Ex-Situ Chemical and Physical Treatment Methods

Paving and construction specialists rely on soil structure to make a quality foundation. Particularly, paving contractors must come up with good foundations that can bear the weight of pedestrian and motor vehicle traffic over a long period. Contaminated soils hinder them from making good foundational structures. Such soils contain lots of unwanted salts and minerals that affect the soil composition, layout and soil water balance. Thankfully, you can fix such soils before starting your paving project. Ex-situ chemical and physical treatment methods enable treating such soils by excavating and backfilling. Here is a look at some of the ex-situ chemical and physical treatment methods at your disposal.

Air Stripping Technique

Air stripping is a highly technical treatment method that allows the technicians to partition volatile contaminants from groundwater. Ultimately, the goal is to remove all the contaminants from soil water into the air, leaving the soil pure and free of pollutants. The process employs a packed tower with a sump on the lower section, fan and spray nozzle at the top. The spray nozzle distributes contaminated groundwater in a packing column as the fan forces a countercurrent flow of air over the water. The contaminant-free water gathers in the sump at the bottom of the tank, ready for backfilling into the soil. Air stripping towers are available as movable trailers, enabling contractors to use them anywhere you want to pave. 

Groundwater Pumping 

Groundwater pumping is another ex-situ treatment method you can employ. It requires pumps and conduit pipes penetrating the contaminated soil structure to reach the groundwater. The pumps use suction to create a pressure difference between the surface of the soil and the groundwater, drawing out groundwater in the process. The contaminated water may undergo thorough purification before reintroduction into the soil or be contained to keep it from migrating to other sections in the ground. Either way, the process leaves a pure and solid soil structure that you can compact before building a paving.

Groundwater Oxidation 

You can also oxidise groundwater to remove soil structure impurities and leave it with harmless compounds. Here, contractors use strong oxidising agents laced with ultraviolet irradiation to contain the harmfulness of unwanted soil minerals. The oxidation converts harmful groundwater minerals into carbon dioxide, inert salts and fresh water.

When you carry out any of the procedures above, you end up with a desirable soil structure that will lay a strong foundation for your paved surface. Prior treatment of the soil is important before compaction to have a quality, crack-free foundation. For more information, contact an ex-situ stabilisation service near you.