Effect and Removal Mechanisms of 6 Different Washing Agents for Building Wastes Containing Chromium

Figure 5

Total Cr and Cr (VI) content variation before and after washing. Washing agent: 1—water; 2—0.05 mol/L EDTA-Na₂; 3—0.1 mol/L EDTA-Na₂; 4—0.1 mol/L citric acid; 5—0.5 mol/L citric acid; 6—0.1 mol/L oxalic acid; 7—0.5 mol/L oxalic acid; 8—0.1 mol/L HCl; 9—0.5 mol/L HCl; 10—1 mol/L HCl; 11—0.1 mol/L acetic acid; 12—0.5 mol/L acetic acid.