Chemical extraction of organic carbon to reduce the leaching potential risk from MSWI bottom ash

Chemical Stabilization of Bottom Ash from Municipal Solid Waste Incineration and Prediction of DOC Leaching in Landfill Sites

“…Nevertheless, more than 12 h was necessary to equally achieve 10 mg/L in fresh ash. These results are corroborated by the findings of our previous research (Guimaraes et al, 2005), which showed that HCl was the most efficient solvent for carbon extraction from MSWI bottom ash sampled at another plant and was able to reduce the DOC leaching potential by about 70%. Zhang et al (2004) also found that HCl was able to extract the majority of organic carbon in bottom ash and hardly leached components, which comprised 40-80% of the organic matter in bottom ash.…”

“…This result indicates that the acid washing of bottom ash by HCl would reduce the time to reach chemical stabilization of landfill site and satisfy with the management level of DOC (10 mg/L) in the simulated landfill by about 80%. These results indicate that HCl washing presents high potential in practical applications aiming at reducing operational costs of landfill treatment facilities and their period of operation along with the landfill site-monitoring time (Guimaraes et al, 2005).…”

“…Mitsumi (2002) and Furuta (2006) evaluated the reduction of the period of water treatment to meet the BOD and COD limit (representative standard value: 10 mg/L) during a few years by using 1m 3 of lysimeter, and reported that WOW system can reduce the period of water treatment from 35 to 20 years, including 15 years of landfilling (Furuta, 2006). We found that the organic carbon leaching from MSWI bottom ash was more remarkably reduced by acid washing than by water alone (Guimaraes et al, 2005). The acid washing could increase the percentage of reduction from 12% (by water washing) to 56%.…”

“…Bottom ash was washed with hydrochloric acid (HCl) at pH 2 (Guimaraes et al, 2005) to evaluate the capacity to decrease the organic carbon leaching and thus the time to reach stabilization in full-scale considerations. An automatic pH controller with acid addition (model TPD-51, TOKO Chemical Corporation) was used to keep the pH value at 2.…”

Organic carbon leaching behavior from incinerator bottom ash

“…To address this problem, previous studies have examined the extraction of organic carbon from bottom ash to reduce the leaching potential from landfills [13]. It was demonstrated that pH value was a prominent parameter for the extraction; acid or neutral condition was necessary to achieve higher extraction efficiency.…”