Home Processes Water purification Search Dutch Nyrstar Budel is part of the Nyrstar Group, an integrated mining and metals company with a leading position in the zinc and lead market. Nyrstar has mines and smelters around the world, and employs more than 6,500 people. Nyrstar is listed on NYSE Euronext Brussels and is headquartered in Switzerland. About us Products Processes Durability Working at Nyrstar Contact News Info for contractors BDS and SRB water treatment Nyrstar Budel has 2 biological water treatment plants. The BDS water purification treats a waste water flow that is released when washing the SO2 gas in the Roosting and Sulfuric Acid Plant. The waste water flow contains fluoride and sulphate, among other things. After neutralizing the acidic wastewater stream, fluoride is removed as calcium fluoride. Subsequently, the sulphate is converted by bacteria into sulphide in a reactor. The bacteria use hydrogen gas for this, which is made in a hydrogen reformer from steam and natural gas. In the conversion of sulfate to sulfides, metals that are present will precipitate as metal sulfides. These are separated and used in the zinc production process. The treated wastewater stream from the BDS then goes to the SRB water treatment plant. Contaminated groundwater is purified in the SRB water treatment plant. The groundwater that is polluted by the leaching of zinc ash is pumped up by means of 12 pump wells. Contaminants in the groundwater include sulphate, zinc and cadmium. In the SRB, just like in the BDS, the sulphate is converted by bacteria into sulphides which subsequently precipitate with the metals present. These metal sulphides are separated from the BDS together with the metal sulphides, dewatered and used in the zinc production process. Unlike the BDS water treatment, the sulphate load is lower and therefore instead of hydrogen gas in the SRB, ethanol is used by the bacteria to convert sulphate to sulphide. Since not all sulphides precipitate with metals, the remaining sulphides are bacteriologically converted to sulfur under oxygen-rich condition. Download the technical diagram of the BDS and SRB water purification . Zinc for Life Nyrstar.com IZA © Copyright 2009-2015 Nyrstar Disclaimer Terms and Conditions Directions Sitemap