Removal of sulphate from landfill leachate by crystallization
Removal of sulphate from landfill leachate by crystallization / Ahmet Aygun, Selim Dogan, Mehmet Emin Argun, Havva Ates
p. 24-30 ; 26 cm
수록자료: Environmental engineering research. Korean Society of Environmental Engineers. Vol.24 no.1(2019 Mar.), p. 24-30 24:1<24 ISSN 1226-1025↔ 저자: Ahmet Aygun, Department of Environmental Engineering, Faculty of Engineering and Natural Sciences, Bursa Technical University 저자: Selim Dogan, Department of Environmental Engineering, Engineering Faculty, Selcuk University 저자: Mehmet Emin Argun, Department of Environmental Engineering, Engineering Faculty, Selcuk University 저자: Havva Ates, Department of Environmental Engineering, Engineering Faculty, Selcuk University
The present study explores the applicability of response surface methodology (RSM) in conjunction with central composite design (CCD) matrix to statistically optimize ettringite crystallization process for the removal of sulphate from landfill leachate. A three factor-five coded level CCD with 20 runs, was performed to estimate the best fitted model. The RSM results indicated that the fitted quadratic regression model could be appropriate to predict sulfate removal efficiency. The pH was identified as the most dominant parameter affecting sulphate removal. 61.6% of maximum sulphate removal efficiency was obtained at pH of 11.06 for a 1.87 of Ca/SO₄ and 0.51 of Al/SO₄ molar ratios. The operating cost for ettringite crystallization at optimized conditions was calculated to be 0.52 $/m³. The significance of independent variables and their interactions were tested by analysis of variance. Scanning electron microscope (SEM) and SEM coupled with energy dispersive X-Ray spectroscopy results confirmed the formation of ettringite crystal and were used to describe its morphology features.