VARIATION OF ORGANIC FRACTIONS IN A LANDFILL MAINLY DISPOSED WITH MUNICIPAL SOLID WASTE INCINERATION RESIDUES

摘要

Organic matter in the municipal solid waste incineration residues (MSWIR) was fractionated into five classes: humic acid (HA), fulvic acid (FA), hydrophilic acids (HiA), bases (BaS) and hydrophilic neutrals (HiN). It was found that the distribution of these organic fractions varied with the landfill age of MSWIR. The MSWIR contained more than 50% of HiN and the percentage of HiN increased with the landfill age. The second abundant organic fractions were BaS in the MSWIR before landfilling, HiA and HSs in 3 years elapsed and 9 years elapsed MSWIR, respectively. Water-soluble organic matter (WOM) decreased with landfill age, while acid-base extractable (AOM) organic matter increased with time. The specific UV absorbance (UV/ TOC ratio) exhibited distinct and characteristic spectrum depending on the age of MSWIR. The study also indicated that pH, EC and TOC of MSWIR decreased with the landfill age. The chemical composition analysis revealed that metal contents of the MSWIR was no obvious change. The leaching ratio of metals from the MSWIR decreased with the landfill age specially for heavymetals. According the results, it could be assumed that the landfill was in the process of stabilzation and HSs immobilized heavy matals in the landfill.