Which method or combination of methods of removal listed below would be best to do a $90\%$ removeal of these Volatile Organic Compounds $($VOCs$),$ o PCE, TCE, cis$-1,2-$DCE, trans$-1,2-$DCE, and Vinyl Chloride?

$1.$ Pump and Treat:

$$ This method involves pumping contaminated groundwater to the surface, treating it to remove the contaminants, and then either reinjecting the treated water or discharging it safely.

$2.$ Air Stripping:

$$ Air stripping is effective for removing volatile organic compounds $($VOCs$)$ like TCE, PCE, cis$-1,2-$DCE, trans$-1,2-$DCE, and vinyl chloride. This method exposes contaminated water to air, allowing the volatile compounds to evaporate.

$3.$ Activated Carbon Adsorption:

$$ Activated carbon can adsorb organic contaminants from water. Passing water through activated carbon can effectively capture TCE, PCE, cis$-1,2-$DCE, trans$-1,2-$DCE, and vinyl chloride. However, proper management of spent carbon is necessary.

$4.$ Chemical Oxidation:

$$ Chemical oxidation involves injecting oxidizing agents $($e$.$g$.,$ hydrogen peroxide, permanganate$)$ into the contaminated area to chemically break down the chlorinated solvents into less harmful byproducts.

$5.$ Bioremediation:

$$ Microorganisms can be used to break down and metabolize contaminants in the soil or water. Bioremediation may be effective for certain chlorinated solvents, but its applicability depends on site$-$specific conditions.

$6.$ In Situ Chemical Reduction:

$$ Injection of reducing agents like zero$-$valent iron into the contaminated area can chemically reduce chlorinated solvents to less harmful compounds.

$7.$ Phytoremediation:

$$ Some plants have the ability to absorb and accumulate certain contaminants. Phytoremediation involves planting vegetation that can assist in the removal of chlorinated solvents from the soil.