Diatomaceous silica filter aid filtration for the effectiveseparation of colloidal Cr(OH)_3 precipitatefrom tanning wastewater
Diatomaceous silica filter aid filtration for the effectiveseparation of colloidal Cr(OH)3 precipitatefrom tanning wastewater

Diatornaceous silica filter aid filtration was used in this study for the separation of colloidal Cr(OH)3 precipitate from tanning wastewater. It was found that the addition of diatomaceous silica to tanningwastewater with PH>8. 2 can increase considerably the filtration rate of Cr(OH)3 precipitate. The experimental results show that the average filtration rate(r, ml/s) is a function of diatomaceous silica content(d ,g/l00ml) in the wastewater , filtration temperature and pressure drop as well as area used. The relationship of r and d was found to be r= 0. 06d+ 0. 045 (d<16g/100ml), over the range of filtration time of 0-270s usedat 14C , and filtration area of 0. 0062m2.