REMEDIATION OF ACID MINE DRAINAGE IMPACTED SOIL USING WATER TREATMENT WASTE AND PHYTOREMEDIATION

Coal Mining is important to our modern way of life. It was an important industry in the last century in the USA. These mining activities caused habitat destruction by disrupting the soils. The disrupted soils contain a high amount of heavy metals and sulfide-containing minerals such as pyrite. In presence of water and oxygen, these pyrites form an acidic solution termed as Acid Mine Drainage (AMD) which contaminates the soil and water. The soils affected by AMD are unstable and prone to erosion. The current study mainly focused on evaluating low-cost, green, technologies for the treatment of AMD impacted soils. The first step of this study was to check the immobilization capacity of locally available industrial by-products from drinking water treatment residuals and to increase the pH of contaminated soils. The second step of this study was to check the metal uptake potential of some known hyperaccumulator plant species like Vetiver and Pokeweed that are known to survive in adverse conditions. The study was carried out on soils from an abandoned coal mine site in southern Illinois. These soils were mixed with different rates of water treatment wastes (WTW’s) and manure. The above mentioned hyperaccumulators were grown on the amended soil. The main goal of this study is to evaluate the dependence of plant growth and metal uptake on different rates of WTW’s and manure and metal immobilization capacity of WTW amended soil. In the experiment, both plants were able to grow in the soils amended with WTW’s. The effect of WTW’s on soil pH and ORP was clearly visible; metal immobilizing capacity of WTW’s was less prominent apparently due to the extremely low metal content of the original soil collected from the abovementioned mine site. Phytoextraction capacity was studied for Vetiver grass and Pokeweed. It was found that Pokeweed has more phytoextraction capacity than Vetiver grass and both have complex root systems which can retard soil erosion in mine reclamation areas