Long-term leaching prediction of constituents in coal bottom ash used as a structural fill material
- 341 Downloads
This study is aimed to assess the long-term leaching of inorganic constituents from structural fills composed of reused coal bottom ash in Korea and identify key parameters that affect the amount of the constituents leached.
Materials and methods
A model for the prediction of long-term leaching by percolation of stormwater through a structural fill is adopted and used. The long-term leaching model is applied to five field sites in Korea using site-specific parameters obtained for each site and coal bottom ash specific parameters determined using column studies for two coal bottom ash samples collected from coal-fired power plants.
Results and discussion
The long-term leaching of trace inorganic constituents, As, Cu, Sb, and Zn, is variable among the sites primarily due to the variation in the total amount of leachable constituents and application depth of a structural fill. First-order leaching rate constant is also one of the key parameters when the leaching rate is relatively small. Because of the significant variability in the leaching rate constants and application depths, the time for the leachate constituent concentration to reach half the initial value, t 50%, ranges from less than a year to more than hundreds of years for the studied sites and constituents.
The long-term leaching characteristics of the trace inorganic constituents are predicted to significantly vary by the type of reused bottom ash and the site conditions, suggesting the need to determine the model parameters in a case-specific manner.
KeywordsApplication depth Coal bottom ash Leaching rate Long-term leaching Structural fill
This study received financial support from the Geo-Advanced Innovative Action (GAIA) project of the Korea Environmental Industry and Technology Institute. We thank the Integrated Research Institute of Construction and Environmental Engineering, Seoul National University, and Water/Environment Research Team of Hyundai Engineering and Construction Co., LTD. for technical assistance.
- Aalbers TG, Rood GA, Vermij PHM, Saft RJ, Broekman MH, Masereeuw P, Kamphuis C, Dekker PM, Valentijn EA (1996) Environmental quality of primary and secundary construction materials in relation to re-use and protection of soil and surface water. Report N. 771402007, National Institute for Public Health and the Environment (RIVM), The NetherlandsGoogle Scholar
- Benson CH, Bradshaw S (2011) User guideline for coal bottom ash and boiler slag in green infrastructure construction. University of Wisconsin, Madison, USA, Recycled Materials Resource CencterGoogle Scholar
- DEC (2014) Survey Report 2014. Department Enterprise City, 283 Provincial assembly. Jeollannamdo, Republic of Korea, pp 1–9 (in Korean)Google Scholar
- Goldman SJ, Jackson K, Bursztynsky TA (1986) Erosion and sediment control handbook. Mcgraw-Hill, New YorkGoogle Scholar
- ISO (2007) Soil quality - Leaching procedures for subsequent chemical and ecotocicological testing of soil and soil materials Part 3: Up-flow percolation test. ISO/TS 21268–4. International Organization for StandardizationGoogle Scholar
- KSEPC (2013) Status of coal ash generation. Korean South East Power Corportation. http://www.kosep.co.kr/kosep/fr/bo/board/main.do?menuCd=FN02011003. Accessed 2 April 2015 (in Korean)
- Lee M (2011) 2011 Inspection of the government offices questionnaire report. Department of Enterprise Ciy, Jeonbuk, Republic of Korea. https://www.mslee.co.kr, pp 1–89 Acessed 5 May 2015 (in Korean)
- MOLIT (2012) Groundwater management plan 2012–2021. Ministry of Land, Infrastructure and Transport, Republic of Korea, pp 1–160 (in Korean)Google Scholar
- MOLIT, K-water (2014) 2014 Groundwater annual report. National Groundwater Information Center, pp 488–534 (in Korean)Google Scholar
- USEPA (2015) Hazardous and solid waste management system; disposal of coal combustion residuals from electric utilities; final rule, CFR Parts 257 and 261 [EPA-HQ-RCRA-2009-0640; FRL-9919-44-OSWER] RIN-2050-AE81. US Environmental Protection Agency, Federal Register, Washington, USAGoogle Scholar
- Van der Sloot HA, Seignette PFAB, Meeussen JCL, Hjelmar O, Kosson DS (2008) A database, speciation modelling and decision support tool for soil, sludge, sediments, wastes and construction products: LeachXS™-Orchestra. Second international symposium on energy from biomass and waste, Nov 17–20 2008, VeniceGoogle Scholar
- Verschoor AJ, Lijzen JPA, van den Broek HH, Cleven RFMJ, Comans RNJ, Dijkstra JJ, Vermij PHM (2007) Kritische emissiewaarden voor bouwstoffen. Milieuhygienische onderbouwing en consequenties voor bouwmaterialen. Report N. 711701043, National Institute for Public Health and the Environment (RIVM), The Netherlands (in Dutch)Google Scholar