ADSORPTION OF LOW-CONCENTRATION AMMONIUM ONTO VERMICULITE FROM HEBEI PROVINCE, CHINA

作者：Wang Mingshan; Liao Libing^*; Zhang Xiuli; Li Zhaohui; Xia Zhiguo; Cao Weida

来源：Clays and Clay Minerals, 2011, 59(5): 459-465.

DOI：10.1346/CCMN.2011.0590503

• Adsorption
• Ammonium
• China
• Vermiculite

Vermiculite is a common layered silicate clay mineral which has good adsorption and ion-exchange properties, and which is used to remove pollutants from groundwater. The adsorption by vermiculite from Heibei Province, China, of low-concentration ammonium in water was assessed here to evaluate the effects of adsorption time, particle size, adsorbent dose, pH, and temperature. Using Fourier-transform infrared spectroscopy, the concentration of NH(4)(+) at 1430 cm(-1) was evaluated after ammonium was adsorbed by vermiculite. Based on Langmuir-model analysis, the adsorption capacity of the Chinese vermiculite (in the particle-size range 0.025-0.075 mm) for ammonium was 18 mg/g after 3 h of equilibration. Optimal adsorption occurred at pH 6-7 and 60 degrees C, which is different from that at high ammonium concentrations. Smaller particle-size fractions showed greater degrees of adsorption. Increase in Mg(2+), K(+), or Na(+) concentrations influenced ammonium adsorption and, therefore, indicated that cation exchange was the mechanism for ammonium uptake from low-concentration solutions.

• 出版日期2011-10
• 单位中国地质大学（北京）