposure to different types of radiations from the soil, rocks, sediments, and groundwater. These processes are often undertaken to reverse the effects of all the harms caused to the environment because of human actions.

Though there are many types of remediation technologies, they are broadly categorized into ex-situ and in-situ methods. In-situ methods are performed right at the spot for the treatment of contamination. On the other hand, in ex-situ methods, certain elements must be extracted and excavated and the actual treatment takes place far from the contaminated area.

Mentioned below are some green technologies that can be utilized for environmental remediation.

Thermal Desorption: This is an ex-situ remediation technique where contaminants are removed from the solid matrix of sludge, soil, or filter cake, utilizing the variation in melting points between different substances.  A collection chamber and thermal desorber are the two components of these systems. Heat is applied to excavated soil within an enclosed container.  Heat turns semi-volatile organic compounds (SVOCs) and volatile organic compounds (VOCs) into vapors, which are collected in a chamber. By further heat treatment, these organic vapors are either converted into carbon dioxide and water or destroyed. Non-evaporating substances present in the soil are subjected to more rigorous treatments.

In situ Oxidation: In this technique, certain types of harmful contaminants are converted into less toxic forms using chemical oxidants.  Many different types of oxidants including Potassium Permanganate or Persulfates, Ozone gas, or Hydrogen Peroxide may be used for in-situ oxidation. This method is particularly useful for the treatment of soil or groundwater contamination.

By pumping oxidants through a contaminated region, fairly harmless byproducts are produced via chemical reactions. If the area to be treated is large, the sludge is sometimes re-circulated.    In order to enhance the rate of oxidation, catalysts are frequently used in this remediation process. For example, the reactivity of hydrogen peroxide is significantly increased in the presence of an iron catalyst.

Surfactant Enhanced Aquifer Remediation (SEAR): In SEAR, a chemical solution is injected across a contaminated area and the waste is pumped out from the point of extraction. If the contaminated area is large, it is covered by using numerous injection and extraction points. The principal aim of this process is to eliminate the maximum amount of contaminants pumping the least amount of chemical while maintaining the diffusion and hydraulic control of chemical as well as waste.

The chemicals used in SEAR are known as surfactants, which are essentially hydrocarbon mitigation agents. The water solubility of organic contaminants can be enhanced significantly by these chemicals. Surfactants are also capable of reducing the interfacial tension between two immiscible liquids and mixing them together. If the soil contains unknown contamination sources, the effect of the surfactant is simulated using numeric modeling.

Nanoremediation: Often referred to as the future of technology, nanoparticles are used extensively these days in computing, medical sciences, and many other fields.  Groundwater treatment is another area where this emerging technology has produced promising results. In this method, a pump-and-treat or direct injection process is used to infuse small-sized particles into the contaminated spot. The surface area to volume ratio of nanoparticles is large, and this makes them highly reactive. Through redox reactions, they can cause several organic contaminants to degrade. Nanoparticles can also immobilize several toxic metals including arsenic, mercury, and lead.

If you want to find out more about different types of environmental remediation solutions and services, you can get all necessary details from Cascade or any other similar technology service provider.

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