for one hour; then the copper and zinc ions
in the form of chloride salts were added to the bottles to make
an initial concentration of (10–100) mg/l, and the bottles were
agitated for further one hour until equilibrium was attained; at
the end of mixing the adsorbent particles were separated from
the suspensions by filtration through 0.43 lm filter paper. The
residual concentration of heavy metals was determined by the
spectrophotometer Model CE3021 made by CECIL Instruments,
USA. In addition to adsorption tests, a set of blank
tests was conducted to evaluate the removal by metal hydroxide
precipitation at various pH values