Formation of Humic Substances in Weathered MSWI Bottom Ash

Haixia Zhang,Takayuki Shimaoka

doi:10.1155/2013/384806

Abstract

The study aimed at evaluating the humic substances (HSs) content from municipal solid waste incinerator (MSWI) bottom ash and its variation with time and the effect of temperature on HSs formation. The process suggested by IHSS was applied to extract HSs from two different bottom ash samples, and the extracted efficiency with NaOH and Na4P2O7 was compared. MSWI bottom ash samples were incubated at 37°C and 50°C for 1 year. HSs and nonhumic substances were extracted from the bottom ash sample with different incubated period by 0.1 M NaOH/Na4P2O7. Results show that the rate of humic acid formation increased originally with incubation time, reached a maximum at 12th week under 37°C and at 18th week under 50°C, and then decreased with time. More humic acid in MSWI bottom ash was formed under 50°C incubated condition compared with that incubated under 37°C. Also, the elemental compositions of HSs extracted from bottom ash are reported.

Highlights

Incineration process displays an important role in the municipal solid waste (MSW) management in Japan
Several researches showed that dissolved organic matter (DOM) in municipal solid waste incinerator (MSWI) bottom ash leachate contributes to Cu leaching [7, 8]
The study determines the humic substances (HSs) extraction reagent from MSWI bottom ash by comparison of NaOH and Na4P2O7

Summary

Introduction

Incineration process displays an important role in the municipal solid waste (MSW) management in Japan. Incineration is a multipurpose strategy aiming at fighting pollution of environment, energy saving, maximizing benefits of waste, mineralizing and stabilizing waste, and reducing the volume of waste. In practice, organic matters in MSW are not completely oxidized by incineration. European countries restrict the organic matter content in the landfill waste to 5% in the aim to reduce the pollution from landfill waste [6]. Several researches showed that dissolved organic matter (DOM) in MSWI bottom ash leachate contributes to Cu leaching [7, 8]. The DOM of MSWI bottom ash would lead to carbonization and to pH value decrease in landfill site [2]

Methods

Results

Conclusion