Recent questions tagged environmental-engineering / GO Civil

0 votes

0 answers

41

GATE2015-1-20
Total Kjeldahl Nitrogen (TKN) concentration (mg/L as N) in domestic sewage is the sum of the concentrations of organic and inorganic nitrogen in sewage organic nitrogen and nitrate in sewage organic nitrogen and ammonia in sewage ammnia and nitrate in sewage

Total Kjeldahl Nitrogen (TKN) concentration (mg/L as N) in domestic sewage is the sum of the concentrations oforganic and inorganic nitrogen in sewageorganic nitrogen and...

Milicevic3306

11.9k points

Milicevic3306 asked Mar 26, 2018

0 votes

0 answers

42

GATE2015-1-21
Solid waste generated from an industry contains only two components, X and Y as shown in the table below. ... $100(c_1 \rho_1 +c_2 \rho_2) \\$ $100 \bigg( \dfrac{\rho_1 \rho_2}{c_1 \rho_1 + c_2 \rho_2} \bigg)$

Solid waste generated from an industry contains only two components, X and Y as shown in the table below.$$\begin{array}{ccc} \textbf{Component} & \textbf{Composition} & ...

Milicevic3306

11.9k points

Milicevic3306 asked Mar 26, 2018

0 votes

0 answers

43

GATE2015-1-49
The concentration of Sulfur Dioxide $(SO_2)$ in ambient atmosphere was measured as $30 \: \mu g /m^3$. Under the same conditions, the above $SO_2$ concentration expressed in ppm is _________. Given: $P/(RT) = 41.6 \: mol/m^3$; where, $P=$ Pressure; $T=$ Temperature; $R=$ universal gas constant; Molecular weight of $SO_2 =64$.

The concentration of Sulfur Dioxide $(SO_2)$ in ambient atmosphere was measured as $30 \: \mu g /m^3$. Under the same conditions, the above $SO_2$ concentration expressed...

Milicevic3306

11.9k points

Milicevic3306 asked Mar 26, 2018

0 votes

0 answers

44

GATE2015-1-50
Consider a primary sedimentation tank (PST) in a water treatment plant with Surface Overflow Rate (SOR) of $40\:m^3/m^2/d$. The diameter of the spherical particle which will have $90$ percent theoretical removal efficiency in this tank is ______ $\mu m$. Assume that settling velocity of the ... $g=9.81 \: m/s^2$; Kinematic viscosity of water $(v) = 1.10 \times 10^{-6} m^2/s$.

Consider a primary sedimentation tank (PST) in a water treatment plant with Surface Overflow Rate (SOR) of $40\:m^3/m^2/d$. The diameter of the spherical particle which w...

Milicevic3306

11.9k points

Milicevic3306 asked Mar 26, 2018

0 votes

0 answers

45

GATE2014-2-47
A surface water treatment plant operates round the clock with a flow rate of $35 \: m^3/min$. The water temperature is $15^{\circ}C$ and jar testing indicated an alum dosage of $25$ mg/l with flocculation at a $Gt$ value of $4 \times 10^4$ producing optimal results. The alum quantity required for $30$ days (in kg) of operation of the plant is _______

A surface water treatment plant operates round the clock with a flow rate of $35 \: m^3/min$. The water temperature is $15^{\circ}C$ and jar testing indicated an alum dos...

Milicevic3306

11.9k points

Milicevic3306 asked Mar 25, 2018

0 votes

0 answers

46

GATE2014-2-48
An effluent at a flow rate of $2670 \: m^3/d$ from a sewage treatment plant is to be disinfected. The laboratory data of disinfection studies with a chlorine dosage of $15$ mg/l yield the model $N_t=N_oe^{-0.145t}$ where $N_t=$ number of micro-organisms surviving ... (at $t=0$). The volume of disinfection unit (in $m^3$) required to achieve a $98\%$ kill micro-organisms is __________

An effluent at a flow rate of $2670 \: m^3/d$ from a sewage treatment plant is to be disinfected. The laboratory data of disinfection studies with a chlorine dosage of $1...

Milicevic3306

11.9k points

Milicevic3306 asked Mar 25, 2018

0 votes

0 answers

47

GATE2014-2-49
A waste water stream (flow $=2 m^3/s$, ultimate BOD$=90$ mg/l) is joining a small river (flow $=12 \: m^3/s$, ultimate BOD $=5$ mg/l). Both water streams get mixed up instantaneously. Cross-sectional area of the river is $50 \: m^2$. Assuming the de-oxygenation rate ... $10$ km downstream of the mixing point is $1.68$ $12.63$ $15.46$ $1.37$

A waste water stream (flow $=2 m^3/s$, ultimate BOD$=90$ mg/l) is joining a small river (flow $=12 \: m^3/s$, ultimate BOD $=5$ mg/l). Both water streams get mixed up ins...

