Biostabilization assessment of MSW co-disposed with MSW incinerator bottom ash and fly ash in landfill bioreactor

• Main Authors: Yuan-Lung Liao, 廖元隆
• Other Authors: Huang-Mu Lo
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/4dkk86

碩士 === 朝陽科技大學 === 環境工程與管理系碩士班 === 94 === Due to the economical development, municipal solid waste (MSW) has increased to a greater amount as the increase of higher consumption and living standard in Taiwan. MSW treatment has evolved to incineration from landfill due to the difficulty of finding appropriate landfill site in Taiwan. However, residues such as bottom ash and fly ash will still remain 15 % of its original MSW volume. Therefore, residues have become another important issue and need to treat them to prevent secondary pollution in Taiwan. Bottom ash has been utilized as backfill, soil amendment, aggregate and landfill cover. Among them, landfill cover has played a major part for the utilization. However, the baseline data of landfill cover practice is still not fully understood. Thus, using bottom ash as landfill cover needs a deep theoretical and experimental investigation for the understanding of landfill mechanisms. For convenience, fly ash was tested and compared as well. For a short term simulation, six landfill bioreactors with 1 m high and 20 cm wide with working volume of 32 L were used to conduct the experiment. Among them, two was used as control bioreactors containing only the mixture of MSW and seeded sludge. The remained four ones were employed as tested bioreactors the same packing as control ones but with the designated bottom ash and fly ash added ratios of 100 and 200 g l-1 and 10 and 20 g l-1 respectively. These six bioreactors were maintained in a homeostatic oven of 35℃ suitable for the anaerobic digestion. For performance assessment of bioreactors, leachates with 100 mL were sampled for pH, conductivity, salinity, Cl-1, SO4-2 (IC) and metals analyses (ICP-OES). Another 100 mL leachates were recirculated. From the results, it showed that pHs were maintained between 6.5 and 7.5 throught the bioreactor operation with the exception of the first two weeks. 100 g l-1 bottom ash added and 10 and 20 g l-1 fly ash added bioreactors were found to enhance the gas production rate with the highest gas accumulation by 20 g l-1 fly ash added bioreactor. Released alkali metals, heavy metals and trace metals such as Ca, Mg, Ni, Co, Mo etc have been found to have potential beneficial rather than detrimental effects on MSW digestion. Thus, it indicated that proper MSW incinerator bottom and fly ash addition on MSW could increase the MSW decomposition and gas production rate and therefore increased the landfill MSW biostabilization.