Abstract: The drainage water from mines in Poland has a daily contribution of, in the order of magnitude, 6,500 tons of chlorides and 0.5 ton of sulphates to the rivers Vistula (Wisla) and Oder (Odra). The largest amounts of these salts, about 78%, derive from 18 mines located mainly in the Katowice mine district. The high salt content in the water from the Vistula prevents at present its use in agriculture and causes tremendous economic losses due to corrosion attacks on pipes, machines, etc., within the industry. At present only about 4% of the river water can be classified as drinking water. To combat this problem a desalination project in Katowice has now almost been completed, including advanced treatment of wastewater for zero discharge from the two adjacent coal mines, Debiensko and Budryk. It implies elimination of 310 tons/d of salt discharge to the Odra River. The complete treatment processes are divided into three main sections: (1) pretreatment before reverse osmosis (RO) of about 12,400 m3/d drainage water from the two mines with a salinity of around 16,000 mg/l TDS on the average; (2) RO plant including post-treatment of the RO permeate; (3) a thermal plant for concentration of brine (about 4,600 m3/d) and separation of sodium chloride (NaCl) by crystallization, centrifuging and drying. The RO pretreatment includes algicide dosing in a storage tank, disinfection, flocculation/sedimentation and dual media filtration as well as granular activated carbon filtration. After a two-stage microfilter system (50 μ and 5 μ, respectively), the pretreated water is desalinated at 6-7 MPa in a RO system with spiral wound RO membranes. The RO permeate is decarbonated in a part-flow followed by addition of chemicals for disinfection and increase of the temporary hardness before distribution in the drinking water net. The flow into the thermal plant consists of the RO reject (about 2,700 m3/d) with a salinity of around 80 g/l TDS and the brine flow (about 1,870 m3/d) from the Budryk mine with about the same salinity. The first section of the thermal plant is composed of two brine concentrators, designed by Resources Conservation Company (RCC), USA. By using the seed crystal recycling technique it is possible to concentrate the feed to near the precipitation point for NaCl. The second section of the thermal plant includes one crystallizer for production of NaCl, two pusher centrifuges for salt removal from supersaturated brine and one fluidized bed dryer. The crystallizer is a forced circulation submerged-tube evaporator equipped with a mechanical vapor compressor. An additional section is also planned to be constructed for treatment of the purge from the crystallizer in order to recover other valuable chemical products and distillate. The process is fully automatic and controlled by programmable logic controllers. The plant has finally been designed by Energotechnika, Poland, after preparation of technical and economical planning of the project in coordination with Nordcap Ltd., RCC and VBB Viak-SWECO, Stockholm. In the summer 1994 the thermal plant was started up, and the RO plant is expected to be in operation during the spring 1995. The paper covers the project design with illustrations of the main parts of the plant and summarizes the results of the initial operation.

Abstract: Constructed wetland treatment system effectiveness has been limited by the alkalinity-producing, or acidity-neutralizing, capabilities of systems. Anoxic limestone drains (ALD's) have allowed for the treatment of approximately 300 mg/L net acidic mine drainage, but current design guidance precludes using successive ALD's to generate alkalinity in excess of 300 mg/L because of concerns with dissolved oxygen. “Compost” wetlands designed to promote bacterially mediated sulfate reduction are suggested as a means of generating alkalinity required in excess of that produced by ALD's. Compost wetlands create two basic needs of sulfate reducing bacteria; anoxic conditions resulting from the inherent oxygen demand of the organic substrate, and quasi-circumneutral pH values resulting from the dissolution of the carbonate fraction of the compost. However, sulfate reduction treatment area needs are generally in excess of area availability and/or cost effectiveness. Second generation alkalinity-producing systems demonstrate that a combination of existing treatment mechanisms has the potential to overcome current design concerns and effectively treat acidic waters ad infinitum. Successive alkalinity-producing systems (SAPS) combine ALD technology with sulfate reduction mechanisms. SAPS promote vertical flow through rich organic wetland substrates into limestone beds beneath the organic compost, discharging the pore waters. SAPS allow for conservative wetland treatment sizing calculations to be made as a rate function based on pH and alkalinity values and associated contaminant loadings. SAPS potentially decrease treatment area requirements and have the further potential to generate alkalinity in excess of acidity regardless od acidity concentrations.