WANG Xingrun, ZHANG Yanxia, WANG Qi, et al. Comparison of different washing agents for disposal of chromium-contaminated construction waste[J]. CIESC Journal, 2012, (10): 3255-3261.
WANG Xingrun, ZHANG Yanxia, WANG Qi, et al. Comparison of different washing agents for disposal of chromium-contaminated construction waste[J]. CIESC Journal, 2012, (10): 3255-3261.DOI: 10.3969/j.issn.0438-1157.2012.10.035.
The chromium-contaminated construction wastes of the Haibei Chemical Plant were selected as test sample.The removal efficiencies of the total Cr and Cr6+ of six different washing agents were investigated to find a suitable washing agent by using the modified BCR method.The removal mechanisms of various forms of chromium by six kinds of washing agents were studied.The total Cr and Cr6+ removal rates were very high for citric acid and concentrated hydrochloric acid
more than 90% of total Cr
more than 99% of Cr6+. Concentrated citric acid
concentrated hydrochloric acid and concentrated acetic acid reduced the pH value of the construction waste
and in acidic conditions Cr6+ was reduced to Cr3+ by organic matter.Six kinds of washing agents were very efficient for acid extractable chromium removal.Due to complexation
citric acid was very good for oxidized state chromium removal.Citric acid was the best washing agent after careful consideration of economic and environmental factors.