CONTAMINATED WATER TREATMENT PLANT VAJSKOVÁ
In connection with accidental pollution of the rock environment, groundwater and surface water in the area of the former antimony smelter in Vajsková (cadastral area Podbrezová), a series of reconnaissance and remediation work was carried out for our company Rudné bane, SOE. As part of the remediation work, a heap of metallurgical waste was reclaimed and a contaminated water treatment plant (CWTP) was built, which cleans the seepage water of the covered landfill of hazardous waste (heap of metallurgical waste) pumped from the drain.
The dominant contaminant of the seepage water is arsenic (As), the accompanying contaminant is antimony (Sb).
Contaminated seepage water is cleaned by precipitation. Ferric chloride and sodium hydroxide are used as coagulants. After addition of coagulants and flocculant, the resulting sludge is separated in a lamella sedimentation tank. The pre-treated water is filtered on sand filters and then discharged into the recipient – the Vajskovský stream. The sludge is dewatered in the filter press and disposed of as hazardous waste at the hazardous waste landfill.
The contaminated water treatment plant has been in operation since January 2006. The CWTP operation for Rudné bane, SOE, Banská Bystrica is provided by ENVIGEO. About 17 ths. m3 of contaminated water are cleaned annualy and up to 3000-4500 kg of arsenic and 50-100 kg of antimony separated from the polluted seepage water in the form of dewatered sludge as hazardous waste are taken for disposal.