Abstract
This study describes the rejection of heavy metal ions using a commercial nanofiltration membrane (NF270). The effect of feed pH, pressure and metal concentration on the metal rejections and permeate flux and in some cases permeate pH was explored. The results showed that with all metals examined (except As (III)), when the feed pH is below the isoelectric point, the rejection increased. NF270 rejected almost 100% of copper ions at low concentrations, but decreased to 58% at the highest concentration examined. Using 1000mg/L concentration level, pH=1.5±0.2 and 4bar the rejection was 99%, 89% and 74% for cadmium, manganese and lead respectively. However at pH above the isoelectric point the average rejections decreased. NF270 was unable to retain As(III). The metals caused a flux decline due to membrane fouling in the order of severity: Cu2+>Cd2+≈Mn2+>Pb2+≈As3+. The correlation between adsorbed amounts of the metals onto NF270 with the normalised flux shows that as the amount increased the normalised flux decreased, except for arsenic that had a higher deposited amount and higher flux. The RMS roughness as obtained by AFM showed that roughness was decreased by membrane fouling.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 2-17 |
| Number of pages | 16 |
| Journal | Desalination |
| Volume | 315 |
| DOIs | |
| State | Published - Apr 5 2013 |
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Keywords
- AFM
- Atomic force microscopy
- Feed pH
- Heavy metals
- Membrane characterisation
- Membrane filtration
- Membrane fouling
- Nanofiltration membrane
- Permeate flux
- Rejection
- Water purification
ASJC Scopus subject areas
- Chemistry(all)
- Chemical Engineering(all)
- Materials Science(all)
- Water Science and Technology
- Mechanical Engineering
Cite this
Removal of heavy metal ions by nanofiltration. / Al-Rashdi, B. A.M.; Johnson, D. J.; Hilal, Nidal.
In: Desalination, Vol. 315, 05.04.2013, p. 2-17.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Removal of heavy metal ions by nanofiltration
AU - Al-Rashdi, B. A.M.
AU - Johnson, D. J.
AU - Hilal, Nidal
PY - 2013/4/5
Y1 - 2013/4/5
N2 - This study describes the rejection of heavy metal ions using a commercial nanofiltration membrane (NF270). The effect of feed pH, pressure and metal concentration on the metal rejections and permeate flux and in some cases permeate pH was explored. The results showed that with all metals examined (except As (III)), when the feed pH is below the isoelectric point, the rejection increased. NF270 rejected almost 100% of copper ions at low concentrations, but decreased to 58% at the highest concentration examined. Using 1000mg/L concentration level, pH=1.5±0.2 and 4bar the rejection was 99%, 89% and 74% for cadmium, manganese and lead respectively. However at pH above the isoelectric point the average rejections decreased. NF270 was unable to retain As(III). The metals caused a flux decline due to membrane fouling in the order of severity: Cu2+>Cd2+≈Mn2+>Pb2+≈As3+. The correlation between adsorbed amounts of the metals onto NF270 with the normalised flux shows that as the amount increased the normalised flux decreased, except for arsenic that had a higher deposited amount and higher flux. The RMS roughness as obtained by AFM showed that roughness was decreased by membrane fouling.
AB - This study describes the rejection of heavy metal ions using a commercial nanofiltration membrane (NF270). The effect of feed pH, pressure and metal concentration on the metal rejections and permeate flux and in some cases permeate pH was explored. The results showed that with all metals examined (except As (III)), when the feed pH is below the isoelectric point, the rejection increased. NF270 rejected almost 100% of copper ions at low concentrations, but decreased to 58% at the highest concentration examined. Using 1000mg/L concentration level, pH=1.5±0.2 and 4bar the rejection was 99%, 89% and 74% for cadmium, manganese and lead respectively. However at pH above the isoelectric point the average rejections decreased. NF270 was unable to retain As(III). The metals caused a flux decline due to membrane fouling in the order of severity: Cu2+>Cd2+≈Mn2+>Pb2+≈As3+. The correlation between adsorbed amounts of the metals onto NF270 with the normalised flux shows that as the amount increased the normalised flux decreased, except for arsenic that had a higher deposited amount and higher flux. The RMS roughness as obtained by AFM showed that roughness was decreased by membrane fouling.
KW - AFM
KW - Atomic force microscopy
KW - Feed pH
KW - Heavy metals
KW - Membrane characterisation
KW - Membrane filtration
KW - Membrane fouling
KW - Nanofiltration membrane
KW - Permeate flux
KW - Rejection
KW - Water purification
UR - http://www.scopus.com/inward/record.url?scp=84875247797&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84875247797&partnerID=8YFLogxK
U2 - 10.1016/j.desal.2012.05.022
DO - 10.1016/j.desal.2012.05.022
M3 - Article
VL - 315
SP - 2
EP - 17
JO - Desalination
JF - Desalination
SN - 0011-9164
ER -