Nickel speciation in cement-stabilized/solidified metal treatment filtercakes

JOURNAL OF HAZARDOUS MATERIALS

卷:321

Article

Roy, Amitava¹  Stegemann, Julia A.² 

[1] Louisiana State Univ, J Bennett Johnston Sr Ctr Adv Microstruct & Devic, Baton Rouge, LA 70806 USA

[2] UCL, Ctr Resource Efficiency & Environm, Dept Civil Environm & Geomat Engn, Chadwick Bldg,Gower St, London WC1E 6BT, England

关键词: Stabilization/solidification;    X-ray absorption spectroscopy;    Electroplating sludge;    Waste treatment;    Wasteform;    Leaching;   

DOI  :  10.1016/j.jhazmat.2016.09.027

来源: Elsevier

【 摘 要 】

Cement-based stabilization/solidification (S/S) is used to decrease environmental leaching of contaminants from industrial wastes. In this study, two industrial metal treatment filtercakes were characterized by X-ray diffractometry (XRD), thermogravimetric and differential thermogravimetric analysis (TG/DTG) and Fourier transform infrared (FTIR); speciation of nickel was examined by X-ray absorption (XAS) spectroscopy. Although the degree of carbonation and crystallinity of the two untreated filtercakes differed, a-nickel hydroxide was identified as the primary nickel-containing phase by XRD and nickel K edge XAS. XAS showed that the speciation of nickel in the filtercake was unaltered by treatment with any of five different S/S binder systems. Nickel leaching from the untreated filtercakes and all their stabilized/solidified products, as a function of pH in the acid neutralization capacity test, was essentially complete below pH 5, but was 3-4 orders of magnitude lower at pH 8-12. S/S does not respeciate nickel from metal treatment filtercakes and any reduction of nickel leaching by S/S is attributable to pH control and physical mechanisms only. pH-dependent leaching of Cr, Cu and Ni is similar for the wastes and s/s products, except that availability of Cr, Cu and Zn at decreased pH is reduced in matrices containing ground granulated blast furnace slag. (C) 2016 Elsevier B.V. All rights reserved.

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