* Whatman Filter paper No – 42
* Silica Crucible
* Take 20 ml of aerated sample and filter it through Previously weighed whatman paper No – 42
* Wait for complete filtration by giving 2-3 washings with distilled water.
* After complete filtration keep the paper in oven at 1000C for 30 min. to 1 Hr.
* Take the weight of filter paper along with residue after complete drying.
Calculations: MLSS in ppm = (B – A) x 106 / ml of Sample Taken
A = Weight of pre-dried filter paper
B = Weight of filter paper & Residue
Determination of Mixed Liquor Suspended Solids