Removal of Chromium(Vi), Copper(Ii) and Arsenic(V) from Aqueous Solution and Wastewater by Ethylenediamine Modified Rice Hull

The potential of aminated rice hull to remove Cr(VI), Cu(II) and As(V) from aqueous solution was investigated. Amination processes enhanced the sorption capacities of rice hull with ethylenediamine being the most economical and efficient aminating agent. Chemical modification of surface functiona...

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Main Author: Tang, Poh Li
Format: Thesis
Language:English
English
Published: 2002
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Online Access:http://psasir.upm.edu.my/id/eprint/9385/1/FSAS_2002_20_A.pdf
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spelling my-upm-ir.93852013-10-01T00:37:20Z Removal of Chromium(Vi), Copper(Ii) and Arsenic(V) from Aqueous Solution and Wastewater by Ethylenediamine Modified Rice Hull 2002-02 Tang, Poh Li The potential of aminated rice hull to remove Cr(VI), Cu(II) and As(V) from aqueous solution was investigated. Amination processes enhanced the sorption capacities of rice hull with ethylenediamine being the most economical and efficient aminating agent. Chemical modification of surface functional groups of ethylenediamine modified rice hull (enRH) indicated that amine and carboxyl groups were the major sorption sites. Both batch and column studies were performed, taking into account parameters such as pH, contact time, initial concentrations, ionic strength, particle size of sorbent, rate of agitation, presence of competitive cation and anions, use of different metal ion sources, sorbent dosage, temperature, bed depth, flow rate and sorptiondesorption process. The results of batch studies indicated that the sorption process was pH and temperature dependent. External mass transfer was not the sole rate-limiting phase and might involve chemisorption. The sorption of metal ions from single metal ion solution was in the order of Cr(VI) > Cu(II) > As(V) which is consistent with the Pearson's theory on hard and soft acid base. Cr(VI) and As(V) sorptions involved electrostatic interactions while Cu(n) sorption involved complexation. Where Cu(n) was present in binary and ternary metal ion solutions, Cr(VI) and As(V) removal also involved complexation. Column studies revealed different equilibrium states compared with batch studies. Breakthrough was bed depth, flow rate and initial concentration dependent. The presence of sulfate significantly affected the breakthrough time of Cr(VI) and Cu(n). The relationship between service time and bed depth was linear. The predicted breakthrough curves obtained from a two-parameter mathematical model agreed well with the experimental values in Cu(II) from all systems and Cr(VI) from binary Cu(II)- Cr(VI) and ternary metal ion solutions when sulfate was absent. Sequential columns could successfully reduce the levels of Cr(VI) and Cu(II) in the wastewater to the allowable limit for discharge into inland water. Cr(VI) and Cu(II) from dilute solution could be preconcentrated on the enRH column and thus this is useful in the analysis of trace amounts of Cr(VI) and Cu(II) in wastewater. Elution ofCr(VI)- and Cu(II)-loaded column could be carried out using 1.07 M NH3 and 0.5 M H2S04, respectively. Ethylenediamine Amination 2002-02 Thesis http://psasir.upm.edu.my/id/eprint/9385/ http://psasir.upm.edu.my/id/eprint/9385/1/FSAS_2002_20_A.pdf application/pdf en public phd doctoral Universiti Putra Malaysia Ethylenediamine Amination Faculty of Science and Environmental Studies English
institution Universiti Putra Malaysia
collection PSAS Institutional Repository
language English
English
topic Ethylenediamine
Amination

spellingShingle Ethylenediamine
Amination

Tang, Poh Li
Removal of Chromium(Vi), Copper(Ii) and Arsenic(V) from Aqueous Solution and Wastewater by Ethylenediamine Modified Rice Hull
description The potential of aminated rice hull to remove Cr(VI), Cu(II) and As(V) from aqueous solution was investigated. Amination processes enhanced the sorption capacities of rice hull with ethylenediamine being the most economical and efficient aminating agent. Chemical modification of surface functional groups of ethylenediamine modified rice hull (enRH) indicated that amine and carboxyl groups were the major sorption sites. Both batch and column studies were performed, taking into account parameters such as pH, contact time, initial concentrations, ionic strength, particle size of sorbent, rate of agitation, presence of competitive cation and anions, use of different metal ion sources, sorbent dosage, temperature, bed depth, flow rate and sorptiondesorption process. The results of batch studies indicated that the sorption process was pH and temperature dependent. External mass transfer was not the sole rate-limiting phase and might involve chemisorption. The sorption of metal ions from single metal ion solution was in the order of Cr(VI) > Cu(II) > As(V) which is consistent with the Pearson's theory on hard and soft acid base. Cr(VI) and As(V) sorptions involved electrostatic interactions while Cu(n) sorption involved complexation. Where Cu(n) was present in binary and ternary metal ion solutions, Cr(VI) and As(V) removal also involved complexation. Column studies revealed different equilibrium states compared with batch studies. Breakthrough was bed depth, flow rate and initial concentration dependent. The presence of sulfate significantly affected the breakthrough time of Cr(VI) and Cu(n). The relationship between service time and bed depth was linear. The predicted breakthrough curves obtained from a two-parameter mathematical model agreed well with the experimental values in Cu(II) from all systems and Cr(VI) from binary Cu(II)- Cr(VI) and ternary metal ion solutions when sulfate was absent. Sequential columns could successfully reduce the levels of Cr(VI) and Cu(II) in the wastewater to the allowable limit for discharge into inland water. Cr(VI) and Cu(II) from dilute solution could be preconcentrated on the enRH column and thus this is useful in the analysis of trace amounts of Cr(VI) and Cu(II) in wastewater. Elution ofCr(VI)- and Cu(II)-loaded column could be carried out using 1.07 M NH3 and 0.5 M H2S04, respectively.
format Thesis
qualification_name Doctor of Philosophy (PhD.)
qualification_level Doctorate
author Tang, Poh Li
author_facet Tang, Poh Li
author_sort Tang, Poh Li
title Removal of Chromium(Vi), Copper(Ii) and Arsenic(V) from Aqueous Solution and Wastewater by Ethylenediamine Modified Rice Hull
title_short Removal of Chromium(Vi), Copper(Ii) and Arsenic(V) from Aqueous Solution and Wastewater by Ethylenediamine Modified Rice Hull
title_full Removal of Chromium(Vi), Copper(Ii) and Arsenic(V) from Aqueous Solution and Wastewater by Ethylenediamine Modified Rice Hull
title_fullStr Removal of Chromium(Vi), Copper(Ii) and Arsenic(V) from Aqueous Solution and Wastewater by Ethylenediamine Modified Rice Hull
title_full_unstemmed Removal of Chromium(Vi), Copper(Ii) and Arsenic(V) from Aqueous Solution and Wastewater by Ethylenediamine Modified Rice Hull
title_sort removal of chromium(vi), copper(ii) and arsenic(v) from aqueous solution and wastewater by ethylenediamine modified rice hull
granting_institution Universiti Putra Malaysia
granting_department Faculty of Science and Environmental Studies
publishDate 2002
url http://psasir.upm.edu.my/id/eprint/9385/1/FSAS_2002_20_A.pdf
_version_ 1747810947562471424