Short-Term Hydraulic Conductivity and Consolidation Properties of Soil-Bentonite Backfills Exposed to CCR-Impacted Groundwater
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 144, Issue 6
Abstract
The present study investigated the effectiveness of two soil-bentonite slurry wall backfills, specifically sand/conventional Na-bentonite (NaB) and sand/hexametaphosphate (SHMP)-amended Ca-bentonite (SHMP-CaB), for the containment of the coal combustion residuals (CCR) impacted groundwater. Several series of laboratory experiments were conducted to determine swell index, liquid limit, slump, hydraulic conductivity, and compressibility of the backfills using distilled water or tap water and simulated CCR impacted groundwater. The results showed that NaB exhibited a higher free swell index as compared with that of SHMP-CaB in both the CCR-impacted groundwater and the distilled water. Both NaB and SHMP-CaB possessed lower liquid limit values with the CCR-impacted groundwater. During the test duration of 96 days, the CCR-impacted groundwater caused 1.39 times increase in the short-term hydraulic conductivity of the sand/NaB backfill, while there was a 0.95–0.91 times decrease in the short-term hydraulic conductivity of the sand/SHMP-CaB backfill. The compression index and rebound index values of the tested backfills prepared with the CCR-impacted groundwater were lower than the backfills prepared with tap water. Scanning electron microscope analysis showed that SHMP promoted the Ca-bentonite to exist in more dispersed particle association with smaller particle size, resulting in the observed results for SHMP-CaB backfill. Additional research is recommended to assess long-term chemical compatibility of the backfills with CCR-impacted groundwater.
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Acknowledgments
Financial support for this project was provided by National Natural Science Foundation of China (Grant Nos. 41472258, 41330641, and 51278100) and Primary Research & Development Plan of Jiangsu Province (Grant No. BE2017715). The authors acknowledge the China Scholarship Council, which made it possible to undertake this research at the University of Illinois at Chicago. The authors thank Colloid Environmental Technologies Company (CETCO) for providing the bentonite used in this research.
References
Abend, S., and Lagaly, G. (2000). “Sol-gel transitions of sodium montmorillonite dispersions.” Appl. Clay Sci., 16(3–4), 201–227.
Andreola, F., Castellini, E., Manfredini, T., and Romagnoli, M. (2004). “The role of sodium hexametaphosphate in the dissolution process of kaolinite and kaolin.” J. Eur. Ceram. Soc., 24(7), 2113–2124.
Ashmawy, A. K., El-Hajji, D., Sotelo, N., and Muhammad, N. (2002). “Hydraulic performance of untreated and polymer-treated bentonite in inorganic landfill leachates.” Clays Clay Miner., 50(5), 546–552.
API (American Petroleum Institute). (2003). “Recommended practice standard procedure for testing water-based drilling fluids.” API Recommended Practice 13B-1, Washington, DC.
ASTM. (2007). “Standard test methods for particle-size analysis of soils.” ASTM D422, West Conshohocken, PA.
ASTM. (2010a). “Standard test methods for liquid limit, plastic limit, and plasticity index of soils.” ASTM D4318, West Conshohocken, PA.
ASTM. (2010b). “Standard test methods for measurement of hydraulic conductivity of saturated porous materials using a flexible wall permeameter.” ASTM D5084, West Conshohocken, PA.
ASTM. (2010c). “Standard test methods for specific gravity of soil solids by water pycnometer.” ASTM D854, West Conshohocken, PA.
ASTM. (2011a). “Standard test methods for classification of soils for engineering purposes (unified soil classification system).” ASTM D2487, West Conshohocken, PA.
ASTM. (2011b). “Standard test methods for hydraulic conductivity compatibility testing of soils with aqueous solutions.” ASTM D7100, West Conshohocken, PA.
ASTM. (2011c). “Standard test methods for one-dimensional consolidation properties of soils using incremental loading.” ASTM D2435, West Conshohocken, PA.
ASTM. (2011d). “Standard test methods for swell index of clay mineral component of geosynthetic clay liners.” ASTM D5890, West Conshohocken, PA.
ASTM. (2012). “Standard test methods for slump of hydraulic-cement concrete1.” ASTM C143/C143M, West Conshohocken, PA.
Blissett, R. S., and Rowson, N. A. (2012). “A review of the multi-component utilisation of coal fly ash.” Fuel, 97, 1–23.
Bohnhoff, G. L., and Shackelford, C. D. (2014a). “Consolidation behavior of polymerized bentonite-amended backfills.” J. Geotech. Geoenviron. Eng., 04013055.