Milicevic3306

11.9k points

Milicevic3306 asked Mar 25, 2018

0 votes

0 answers

48

GATE2014-2-21
The dominating microorganisms in an activated sludge process reactor are aerobic heterotrophs anaerobic heterotrophs autotrophs phototrophs

The dominating microorganisms in an activated sludge process reactor areaerobic heterotrophsanaerobic heterotrophsautotrophsphototrophs

Milicevic3306

11.9k points

Milicevic3306 asked Mar 25, 2018

0 votes

0 answers

49

GATE2014-2-22
The two air pollution control devices that are usually used to remove very fine particles from the flue gas are Cyclone and Venturi Scrubber Cyclone and Packed Scrubber Electrostatic Precipitator and Fabric Filter Settling Chamber and Tray Scrubber

The two air pollution control devices that are usually used to remove very fine particles from the flue gas areCyclone and Venturi ScrubberCyclone and Packed ScrubberElec...

Milicevic3306

11.9k points

Milicevic3306 asked Mar 25, 2018

0 votes

0 answers

50

GATE2014-1-48
For a sample water with the ionic composition shown in the figure below, the carbonate and non-carbonate hardness concentrations (in mg/l as $CaCO_3$), respectively are: $200$ and $50$ $175$ and $75$ $75$ and $175$ $50$ and $200$

For a sample water with the ionic composition shown in the figure below, the carbonate and non-carbonate hardness concentrations (in mg/l as $CaCO_3$), respectively are:$...

Milicevic3306

11.9k points

Milicevic3306 asked Mar 25, 2018

0 votes

0 answers

51

GATE2014-1-46
$16$ MLD of water is flowing through a $2.5$ km long pipe of diameter $45$ cm. The chlorine at the rate of $32$ kg/d is applied at the entry of this pipe so that disinfected water is obtained at the exit. There is a proposal to increase the flow through this ... per day) to be applied to achieve the same degree of disinfection for the enhanced flow is $60.50$ $44.00$ $38.00$ $23.27$

$16$ MLD of water is flowing through a $2.5$ km long pipe of diameter $45$ cm. The chlorine at the rate of $32$ kg/d is applied at the entry of this pipe so that disinfec...

Milicevic3306

11.9k points

Milicevic3306 asked Mar 25, 2018

0 votes

0 answers

52

GATE2014-1-21
Some of the nontoxic metals normally found in natural water are arsenic lead and mercury calcium sodium and silver cadmium, chromium and copper iron, manganese and magnesium

Some of the nontoxic metals normally found in natural water arearsenic lead and mercurycalcium sodium and silvercadmium, chromium and copperiron, manganese and magnesium

Milicevic3306

11.9k points

Milicevic3306 asked Mar 25, 2018

0 votes

0 answers

53

GATE2014-1-22
The amount of $CO_2$ generated (in kg) while completely oxidizing one kg of $CH_4$ to the end products is _________

The amount of $CO_2$ generated (in kg) while completely oxidizing one kg of $CH_4$ to the end products is _________

Milicevic3306

11.9k points

Milicevic3306 asked Mar 25, 2018

0 votes

0 answers

54

GATE Civil 2013 | Question: 43
A student began experiment for determination of $5$-day, $20^{\circ}C$ BOD on Monday. Since the $5$th day fell on Saturday, the final DO readings were taken on next Monday. On calculation, BOD (i.e. $7$ day, $20^{\circ}C$ was found to be $150$ ... )? Assume value of BOD rate constant $(k)$ at standard temperature of $20^{\circ}C$ as $0.23/day$ (base $e$). ___________

A student began experiment for determination of $5$-day, $20^{\circ}C$ BOD on Monday. Since the $5$th day fell on Saturday, the final DO readings were taken on next Monda...

Milicevic3306

11.9k points

Milicevic3306 asked Mar 25, 2018

0 votes

0 answers

55

GATE Civil 2013 | Question: 42
A settling tank in a water treatment plant is designed for a surface overflow rate of $30 \dfrac{m^3}{\text{day} \cdot m^2}$. Assume specific gravity of sediment particles $=2.65$, density of water $(\rho) =1000 \: kg/m^3$, dynamic viscosity of ... The approximate minimum size of particles that would be completely removed is $0.01$ mm $0.02$ mm $0.03$ mm $0.04$ mm

A settling tank in a water treatment plant is designed for a surface overflow rate of $30 \dfrac{m^3}{\text{day} \cdot m^2}$. Assume specific gravity of sediment particle...

Milicevic3306

11.9k points

Milicevic3306 asked Mar 25, 2018

0 votes

0 answers

56

GATE Civil 2013 | Question: 20
Some of the water quality parameters are measured by titrating a water sample with a titrant. Group I gives a list of parameters and Group-II gives the list of titrants. ... $P - 2, Q - 1, R - 4, S - 3$ $P - 4, Q - 3, R - 2, S - 1$

Some of the water quality parameters are measured by titrating a water sample with a titrant. Group I gives a list of parameters and Group-II gives the list of titrants.$...

