Recent questions tagged water-treatment-methods

Which of the following options is/are TRUE about reverse osmosis process?Reverse osmosis is used as a pretreatment for microfiltration process.Ultrafiltration is used as ...

Which of the following options is/are TRUE about coagulation-flocculation process?Collision of colloidal particles due to their Brownian motion results in orthokinetic fl...

A sewage treatment plant employing activated sludge process is operated under the following conditions:Wastewater flow rate into the aeration $\operatorname{tank}=0.150 \...

​​​​Multiple effect evaporator is commonly used, in the zero liquid discharge (ZLD) scheme, for $\_\_\_\_\_\_\_$oxidation of organic pollutantsprecipitation of heavy meta...

​​​​Consider the following figure of an activated sludge process (ASP), depicting the flow $(\mathbf{Q})$, substrate $(\mathbf{S})$, and microorganism concentration $(\ma...

​Choose the correct option(s) for removing solids from water.chlorinationcoagulation-flocculation-sedimentation followed by slow sand filtrationchlorination followed by a...

A common effluent treatment plant with a capacity of $2$ million litres per day (MLD) employs reverse osmosis (RO) for water reuse. The RO unit removes $95 \%$ of the tot...

The processes of removal of particles in a rapid sand filter with their description is given in the table.ProcessDescription$\text{(i)}$ StrainingP:Removes only particles...

With respect to particle settling in wastewater treatment systems; the correct statement(s) is/areSettling in grit chamber and primary sedimentation tanks are examples of...

The Streeter-Phelp's oxygen sag equation for a river is based on a few assumptions. The correct assumption$\text{(s)}$ is/areAt any instant the deoxygenation rate is dire...

An industry discharges $2$ million liters per day $\text{(MLD)}$ of wastewater with a temperature of $45^{\circ} \mathrm{C}$ and a $\mathrm{pH}$ of $2$, whereas the neigh...

One million liters per day $\text{(MLD)}$ of wastewater with a soluble $\text{BOD}$ of $200 \mathrm{mg} / \mathrm{L}$ is treated in an activated sludge process. The $\tex...

A person consumes $2.5$ liters of water per day. The water quality test indicated that the supplied water has a $\mathrm{Pb}$ concentration of $0.6 \mathrm{mg} / \mathrm{...

River water containing two types of spherical suspended particles $\text{(clay particles, metal particles)}$ is retained in a sedimentation tank. The clay particles havin...

A biological reactor is getting wastewater containing 1 mole/L acetate ions as carbon source. The following reaction takes place in the bio-reactor:\[\begin{array}{l}0.12...

A flask (100 ml volume) has wastewater, which has $0.12 \mathrm{mg} / \mathrm{L}$ geosmin. Activated carbon is added in this flask for adsorbing geosmin as per the Freund...

You are doing an experiment to find out $\mathrm{BOD}_5$ of a wastewater. You have taken $25 \mathrm{~mL}$ wastewater having ultimate BOD of $75 \mathrm{mg} / \mathrm{L}$...

An aeration tank needs to be installed for the removal of VOC from water, where the required rate of flow of water through the aeration tank is $180,000 \mathrm{~m}^{3} /...

Which of the following causes $\text{'Type-I'}$ settling in a sedimentation tank? AgglomerationCompression Force of gravityCharge neutralization

Chlorine is most effective as a water disinfectant at a $\text{pH}$ of _____________.$6$ $8$$10$$12$