Having noticed that the filter media can easily be blocked by suspended materials from the sludge liquid, the concentrations of pollutants were later reduced and the samples were left in a sedimentation unit for one day.
A part of the disintegrated materials precipitated, due to which the highest concentrations of TSS were obtained at the bottom of the sedimentation unit, lower concentrations were observed on the surface and the minimum in the middle.
The volume of 13 L of sludge liquid from the sedimentation unit was filtered through the filler layer of 0.5 m height (0.8-1.6 mm zeolite fraction).
From Figures 3 and 5, the removal rates of DBP and DiOP in raw water of coagulating sedimentation unit were at range of 8.08%-10.94% and 5.54%-7.18%, respectively, and average removal rates were 9.92% and 6.25%, respectively.
(2) The average removal rate of DiOP in influent of the process by coagulating sedimentation unit was 6.25%; the average removal rate of DiOP in effluent of coagulating sedimentation by ozone contact column unit was 19.05%; the average removal rate of DiOP in effluent of ozone by biological sand filter column was 17.05%; the average removal rate of DiOP in effluent of biological sand filter column by active carbon column was 51.36%.
(1) The average removal rate of DBP in influent by coagulation sedimentation units was 9.92%; the average removal rate of DBP in effluent of coagulating sedimentation by ozone column unit was 28.99%; the average removal rate of DBP in effluent of ozone contact column by biological sand filter column was 22.01%; the average removal rate of DBP in effluent of biological sand filter by active carbon unit was 70.28%.
The one of pretreatment units is sedimentation unit
. This unit is use to settling of suspended solids from water before entrance to plant treatment units and called presedimentation unit.
Of the sedimentation units
identified in the sediment cores, 33% were laminated (individual sedimentation units
<10 mm thick) and a further 24% were stratified (individual sedimentation units
>10 mm thick).