Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5749165 | Environmental Pollution | 2017 | 7 Pages |
â¢nZVI/Ni was used to remediate Cr(â ¥) in the soil leachate and has good reduction rate.â¢The reduction rate of Cr(â ¥) exceeded 99% at pH 5 and temperature 313 K.â¢SO42-, HCO3â and CO32- could inhibit the reaction rate between nZVI/Ni and Cr(â ¥).â¢The reduction process followed Langumir-Hinshelwood first order kinetic model.
Nano zero valent iron/Ni bimetal materials (nZVI/Ni) were prepared by borohydride reduction method to remediate toxic Cr(â ¥) contaminated in soil leachate. nZVI/Ni was characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS). Different factors including pH value of soil leachate, reaction time, temperature, humic acid and coexisting anions (SO42-, NO3â, HCO3â, CO32-) were studied to analyze the reduction rate. Results showed that the reduction rate of Cr(â ¥) could reach 99.84% under the condition of pH of 5 and temperature of 303Â K. pH values and temperature of soil leachate had a significant effect on the reduction efficiency, while humic acid had inhibition effect for the reduction reaction. SO42-, HCO3â and CO32- had inhibition effect for reduction rate, while NO3â barely influenced the reduction process of nZVI/Ni. Moreover, Langumir-Hinshelwood first order kinetic model was studied and could describe the reduction process well. The thermodynamic studies indicated that the reaction process was endothermic and spontaneous. Activation energy was 143.80Â kJÂ molâ1, showing that the reaction occurred easily. Therefore, the study provides an idea for nZVI/Ni further research and practical application of nZVI/Ni in soil remediation.
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