Aeration of water is employed for removal of

In the design of sedimentation tank, the most essential factor considered is

Methemoglobinemia is caused by excess of the following in drinking water :

Which of the following are the common problems associated with operation of rapid sand filter?\n(I) Air binding\n(II) Mud ball formation\n(III) Zoogleal layer development\n(IV) Cracking of sand beds

The electrical conductivity generally ______ with increase in total dissolved solids in water.

Summits are points of

Ethyl diaminetetraacetic acid is used to determine ______ of water.

Jet pumps are used for

In design of water conduits, selection of smaller velocity will result in

______ is a unit used to measure the loudness of sounds.

Explain the concept of indicator organism in the determination of bacteriological quality of water. What are the reasons for selecting E.coli as the indicator organism for water quality?

A new town A is coming up in Madhya Pradesh which is expected to grow with a rate similar to town X. Town X started developing as a new town in 1941 and its population grew as per the data given below :\n\n| Year | 1941 | 1951 | 1961 | 1971 | 1981 |\n| :--- | :--- | :--- | :--- | :--- | :--- |\n| Population | 196415 | 283479 | 364594 | 475300 | 813963 |\n\nThe population of town A, as described above, is 200000 in 2016. Explain, with reasons, the growth model you will apply for population forecasting of town A and forecast the population of town A for a water supply scheme with period of design as 30 years.

Draw a neat flow diagram for treatment of drinking water sourced from surface water with justification of each treatment unit employed for the treatment.

For water supply of a small town with daily requirement of 225000 litres, it is proposed to build a distribution reservoir. The pattern of draw of water is as follows :\n\n| Time | % of daily supply |\n| :--- | :--- |\n| 7:00 AM-8:00 AM | 30% of daily supply |\n| 8:00 AM-5:00 PM | 35% of daily supply |\n| 5:00 PM-6:30 PM | 30% of daily supply |\n| 6:30 PM-7:00 AM | 5% of daily supply |\n\nThe pumping is to be done for 8 hours per day between 8:00 AM to 4:00 PM. Determine the storage capacity of reservoir.

Give a neat sketch of a rapid sand filter and explain the operation sequence of valves during normal filtration and backwashing.

A $300\text{ m}^3$ rectangular primary sedimentation tank receives water containing 100 mg/l of single-size spherical suspended particle of diameter 0.5 mm and specific gravity 2.65 at $20^\circ\text{C}$ at a rate of $10^9$ liters per day. Depth of water in tank is 3 m. The settling velocity of particle was found to be 0.093 m/s. Calculate the amount of suspended solids in this water after primary sedimentation, weight of dry settled particles produced per day from this primary sedimentation tank. Also, calculate the length and width of tank assuming length : width as 3 : 1 if the primary sedimentation tank had 100% removal efficiency.

Explain the terms, free available chlorine, combined chlorine and break-point chlorination.

For disinfecting water supply, it is required to treat 400000 litres of daily water supply with 0.5 mg/l of chlorine. The disinfectant is available in form of bleaching powder containing 30% available chlorine. Calculate the amount of bleaching powder required to treat the water.

Describe with chemical reactions any two coagulants used for treatment of drinking water.

A water treatment plant is to process $30000\text{ m}^3\text{/day}$ raw water. The rapid mixing tank will blend 35 mg/l alum with the flow and is to have detention time of 2 min. The tank is to have square cross section. Determine-\n(i) quantity (kg per day) of alum added;\n(ii) power input (kilowatts) necessary for G value of 900 per second.

What are the different impacts of noise pollution?

Discuss the regulatory guidelines for noise pollution.

Define hardness of water, its various types and explain its significance in context of water supply for domestic and industrial purposes.

Lime soda process was employed for cold softening of water supply of 100000 litres of raw water per day. The water had following composition :\nDissolved $CO_2 = 39.6\text{ mg/l}$\n$Ca^{++} = 44\text{ mg/l}$\n$Mg^{++} = 18\text{ mg/l}$\n$Na^+ = 16\text{ mg/l}$\nAlkalinity $(HCO_3^-) = 122\text{ mg/l}$\nCalculate the requirements of lime and soda per day.

