Iranian Association of Environmental Health (IAEH)
Abstract
In this study impregnated almond shell activated carbon by Zn° and
ZnSO4 were used as adsorbent with a particle size of 10-20 mesh. The
objective of this research was to determine the ability of impregnated
activated carbon in nitrate removal. The modified activated carbon had
1mm effective size, with a uniformity coefficient of 1.18. Potassium
nitrate solution was used in batch adsorption experiments for nitrate
removal from water. The effects of nitrate concentration, activated
carbon dosage and time of contact were studied. Experimental data
showed that modified activated carbon by Zn° and ZnSO4 was more
effective than virgin almond activated carbon for nitrate removal. The
maximum nitrate removal was 64%-80% and 5%-42% for modified activated
carbon and virgin activated carbon, respectively. While virgin
activated carbon used, nitrate-N decreased from 20 to 15mg/L in 30min
reaction. The final nitrate concentration was not in the standard range
of WHO recommendations for water quality; while impregnated activated
carbons were used, nitrate drcreased to <10mg/L. Maximum removal was
over 16-17mg nitrate-N per 1g activated carbon for impregnated
activated carbon. The experiments were conducted at pH=6.2, 20ºC
and initial concentrations of 20mg/L nitrate-N. Increase in modified
activated carbon dosage increased the nitrate removal efficiency. The
equilibrium time was found to be 45min for modified activated carbon
