연구홍보포털

논문 초록 (Abstract)

In South Korea, ocean dumping of organic sludges has been prohibited by the London Convention and by Korean regulations. Therefore, the Government of South Korea has sought an alternative process for the disposal of organic sludges. Recently, the combined fry-drying and melting system has been recognized as an efficient way to util ize the energy content of organicindustrial sludge. Three kinds of fr y-dried industrial sludges (obtained from industrial sites DG, DJ and GM), which hadaverage heating value of 20,470 kJ/kg and less than 5% water content, were tested. Unlike sewage sludge, industrial sludge contains high concentrations of heavy metals and thus cannot be direct ly utilized as refuse-derived fuel. The dried sludges were melte d in a furnace and then rapidly cooled to form vitrified slags; the vitrification of SiO2 securely encapsulates hazardous heavy metals within the crystalline structure of the slag. To evaluate t he hazard of vitrified slag, theheavy metal elution concentration was a nalyzed. Following vitrification, Hg, Cd, Cr+6, HCN and Pb concentra tions were notdetectable, whereas Cu concentration decreased from 26. 78 mg/L to 0.42 mg/L in DJ sludge, from 27.10 mg/L to 0.13 mg/L in DG and from 49.47 mg/L to 0.047 mg/L in GM sludge. (C) 2016 Elsevier B .V. All rights reserved.