I was investigating the sorption of activated carbon on different concentrations of copper(II)sulfate and came across rather unexpected results where the conductivity increased at 0,00001 , 0,0001 , 0,001 moldm-3. At 0,1 and 0,01 moldm-3 the conductivity decreased however, very little. Is this really because the activated carbon may have been impure or can there be other reasons for such results?
Hi Lidia,
if you haven't washed the activated carbon my guess would be that minerals leached out from it causing the increase in conductivity. The decrease you observed at higher molar concentrations of Cu, is it statistically significant? If it is real maybe Cu has precipitated. To check that and get an idea of the Cu speciation you can use Visual Minteq (https://vminteq.lwr.kth.se/). Measure pH too since Cu precipitates as Cu(OH)2.
In terms of experimental design have you included negative controls of your Cu solution only and activated carbon only and measured Cu concentration and conductivity (and pH) over time?
All the best!
How did you carry the conductivity test? did you use the AC as an electrode in CuSO4 solutions with different strengths? or you just dipped an electrode into the aqueous mixture of the AC and CuSO4 to measure it?
Have you checked the electrical conductivity of the pristine AC as well? If yes, then what was the outcome?
Thank you Robert Thomas Bachmann I will look into the precipitation and measure the pH as well. In terms I have only included cupric sulfate solution of different concentrations, granular activated carbon (equal amount and size), and the conductivity meter (not two electrodes etc) measuring it before and then after carbon "treatment", creating a relationship of concentration vs conductivity before and after the sorption. The AC was filtered out before measuring conductivity the second time. I hope that answers some of your questions Arpan Sarkar
- Badges
- Science topic
- Similar topics
- Chemistry