Environmental impact of coal-carbonization and its bioremediation

The mineral rich state Jharkhand produces more than 72 thousands million tonnes of coal which accounts 17.45% of national coal production prior to its use as fuel, coal is carbonized and present coal carbonization capacity of this state is approximately 28.35 mt/year. During the process of coal carbonization, crude mineral is crushed and transported to coke oven plants. This is followed by heating of oven by oil firing. Later on coal is quenched with the help of water jet. The effluent thus generated contains several poolutants which includes benzene, toluene, xylene, phenolic compounds and vyanides. During the process of quenching coal fine and other particles. The ammonical liqure generated during coal carbonization is highly toxic and adversely affect the biota. In absence of proper pollution control measures, this toxic discharge finds its way to nearby water bodies. They also percolate and pollute the underground water resource. High cost involved in running and maintaining pollution control equipments other prove to be a bottle neck for coal companies. Bioremediation however is an eco-friendly and cost effective option. It has been established that some of the plants are hyper accumulators of various organic compounds. In addition to that some specific plants have capacity to catch hold fine particles. These are commonly known as rhizosphere technology and rhizofilteration respectively. An artificial wetland having suitable plant just near putlet of effluent can be utilized for cleaning the discharge. Experimental evidences have revealed that 78–91% reduction of pollution load is possible through this method. Design of wetland, selection of plants etc. are some significant factors. The paper deals with this technology in detail.