Journal of Environmental Science and Technology1994-78872077-2181Asian Network for Scientific Information10.3923/jest.2008.124.134LoriJ.A. LawalA.O. EkanemE.J. 3200813Pyrolysis of bagasse, sorghum and millet straws impregnated
with ortho phosphoric acid, produced carbon with heterogeneous pore structure
and high adsorption capacities. Carbon precursors with particle size of
1180 μm were pyrolysed, to overcome difficulties caused by low density
and high ash content. The active carbons obtained from low impregnation
ratios (<13.6) were largely microporous. Higher impregnation ratio
did not substantially benefit the evolution of micropores in the pyrolysed
samples. Fast attainment of sorption equilibrium was skewed towards high
initial concentrations of methylene blue. The impregnation ration, controlled
by varying the proportion of H3PO4, had strong influence
on the yield of carbon. Equilibrium yields were highest at 450°C,
with impregnation ratio of 13.6. Production of active carbons was completed
in 45 min. The adsorptive capacities of the active carbons for large molecular
weight compounds such as methylene blue were 502, 662 and 390 mg g-1
for bagasse, sorghum and millet straws, respectively. The iodine numbers
which indicate the adsorptive capacities for low molecular weight substances
were 626, 667 and 593 mg g-1 for bagasse, sorghum and millet
straws, respectively. These iodine numbers are more than 18% higher than
the value recommended for low molecular weight compounds by American Water
Works Association.]]>ASTM D3860-98,20032003ASTM D4607-94,20062006Baquero, M.C., L. Giraldo, J.C. Moreno, F. Suarez-Garcia, A. Martinez-Alonso and J.M.D. Tascon,200370779784Barata-Rodrigues, P.M., T.J. May and G.D. Moggridge,20034122312246Bhatia, S.K., F. Liu and G. Arvind,20001640014008Brunauer, S., P.H. Emmett and E. Teller,193860309319Darmstadt, H., D. Pantea, L. Summchen, U. Roland, S. Kaliaguine and C. Roy,200053117Das, D., V. Gaur and N. Verma,20044229492962Ekanem, E.J.,199616165Ekezie, F.U. and F.A. Onwodi,2005306769El-Hendawy, A.N.A., S.E. Samra and B.S. Girgis,2001180209221Garcia-Perez, M., A. Chaala and C. Roy,200265111136Gimba, C.E., J.Y. Olayemi, D.O.H. Ifijeh and J.A. Kagbu,2001262327Guo, Y., K. Yu, Z. Wang and H. Xu,20004116451687Hayashi, J., A. Kazehaya, K. Muroyama and A.P. Watkinson,20003818731878Hayash, J., T. Horikawa, I. Takeda, K. Muroyama and F.N. Ani,20022CO3.]]>4021812186Ikhuoria, E.U. and S.I. Omonmhenle,2006Telfairia occidentalis Hook) seed husk.]]>31109113Imagawa, A., R. Seto and Y. Nagaosa,200038628630Jaguaribe, E.F., L.L. Medeiros, M.C.S. Barreto and L.P. Araujo,200522111Japanese Industrial Standard (JISK 1474),19921992Lori, J.A., A.O. Lawal and E.J. Ekanem,2007732493255Maroto-Valer, M.M., I. Dranca, T. Lupascu and R. Nastas,20044226552659Minkova, V., S.P. Marinov, R. Zanzi, E. Bjornbom, T. Budinova, M. Stefanova and L. Lakov,2000624552Minkova, V., M. Razvigorova, E. Bjornbom, R. Zanzi, T. Budinova and N. Petrov,2001705361Mui, E.L.K., D.C.K. Ko and G. Mckay,20044227892805Ochonogor, A.E.,2005Terminalia catapa and Cinnarium schweinfurthi nutshell.]]>308790Ochonogor, A.E. and P.M. Ejikeme,2005Cinnarium schweinfurthi nut shell activated carbon.]]>309195Oh, G.H. and C.R. Park,200281327336Omonmhenle, S.I., A.E. Ofomaja and F.E. Okieimen,200631161164Su, W., L. Zhou and Y. Zhuo,200341861863Suarez-Garcia, F., A. Martinez-Alonso and J.M.D. Tascon,20044214191426Yun, C.H., Y.H. Park and C.R. Park,200139559567Yun, C.H., Y.H. Park, G.H. Oh and C.R. Park,20024120092012Zanzi, R.,20012001