Phosphorylated wood, useful as a bio:adsorbent for heavy metal ions - prepd. by treating wood with phosphoric acid and urea and then washing with aq. sodium hydroxide

摘要

Phosphorylated wood prepd. by: (a) stirring 10g wood powder (particle size 0.05-3mm) with 25.0g phosphoric acid (80%), 33.0g water and 44.6g urea; (b) drying the slurry for ca. 1 hr. at ca. 80 deg.C.; (c) heating the obtd. reaction mixt. for ca. 70 minutes at ca. 170 deg.C; (d) washing the prod. with hot water until the washing liq. appears colourless; (e) washing the prod. with 100ml aq. sodium hydroxide soln. (0.1M, satd. with sodium chloride); and (f) washing the prod. until the filtrate appears colourless, and then drying is claimed. The phosphoric acid may be replaced by 17.5g ammonium dihydrogenphosphate or 33.1g diammonium hydrogenphosphate. Pref. steps (a)-(d) are repeated before step (e), using 14 instead of 33g water. The wood powder pref. has a particle size of 0.1-1mm, and is pref. obtd. from beechwood. USE/ADVANTAGE - Useful as a bio-adsorbent material, esp. for heavy metals (esp. cadmium or silver ions) in aq. soln. of effluent (claimed). The adsorbent utilises readily-available organic material and is efficient in removing trace amts. of heavy metal ions, amongst other materials.