Removal of sulphates from aluminium powder coating effluent using basic oxygen furnace slag and granulated blast furnace slag

Abstract: Pollution of South Africa water puts a strain on natural resources and Aluminium Powder Coating Effluent (APCE) is one of the pollution sources among industrial effluents. These effluents contain high levels of sulphates about 1230 ppm. This study only focused on the removal of sulphates. The objective of this study was to investigate the removal of sulphates from APCE using Basic Oxygen Furnace Slag (BOFS) and Granulated Blast Furnace Slag (GBFS) as an adsorbent. BOFS was used as the basis of all the experiments as it increased the pH of the effluent to be around 12. BOFS removed more than 80% of sulphates. Adsorption experiments were carried out under different operating conditions. Freundlich and Langmuir isotherms were studied and the experimental data best fitted the Langmuir model. Adsorption kinetics was also studied and the pseudo second order gave the best fit at all operating conditions. This brought about a conclusion that BOFS can be used as an absorbent for removal of sulphates