Bohnhoff, G. L., and Shackelford, C. D. (2014b). “Hydraulic conductivity of polymerized bentonite-amended backfills.” J. Geotech. Geoenviron. Eng., 04013028.
Bradshaw, S. L., Benson, C. H., and Rauen, T. L. (2015). “Hydraulic conductivity of geosynthetic clay liners to recirculated municipal solid waste leachates.” J. Geotech. Geoenviron. Eng., 04015074.
D’Appolonia, D. J. (1980). “Soil-bentonite slurry trench cutoffs.” J. Geotech. Eng. Div., 106(4), 399–417.
Deng, A., and McBride, L. (2014). “Hydraulic conductivity of Hindmarsh clay amended by polymeric additive.” 7th Int. Congress on Environmental Geotechnics: ICEG2014, A. Bouazza, S. Yuen, and B. Brown, eds., Engineers Australia, Barton, Australia, 431–439.
Di Emidio, G. (2010). “Hydraulic and chemico-osmotic performance of polymer treated clays.” Ph.D. dissertation, Univ. of Ghent, Ghent, Belgium.
Di Emidio, G., Verastegui Flores, R. D., and Bezuijen, A. (2013). “Beneficial impact of polymer treatment on the swelling and long-term hydraulic efficiency of Ca-bentonites compared to the standard sodium activation method.” Proc., Geosynthetics 2013, Long Beach, CA, 588–594.
Du, Y. J., Fan, R. D., Liu, S. Y., Reddy, K. R., and Jin, F. (2015a). “Workability, compressibility and hydraulic conductivity of zeolite-amended clayey soil/calcium-bentonite backfills for slurry-trench cutoff walls.” Eng. Geol., 195, 258–268.
Du, Y. J., Fan, R. D., Reddy, K. R., Liu, S. Y., and Yang, Y. L. (2015b). “Impacts of presence of lead contamination in clayey soil-calcium bentonite cutoff wall backfills.” Appl. Clay Sci., 108, 111–122.
Du, Y. J., Yang, Y. L., Fan, R. D., and Wang, F. (2016). “Effects of phosphate dispersants on the liquid limit, sediment volume and apparent viscosity of clayey soil/calcium-bentonite slurry wall backfills.” KSCE J. Civ. Eng., 20(2), 670–678.
Evans, D. W., and Whysner, K. (2017). “Use of slurry wall systems to support CCR impoundment closure and corrective action.” 2017 World of Coal Ash (WOCA) Conf., Lexington, KY.
Evans, J. C. (1993). “Vertical cutoff walls.” Geotechnical practice for waste disposal, D. E. Daniel, ed., Chapman & Hall, London, 430–454.
Evans, J. C., Costa, M., and Cooley, B. (1995). “The state of stress in soil-bentonite slurry trench cutoff walls.” Proc., Geoenvironment 2000, Y. B. Acar and D. E. Daniel, eds., ASCE, Reston, VA, 1173–1191.
Evans, J. C., Huang, H., and Ruffing, D. G. (2016). “Evaluation of soil-bentonite backfill consolidation properties.” Proc., Int. Conf. on Deep Foundations, Seepage Control and Remediation (41st Annual), New York.
Fan, R. D., Liu, M., Du, Y. J., and Horpibulsuk, S. (2016). “Estimating the compression behaviour of metal-rich clays via a disturbed state concept (DSC) model.” Appl. Clay Sci., 132, 50–58.
Fan, R. D., Liu, S. Y., Du, Y. J., Reddy, K. R., and Yang, Y. L. (2017). “Impacts of presence of lead contamination on settling behavior and microstructure of clayey soil-calcium bentonite blends.” Appl. Clay Sci., 142, 109–119.
Filz, G. M. (1996). “Consolidation stresses in soil-bentonite backfilled trenches.” Proc., 2nd Int. Congress on Environmental Geotechnics, A.A. Balkema, Rotterdam, Netherlands, 497–502.
Gleason, M. H., Daniel, D. E., and Eykholt, G. R. (1997). “Calcium and sodium bentonite for hydraulic containment applications.” J. Geotech. Geoenviron. Eng., 438–445.
Goh, R., Leong, Y. K., and Lehane, B. (2011). “Bentonite slurries-zeta potential, yield stress, adsorbed additive and time-dependent behaviour.” Rheol. Acta, 50(1), 29–38.
Hong, C. S., Shackelford, C. D., and Malusis, M. A. (2012). “Consolidation and hydraulic conductivity of zeolite-amended soil-bentonite backfills.” J. Geotech. Geoenviron. Eng., 15–25.
Izquierdo, M., Tye, A. M., and Chenery, S. R. (2013). “Measuring reactive pools of Cd, Pb and Zn in coal fly ash from the UK using isotopic dilution assays.” Appl. Geochem., 33, 41–49.
