Recent questions in Water & Wastewater Treatment and Management

In the reversible reaction shown below, $k_{f}$ is the forward reaction rate constant and $k_{r}$ is the reverse reaction rate constant.The CORRECT expression representin...

Which ONE of the following options CORRECTLY matches the processes associated with the growth condition given in the table?$$\begin{array}{|ll|ll|}\hline & \textbf{Proces...

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...

Reaction $\mathrm{A} \rightarrow \mathrm{B}$ follows first-order elementary kinetics and the reaction rate constant for $\text{A}$ is $0.01$ per min.The time taken to red...

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

A continuous flow stirred tank reactor (CSTR) operates under a steady-state condition with a flow rate of $300$ $\text{L}$ per hour. The influent concentration of a subst...

​​​​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...

Aerobic biomass has yield coefficient value of $0.4$ for glucose (molecular weight $= 180 \mathrm{~g} / \mathrm{mole}$) substrate. Bacteria is represented as $\mathrm{C}_...

You conducted a batch experiment in the lab for $10$ minutes to degrade a toxic compound, which follows first order kinetics. The compound degrades from $2 \times 10^{-3}...

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...

Consider second order kinetics $\left(r_{c}=-k C^{2}\right)$ under steady state condition. The ratio of volume of a complete mixed reactor (CMR) to that of a plug flow re...

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...

For a biodegradable waste with a chemical formula $\mathrm{C}_{50} \mathrm{H}_{100} \mathrm{O}_{40} \mathrm{~N}$, the maximum theoretical methane production per ton of wa...

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 $75 \mathrm{mg} / \mathrm{L}$...