Milicevic3306

11.9k points

Milicevic3306 asked Mar 25, 2018

0 votes

0 answers

57

GATE Civil 2013 | Question: 21
A water treatment plant is designed to treat $1 \: m^3/s$ of raw water. It has $14$ sand filters. Surface area of each filter is $50 \: m^2$. What is the loading rate (in $\dfrac{m^3}{\text{day} \cdot m^2}$) with two filters out of service for routine backwashing? __________

A water treatment plant is designed to treat $1 \: m^3/s$ of raw water. It has $14$ sand filters. Surface area of each filter is $50 \: m^2$. What is the loading rate (in...

Milicevic3306

11.9k points

Milicevic3306 asked Mar 25, 2018

0 votes

0 answers

58

GATE Civil 2012 | Question: 50
An activated sludge system (sketched below) is operating at equilibrium with the following information. Wastewater related data: flow rate $= 500 \: m^3/hour$, influent BOD $=150 \: mg/L$, effluent BOD $=10 \: mg/L$. Aeration tank related data: hydraulic retention ... ratio (in kg BOD per kg biomass per day) for the aeration tank is $0.015$ $0.210$ $0.225$ $0.240$

An activated sludge system (sketched below) is operating at equilibrium with the following information. Wastewater related data: flow rate $= 500 \: m^3/hour$, influent B...

Milicevic3306

11.9k points

Milicevic3306 asked Mar 25, 2018

0 votes

0 answers

59

GATE Civil 2012 | Question: 51
An activated sludge system (sketched below) is operating at equilibrium with the following information. Wastewater related data: flow rate $=500 \: m^3/hour$, influent BOD $= 150 mg/L$, effluent BOD $=10 \: mg/L$ ... $24000$ $1000$ $800$ $33$

An activated sludge system (sketched below) is operating at equilibrium with the following information. Wastewater related data: flow rate $=500 \: m^3/hour$, influent BO...

Milicevic3306

11.9k points

Milicevic3306 asked Mar 25, 2018

0 votes

0 answers

60

GATE Civil 2012 | Question: 42
A water sample has a pH of $9.25$. The concentration of hydroxyl ions in the water sample is $10^{-9.25}$ moles/L $10^{-4.75}$ mmoles/L $0.302$ mg/L $3.020$ mg/L

A water sample has a pH of $9.25$. The concentration of hydroxyl ions in the water sample is$10^{-9.25}$ moles/L$10^{-4.75}$ mmoles/L$0.302$ mg/L$3.020$ mg/L

Milicevic3306

11.9k points

Milicevic3306 asked Mar 25, 2018

0 votes

0 answers

61

GATE Civil 2012 | Question: 43
A town is required to treat $4.2 \: m^3/min$ of raw water for daily domestic supply. Flocculating particles are to be produced by chemical coagulation. A column analysis indicated that an overflow rate of $0.2$ mm/s will produce satisfactory particles removal in a ... depth of $3.5$ m. The required surface area (in $m^2$) for settling is $210$ $350$ $1728$ $21000$

A town is required to treat $4.2 \: m^3/min$ of raw water for daily domestic supply. Flocculating particles are to be produced by chemical coagulation. A column analysis ...

Milicevic3306

11.9k points

Milicevic3306 asked Mar 25, 2018

0 votes

0 answers

62

GATE Civil 2012 | Question: 21
... $\textbf{[a]}$ and $\textbf{[r]}$ are false $\textbf{[a]}$ is true but $\textbf{[r]}$ is false

$\begin{array}{lcl} \textbf{Assertion [a]} &: & \text{At a manhole, the crown of the outgoing sewer should not be higher} \\ & & \text{than the crown of the incoming sewe...

Milicevic3306

11.9k points

Milicevic3306 asked Mar 25, 2018

0 votes

0 answers

63

GATE2018 CE-2: 52
A schematic flow diagram of a completely mixed biological reactor with provision for recycling of solids shown in the figure. $S_0$, $S$ = readily biodegradable soluble BOD, mg/L $Q, \: Q_r, \: Q_w$ = flow rates $m^3/d$ ... (mixed liquor soils volatile suspended solids or MLVSS ), mg/l The mean cell residence time (in days, up to one decimal place) is _____

A schematic flow diagram of a completely mixed biological reactor with provision for recycling of solids shown in the figure. $S_0$, $S$ = readily biodegradable soluble B...

