Cement Based Solidification/Stabilization Leaching Performances of Selected Heavy Metal Ions under Different pH Extractions
Engineering and Technology Journal,
2019, Volume 37, Issue 2C, Pages 268-274
AbstractLiquid to solid partitioning as a function of pH leaching Procedure LSP EPA method 1313 was carried out to test the effectiveness , performance and efficiency of the cement-based solidification / stabilization (S/S) of heavy metals contaminated sand samples using Ordinary Portland Cement OPC type A . Two cement based mix designs ( 7 and 25 % ) have been applied to (S/S) sand contaminated samples with different heavy metal ions ( Pb , Cu , Cr , and Cd ) having the following concentrations ( 500 , 1500 and 3000 mg / kg ). Fixed water to cement ratio of 0.45 was maintained for all the experiments. Effective retention levels for the heavy metal ions was achieved using a 25 % OPC mix ratio to (S/S) the contaminated samples even when the extraction solutions were of pH levels as low as 2. Leaching experiments showed that as the pH level of the extraction solution is reduces and as the OPC content in the (S/S) samples is reduced the more heavy metal ions that can leach out. Up to 80 % of chromium, cadmium, lead, and copper ions leachability can be prevented when higher cement content is introduced to the solidification / stabilization process under the same pH extraction. Acidic extraction effects and solubilized the Calcium – Silica – Hydrate (C-S-H) gel that is created by the OPC binder, which holds, and contain the heavy metal ions and thus results in more release of those ions into the extraction solutions. The alkaline environments provided by the cement binder are believed to have participated in the precipitation of several metal ions such as cadmium and lead io, leading to their less detection in the leaching extracts. Alkaline extraction experiments (pH 8-13) showed that the mobility of the metal ions under the same experimental conditions followed the order of pb> Cr > Cu > Cd in samples of various cement contents.
 W. Salomons., W.M. Stigliani, “Bio Geodynamics of
Pollutants in Soils and Sediments: Risk Assessment of
Delayed and Non-Liner Responses,” Environmental
Science, Springer - verlag, pp. 331-343, 1995.
 T.H. Christensen, P. Kjeldsen, P.L. Bjerg., D.L. Jensen,
J.B. Christensen, A. Baun, “Biogeochemistry of Landfill
Leachate Plumes,” ApplGeochem, Vol. 16, pp. 659–718,
 L.G. Hansen, and R.L. Chaney, “Environmental and
Food Chain Effects of the Agricultural Use of Sewage
Sludges,” Rev. Environ. Toxicol, Vol. 1, pp. 103-110, 1984.
 J.R Conner, “Considerations of Selecting Chemical
Fixation and Solidification Alternatives,” The Engineering
Approach. Second Annual Conference of Applied Research
and Practice on Municipal and Industrial Waste, .Madison,
Wisconsin, 9, 1979.
 EPA, “National Waste Management Plan 2014-2020,”
6] S.K. Gupta, and M.T. Surwade, “Immobilization of
Heavy Metals from Steel Plating Industry Sludge Using
Cement as Binder at Different pH. In confer on moving
forward wastewater bio solids sustainability,” Technical,
Managerial, and Public Synergy, New Brunswick. PP. 773-
 R.N. Yong, A.M.O. Mohamed and B.P. Warkentin,
“Principles of Contaminant Transport in Soils,” Elsevier,
 W.R. Eugene, B. Rodger, D.E. Andrew, S. Lenore, C,
“Standard Methods of Water and Wastewater, 22nd
edition,” American Public Health Association, Washington,
 O.E. Omotoso, D.G. Ivery, R. Mikula, “Hexavalent
Chromium in Tricalcium silicate,” J .Mater, Sci., Vol. 33,
pp. 507-513, 1998.
 P.L. Bishop, “Leaching of Inorganic Hazardous
Constituents from Stabilized / Solidified Hazardous
Wastes,” Hazard waste Mater, Vol. 5, No. 2, pp. 129-143,
 F.K. Cartledgeet, L.G. Butler, D. Chalasani, H.C.
Eaton, F. P. Frey, E. Herrera, M.E. Tittlebaum, S.L. Yang,
“Immobilization Mechanisms in Solidification /
Stabilization of Cd and Pb Salts using Portland Cement
Fixing Agents,” Environ .Sci. Techno., Vol. 24, pp. 867-
 A. Coz, A. Andres., S. Sorino, A.
Irabin,“Environmental Behavior of Stabilized Foundry
Sludge,” J. Hazard. Mater, Vol. B109, pp. 95-104, 2004.
 M. Rachana and C. Rubina, “Evaluation of Leaching
Characteristics and Environmental Compatibility of
Solidified / Stabilized Industrial Waste,” J Mater Cycles
Waste Manag, Vol. 8, pp.78- 87, 2006.
 K.K. Athanasios, A.V. Evangelos, “Leaching
Behaviour of Metals Released From Cement - Stabilized /
Solidified Refinery Oily Sludge by Means of Sequential
Toxicity Characteristic Leaching Procedure, 2008.
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