REMOVAL OF ANTIMONY FROM WATER BY COAGULATION

Abstract

Increased pollution of water resources leads to a deterioration of surface water and groundwater quality, and it initiates the application of various methods for water treatment. The enactment of the Slovak Technical Standard 75 7111 for Drinking Water in 1998 resulted in a reduction in heavy metal concentrations and, for the first time, defined the limit concentrations for some heavy metals (As, Sb), respectively. Based on this fact some water resources in Slovakia became unsuitable for further use and require appropriate treatment. The aim of this work was to investigate the effectiveness of coagulation to remove antimony from the surface water of Bukovec water tank and groundwater source of Dúbrava, determine the optimum dose of coagulant and optimize the coagulation process. Ferric sulphate was used (Prefloc) as coagulation reagent. The results showed that the dose of 11 mg.l^-1 of Fe³⁺ into the surface water of Bukovec is sufficient to reduce the antimony below the limit value of 5 mg.l^-1. To the groundwater from the site Dúbrava be added more than 30 mg.l^-1 of Fe³⁺ to reach the limit for drinking water.