پديدآورندگان :
mohammadi Fatemeh - University of Mohaghegh Ardabili, Ardabil , Khoshkam Maryam khoshkam@uma.ac.ir University of Mohaghegh Ardabili, Ardabil , Amiri Mandana - University of Mohaghegh Ardabili, Ardabil
چكيده فارسي :
In any experimental procedure, several experimental variables or factors may influence the result [1]. While only one parameter is changed, others are kept at a constant level. This optimization technique is called one-variable-at-a-time. The disadvantages of this technique are 1) it does not include the interactive effects among the variables studied 2) it does not depict the complete effects of the parameter on the response and 3) the number of experiments will increase when the number of factors increase, which leads to an increase of time and expenses as well as an increase in the consumption of reagents and materials .In order to overcome this problem, experimental methods have been proposed. Several methods are available for experimental design [2]. The purpose of all of these methods is to simultaneously optimize the levels of these variables to attain the best system performance [3].In this study carbon paste electrode which is modified by poly rhodanine functionalized nanomagnetic particles was used as an adsorbent for 〖Hg〗^(2+). Several experimental factors including pH, mixing time, mixing rate, concentration of adsorbent and initial concentration of mercury seem to be important in adsorption of 〖Hg〗^(2+) on the surface of modified electrode. Applying a screening experiment with a two level full factorial design showed that pH, mixing time and interaction of pH and concentration of adsorbent are the most significant factors. In the next step Box-Behnken design was used to optimize the most significant experimental system. In this step it was concluded that the pH is the most important factor and a decrease in pH will lead to increase in the amount of adsorbed 〖Hg〗^(2+). The other factors were not important. According the obtained results and knowledge about the experimental condition, pH=2 and the absorbant concentration equal to 0.5 mg/ml was selected as an optimal condition.