Jo, H. Y., Katsumi, T., Benson, C. H., and Edil, T. B. (2001). “Hydraulic conductivity and swelling of non-prehydrated GCLs permeated with single species salt solutions.” J. Geotech. Geoenviron. Eng., 557–567.
Katsumi, T., Ishimori, H., Onikata, M., and Fukagawa, R. (2008). “Long-term barrier performance of modified bentonite materials against sodium and calcium permeant solutions.” Geotex. Geomembr., 26(1), 14–30.
Kenney, T. C., Veen, W. A. V., Swallow, M. A., and Sungaila, M. A. (1992). “Hydraulic conductivity of compacted bentonite-sand mixtures.” Can. Geotech. J., 29(3), 364–374.
Lagaly, G. (1989). “Principles of flow of kaolin and bentonite dispersions.” Appl. Clay Sci., 4(2), 105–123.
Lagaly, G., and Ziesmer, S. (2003). “Colloid chemistry of clay minerals: The coagulation of montmorillonite dispersions.” Adv. Colloid Interface Sci., 100, 105–128.
Lambe, T. W. (1954). “The improvement of soil properties with dispersants.” Boston Soc. Civ. Eng., 41(2), 184–207.
Lee, J. M., Shackelford, C. D., Benson, C. H., Jo, H. Y., and Edil, T. B. (2005). “Correlating index properties and hydraulic conductivity of geosynthetic clay liners.” J. Geotech. Geoenviron. Eng., 1319–1329.
Ma, M. (2012). “The dispersive effect of sodium hexametaphosphate on kaolinite in saline water.” Clays Clay Miner., 60(4), 405–410.
Malusis, M. A., Barben, E. J., and Evans, J. C. (2009). “Hydraulic conductivity and compressibility of soil-bentonite backfill amended with activated carbon.” J. Geotech. Geoenviron. Eng., 664–672.
Malusis, M. A., Evans, J. C., Mclane, M. H., and Woodward, N. R. (2008). “A miniature cone for measuring the slump of soil-bentonite cutoff wall backfill.” Geotech. Test. J., 31(5), 373–380.
Malusis, M. A., and McKeehan, M. D. (2013). “Chemical compatibility of model soil-bentonite backfill containing multiswellable bentonite.” J. Geotech. Geoenviron. Eng., 189–198.
Mazzieri, F., Di Emidio, G., and Di Sante, M. (2014). “Discussion of ‘Chemical compatibility of model soil-bentonite backfill containing multiswellable bentonite’ by Michael A. Malusis and Matthew D. McKeehan.” J. Geotech. Geoenviron. Eng., 262–263.
Mei, D. B., Fan, R. D., Du, Y. J., and Yang, Y. L. (2015). “Workability of soil-bentonite backfills for vertical slurry cutoff wall.” 2nd Geotechnical Engineering Young Scholar Forum, Yixing, China.
Naeem, A., Westerhoff, P., and Mustafa, S. (2007). “Vanadium removal by metal (hydr)oxide adsorbents.” Water Res., 41(7), 1596–1602.
NCDENR (North Carolina Department of Environment and Natural Resources). (2015). “Duke energy groundwater assessment plans for coal-fired power stations.” ⟨http://portal.ncdenr.org/web/wq/coal_ash_gw_assessment_plans⟩ (May 2, 2015).
Onikata, M., Kondo, M., Hayashi, N., and Yamanaka, S. (1999). “Complex formation of cation-exchanged montmorillonites with propylene carbonate: Osmotic swelling in aqueous electrolyte solutions.” Clays Clay Miner., 47(5), 672–677.
Ouhadi, V. R., Yong, R. N., and Sedighi, M. (2006). “Influence of heavy metal contaminants at variable pH regimes on rheological behaviour of bentonite.” Appl. Clay Sci., 32(3), 217–231.
Razakamanantsoa, A. R., Barast, G., and Djeran-maigre, I. (2012). “Hydraulic performance of activated calcium bentonite treated by polyionic charged polymer.” Appl. Clay Sci., 59–60, 103–114.
Reddy, K. R., Khodadoust, A. P., and Darko-Kagya, K. (2014). “Transport and reactivity of lactate-modified nanoscale iron particles for remediation of DNT in subsurface soils.” J. Environ. Eng., 04014042.
Rome, S. (2017). “Utilizing cut-off walls for groundwater remediation issues associated with coal ash landfills and impoundments.” 2017 World of Coal Ash (WOCA) Conf., Lexington, KY.
