The dispersion of K\-2CO\-3 on \%γ\%\|Al\-2O\-3 and the adsorption performance of K\-2CO\-3/\%γ\%\|Al\-2O\-3 to SO\-2 are investigated.The results show that K\-2CO\-3 can disperse onto the surface of \%γ\%\|Al\-2O\...The dispersion of K\-2CO\-3 on \%γ\%\|Al\-2O\-3 and the adsorption performance of K\-2CO\-3/\%γ\%\|Al\-2O\-3 to SO\-2 are investigated.The results show that K\-2CO\-3 can disperse onto the surface of \%γ\%\|Al\-2O\-3 as a monolayer and the dispersion threshold is 0.31\[\%m\%(K\-2CO\-3)/\%m\%(\%γ\%\|Al\-2O\-3), \%m\%/g\], which is close to the theoretical value calculated by assuming a bidentate vertical dispersion model of CO\-2 on the \%γ\%\|Al\-2O\-3 surface . The SO\-2 adsorption\|capacity on K\-2CO\-3/\%γ\%\|Al\-2O\-3 sample increases with the K\-2CO\-3 loading and reaches an extremum at its threshold. The adsorbent conversion of K\-2CO\-3/\%γ\%\|Al\-2O\-3 at the threshold is up to 72%. When the loading is higher than the threshold, the SO\-2 adsorption capacity decreases at first, then increases again. This phenomenon is caused by the reaction between SO\-2 and the bulk phase of K\-2CO\-3 crystallites. The sample decreases with the loading, and the sample with \{0.10\}\[\%m\%(K\-2CO\-3)/\%m(γ\%\|Al\-2O\-3), \%m\%/g\] loading shows the highest regeneration percentage of 63%. Compared with Na\-2CO\-3/\%γ\%\|Al\-2O\-3, K\-2CO\-3/\%γ\%\|Al\-2O\-3 might have some advantages.展开更多
The purpose of this study is to develop low cost adsorbing materials to remove the heavy metals from waste waters. The outer covering of coconut, coconut shell, is the most abundant in the countries of its plantation ...The purpose of this study is to develop low cost adsorbing materials to remove the heavy metals from waste waters. The outer covering of coconut, coconut shell, is the most abundant in the countries of its plantation and enormous use. Utilization of agricultural waste （coconut shell） in the production of activated carbon potentially leads to produce a highly effective adsorbent generated from low cost raw materials that are available in huge quantity as renewable resources. At present coconut shell is not in use as valuable entity due to which disposal and ultimate environmental problems are faced. In this study coconut shells were impregnated with phosphoric acid and chemically activated at 450 C. The potential to remove chromium （VI） from aqueous solution by using activated coconut shells was investigated by batch experiment. The various sorption parameters i.e pH, sorbent dose, sorbate concentration, agitation time and agitation speed were optimized. The sorption of Cr （VI） onto activated carbon, developed from coconut shell, at pH 2 was achieved 81.25%. The best optimum conditions were obtained when 0.75 gm of sorbent was agitated at 150 rpm with 60 mg/L of sorbate for 40 min. Activated coconut shells has potential to be a good resource material for effective removal of chromium （VI） of low concentration from wastewater.展开更多
文摘The dispersion of K\-2CO\-3 on \%γ\%\|Al\-2O\-3 and the adsorption performance of K\-2CO\-3/\%γ\%\|Al\-2O\-3 to SO\-2 are investigated.The results show that K\-2CO\-3 can disperse onto the surface of \%γ\%\|Al\-2O\-3 as a monolayer and the dispersion threshold is 0.31\[\%m\%(K\-2CO\-3)/\%m\%(\%γ\%\|Al\-2O\-3), \%m\%/g\], which is close to the theoretical value calculated by assuming a bidentate vertical dispersion model of CO\-2 on the \%γ\%\|Al\-2O\-3 surface . The SO\-2 adsorption\|capacity on K\-2CO\-3/\%γ\%\|Al\-2O\-3 sample increases with the K\-2CO\-3 loading and reaches an extremum at its threshold. The adsorbent conversion of K\-2CO\-3/\%γ\%\|Al\-2O\-3 at the threshold is up to 72%. When the loading is higher than the threshold, the SO\-2 adsorption capacity decreases at first, then increases again. This phenomenon is caused by the reaction between SO\-2 and the bulk phase of K\-2CO\-3 crystallites. The sample decreases with the loading, and the sample with \{0.10\}\[\%m\%(K\-2CO\-3)/\%m(γ\%\|Al\-2O\-3), \%m\%/g\] loading shows the highest regeneration percentage of 63%. Compared with Na\-2CO\-3/\%γ\%\|Al\-2O\-3, K\-2CO\-3/\%γ\%\|Al\-2O\-3 might have some advantages.
文摘The purpose of this study is to develop low cost adsorbing materials to remove the heavy metals from waste waters. The outer covering of coconut, coconut shell, is the most abundant in the countries of its plantation and enormous use. Utilization of agricultural waste （coconut shell） in the production of activated carbon potentially leads to produce a highly effective adsorbent generated from low cost raw materials that are available in huge quantity as renewable resources. At present coconut shell is not in use as valuable entity due to which disposal and ultimate environmental problems are faced. In this study coconut shells were impregnated with phosphoric acid and chemically activated at 450 C. The potential to remove chromium （VI） from aqueous solution by using activated coconut shells was investigated by batch experiment. The various sorption parameters i.e pH, sorbent dose, sorbate concentration, agitation time and agitation speed were optimized. The sorption of Cr （VI） onto activated carbon, developed from coconut shell, at pH 2 was achieved 81.25%. The best optimum conditions were obtained when 0.75 gm of sorbent was agitated at 150 rpm with 60 mg/L of sorbate for 40 min. Activated coconut shells has potential to be a good resource material for effective removal of chromium （VI） of low concentration from wastewater.
