Article: Effect of MGO additive on preventing leakage of Cr(VI) Journal: International Journal of Environment and Waste Management (IJEWM) 2015 Vol.15 No.1 pp.1 - 14 Abstract: The effect of a new additive, oxide magnesium (MgO), on preventing or reducing the leakage of Cr(VI) from a fly ash (coal ash) has been investigated by batch contact and column percolation tests. The test results indirectly indicate that the MgO additive has an obvious effect on reducing Cr(VI) to Cr(III), which is less environmentally hazardous. However, the process of reducing Cr(VI) to Cr(III) may be reversible because adding H2SO4 or CaH2O2 into the balanced solid-liquid mixture for partially simulating possible environmental change increased Cr(VI) concentration in the liquid phase. Adding 10% to 30% of Ariake clay into the fly ash not only further reduced Cr(VI) concentration, but also reduced total Cr concentration. Hence, Cr(III) ions may be absorbed by the clay minerals. For the conditions investigated, the column percolation test resulted in higher initial Cr(VI) concentration in the liquid phase than that of the batch contact test. Further, the results of the column percolation test using the samples with different curing time (up to three weeks) indicate that with MgO additive, curing the sample does not have an obvious effect on Cr(VI) concentration. Inderscience Publishers - linking academia, business and industry through research

Title: Effect of MGO additive on preventing leakage of Cr(VI)

Authors: Jin-Chun Chai; Takanori Hino; Satoshi Shimoda; Shuilong Shen

Addresses: Department of Civil Engineering and Architecture, Saga University, 1 Hojyo-Machi, Saga 840-8502, Japan ' Institute of Lowland and Marine Research, Saga University, 1 Hojyo Machi, Saga 840-8502, Japan ' Geo-disaster Prevention Group, Nagoya Branch, Nippon Koei Co. Ltd., 2-17-14, Higashisakura, Higashi-ku Nagoya-shi, Aichi, 461-0005, Japan ' State Key Laboratory of Ocean Engineering, School of Naval Architecture, Ocean, and Civil Engineering, Shanghai Jiao Tong University, 800 Dong Chuan Road, Minhang, Shanghai 200240, China

Abstract: The effect of a new additive, oxide magnesium (MgO), on preventing or reducing the leakage of Cr(VI) from a fly ash (coal ash) has been investigated by batch contact and column percolation tests. The test results indirectly indicate that the MgO additive has an obvious effect on reducing Cr(VI) to Cr(III), which is less environmentally hazardous. However, the process of reducing Cr(VI) to Cr(III) may be reversible because adding H₂SO₄ or CaH₂O₂ into the balanced solid-liquid mixture for partially simulating possible environmental change increased Cr(VI) concentration in the liquid phase. Adding 10% to 30% of Ariake clay into the fly ash not only further reduced Cr(VI) concentration, but also reduced total Cr concentration. Hence, Cr(III) ions may be absorbed by the clay minerals. For the conditions investigated, the column percolation test resulted in higher initial Cr(VI) concentration in the liquid phase than that of the batch contact test. Further, the results of the column percolation test using the samples with different curing time (up to three weeks) indicate that with MgO additive, curing the sample does not have an obvious effect on Cr(VI) concentration.

Keywords: fly ash; hexagon chromium leakage; oxide magnesium; MgO additive; batch contact test; column percolation test; clay minerals; Cr(VI) concentration.

DOI: 10.1504/IJEWM.2015.066942

International Journal of Environment and Waste Management, 2015 Vol.15 No.1, pp.1 - 14

Received: 30 Jul 2013
Accepted: 18 Feb 2014
Published online: 09 May 2015 *

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Title: Effect of MGO additive on preventing leakage of Cr(VI)

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