Sorption of Phosphate and Cr(VI) by Fe(III) and Cr(III) Hydroxides |
| |
Authors: | Y M Tzou M K Wang R H Loeppert |
| |
Institution: | (1) Department of Agricultural Chemistry, National Taiwan University, Taipei, Taiwan, 106, TW;(2) Department of Soil and Environmental Sciences, National Chung Hsing University, Taichung, Taiwan, 402, TW;(3) Department of Soil and Crop Sciences, Texas A & M University, College Station, Texas 77840, USA, US |
| |
Abstract: | Understanding the chemical behavior and interactions of Cr(VI) (e.g., HCrO4
−) and other anions, such as orthophosphate (P) with insoluble metal hydroxides (i.e., CrIII] and FeIII]) in disposal landfills or in chromite ore processing residue (CORP)–enriched soil is very important in
predicting the movement and the fate of Cr(VI). This study evaluates the sorption behavior of P and Cr(VI) by Fe(III) (i.e., ferrihydrite), Cr(III) (i.e., CrOH]3), and coprecipitated Fe(III)/Cr(III) hydroxides. These metal hydroxide sorbents were synthesized, and sorption of P and Cr(VI)
were conducted at different pH using a batch technology. Our results show that P and Cr(VI) sorption by metal hydroxides decreased
with increasing suspension pH. Greater decrease in P sorption was observed when Cr(III) was present in the structures of hydroxides.
Following the sorption of low concentration of P (i.e., 0.5 mM), the sorption of subsequently added Cr(VI) by hydroxides was less influenced. However, Cr(VI) sorption was greatly
inhibited when high concentration of P (i.e., 10 mM) prereacted with hydroxides, particularly in Fe(III) hydroxide system. Results also indicated that high concentration
of Cr(VI) (10 mM) could dissolve Cr(III) hydroxide at pH 3 and reprecipitate as an amorphous form of Cr(VI) and Cr(III) compound
at pH about 6.5. Although coprecipitation of Cr(VI) with Cr(III) can inhibit Cr(VI) movement through soil profiles, the inhibition
seems to be low due to the gradual release of Cr(VI) with increasing pH.
Received: 16 April 2002/Accepted: 29 October 2002 |
| |
Keywords: | |
本文献已被 PubMed SpringerLink 等数据库收录! |
|