Indian Journal of Chemical Technology, Vol.9, No.1, 54-59, 2002
Physico-chemical treatment of coke plant effluents for control of water pollution in India
Coal carbonizing industries in India are important and are growing every year. Naturally found coal is converted to coke which is suitable for metallurgical industries. Large quantities of liquid effluents produced in this industry contain a large amount of suspended solids, high biochemical oxygen demand (BOD), chemical oxygen demand (COD), phenols, ammonia and other toxic substances, which are causing serious surface water pollution in the area. There is a large number of coke plants in the vicinity of Jharia Coal Field (JCF). Working principle of coke plant and the effluents produced has been described in this paper. One large coke plant was chosen to evaluate characteristics of the effluent and to suggest a proper treatment method. Present effluent treatment system was not found to be adequate and a large quantity of a very good quality coke breeze is being lost, which is also causing siltation on the riverbed in addition to surface water pollution. Physico-chemical treatment has been considered as a suitable option for the treatment of coke plant effluents. A scheme has been proposed for the treatment, which can be suitably adopted for the recycling, reuse or safe disposal of the treated effluent. Various unit process and unit operations have been discussed. The process may be useful on industrial scale for various sites so as to maintain a clean environment.