TREATMENT AND DISPOSAL OF SALINE WASTE-WATER FROM COAL-MINES IN POLAND

Some Polish coal mines are reviewed with respect to the disposal of sa line wastewater into rivers and its environmental impact. The drainage water from mines has a daily contribution of, in the order of magnitu de, 6,500 tons chlorides (Cl-) and 0.5 tons sulphates (SO42-) to the r ivers Wisla and Odra. The river Wisla contributes to about 55 % of the water resources in Poland. This report is based on a part of a commis sion for the Ministry of Environmental Protection, National Resources and Forestry of Poland by COWI-VBB VIAK joint venture. Different treat ment and disposal schemes are described and compared from a technical- economical point of view, out of which methods for desalination with z ero discharge as well as deep well injection are the most promising on es. The desalination methods include reverse osmosis (RO) plant, therm al powered desalination and crystallization plant as well as facilitie s for dewatering and drying of sodium chloride (NaCl) to be sold in Po land and/or on the export market, The valuable main products are potab le water, boiler feed water and sodium chloride. A special problem in this connection may be the radioactivity in the wastewater from some o f the mines. Special treatment methods for radioactivity removal in th e selected treatment and disposal scheme for the mine wastewater are d iscussed with respect to the effects of radioactivity on the saleabili ty of the recovered salt. In addition methods for recovery of the by-p roducts magnesium hydroxide, iodine and bromine are considered from th e point of view of economy and environmental protection. Finally, the desalination project in Katowice for the coal mines Debiensko and Budr yk is now in the end of the construction phase. Some modifications of the original design ace shown.