Analysis of weathering of solid waste incineration ash evaluated by indices for natural rock

May 28, 2013
Waste incineration bottom ash and weathering index applicability.

Incineration treatment of municipal solid waste generates inorganic ash. The question arises as to whether waste incineration ash is converted to natural soil after it is disposed in landfill sites? And importantly, if so, how long would take?

Although waste incineration ash is weathered physically in a landfill, it still not known how its chemical and mineralogical properties are affected.

To resolve these issues, Tokyo Tech's Fumitake Takahashi and Takayuki Shimaoka at Kyushu University investigated the geochemical conversion of waste incineration ash during early and late weathering stages, and then the impact of weathering on metal immobilization. The researchers propose that one approach to investigate the weathering of waste incineration ash is by using mineralogical weathering indices for natural rocks.

Fresh and landfilled (weathered) waste incineration ash were collected and their and metal leachability analyzed. Ten weathering indices (WPI, R, WIP, V, CIA, CIW, PIA, STI, Wm, and Ks) were compared with weathering time, leaching pH, and metal leaching concentrations. All the results were statistically analyzed according to heterogeneity of the ash samples.

Welch's t-test accepted at 0.2% of significance level that all weathering indices could distinguish fresh and landfilled MSWI bottom ash. In particular, 4 weathering indices (WPI, WIP, Wm, and Ks) had a strong correlation with weathering time and alkali element leaching concentrations.

These weathering indices are good indicators to assess weathering stages of ash and expect necessary time to reach stable phase.

Explore further: Better forecasts for sea ice under climate change

More information: Takahashi, F. and Shimaoka, T. The Weathering of Municipal Solid Waste Incineration Bottom Ash Evaluated By Some Weathering Indices For Natural Rock, Waste Management 32, 2294–2305 (2012). DOI: 10.1016/j.wasman.2012.06.009

add to favorites email to friend print save as pdf

Related Stories

Radioactive ash found in waste plants near Tokyo

Jul 12, 2011

Japanese waste incineration plants near Tokyo have found high levels of radiation in ash, and officials said Tuesday it may be from garden waste contaminated by the Fukushima nuclear disaster.

Ash from refuse could become hydrogen gas

Mar 25, 2013

Every year, millions of tons of environmentally harmful ash is produced worldwide, and is mostly dumped in landfill sites or, in some countries, used as construction material. The ash is what is left when ...

Synthetic nano-waste does not disappear

May 25, 2012

(Phys.org) -- Tiny particles of cerium oxide do not burn or change in the heat of a waste incineration plant. They remain intact on combustion residues or in the incineration system, as a new study by Swiss ...

Improving forecasts of volcanic ash concentrations

Feb 14, 2012

Volcanic ash can severely damage airplanes, and eruptions such as the 2010 Eyjafjallajokull eruption may result in major disruption to air travel. Improved forecasting of ash cloud locations and concentrations could benefit ...

Recommended for you

Better forecasts for sea ice under climate change

18 hours ago

University of Adelaide-led research will help pinpoint the impact of waves on sea ice, which is vulnerable to climate change, particularly in the Arctic where it is rapidly retreating.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.