Importance of fluorides in drinking water

Fire demand and coincidental draft

Intermittent vs. continuous supply of water

Intake well

Coagulant aids

Jar test

Effects of noise pollution on people's health

According to IS 10500 : 1991, the desirable limits for pH in drinking water is

DDT has property of

Displacement efficiency of a sedimentation tank may defined as

Coincident draft is

Drinking water supply scheme for Patna Municipal area is based on

Adsorption process may be adopted for the removal of

BOD value of potable water should be

Jaundice is caused by

In drinking water distribution network, which valve is required to be installed at all summits?

The method employed for the determination of hardness is

With the help of flow diagram, show the connections of various components involved in supplying drinking water to a city, when the source of water is a river.

A water supply scheme has to be designed for a city having population of 100000. Estimate the important kinds of draft namely average daily draft, maximum daily draft, maximum hourly draft and coincident draft employing 250 lpcd average water consumption.

Derive an expression for the settling velocity of a spherical particle in liquid when the Reynolds number is less than 0.5.

For a continuous flow settling tank of 3 m deep and 60 m long in size, calculate the flow velocity of water for effective removal of 0.025 mm particle at $25^\circ\text{C}$. (sp. gravity of the particle = 2.65, kinematic viscosity of water at $25^\circ\text{C} = 0.01\text{ cm}^2\text{/sec}$)

How do you determine the optimal dose of a coagulant in laboratory?

Indicate the various components of a slow sand filter with the help of a neat sketch.

A water treatment plant consists of the unit processes coagulation, flocculation, sedimentation, filtration and disinfection. The suspended solids concentration of the raw water is 500 mg/L and the plant treats 36400 m^3$/d. Alum $[Al_2(SO_4)_3 \cdot 14H_2O] is used as a coagulant with a dose rate of 500 mg/L. Compute the sludge solids produced daily if complete reaction of alum to aluminium hydroxide $[Al(OH)_3]$ occurs and 98% total solids are removed by sedimentation unit. (Molecular weight : Al=27, S=32, O=16, H=1)

Calculate the hardness in mg/L as $CaCO_3$ of the following water sample :\n\n| Cation | Concentration (mg/L) | Molecular wt. |\n| :--- | :--- | :--- |\n| $Na^+$ | 15 | 23 |\n| $Mg^{2+}$ | 9 | 24.4 |\n| $Ca^{2+}$ | 48 | 40 |

What do you understand by break-point chlorination? Describe in brief.

Results of chlorine demand test on raw water are given below :\n\n| Sample No. | Chlorine dose (mg/L) | Residual chlorine after 10 minutes contact (mg/L) |\n| :--- | :--- | :--- |\n| 1 | 0.2 | 0.19 |\n| 2 | 0.4 | 0.36 |\n| 3 | 0.6 | 0.50 |\n| 4 | 0.8 | 0.48 |\n| 5 | 1.0 | 0.20 |\n| 6 | 1.2 | 0.40 |\n| 7 | 1.4 | 0.60 |\n| 8 | 1.6 | 0.80 |\n\nDetermine the break-point chlorine dose and chlorine demand.

A town with a population of one lakh is to be supplied with water daily at 200 litres per head. The variation in demand is as follows :\n\n| Time | % of total |\n| :--- | :--- |\n| 6 a.m. to 9 a.m. | 40% |\n| 9 a.m. to 12 noon | 10% |\n| 12 noon to 3 p.m. | 10% |\n| 3 p.m. to 6 p.m. | 15% |\n| 6 p.m. to 9 p.m. | 25% |\n\nDetermine the capacity of the service reservoir employing (a) mass balance curve and (b) analytical method for 12 hours uniform pumping rate from 6 a.m. to 6 p.m.

Two power generator sets namely A and B have capacity to produce noise 80 dB and 83 dB respectively. Find out the noise level at the place where both the generators running simultaneously.

