Other Random Media
||Material of construction – PVC.
||Material of construction – PP in different shapes and sizes.
||Shape of spirals specially derived for fluidizing.
||Simple rings with serrations or with diagonals.
||Specific gravity 1.05
||Specific gravity 0.98
||Behavior of spirals similar to sludge
||Media lighter than sludge and water
||Spirals swirl and fluidize with slightest disturbance.
||Media floats on water.
||No fine bubble diffusers required.
||Fine bubble diffusers a must.
||8 – 10% of liquid volume would be the max. media requirement irrespective of the organic load.
||Minimum 25% of liquid volume required. Quantity dependent on organic load.
||Shut down and restart possible with ease as spiral support attached growth.
||Shut down and restart sluggish as media floats on water and wetting surface of media inadequate.
||Mass transfer efficiency high - Continuous shearing of bio mass from the media occurs to provide a large population of bio mass for treatment.
||Mass transfer efficiency low – tubular shape of media may allow sludge accumulation inside the tube. The generation of bio mass not as in spirals. Hence requirement of media would be much more.
||6 hrs retention in aeration tank for sewage treatment adequate.
||May require at least 8- 12 hrs of retention in aeration tank.
||Spirals is the only PVC medium that fluidizes.
||No other PVC media such as pipe
cuttings or moulded product fluidizes.
Media settles at the bottom of the aeration tank.
||As spirals fluidizes along with sludge, no dead pockets in the reactor and no choking occurs in the media.
||Accumulation of sludge in the aeration tank floor over a period of time reduces treatment efficiency. This occurs as the PVC media is stacked and does not fluidize.