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Reporter : Weikang Zhang
Date : 2012-12-11
Adsorption removal of phosphate from water by model-La/Al zeolite adsorbents
Tianjin University
Contents
Background
Current situation
The treatment technologies presently available for phosphorus removal include:
a)biological treatment
b)chemical precipitation
c)ion exchange
d)Adsorption Most of these approaches are generally more suitable for
the removal of phosphate of higher concentration.
• Adsorption is recommended as one of the most effective removal processes for the low concentrations of phosphorus.
• Many types of adsorbents for phosphate removal have been investigated.
AdsorbentActive
component SupportPreparation
methods Source
LaAl-PILC La2O3/Al2O3Montmorillonite
100 meshSolid-liquid mixed
Stirred for 5hStanded for 24h
Kunming university of science and technology
La-Ves La2O3Vesuvianite
Solid-liquid mixedStanded for 40h
Calclined at 673K for 3h
Yunnan Normal
University
La-Zeo La2O3
Naturalzeolite
Diameter of 90μmSolid-liquid mixed
calcined
Southeast University
Main work
• Materical characterization
• Phosphate adsorption experiment
• Adsorption isotherm
• Phosphate adsorption kinetics
• Influence on adsorption of phosphate
• Stability
• Regeneration studies
Adsorption isotherm and kinetics
1mol/L NH4Cl 100ml
Natrual zeolite 50g
Washing with deionized water
25 ℃
12h
3.44gLaCl3·7H2O
2.61gAl(NO3)3·6H2O20ml deionized water
Dry 100 ℃
Calcined 550 8h℃
25℃
impregnated24h
Dry 80 ℃
Calcined 500 2h℃La/Al-zeo Catalyst
Figure 1. Process of impregnation method to prepare La/Al-zeo catalyst
Experiment
Figure 2.1ppm 100ml, contact time is 12h,0.1g
2 3 4 5 6 7 8 9 100.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
Adso
rptio
n c
apaci
ty (m
g/g
)
Initial PH
Adsorption kinetics
0 2 4 6 8 100.0
0.2
0.4
0.6
0.8
1.0
1.2
Adso
rptio
n c
apaci
ty (m
g/g
)
contact time (h)
Figure 3. initial concentration is 5ppm, 200ml, 0.2g
Adsorption isotherm
Figure 4. various initial concentrations 100ml,50mg, contact time is 48h
0 5 10 15 20 250
2
4
6
8
10
12
14
16
Ads
orpt
ion
capa
city
(m
g/g)
Equilibrium concentration (mg/L)
Next work• Regeneration studies
10mg/L solution
Fresh absorbent
0.8mol/L NaCl
PH=10.5
25 ℃
Washing with deionized water
25 ℃
Impregnated3.5h
Dry25℃
500℃
Calcined 1h
regeneratedabsorbent