According to IS 10500 : 1991, permissible limit for dissolved solids in drinking water in absence of alternative source is

Which one of the following pollutants does not leave any residue?

For a given discharge, efficiency of sedimentation tank can be increased by

The maximum hourly consumption is generally takes as

Groundwater is generally free from

As per IS 1172-1972, the average domestic water consumption in an Indian city is

Modern turbidity meters working on the principle of 'scattering of light' are known as

Typhoid is caused by

In which water distribution system the minimal length of distribution pipe is required?

Most suitable disinfection process for Indian condition is

What do you understand by design period of a water-supply scheme? Describe in brief the factors considered in estimating design period of a water-supply scheme.

In two periods, each of 20 years, a city has grown from 30,000 to 1,70,000 and then to 3,00,000. Using the above data, determine the saturation population and the equation of the logistic curve for the prediction of future population.

Describe, in brief, infiltration galleries and infiltration well with the help of neat sketches.

Why are tube wells generally preferred as source of drinking water supply for a relatively larger population over open well?

With the help of a neat sketch, differentiate between dry intake wet and intake tower.

In a water treatment plant, the pH of incoming and outgoing waters are 7.2 and 8.4 respectively. Assume a linear variation of pH with time, determine the average pH value of water.

Differentiate between slow sand filter and rapid sand filter.

A filter unit is $4\text{ m} \times 9\text{ m}$. Daily the unit filters 10000 $m^3$ and spends 15 minutes time for backwashing. The rate of backwash water supply is $10\text{ L/m}^2\text{/s}$. Compute the average filtration rate, quantity, and the percentage of treated water used in washing, and the rate of wash water flow in each trough. Assume 4 troughs.

What are the requirements of a good distribution system?

From a water reservoir 3 m deep and maximum water level at 30 m, water is to be pumped through rising main to a distance 1500 m and an elevation 75 m at the constant rate of 900000 L/hour. Calculate the economical diameter of the rising main and the horsepower of the pump. [Neglect minor losses and use $f=0.01$]

Find the settling velocity of a discrete particle in water under conditions when Reynolds number is less than 0.5. The diameter and the specific gravity of the particle are $5 \times 10^{-3}$ cm and 2.65 respectively. Water temperature is $20^\circ\text{C}$. [Kinematic viscosity of water at $20^\circ\text{C} = 1.01 \times 10^{-2}\text{ cm}^2\text{/s}$]

Define noise pollution. Enumerate the sources and effects of noise pollution.

The population of a city in three consecutive decades are 2 lakh, 2.7 lakh and 3.6 lakh respectively. The population of this city in the fourth consecutive decade, according to geometric method, would be

The permissible limit of nitrate content in potable water is

The pipe mains carrying water from the source to the reservoir are designed for the

The valve which allows the flow only in one direction is

The amount of dissolve oxygen for potable waters should not exceed

The treatments which are generally given to treat raw water supplies follow the sequence:

Stokes' law gives the equation for settling velocity ($u_s$) of small particles and viscous flow is

Air binding phenomenon in rapid sand filters may occur due to

The percentage of chlorine in fresh bleaching powder is about

According to Indian Standards, the consumption of water per capita per day for nursing homes, boarding schools and hostels is

What are the factors that affect per capita demand for water? Explain in detail.

The population of a locality as obtained from census report is as follows:

Examine the population of the locality in the year 2020 by using arithmetical and geometrical increase methods.

What are intake towers? Differentiate between 'dry' and 'wet' intake towers.

A 30 cm diameter well penetrates 25 m below the static water table. After 24 hours of pumping @ 5000 litres/minute, the water level in a test well at 90 m is lowered by 0.53 m, and in a well 30 m away the drawdown is 1.11 m. (i) What is the transmissibility of the aquifer? (ii) Also determine the drawdown in the main well.

Explain the sedimentation process used in a water treatment plant. Draw a neat sketch of a sedimentation tank in which coagulant is used.

