فهرست نشریات علمی دسترسی آزاد ایران

In this study, activated nanokaolin was produced from raw kaolin by the acid-thermal method and used as a cheap and abundant natural adsorbent for the removal of ammonium from polluted waters and industrial wastewater and for preconcentration of ammonium ions for spectrophotometric determination. The main removal mechanism in this method is ion exchange between ammonium ions present in the samples and ions present in the structure of the activated nanokaolin. To investigate the chemical properties of activated nanokaolin, Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy were used. In order to optimize the ammonium removal conditions, the parameters such as pH of the analyte solution, contact time, ammonium concentration in the solution, and adsorbent amount were changed at the same time, and the effect of each parameter on the adsorption efficiency was investigated, while keeping the other parameters constant. Also, the removal efficiency and adsorption coefficient of ammonium were calculated, and the optimal values for each were obtained by plotting the graphs. The calibration curve was drawn under optimal conditions. The detection limit of the measurement method was 0.006 ppm, and the quantification limit was 0.019 ppm for ammonium. The dynamic linear range was 0.001 - 90 ppm for ammonium, and the correlation coefficient R2 was 0.995. The relative standard deviation was 10.07%, and the relative recovery of this method for ammonium in real samples was 90.056 to 103.937%.