Adsorption of arsenic on polyaluminum granulate.
The kinetics and efficiencies of arsenite and arsenate removal from water were evaluated using polyaluminum granulates (PAG) with high content of aluminum nanoclusters. PAG was characterized to be meso- and macroporous, with a specific surface area of 35 ± 1 m(2) g(-1). Adsorption experiments were conducted at pH 7.5 in deionized water and synthetic water with composition of As-contaminated groundwater in the Pannonian Basin. As(III) and As(V) sorption was best described by the Freundlich and Langmuir isotherm, respectively, with a maximum As(V) uptake capacity of ~200 μmol g(-1) in synthetic water. While As(III) removal reached equilibrium within 40 h, As(V) was removed almost entirely within 20 h. Micro X-ray fluorescence and electron microscopy revealed that As(III) was distributed uniformly within the grain, whereas As(V) diffused up to 81 μm into PAG. The results imply that As(V) is adsorbed 3 times faster while being transported 10(5) times slower than As(III) in Al hydroxide materials.
Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, Universitätsstrasse 16, 8092 Zürich, Switzerland. jasmin.mertens@env.ethz.ch
Jasmin
J
Mertens
Jérôme
J
Rose
Ralf
R
Kägi
Perrine
P
Chaurand
Michael
M
Plötze
Bernhard
B
Wehrli
Gerhard
G
Furrer
D000327:Adsorption; D017607:Aluminum Compounds / Q000737:chemistry*; D001149:Arsenates / Q000302:isolation & purification*; D018053:Arsenites / Q000302:isolation & purification*; D002118:Calcium / Q000737:chemistry; D060587:Groundwater / Q000032:analysis; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D016062:Porosity; D014867:Water / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
D017607:Aluminum Compounds; D001149:Arsenates; D018053:Arsenites; D014874:Water Pollutants, Chemical; D014867:Water; C015001:arsenite; C025657:arsenic acid; D002118:Calcium