Ruffing, D. G., Evans, J. C., and Ryan, C. R. (2015). “Strength and stress estimation in soil bentonite slurry trench cutoff walls using cone penetration test data.” Proc., Int. Foundations Congress and Equipment Expo 2015, M. Iskander, M. T. Suleiman, J. B. Anderson, and D. F. Laefer, eds., ASCE, Reston, VA, 2567–2576.
Ruhl, L., et al. (2012). “The impact of coal combustion residue effluent on water resources: A North Carolina example.” Environ. Sci. Technol., 46(21), 12226–12233.
Ruhl, J., and Daniel, D. E. (1997). “Geosynthetic clay liners permeated with chemical solutions and leachates.” J. Geotech. Geoenviron. Eng., 369–381.
Ruhl, L., Vengosh, A., Dwyer, G. S., Hsu-Kim, H., and Deonarine, A. (2010). “Environmental impacts of the coal ash spill in Kingston, Tennessee: An 18-month survey.” Environ. Sci. Technol., 44(24), 9272–9278.
Scalia, J., IV, Benson, C. H., Bohnhoff, G. L., Edil, T., and Shackelford, C. (2014). “Long-term hydraulic conductivity of a bentonite-polymer composite permeated with aggressive inorganic solutions.” J. Geotech. Geoenviron. Eng., 04013025.
Schenning, J. A. (2004). “Hydraulic performance of polymer modified bentonite.” M.S. thesis, Univ. South Florida, Tampa, FL.
Shackelford, C. D. (1994). “Waste-soil interactions that alter hydraulic conductivity.” Hydraulic conductivity and waste contaminant transport in soil, D. E. Daniel and S. G. Trautwein, eds., ASTM, West Conshohoken, PA, 111–168.
Shackelford, C. D., Benson, C. H., Katsumi, T., Edil, T. B., and Lin, L. (2000). “Evaluating the hydraulic conductivity of GCLs permeated with non-standard liquids.” Geotext. Geomembr., 18(2-4), 133–161.
Shackelford, C. D., and Redmond, P. (1995). “Solute breakthrough curves for processed kaolin at low flow rates.” J. Geotech. Eng., 17–32.
Shackelford, C. D., and Sample-Lord, K. M. (2014). “Hydraulic conductivity and compatibility of bentonite for hydraulic containment barriers.” Principles and practices in geotechnical engineering, J. Garlanger, M. Hussein, and M. Iskander, eds., ASCE, Reston, VA.
Sharma, H. D., and Reddy, K. R. (2004). Geoenvironmental engineering: Site remediation, waste containment, and emerging waste management technologies, Wiley, Hoboken, NJ.
USEPA (U.S. Environmental Protection Agency). (2015). “Hazardous and solid waste management system; disposal of coal combustion residuals from electric utilities: Final rule.”, Washington, DC.
World Energy Council. (2013). “Survey of energy resources 2013.” ⟨www.worldenergy.gov⟩ (Jul. 20, 2016).
Yang, Y. L., Du, Y. J., Reddy, K. R., and Fan, R. D. (2016). “Effect of phosphate amendment on hydraulic conductivity of soil-calcium bentonite backfill for vertical cutoff walls.” GeoChicago 2016: Sustainability, Energy, and the Geoenvironment, ASCE, Chicago.
Yang, Y. L., Du, Y. J., Reddy, K. R., and Fan, R. D. (2017a). “Phosphate-amended sand/Ca-bentonite mixtures as slurry trench wall backfills: Assessment of workability, compressibility and hydraulic conductivity.” Appl. Clay Sci., 142, 120–127.
Yang, Y. L., Du, Y. J., Reddy, K. R., and Fan, R. D. (2017b). “Effect of phosphate dispersant amendment on workability of Ca-bentonite slurry for slurry trench cutoff-wall construction.” Indian Geotech. J., 47(4), 445–452.
Yang, Y. L., Du, Y. J., Ren, W. W., and Fan, R. D. (2015). “Experimental study on effect of phosphates on sedimentation behavior of lead-contaminated soil-bentonite slurry wall backfills.” Chin. J. Geotech. Eng., 37(10), 1856–1864 (in Chinese).
Yeo, S. S., Shackelford, C. D., and Evans, J. C. (2005). “Consolidation and hydraulic conductivity of nine model soil-bentonite backfills.” J. Geotech. Geoenviron. Eng., 1189–1198.
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Journal of Geotechnical and Geoenvironmental Engineering
Volume 144 • Issue 6 • June 2018
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©2018 American Society of Civil Engineers.
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Received: Apr 15, 2017
Accepted: Nov 9, 2017
Published online: Mar 19, 2018
Published in print: Jun 1, 2018
Discussion open until: Aug 19, 2018
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