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Modification of Rice Straw for Heavy Metal Ion Adsorbents by Microwave Heating
Author(s) -
Rungrodnimitchai Supitcha
Publication year - 2010
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.200900146
Subject(s) - straw , chemistry , adsorption , cellulose , sorption , rice straw , metal ions in aqueous solution , phosphorus , microwave , metal , ion exchange , nuclear chemistry , rice hulls , ion , materials science , inorganic chemistry , organic chemistry , quantum mechanics , composite material , physics
Abstract Summary: Cellulose in rice straw was chemically modified by phosphorylation using conventional heating or microwave heating. Rice straw pretreated by NaOH solution gave the highest phosphorus content when it was phosphorylated using microwave heating at 450 watt (7.07%P, ion exchange capacity 2.60 meq/g). The 3 hour‐reaction in oil bath yielded the modified rice straw with lower of phosphorus content (6.32%P) and higher ion exchange capacity (2.99 meq/g) than that of microwave heating. The feasibility of the modified rice straw as cation sorbents for removing heavy metal was investigated. Cd 2+ , Cr 3+ and Pb 2+ were used as sorbates. In sorption test of 40 ppm with 2.0 g/L of the modified rice straw, both modified rice straws could adsorb metal ions faster than the commercial ion exchange resin (dowax) at the time less than 60 min. The modified rice straw prepared by microwave heating (A‐MCW2) could remove 90% of Cd 2+ and Cr 3+ in 60 minutes and remove 99% of Pb 2+ after 30 min.