GATE CE 2020 National Champion Quiz 7 (App update required to attempt this test)
Attempt now to get your rank among 493 students!
Question 1
An industry requires water of maximum hardness 0.1 gm/l with a daily usage of 12 MLD. It has installed softener containing resins having the efficiency 90%. What should be the bypass flow rate for the water which has hardness of 500 mg/l as CaCO3.
Question 2
List 1 contains chemical substances and List 2 contains their permissible limits. Choose the correct options. List 1 P. Lead Q. Sulphur R. Zinc S. Chloride List 2 1) 250 2) 0.05 3) 200 4) 5
Question 3
Following observations have been made for the elevation and temperature to ascertain the stability of the atmosphere: The atmosphere is classified as
Question 4
Determine the contact period in minutes required for the disinfection of water using ozone for 95% removal. Assume k=0.13 per minute.
Question 5
A landfill area of 160m × 100 m is used for handing municipal solid waste for 25 years of a town with population 5,00,000. With 25% of the total landfill area used for auxiliary services and assuming the average per capita MSW discharge per year in town is 0.06 tonne, landfill density 500 kg/m3 and 20% of the actual landfill volume is used for soil cover, the number of years for which the land fill can be used if the landfill can’t be increased beyond 25m will be
Question 6
Find the design demand in MLD required for the design of a water supply scheme of a city having population 200000 and per capita demand of 225 litres per day.
Question 7
BOD5 of wastewater has been measured as 500 mg/l. Rate constant = 0.26 /day ( base e ). What proportion of BOD would remain unutilised after 20 days.
Question 8
A solid waste sample has following composition:
What is the moisture content of the solid waste sample?
Question 9
A circular sewer is to carry 0.08 m3/sec when flowing half full and slope is 5 m for 1 k m. What is the velocity (in m/sec) of flow? [Assume n = 0.013]
Question 10
A schematic flow diagram of a completely mixed biological reactor with provision for recycling of solids is shown in the figure.
readily biodegradable soluble BOD, mg/L
flow rates,
microorganism concentrations (mixed-liquor volatile suspended solids or MLVSS), mg/L
The mean cell residence time (in days, up to one decimal place) is ___________
Question 11
A city has population of 2,00,000 and water demand is 225 lpcd. If the water contains 7 mg/l alkalinity as CaCO3, determine the quantity of quick lime required for the treatment if water is treated using coagulation with alum having a dosage of 22 mg/l. State your answer in kg per day correct upto two places after decimal.
Question 12
An average data for conventional activated sludge treatment plant is as follows:
Wastewater flow = 35000 m3/d
Volume of aeration tank = 10500 m3
Influent BOD = 230 mg/L
Effluent BOD = 20 mg/L
Mixed Liquor suspended solids (MLSS) = 2200 mg/L
Effluent suspended solids = 30 mg/L
Waste sludge suspended solids = 9500 mg/L
Quantity of waste sludge = 200 m3/day
Assume MLVSS = 75% MLSS
Based on the above information, the oxygen requirement of the aeration tank is _________ tonnes/day.
readily biodegradable soluble BOD, mg/L
flow rates,
microorganism concentrations (mixed-liquor volatile suspended solids or MLVSS), mg/L