gatecse

4.0k points

gatecse asked Feb 17, 2018

0 votes

1 answer

64

GATE2018 CE-2: 51
At a small water treatment plant which has $4$ filters, the rates of filteration and backwashing are $200 \: m^3/d/m^2$ and $1000 m^3/d/m^2$, respectively. Backwashing is done for $15$ min per day. The maturation, which ... the water being wasted during backwashing and maturation. The percentage increase in the filtered water produced (up to two decimal places) would be ______

At a small water treatment plant which has $4$ filters, the rates of filteration and backwashing are $200 \: m^3/d/m^2$ and $1000 m^3/d/m^2$, respectively. Backwashing is...

gatecse

4.0k points

gatecse asked Feb 17, 2018

0 votes

1 answer

65

GATE2018 CE-2: 14
As per $\text{IS }10500:2012$, for drinking water in the absence of alternate source of water, the permissible limits for chloride and sulphate, in mg/L, respectively are $250$ and 200$ $1000$ and 400$ $200$ and 250$ $500$ and 1000$

As per $\text{IS }10500:2012$, for drinking water in the absence of alternate source of water, the permissible limits for chloride and sulphate, in mg/L, respectively are...

gatecse

4.0k points

gatecse asked Feb 17, 2018

0 votes

0 answers

66

GATE2018 CE-2: 15
In the figures, Group I represents the atmospheric temperature profiles (P, Q, R and S) and Group II represents dispersion of pollutants from a smoke stack $(1, 2, 3$ and $4)$. In the figures of Group I, the dashed line represents the dry adiabatic lapse rate, whereas the horizontal axis represents temperature and ... $P-1, Q-4, R-3, S-2$ $P-3, Q-1, R-2, S-4$

In the figures, Group I represents the atmospheric temperature profiles (P, Q, R and S) and Group II represents dispersion of pollutants from a smoke stack $(1, 2, 3$ and...

gatecse

4.0k points

gatecse asked Feb 17, 2018

0 votes

1 answer

67

GATE2018 CE-1: 52
The ultimate BOD $(L_0)$ of a wastewater sample is estimated as $87 \%$ of COD. The COD of this wastewater is $300$ mg/L. Considering first order BOD reaction rate constant $k$ (use natural log) $= 0.23$ ... value in (in mg/L, up to one decimal place) after three days of incubation at $27^{\circ}$C for this wastewater will be _____

The ultimate BOD $(L_0)$ of a wastewater sample is estimated as $87 \%$ of COD. The COD of this wastewater is $300$ mg/L. Considering first order BOD reaction rate consta...

gatecse

4.0k points

gatecse asked Feb 17, 2018

0 votes

1 answer

68

GATE2018 CE-1: 51
A water sample analysis data is given below, ... $CaCO_3$, up to one decimal place), for the water sample, is ____

A water sample analysis data is given below,$$\begin{array}{|c|c|} \hline \textbf{Ion} & \textbf{Concentration, mg/L} & \textbf{Atomic Weight} \\ \hline Ca^{2+} & 60 & 40...

gatecse

4.0k points

gatecse asked Feb 17, 2018

0 votes

1 answer

69

GATE2018 CE-1: 53
A waste activated sludge (WAS) is to be blended with green waste (GW). The carbon (C) and nitrogen (N) contents, per kg of WAS and GW, on dry basis are given in the table. ... $C: N$ ratio of $20:1$ on dey basis is ____

A waste activated sludge (WAS) is to be blended with green waste (GW). The carbon (C) and nitrogen (N) contents, per kg of WAS and GW, on dry basis are given in the table...

gatecse

4.0k points

gatecse asked Feb 17, 2018

0 votes

1 answer

70

GATE2018 CE-1: 33
A rapid sand filter comprising a number of filter beds is required to produce $99$ MLD of potable water. Consider water loss during backwashing as $5\%$, rate of filtration as 6.0 m/h and length to width ratio of filter bed as $1.35$. The width of each ... to take care of break-down, repair, and maintenance. The total number of filter beds required will be $19$ $20$ $21$ $22$

A rapid sand filter comprising a number of filter beds is required to produce $99$ MLD of potable water. Consider water loss during backwashing as $5\%$, rate of filtrati...

gatecse

4.0k points

gatecse asked Feb 17, 2018

0 votes

1 answer

71

GATE2018 CE-1: 25
A city generates $40 \times 10^6$ kg of municipal solid waste (MSW) per year, out of which only $10\%$ is recovered/recycled and the rest goes to landfill. The landfill has a single life of $3$ m height and is compacted to a density of $550 \: kg/m^3$. If $80 \%$ of the landfill is assumed to be MSW, the landfill area (in $m^2$, up to one decimal place) required would be _______

A city generates $40 \times 10^6$ kg of municipal solid waste (MSW) per year, out of which only $10\%$ is recovered/recycled and the rest goes to landfill. The landfill h...

gatecse

4.0k points

gatecse asked Feb 17, 2018