NITRATE UPTAKE FROM WATER BY MEANS OF TAILORED ADSORBENTS

G. NUNELL; M. E. FERNANDEZ; P. BONELLI; A. L. CUKIERMAN

WATER AIR AND SOIL POLLUTION

SPRINGER

Lugar: Berlin; Año: 2015 vol. 226 p. 1 - 13

0049-6979

Two different adsorbents directed to nitrate removal from water were developed from Parkinsoniaaculeata wood. An activated carbon was obtained by chemical activation with K2CO3 at 800 °C, whereas another adsorbent was prepared using a dilute solution of NH4Cl at 450 °C. Elemental compositions, surface functional groups, and textural parameters of both adsorbents were  determined and compared with those of a commercial activated carbon used as a reference. Nitrate adsorption assays were carried out to examine the effects of solution pH, adsorbent  dosage, contact time, and equilibriumadsorption isotherms. The adsorbent obtained with K2CO3 showed a well-developed pore structure (SBET=777m2/g; VT=0.35 cm3/g) and neutral character, while the one prepared with NH4Cl exhibited a low porous development (SBET=58 m2/g; VT=0.03 cm3/g), acidic nature, and a noticeably high N content. The latter attained the highest nitrate removal efficiency, with a maximumadsorption capacity (XmL=0.40 mmol/g) higherthan those estimated for the former (XmL=0.34 mmol/g) and the commercial sample (XmL=0.23 mmol/g), pointing to a predominant role of the chemical surface characteristics, mainly of  N-containing groups and basic functionalities. Accordingly, the adsorbent obtained with NH4Clrepresents a friendly novel material especially suited for nitrate removal.