Quality Control of Water · Environmental Engineering · GATE CE
Marks 1
The following table gives various components of Municipal Solid Waste (MSW) and a list of treatment/separation techniques.
| Component of MSW | Treatment/separation technique |
|---|---|
| P - Ferrous metals | i - Incineration |
| Q - Aluminum and copper | ii - Rapid composting |
| R - Food waste | iii - Eddy current separator |
| S - Cardboard | iv - Magnetic separator |
The CORRECT match is
A 100 mg of HNO3 (strong acid) is added to water, bringing the final volume to 1.0 liter. Consider the atomic weights of H, N, and O, as 1 g/mol. 14 g mol. and 16 g/mol, respectively. The final pH of this water is (Ignore the dissociation of water.)
The total hardness in raw water is 500 milligram per liter as CaCO3. The total hardness of this raw water, expressed in milligram equivalent per liter, is (Consider the atomic weights of Ca, C, and O as 40 g/mol, 12 g/mol, and 16 g/mol, respectively.)
In a water sample, the concentrations of Ca2+, Mg2+ and HCO$$_3^ - $$ are 100 mg/L, 36 mg/L and 122 mg/L, respectively. The atomic masses of various elements are : Ca = 40, Mg = 24, H = 1, C = 12, O = 16. The total hardness and the temporary hardness in the water sample (in mg/L as CaCO3) will be
Marks 2
Activated carbon is used to remove a pollutant from wastewater in a mixed batch reactor, which follows first-order reaction kinetics.
At a reaction rate of 0.38 /day, the time (in days) required to remove the pollutant by 95% is _______________ (rounded off to 1 decimal place).
A water treatment plant treats 25 MLD water with a natural alkalinity of 4.0 mg/L (as CaCO3). It is estimated that, during the coagulation of this water, 450 kg/day of calcium bicarbonate (Ca(HCO3)2) is required based on the alum dosage.
Consider the atomic weights as: Ca-40, H-1, C-12, O-16.
The quantity of pure quick lime, CaO (in kg) required for this process per day is _______ (rounded off to 2 decimal places).
The total hardness (in mg/L as $${\mathrm{CaCO}}_3$$) of the water sample is ______.
The non-carbonate hardness (expressed in mg/L as $${\mathrm{CaCO}}_3$$) of the sample is
| Ion | $$Ca^{2+}$$ | $$Mg^{2+}$$ | $$Na^+$$ | $$HCO_3^-$$ | $$SO_4^{2-}$$ | $$Cl^{-}$$ |
|---|---|---|---|---|---|---|
| Ionconcentration(mg/L) | 100 | 6 | 15 | 250 | 45 | 39 |
| Atomic Weight | Ca=40 | Mg=24 | Na=23 | H=1,C=12,O=16 | S=32,O=16 | Cl=35.5 |
Total hardness (mg/L as $$CaCO_3$$) present in the above water sample is
| Ion | $$Ca^{2+}$$ | $$Mg^{2+}$$ | $$Na^+$$ | $$HCO_3^-$$ | $$SO_4^{2-}$$ | $$Cl^{-}$$ |
|---|---|---|---|---|---|---|
| Ionconcentration(mg/L) | 100 | 6 | 15 | 250 | 45 | 39 |
| Atomic Weight | Ca=40 | Mg=24 | Na=23 | H=1,C=12,O=16 | S=32,O=16 | Cl=35.5 |
Carbonate hardness (mg/L as $$CaCO_3$$) present in the above water sample is