Fixed-bed operation for manganese removal from water using chitosan/bentonite/MnO composite beads

A. M. Muliwa, Taile Leswifi, A. Maity, Aoyi Ochieng, Maurice S. Onyango

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

In the present study, a new composite adsorbent, chitosan/bentonite/manganese oxide (CBMnO) beads, cross-linked with tetraethyl-ortho-silicate (TEOS) was applied in a fixed-bed column for the removal of Mn (II) from water. The adsorbent was
characterised by scanning electron microscopy (SEM), Fourier transform infra-red (FT-IR), N2 adsorption-desorption and X-ray
photoelectron spectroscopy (XPS) techniques, and moreover the point of zero charge (pHpzc) was determined. The extend of Mn
(II) breakthrough behaviour was investigated by varying bed mass, flow rate and influent concentration, and by using real
environmental water samples. The dynamics of the column showed great dependency of breakthrough curves on the process conditions. The breakthrough time (tb), bed exhaustion time (ts), bed capacity (qe) and the overall bed efficiency (R%) increased with an increase in bed mass, but decreased with the increase in both influent flow rate and concentration. Non-linear regression suggested that the Thomas model effectively described the breakthrough curves while large-scale column performance could be estimated by the bed depth service time (BDST) model. Experiments with environmental water revealed that coexisting ions had little impact on Mn (II) removal, and it was possible to achieve 6.0 mg/g breakthrough capacity (qb), 4.0 L total treated water and
651 bed volumes processed with an initial concentration of 38.5 mg/L and 5.0 g bed mass. The exhausted bed could be regenerated with 0.001 M nitric acid solution within 1 h, and the sorbent could be reused twice without any significant loss of capacity. The findings advocate that CBMnO composite beads can provide an efficient scavenging pathway for Mn (II) in polluted water.
Original languageEnglish
Pages (from-to)18081-18095
Number of pages15
JournalEnvironmental Science and Pollution Research
Volume25
DOIs
Publication statusPublished - 2018

Fingerprint

Manganese removal (water treatment)
Bentonite
Chitosan
Manganese
bentonite
manganese
Water
Composite materials
Manganese oxide
manganese oxide
breakthrough curve
Adsorbents
water
Flow rate
Nitric Acid
Silicates
Scavenging
Fourier Analysis
Nitric acid
Sorbents

Cite this

Muliwa, A. M. ; Leswifi, Taile ; Maity, A. ; Ochieng, Aoyi ; Onyango, Maurice S. / Fixed-bed operation for manganese removal from water using chitosan/bentonite/MnO composite beads. In: Environmental Science and Pollution Research. 2018 ; Vol. 25. pp. 18081-18095.
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abstract = "In the present study, a new composite adsorbent, chitosan/bentonite/manganese oxide (CBMnO) beads, cross-linked with tetraethyl-ortho-silicate (TEOS) was applied in a fixed-bed column for the removal of Mn (II) from water. The adsorbent wascharacterised by scanning electron microscopy (SEM), Fourier transform infra-red (FT-IR), N2 adsorption-desorption and X-rayphotoelectron spectroscopy (XPS) techniques, and moreover the point of zero charge (pHpzc) was determined. The extend of Mn(II) breakthrough behaviour was investigated by varying bed mass, flow rate and influent concentration, and by using realenvironmental water samples. The dynamics of the column showed great dependency of breakthrough curves on the process conditions. The breakthrough time (tb), bed exhaustion time (ts), bed capacity (qe) and the overall bed efficiency (R{\%}) increased with an increase in bed mass, but decreased with the increase in both influent flow rate and concentration. Non-linear regression suggested that the Thomas model effectively described the breakthrough curves while large-scale column performance could be estimated by the bed depth service time (BDST) model. Experiments with environmental water revealed that coexisting ions had little impact on Mn (II) removal, and it was possible to achieve 6.0 mg/g breakthrough capacity (qb), 4.0 L total treated water and651 bed volumes processed with an initial concentration of 38.5 mg/L and 5.0 g bed mass. The exhausted bed could be regenerated with 0.001 M nitric acid solution within 1 h, and the sorbent could be reused twice without any significant loss of capacity. The findings advocate that CBMnO composite beads can provide an efficient scavenging pathway for Mn (II) in polluted water.",
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Fixed-bed operation for manganese removal from water using chitosan/bentonite/MnO composite beads. / Muliwa, A. M.; Leswifi, Taile; Maity, A.; Ochieng, Aoyi; Onyango, Maurice S.

