The use of the clinoptilolite for wastewater remediation N. Russo, - - PowerPoint PPT Presentation
The use of the clinoptilolite for wastewater remediation N. Russo, D. Fino, M. Piumetti, G. Mancini, G. Saracco Dipartimento di Scienza Applicata e Tecnologia Politecnico di Torino OUTLINE CHARACTERIZATION: Physico-chemical properties of
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The crystal structure of clinoptilolite with cation positions. EDS values There are more than 50 natural and 150 synthetic types of zeolites. Natural clinoptilolite is the most widely used type due to its high absorption rate, cation exchange, catalysis and dehydration capacities.
Textural properties (N2 sorption at 77 K) XRD TEM Adsorption-desorption isotherms
FESEM
Concentration (a), abatement (b) and quantity (c) of MB absorbed as function of the time for the solution 250 mg l-1 (5 g of clinoptilolite) MB abatement > 90 % after 20 min. and 96 % after 2 h, under stirring conditions, room temperature
20 40 60 80 100 120 140 160 180 20 40 60 80 100
Adsorption (%) Time (min.) 10 g l
20 g l
40 g l
60 g l
Cd (200 ppm)
20 40 60 80 100 120 140 20 40 60 80 100
Adsorption (%) Time (min.) 10 g l
20 g l
40 g l
60 g l
Zn (200 ppm)
Element Clinoptilolite Weight (%) Fe-Clinoptilolite Weight (%)1 O 41.7 ± 0.4 52.4 ± 0.4 Si 39.9 ± 0.3 33.2 ± 0.33 Al 7.8 ± 0.2 6.2 ± 0.15 K 5.5 ± 0.2 2.2 ± 0.12 Ca 2.8 ± 0.2 2.0 ± 0.13 Fe 1.7 ± 0.2 3.6 ± 0.26 Mg 0.5 ± 0.1 0.3 ± 0.06 Na 0.1 ± 0.00
100.00 100.00
iron (III) nitrate was added to the solution containing clinoptilolite (Clin). The mixture was stirred for 2 hours at 50 °C and subsequently the slurry solution was centrifugated for 10 minutes. Then, the powder was washed with deionized water, dried overnight and finally calcinated at 550 °C for 4 h. EDS values
Element Fe-ZSM-5 Weight (%) O 55.2 ± 0.4 Si 40.7 ± 0.3 Al 1.5 ±0.1 K
3.1 ± 0.2 Mg
0.5 ± 0.1 Tot. 100.00
EDS values for the comparative sample (3 wt.% Fe-ZSM-5) prepared by the ion-exchange method of the ZMS-5 zeolite
ZSM-5
The introduction of 3 wt.% Fe does not modify the XRD patterns No FeOx clusters (XRD, XPS data)
The Fe-Clin sample exhibited the best performances towards the AO7 degradation (in terms of AO7 total conversion, %), particularly in the presence of both ascorbic acid and H2O2 (Fenton-type mechanism).