I am doing adsorption study with TiO2 for arsenite. But in dark experiment, I stirred the solution containing 100/200/500 ppb of arsenite for 30 min & then left those for 24 hrs. The results that I got was haunting. The better removal was found with 0.1 g/L dose as compared to 0.2 & 0.5 g/L dose. Why?
Anyone please help me in this matter with some good suggestions.
So Jorge can you just explain the haunting nature of the above results?
Thanks.
As I understand, I think the problem maybe in the adsorbent (TiO2), as it cannot uptake more arsenate, can you compare the result with activated carbon?
Regards,
Which filter material did you use for TiO2 separation from water? Maybe problem is in pore size of filter. If TiO2 is smaller than pores it will increase absorbance. Higher dose increases adsorbance more significantly, that's why 0.1 g/l demonstrated better results. Try to use other filter.
Thanks Marta, but the method SDDC results in evolution of arsine gas which forms complex with SDDC. The resulting colour of the SDDC solution is checked for absorbance. So I hope if TiO2 also gets into the measuring flask, it will be restricted by the absorber tube & so will not hamper arsine generation.
Check the attached file.
Maybe TiO2 makes problems in arsine production due its oxidation properties?