Cement kiln dust as an alternative technique for wastewater treatment

Abstract

This study was conducted to examine cement kiln dust (CKD) efficiency for wastewater treatment. We analyzed the physicochemical characteristics of wastewater before and after treatment and then we determined its removal potential. The optimum factors of the treatment process were determined using a jar test technique. It was pH (8.1), dosage (1.9 g) and grain size (0.1 mm) with contact time of 30 min at 150 rpm. CKD pollutant removal efficiency reached 85.3, 81.6, 97.1, 86.8, 36, 74, 61.2, and 94.6% for BOD, COD, TP, TN, TDS, salinity, conductivity and turbidity, respectively, with an increase in the concentration of DO of 84%. On the other hand, removal percent of heavy metals achieved were 88.4, 90.9, 88.5, 97.2, 94.2, 70, and 79.9% for Pb, Cd, Zn, Fe, Co, Ni, and Cu, respectively. These results were compared with alum removal potential of wastewater treatment for confirmation. Alum pollutant removal efficiency reached 86.6, 79.6, 96.6, 59.9, 39.7, 65, 59 and 95.2% for BOD, COD, TP, TN, TDS, salinity, conductivity and turbidity, respectively, with an increase in the concentration of DO of 85.3%. On the other hand, removal percent of heavy metals achieved were 82.1, 90.6, 89.1, 96.8, 93.2, 72.8, and 84.1% for Pb, Cd, Zn, Fe, Co, Ni, and Cu, respectively. The methodology carried out in this study indicated that CKD can be used as a good environmental alternative coagulant for low to moderate wasted water as it achieved removal percent similar to that achieved by the common coagulant alum.