Effect of reducing conditions on sludge melting process.
The objective of this study was to compare the effects of CO/CO(2) reducing conditions with those of air oxidizing conditions on the pouring temperature of the sludge melting process and the heavy metal leachability of the resultant sludge slag. Synthetic sludge ash composed of SiO(2), CaO and Al(2)O(3), as well as sewage sludge ash generated from a laboratory incinerator was employed. The experimental results indicated that the pouring temperatures are significantly reduced under the reducing conditions of CO/CO(2), or 24 and 77 degrees C lower than under air conditions for synthetic and sludge ash, respectively. The heavy metal leaching tests further indicate lower heavy metal concentrations present in the leachate under the reducing conditions, notably an order of magnitude lower in Zn. However, X-ray diffractogram indicates similar peaks for these two slags produced under different conditions.
Huang
Yi-chin
YC
Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chou-Shan Rd, Taipei 10617, Taiwan, ROC.
Li
Kung-cheh
KC
D002245:Carbon Dioxide / Q000737:chemistry; D002248:Carbon Monoxide / Q000737:chemistry; D017745:Incineration; D019216:Metals, Heavy / Q000032:analysis*; D010084:Oxidation-Reduction; D012722:Sewage / Q000737:chemistry*; D013696:Temperature; D014865:Waste Disposal, Fluid; D014961:X-Ray Diffraction
D019216:Metals, Heavy; D012722:Sewage; D002245:Carbon Dioxide; D002248:Carbon Monoxide