TITLE:
Kinetic and Thermodynamic Study of Arsenic (V) Adsorption on P and W Aluminum Functionalized Zeolites and Its Regeneration
AUTHORS:
Adriana Medina Ramírez, Prócoro Gamero Melo, José Manuel Almanza Robles, María Esther Sánchez Castro, Sasirot Khamkure, Roberto García de León
KEYWORDS:
Fly Ash; Zeolite; Arsenic (V) Removal; Adsorbent Regeneration
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.5 No.8A,
August
23,
2013
ABSTRACT: In the “Laguna” region of
Coahuila state, Mexico like other places in the world, the groundwater needs to
be treated to meet the quality required for human consumption. The study had
probed that a Mexican fly ash can be used as a raw material to obtain effective
low cost adsorbents for drinking water treatment, as well evaluated the effects
of pH, ion coexistence, dose, arsenic (As) concentration and temperature on the
As(V) uptake by using P and W modified zeolites (PMOD and WMOD) obtained from a
Mexican fly ash. The As(V) adsorption capacity of the WMOD zeolite was not affected
by pH and As(V) concentrations in aqueous solution was achieved 0.01 mg/L in the studied pH range; however, the As(V) removal by
using PMOD zeolite decreased at high pH values. Carbonate concentration had a
negative effect on the As(V) uptake of both zeolites but this effect was higher
for the PMOD zeolite. The maximum adsorption capacities (Qmax) were 76.11 and
44.44 mg of As(V)/g of zeolite for the WMOD and the PMOD zeolites, respectively.
The adsorption process was endothermic, spontaneous and occurred by chemical exchange.
The experimental data were best interpreted by a pseudo-second order kinetic
model. The WMOD zeolite showed a higher adsorption capacity and rate than the
PMOD even at the highest evaluated As(V) concentration. The adsorption capacity
of the regenerated WMOD zeolite was similar to the original zeolite. Because of
the high As(V) adsorption capacity, chemical stability and regenerability, the
WMOD zeolite is potentially useful as low-cost adsorbent for As(V) removal from
aqueous effluents.