[Removal of arsenate from drinking water by activated carbon supported nano zero-valent iron].
A new adsorbent, activated carbon impregnated with nano zero-valent iron was prepared, which size of the needle-shaped iron particles in the pores of carbon was (30-500) nm x (1000-3000) nm and approximately 8.2% of iron was loaded onto it. The arsenate removal percentage was 99.5% by 1.5 g/L NZVI/AC in the 2 mg/L arsenic solution at pH 6.5 and (25 +/- 2) degrees C. The adsorption capacity was about 15.4 mg/g when equilibrium concentration was 1.0 mg/L. Kinetics revealed that uptake of arsenate ion by NZVI/AC was 91.4% in the first 12 h and equilibrium time was about 72 h. The intraparticle diffusion model was applied to study the mechanics of arsenate in the activated carbon. The presence of phosphate and silicate could significantly decrease arsenate removal while the effects of the other anions and cations on the arsenic removal were neglectable. NZVI/AC can be effectively regenerated when elution is done with 0.1 mol/L NaOH solution. Our results suggest that NZVI/AC is a suitable candidate for drinking water treatment due to its high reactivity.
Zhu
Hui-jie
HJ
Key Laboratory of Terrestrial Ecological Process, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China. zhuhuijie@yahoo.cn
Jia
Yong-feng
YF
Yao
Shu-hu
SH
Wu
Xing
X
Wang
Shu-ying
SY
D001149:Arsenates / Q000032:analysis / Q000302:isolation & purification*; D002606:Charcoal / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry; D010710:Phosphates / Q000737:chemistry; D017640:Silicates / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*; D014881:Water Supply / Q000032:analysis
D001149:Arsenates; D010710:Phosphates; D017640:Silicates; D014874:Water Pollutants, Chemical; D002606:Charcoal; D007501:Iron; C025657:arsenic acid