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Showing 2 results for Cadmium (ii)

R Fouladi Fard, A.a Ebrahimi,
Volume 3, Issue 4 (1-2011)
Abstract

Background and Objective: Nickel (II) and cadmium (II) are important in environmental pollutant. Biosorption of heavy metals can be an effective process for the removal and recovery of heavy metal ions from aqueous solutions because of the decrease in sludge problems, economical issues, high efficiency and compatibility with the environment.
Materials and Methods: power of wasted activated sludge have been contact with nickel (II) and cadmium (II) solutions in 0.25 and 0.75 milli molar invarious pHs and mixing pace, at 24-26 0C temperature on batch reactor system .After two hours (continuously 5-420 min in kinetic study) samples were analyzed with atomic absorption spectrophotometer.
Results:The kinetic study results show that equilibrium adsorption time for nickel (II) and cadmium
(II) reached within 2 hr, but the profile curve of cadmium (II) biosorption was smoother than nickel (II) biosorption. Both metals adsorption followed the Langmuir model and the maximum adsorption capacity (qmax) for nickel (II) and cadmium (II) was 0.195 and 0.37 milli mole per gram respectively. The increase in pH resulted in adsorption increase for both metals. For cadmium (II) at 0.25 and 0.75 mMinitial concentration there was no adsorption at pH 2 where as nickel (0.25 mM) adsorption was observed at the same pH. The optimum mixing rate for both metals was 200 rpm and this effect was more obviously in greater concentration.
Conclusion: Like othe biosorbents ,wasted activated sludge showed greater capacity for cadmium(II) biosorption than nickel (II). Cadmium (II) in modeling and biosorption characteristics study had more conformity than nickel (II).


Mohammad Reza Jalali Sarvestani, Zohreh Doroudi ,
Volume 13, Issue 3 (11-2020)
Abstract

Background and Objective: Cadmium is a potential environmental contaminant that causes adverse effects on the environment and the health of living organisms. Therefore, designing a simple and economic technique for its determination is very important. In this respect, a potentiometric sensor based on nefazodone as the ionophore and [BMIM]PF6 as the ionic additive were developed for the determination of ultra-trace amounts of cadmium (II),.
Materials and Methods: In this study, a new membrane ion selective electrode was constructed with a composition entailed of 10% nefazodone, 2% [BMIM]PF6, 30% PVC and 58% dioctyl phthalate (DOP).The created potential discrepancy between the membrane and reference electrodes was used as a signal which demonstrates a direct relationship with the logarithmic concentration of cadmium (II) for  its determination.
Results: The constructed sensor showed an appropriate Nernstian slope (30.5 mV. Decade-1) in a wide concentration range (1×10-9 - 8×10-2 M) with the detection limit of 6×10-9 M. The electrode potential was pH-independent in the range of 3.5-8.0. The response time and lifetime of the electrode obtained 5 s and 15 weeks, respectively.
Conclusion: The constructed sensor independent of sample preparation was employed successively for the measurement of low concentrations of cadmium (II) in the environmental samples .Moreover,  the obtained findings were in a good agreement with the results of flame atomic absorption spectroscopy. Therefore, the designed electrode established pinpoint accuracy and it can be used for the determination of cadmium (II) in aqueous samples.


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