Recent questions tagged environmental-engineering

Column $\text{I}$ presents common air pollutants, and column $\text{II}$ presents treatment technologies commonly employed to control air pollutants.\[\begin{array}{|c|l|...

One-third of the solid matter in a sludge containing $90 \%$ water is composed of fixed mineral solids with specific gravity $2.5$, and two-third is composed of volatile ...

The grown algae are useful in the operation ofoxidation pond.slow sand filter.cyclone separator.septic tank.

The $2.4$ ml of raw sewage is diluted to $240$ ml. The Dissolved Oxygen (DO) of the diluted sample at the beginning of Biochemical Oxygen Demand (BOD) test was $8 \mathrm...

Anaerobic bacteria are being utilized for the destruction of biodegradable organic content of wastewater measured in terms of Chemical Oxygen Demand (COD). The yield coef...

A rapid sand filter bed of depth $0.8$ m has $40 \%$ porosity during service cycle. It is recommended that during backwash operation, the expanded filter bed should have ...

Which of the following components is/are NOT removed in the secondary treatment of sewage?Suspended settleable organic solidsColloids including dissolved organic matterPa...

The average sewage from a city is $90$ million litres per day and the average $5$-day Biochemical Oxygen Demand ($\text{BOD5}$) is $300 ~\mathrm{mg} / \mathrm{l}$. Averag...

An Activated Sludge Process $\text{(ASP)}$ has an inlet wastewater flowrate of $20000 \mathrm{~m}^{3} /$ day with a Biochemical Oxygen Demand $\text{(BOD)}$ concentration...

Free residual chlorine concentration in water was measured to be $2 \mathrm{mg} / 1\left(\right.$ as $\left.\mathrm{Cl}_{2}\right)$. The pH of water is $8.5$. By using th...

A compound has a general formula $\mathrm{C}_{\mathrm{a}} \mathrm{H}_{\mathrm{b}} \mathrm{O}_{\mathrm{c}} \mathrm{N}_{\mathrm{d}}$ and molecular weight $187$. A $935 \: \...

​​​​​A hydrocarbon $\left(\mathrm{C}_{\mathrm{n}} \mathrm{H}_{\mathrm{m}}\right)$ is burnt in air $\left(\mathrm{O}_{2}+3.78 \mathrm{~N}_{2}\right)$. The stoichiometric f...

​​​​​$\mathrm{MgCl}_{2}$ and $\mathrm{CaSO}_{4}$ salts are added to $1$ litre of distilled deionized water and mixed until completely dissolved. Total Dissolved Solids (T...

Organic fraction of municipal solid waste (OFMSW) with bulk density of $315 \mathrm{~kg} / \mathrm{m}^{3}$ and water content of $30 \%$ is mixed with municipal sludge of ...

A circular settling tank is to be designed for primary treatment of sewage at a flow rate of $10$ million liters/day. Assume a detention period of $2.0$ hours and surface...

An organic waste is represented as $\mathrm{C}_{240} \mathrm{O}_{200} \mathrm{H}_{180} \mathrm{~N}_{5} \mathrm{~S}$.(Atomic weights: $\mathrm{S}-32, \mathrm{H}-1, \mathrm...

For the elevation and temperature data given in the table, the existing lapse rate in the environment is _______________ $\text{C}^{\circ} / 100 \mathrm{~m}$ (round off t...

In the context of water and wastewater treatments, the correct statements are:particulate matter may shield microorganisms during disinfectionammonia decreases chlorine d...

The theoretical aerobic oxidation of biomass $\left(\mathrm{C}_5 \mathrm{H}_7 \mathrm{O}_2 \mathrm{~N}\right)$ is given below:$\mathrm{C}_5 \mathrm{H}_7 \mathrm{O}_2 \mat...

A system of seven river segments is shown in the schematic diagram. The $\mathrm{R}_{\mathrm{i}}$ 's, $\mathrm{Q}_{\mathrm{i}}$ 's, and $\mathrm{C}_{\mathrm{i}}$ 's $(\ma...

Which one of the following statements is TRUE for Greenhouse Gas $(\mathrm{GHG})$ in the atmosphere?$\mathrm{GHG}$ absorbs the incoming short wavelength solar radiation t...

Identify the waterborne diseases caused by viral pathogens: Acute anterior poliomyelitisCholera Infectious hepatitis Typhoid fever

In the following table, identify the correct set of associations between the entries in Column-$1$ and Column-$2.$$$\begin{array}{|l|l|}\hline {\qquad \text{Column-1} } &...

The composition and energy content of a representative solid waste sample are given in the table. If the moisture content of the waste is $26 \%$, the energy content of t...

The wastewater inflow to an activated sludge plant is $0.5 \mathrm{~m}^3 / \mathrm{s}$, and the plant is to be operated with a food to microorganism ratio of $0.2 \mathrm...

A $100 \; \text{mg}$ of $\text{HNO}_{3}$ (strong acid) is added to water, bringing the final volume to $1.0 \; \text{liter}.$ Consider the atomic weights of $\text{H, N,}...

In a city, the chemical formula of biodegradable fraction of municipal solid waste $\text{(MSW)}$ is $\text{C}_{100} \text{H}_{250} \text{O}_{80} \text{N}.$ The waste has...

A sewage treatment plant receives sewage at a flow rate of $5000 \; \text{m}^{3}\text{/day}.$ The total suspended solids $\text{(TSS)}$ concentration in the sewage at the...

A sample of air analyzed at $25 \; ^{\circ}\text{C}$ and $1 \; \text{atm}$ pressure is reported to contain $0.04 \; \text{ppm}$ of $\text{SO}_{2}.$ Atomic mass of $\text{...