1. Ca(2+) and OH(-) release of ceramsites containing anorthite and gehlenite prepared from waste lime mud.
- Author
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Qin J, Yang C, Cui C, Huang J, Hussain A, and Ma H
- Subjects
- Aluminum Silicates, Calcium chemistry, Calcium Compounds, Kinetics, Models, Chemical, Oxides, Waste Products, Water Pollutants, Chemical, Calcium analysis, Hydroxyl Radical chemistry, Incineration, Industrial Waste analysis, Paper
- Abstract
Lime mud is a kind of solid waste in the papermaking industry, which has been a source of serious environmental pollution. Ceramsites containing anorthite and gehlenite were prepared from lime mud and fly ash through the solid state reaction method at 1050°C. The objective of this study was to explore the efficiency of Ca(2+) and OH(-) release and assess the phosphorus and copper ion removal performance of the ceramsites via batch experiments, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that Ca(2+) and OH(-) were released from the ceramsites due to the dissolution of anorthite, gehlenite and available lime. It is also concluded that gehlenite had stronger capacity for Ca(2+) and OH(-) release compared with anorthite. The Ca(2+) release could be fit well by the Avrami kinetic model. Increases of porosity, dosage and temperature were associated with increases in the concentrations of Ca(2+) and OH(-) released. Under different conditions, the ceramsites could maintain aqueous solutions in alkaline conditions (pH=9.3-10.9) and the release of Ca(2+) was not affected. The removal rates of phosphorus and copper ions were as high as 96.88% and 96.81%, respectively. The final pH values of both phosphorus and copper ions solutions changed slightly. The reuse of lime mud in the form of ceramsites is an effective strategy., (Copyright © 2016. Published by Elsevier B.V.)
- Published
- 2016
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