Use of an iron-overexchanged clinoptilolite for the removal of Cu2+ ions from heavily contaminated drinking water samples.
Clinoptilolite, a natural zeolite, was used for the synthesis of a high surface area clinoptilolite-iron oxide system, in order to be used for the removal of Cu2+ ions from drinking water samples. The solid system was obtained by adding natural clinoptilolite in an iron nitrate solution under strongly basic conditions. The Clin-Fe system has specific surface area equal to 151 m2 g(-1) and is fully iron exchanged (Fe/Al=1.23). Batch adsorption experiments were carried out to determine the effectiveness of the Clin and the Clin-Fe system in removal of copper from drinking water. Adsorption experiments were conducted by mixing 1.00 g of each of the substrates with certain volume of water samples contaminated with 10 different Cu concentrations (from 3.15x10(-5) to 315x10(-2) M or from 2.00 to 2000 ppm Cu). For our experimental conditions, the maximum adsorbed Cu amount on Clin was 13.6 mg g(-1) whereas on the Clin-Fe system was 37.5 mg g(-1). The main factors that contribute to different adsorption capacities of the two solids are due to new surface species and negative charge of the Clin-Fe system. In addition, the release of counterbalanced ions (i.e. Ca2+, Mg2+, Na+ and K+) was examined, as well as the dissolution of framework Si and Al. It was found that for the most of the samples the Clin-Fe system releases lower concentrations of Ca, Mg and Na and higher concentrations of K than Clin, while the dissolution of Si/Al was limited. Changes in the composition of water samples, as well as in their pH and conductivities values were reported and explained.
Doula
M K
MK
National Agricultural Research Foundation of Greece, Soil Science Institute of Athens, 1 Sof. Venizelou St., 14123 Lycovrisi, Greece. mdoula@otenet.gr
Dimirkou
A
A
D000327:Adsorption; D003300:Copper / Q000737:chemistry*; D007477:Ions; D007501:Iron / Q000737:chemistry*; D008274:Magnesium / Q000737:chemistry; D008956:Models, Chemical; D011188:Potassium / Q000737:chemistry; D012964:Sodium / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods; D014867:Water; D014874:Water Pollutants, Chemical / Q000032:analysis; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*; D014881:Water Supply; D017641:Zeolites / Q000032:analysis / Q000737:chemistry*
D007477:Ions; D014874:Water Pollutants, Chemical; D014867:Water; C083175:clinoptilolite; D017641:Zeolites; D003300:Copper; D012964:Sodium; D007501:Iron; D008274:Magnesium; D011188:Potassium