Two million liters of water per day is passing through a sedimentation tank which is 6.0 m wide, 15.0 m long and having a water depth of 4.0 m. (i) Find the detention time of the tank. (ii) Find the average flow velocity through the tank. (iii) If 75 ppm is the concentration of suspended solids present in turbid raw water, how much dry solids will be deposited per day in the tank, assuming 70% removal in the basin, the average specific gravity of the deposit as 2? (iv) Compute the overflow rate.

How does water quality criteria differ for industrial supplies from those for domestic municipal supplies?

Design seven slow sand filter beds from the following data: Population to be served = 50000 persons Per capita demand = 150 liters/head/day Rate of filtration = 180 liters/hr./sq.m Length of each bed = Twice the breadth

Illustrate with sketches the different types of layouts of pipe systems in distributing water and compare their comparative merits and demerits.

The observed cumulative drafts by a town are stated below; the drafts are at four-hour interval:

Determine the equalizing storage for the above draft, when the pumping is (i) 24 hours and (ii) between 10 am and 10 pm.

What is pollutant? Explain in brief about primary and secondary air pollutants.

Explain equivalent noise level ($L_{eq}$). How shall we calculate equivalent noise level ($L_{eq}$)? Explain with example.

125 cumecs of sewage of a city is discharged in a perennial river which is fully saturated with oxygen and flows at a minimum rate of 1600 cumecs with a minimum velocity of 0.15 m/sec. If the 5-day BOD of the sewage is 300 mg/l, find out whether the critical DO will occur in the river. Assume— (i) coefficient of purification of the river as 4.0; (ii) coefficient of DO is 0.12; (iii) ultimate BOD is 120% of the 5-day BOD of the mixture of sewage and river water.

Explain the different characteristics and quality of sewage.

Water-borne diseases

Biochemical oxygen demand

Metering in distributed systems

Intensity of sound

Air pollution control of gaseous pollutants

Physical characteristics of water

The distribution mains are designed for

As compared to geometrical increase method of forecasting population, arithmetic increase method gives

Methemoglobinemia, the "blue baby" syndrome is caused by consuming water containing excess of

The temporary hardness in water is caused by the presence of

A wastewater sample contains $10^{-5.6}$ mmol/L of $OH^-$ ions at $25^\circ C$. The pH of this sample is

Which of the following chemicals is employed for dechlorination of water?

Turbidity is measured on

Zero hardness of water is achieved by

Why are the gate valves provided in distribution system?

Coal based thermal power stations pollute the atmosphere by adding

Discuss in detail, the various factors which affect the rate of demand.

The population of 5 decades from 1930 to 1970 are given below:

Find out the population after one, two and three decades beyond the last known decade, by using arithmetic increase method.

What are 'infiltration galleries' and 'infiltration wells'? Explain both with neat sketches.

Water contains 210 g of $CO_3^{2-}$, 122 g of $HCO_3^-$ and 68 g of $OH^-$. What is the total alkalinity of water expressed as $CaCO_3$?

What is turbidity? What are principles involved in the measurement of turbidity by Jackson's and Nephelo turbidity meter?

In a water treatment plant, the pH values of incoming and outgoing waters are 7.2 and 8.4 respectively. Assuming a linear variation of pH with time, determine the average pH value of water.

Describe in detail, the methods employed to purify water before supplying to the consumers.

Compute the dimensions of a continuous flow rectangular settling tank treating average of $24 \times 10^5$ litres/day. Take detention period for raw water sedimentation to be 6 hours.

Describe with a neat sketch the working of a pressure filter. What are the relative advantages and disadvantages of this type over those of the gravity types?

Mention any three methods of softening water. Describe zeolite process of softening water in detail.

Illustrate with sketches the different types of layouts of pipe systems in distributing water and compare their comparative merits and demerits.

Mention the methods of disinfection. Describe chlorination in detail.

Alkalinity

Coagulation and flocculation

Disinfection and sterilization

Secondary air pollutants

Aeration

Fabric filter