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Objective To establish a new method for the determination of chromium (Ⅵ) in printing and dyeing wastewater. Methods A combined technique was employed for the determination of chromium (Ⅵ) by flow injection on-line separation and preconcentration on a micro column packed with alumina(acidic form) and inductively coupled plasma-atomic emission spectrometry (ICP-AES).The effect of acidity,concentration of eluent and coexistence ion on separation and enrichment was detected.Results The detection limit was 0.72 ?g/L.The LOQ was 2.38 ?g/L.RSDs were 1.45%～2.12%.The recovery rates were 96.0%-104.0%.The concentration enhancement of chromium (Ⅵ) was 10 times for 45 s sample loading.Analytic frequency was 33 samples one hour. Conclusion This method is sensitive,rapid and applicable to the determination of chromium (Ⅵ) in dyeing wastewater.
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Objective To observe the removal of Cr(Ⅵ) and effects of some factors in solution on Cr(Ⅵ) with zero valent iron(ZVI).Methods A certain amount ZVI were added in a 50 ml solution with Cr(Ⅵ),the effects on removal ratio were observed when the initial Cr(Ⅵ) concentration was 5,10,20 and 30 mg / L,temperatures was 5,15,25 and 35 ℃,the ZVI dosage was 0.25,0.5,0.75,1.0,1.25 and 1.50 g and anions such as Cl-,NO3-,SO42-,CO32-and PO43-.The removal ratio of Cr(Ⅵ) was evaluated by Cr(Ⅵ) concentration difference pre and post-treatment with ZVI.Results Cr(Ⅵ) could be removed effectively with ZVI and removal ratio of Cr(Ⅵ) could reach over 90% in 5 min,the Cr(Ⅵ) concentration of the solution could meet the requirement of GB5749-2006 Sanitary Standard for Drinking Water Quality [ Cr(Ⅵ) concentration≤0.05 mg/L].The best reaction conditions was 35 ℃,pH=2,dosage of ZVI =1.0 g.Conclusion Cr(Ⅵ) can be removed by ZVI in solution,the removal ratio can be impacted by some factors such as pH value,Cr(Ⅵ) initial concentration,temperature.
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Objective To establish a simple and rapid method for determination of trace chromium(Ⅵ) in drinking water. Methods In the weak acid solution containing n-butyl alchhol,trace chromium (Ⅵ) in the water connected with diphenylcarbazide and sodium dodecyl sulfate into purplish red ternary iron compound,which could be extracted by chloroform and quantified at wavelength of 550 nm. Results The detection limit was 0.001 mg/L,the RSDs were 1.1%-1.4% and the recovery rate was 96%-113%. Conclusion The method was rapid,simple and the sensitivity and accuracy will meet the requirement of standard test methods for drinking water.
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Objectiv To explore the effects of chromium (Ⅵ) on the levels of malondialdehyde (MDA), the final product of lipid peroxidation in peripheral blood of mice and the micronucleus rate of polychromatic erythrocytes (PCE) in peripheral blood. Method 60 Kunming mice were divided randomly into 6 groups averagely. 4 groups were selected as exposure groups which were exposed to 10.27, 13.83, 20.74, 41.48 mg/kg calcium chromate by oral perfusion, one time per day, for 6 days. The negative and positive control group was exposed to distilled water and cyclophos phamide (40 mg/kg) respectively. After exposure, the levels of MDA and micronucleus rates of PCE were determined. Results Significant increases of the levels of MDA and the micronucleus rates of PCE in peripheral blood of mice were observed, which were associated with the increases of the exposure doses of chromium (Ⅵ). Significant positive correlation was observed between the micronucleus rates of PCEs (x) and MDA(nmol/ml) levels (y) in peripheral blood (y=3.705+930x,r=0.958, P