INFLUENCE OF pH AND PRECIPITATING AGENT ON THE REMOVAL OF HEAVY METAL CATIONS FROM INDUSTRIAL SAMPLES

The purpose of this research was to examine the influence of pH and type of precipitating agent on the removal of heavy metal cations from industrial wastewater samples by method of chemical precipitation. Three precipitating agents were used: Na2CO3, NaOH and waste sludge from the Solvay process. Samples of industrial wastewater, in which the presence of Cu (II) and Ni (II) was determined, have been taken from the electroplating process, and samples in which the presence of Zn (II) was determined, have been taken from the galvanizing process. The experimental results showed that the highest percentage of removal of these cations was at pH > 7 for each precipitant used, with NaOH proving to be the best precipitating agent, followed by Solway waste sludge and Na2CO3.