# In class quiz

```CH2140: Environmental Science and Technology
Index No:…………
In Class Quiz 01
1) Following data was obtained for a wastewater sample obtained from a wastewater treatment
plant. The sample size 50ml. Analyze the solid profile.
Parameter
Mass (g)
Tare mass of evaporating dish (X)
53.5433
X+ residue after evaporation at 105 0C
53.5794
X+ residue after ignition at 550 0C
53.5625
Tare mass of filter paper (Y) after dried at 105 0C
1.5433
Y +residue after evaporation at 105 0C
1.5554
Y+ residue after ignition at 550 0C
1.5476
2) Determine the amount of liquid alum required to precipitate phosphorous in a wastewater that
contains 8 mg P L-1. Also determine the required alum storage capacity, if a 30- day supply is to
be stored at the treatment facility. Based on the laboratory testing, 1.5 mole of Al will be required
per mole of P. The flow rate is 12 000 m3 day-1. the following data are for the liquid alum supply.
Formula for liquid alum: Al2(SO4)3.18H2O
Alum strength: 48%
Density of the liquid alum solution: 1.2 kg L-1
The reaction of PO43- with aluminum.
Al3++ PO43- →AlPO4↓
12 March 2020
```