Dynamic Sand Filter Performance against High Solids Loads in Raw Water

Abuelkhair, N.Y.; El Nadi, M.H.; Fouad, H.A.; Hefny, R.M.

doi:10.21608/bjas.2022.254551

Dynamic Sand Filter Performance against High Solids Loads in Raw Water

Document Type : Original Research Papers

Authors

¹ Sanitary Eng. Section, Civil Eng. Dept., Shobra Faculty of Eng., Benha Univ., Cairo, Egypt

² Sanitary & Environmental Eng. Sec., Public Works Dept., Faculty of Eng., ASU, Cairo, Egypt.

³ Sanitary Eng. Section, Civil Eng. Dept., Shobra Faculty of Eng., Benha Univ., Cairo, Egypt.

10.21608/bjas.2022.254551

Abstract

Dynamic sand filter is a new technique for filtration depends on the continues washing for the up flow sand filter using
diffused air for sand stirring to remove solids impurities from it. Egypt started to apply this system in its new plants for its
high efficiency that leads to minimize required area. With the pollution increase in the water resources that raise the solids
loads in it and increase the rewash needs in the traditional rapid sand filters specially these solids mainly are algae and
bacteria. Also, the increase in water needs with the high cost for extension land for existing plants increase the need of
applying such system to overcome this problem and increase the plant productivity.
This study was made to check the dyna- sand filter suitability to meet high suspended solids loads and overcome it to
ensure its capability for application in different cases as direct filtration water plants. Tertiary treatment for wastewater and
replacing rapid sand filters in existing plants without any changes in prior treatment units.
A lab scale pilot used was designed according to the Nordic company system book and synthetic water was applied
with variable TSS loads form 50 - 150ppm under several filtration hydraulic rates variable from 150-250 m3/m2/day to
determine the study aim.
The results showed that the removal ratios of turbidity varied between (80-89%) with 50 ppm TSS and R.O.F 150
m3/m2/d down to (40-63%) with 150ppm TSS and R.O.F 250 m3/m2/d which could be more in the real plant scale. The
system suitability was very successful to meet high solid loads with high filtration rates that achieves the targets of
application as direct filtration in water treatment, minimize the area for filtration in new plants and give the suitability for
replacing the existing filters without changing the prier treatment units just decrease their removal efficiency depending on
the system ability to meet higher loads.

Keywords

Main Subjects