In: Environmental Science and Pollution Research, Vol. 25, 2018, p. 18081-18095.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Fixed-bed operation for manganese removal from water using chitosan/bentonite/MnO composite beads

AU - Muliwa, A. M.

AU - Leswifi, Taile

AU - Maity, A.

AU - Ochieng, Aoyi

AU - Onyango, Maurice S.

PY - 2018

Y1 - 2018

N2 - In the present study, a new composite adsorbent, chitosan/bentonite/manganese oxide (CBMnO) beads, cross-linked with tetraethyl-ortho-silicate (TEOS) was applied in a fixed-bed column for the removal of Mn (II) from water. The adsorbent wascharacterised by scanning electron microscopy (SEM), Fourier transform infra-red (FT-IR), N2 adsorption-desorption and X-rayphotoelectron spectroscopy (XPS) techniques, and moreover the point of zero charge (pHpzc) was determined. The extend of Mn(II) breakthrough behaviour was investigated by varying bed mass, flow rate and influent concentration, and by using realenvironmental water samples. The dynamics of the column showed great dependency of breakthrough curves on the process conditions. The breakthrough time (tb), bed exhaustion time (ts), bed capacity (qe) and the overall bed efficiency (R%) increased with an increase in bed mass, but decreased with the increase in both influent flow rate and concentration. Non-linear regression suggested that the Thomas model effectively described the breakthrough curves while large-scale column performance could be estimated by the bed depth service time (BDST) model. Experiments with environmental water revealed that coexisting ions had little impact on Mn (II) removal, and it was possible to achieve 6.0 mg/g breakthrough capacity (qb), 4.0 L total treated water and651 bed volumes processed with an initial concentration of 38.5 mg/L and 5.0 g bed mass. The exhausted bed could be regenerated with 0.001 M nitric acid solution within 1 h, and the sorbent could be reused twice without any significant loss of capacity. The findings advocate that CBMnO composite beads can provide an efficient scavenging pathway for Mn (II) in polluted water.

AB - In the present study, a new composite adsorbent, chitosan/bentonite/manganese oxide (CBMnO) beads, cross-linked with tetraethyl-ortho-silicate (TEOS) was applied in a fixed-bed column for the removal of Mn (II) from water. The adsorbent wascharacterised by scanning electron microscopy (SEM), Fourier transform infra-red (FT-IR), N2 adsorption-desorption and X-rayphotoelectron spectroscopy (XPS) techniques, and moreover the point of zero charge (pHpzc) was determined. The extend of Mn(II) breakthrough behaviour was investigated by varying bed mass, flow rate and influent concentration, and by using realenvironmental water samples. The dynamics of the column showed great dependency of breakthrough curves on the process conditions. The breakthrough time (tb), bed exhaustion time (ts), bed capacity (qe) and the overall bed efficiency (R%) increased with an increase in bed mass, but decreased with the increase in both influent flow rate and concentration. Non-linear regression suggested that the Thomas model effectively described the breakthrough curves while large-scale column performance could be estimated by the bed depth service time (BDST) model. Experiments with environmental water revealed that coexisting ions had little impact on Mn (II) removal, and it was possible to achieve 6.0 mg/g breakthrough capacity (qb), 4.0 L total treated water and651 bed volumes processed with an initial concentration of 38.5 mg/L and 5.0 g bed mass. The exhausted bed could be regenerated with 0.001 M nitric acid solution within 1 h, and the sorbent could be reused twice without any significant loss of capacity. The findings advocate that CBMnO composite beads can provide an efficient scavenging pathway for Mn (II) in polluted water.

U2 - 10.1007/s11356-018-1993-3

DO - 10.1007/s11356-018-1993-3

M3 - Article

VL - 25

SP - 18081

EP - 18095

JO - Environmental Science and Pollution Research

JF - Environmental Science and Pollution Research

SN - 0944-1344

ER -