Abstract: Some Polish coal mines are reviewed with respect to the disposal of saline wastewater into rivers and its environmental impact. The drainage water from mines has a daily contribution of, in the order of magnitude, 6,500 tons chlorides (Cl-) and 0.5 tons sulphates (SO42-) to the rivers 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 commission for the Ministry of Environmental Protection, National Resources and Forestry ofPoland by COWI-VBB VIAK joint venture.Different treatment and disposal schemes are described and compared from a technical-economical point of view, out of which methods for desalination with zero discharge as well as deep well injection are the most promising ones.The desalination methods include reverse osmosis (RO) plant, thermal powered desalination and crystallization plant as well as facilities for dewatering and drying of sodium chloride (NaCl) to be sold in Poland and/or on the export market, The valuable main products are potable water, boiler feed water and sodium chloride. A special problem in this connection may be the radioactivity in the wastewater from some of the mines. Special treatment methods for radioactivity removal in the selected treatment and disposal scheme for the mine wastewater are discussed with respect to the effects of radioactivity on the saleability of the recovered salt. In addition methods for recovery of the by-products magnesium hydroxide, iodine and bromine are considered from the point of view of economy and environmental protection.Finally, the desalination project in Katowice for the coal mines Debiensko and Budryk is now in the end of the construction phase. Some modifications of the original design ace shown.

Abstract: ERWAT's Ancor Wastewater Treatment Works on the Far East Rand commissioned a 10 Ml/day full-scale plant to treat toxic mine-water from the Grootvlei gold mine using primary sewage sludge. The R15-million plant is treating sulphate rich acid mine drainage using the Rhodes BioSURE Process. First, the pumped mine-water is treated at a high-density separation (HDS) plant to remove iron and condition pH levels. Then it is pumped two km via a newly-constructed 10 Ml capacity pipeline to the Ancor works. This mine-water is then mixed together with primary sewage sludge in a mixing tank from where a splitter box directs the material to eight biological sulphate reducing reactors or bioreactors. The overflow water which is rich in sulphide is pumped through the main pump station to another mixing box. Here, iron slurry is mixed with the material before it is again divided between four reactor clarifiers for sulphide removal. The overflow water, now containing reduced sulphate levels and virtually no sulphide is pumped to Ancor's biofilters for removal of remaining Chemical Oxygen Demand (COD) and ammonia following the conventional sewage treatment process for eventual release into the Blesbokspruit.