Graphene oxide/ferric hydroxide composites for efficient arsenate removal from drinking water.
A series of novel composites based on graphene oxide (GO) cross-linked with ferric hydroxide was developed for effective removal of arsenate from contaminated drinking water. GO, which was used as a supporting matrix here, was firstly treated with ferrous sulfate. Then, the ferrous compound cross-linked with GO was in situ oxidized to ferric compound by hydrogen peroxide, followed by treating with ammonium hydroxide. The morphology and composition of the composites were analyzed by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The ferric hydroxide was found to be homogenously impregnated onto GO sheets in amorphous form. These composites were evaluated as absorbents for arsenate removal from contaminated drinking water. For the water with arsenate concentration at 51.14 ppm, more than 95% of arsenate was absorbed by composite GO-Fe-5 with an absorption capacity of 23.78 mg arsenate/g of composite. Effective arsenate removal occurred in a wide range of pH from 4 to 9. However, the efficiency of arsenate removal was decreased when pH was increased to higher than 8.
Zhang
Kai
K
Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore.
Dwivedi
Vineet
V
Chi
Chunyan
C
Wu
Jishan
J
D001149:Arsenates / Q000302:isolation & purification*; D002244:Carbon / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D014881:Water Supply / Q000032:analysis*
D001149:Arsenates; D005290:Ferric Compounds; D014874:Water Pollutants, Chemical; C021024:ferric hydroxide; D002244:Carbon; C025657:arsenic acid