Q.2 (a) Explain various forces acting on the sewer when laid below ground level and running full along with mathematical expressions.
(b) A raw wastewater with the following characteristics is being treated in an activated sludge plant. Given that. BOD5 of raw wastewater 220 gm/l; effluent BOD5 desired = 20 mg/l; inflow rate to aeration tank = 100m3/d; mixed liquor volatile suspended solid concentration 2000 mg/l; volume of aeration tank = 500m3; water depth in aeration tank = 2.5 m. Determine the
(i) food to microorganisms (F/M) ratio,
(ii) space loading on aeration tank,
(iii) hydraulic loading on the aeration tank and
(iv) detention period in the aeration tank.
Q. 3 (a) Explain the various types of solid wastes in detail:
(b) Discuss the types of composition of municipal solid wastes.
Q. 4 Compare between separate and combined systems of sewerage. Enumerate the advantages of egg-shape sewer over circular sewer. Explain the rational formula for estimation of storm run-off along with assumptions. Determine the size of a circular sewer for a discharge of 2.25m/sec and the sewer is to be laid at u gradient of 7500. Manning's rugosity coefficient = 0.015.
Q. 5 (a) Explain the difference between compaction and size reduction and their importance in solid waste management.
(b) Explain the types, mode of action, and applications of equipment used for size reduction and component separation detail. https://www.akubihar.com
Q. 6 (a) List the various materials that can be recovered from the municipal solid waste generated from a typical Indian city
(b) Describe in brief the various methods employed for the disposal municipal solid waste.
Q. 7 (a) Explain the importance of the following in the design of sewers:
(i) Self-cleansing velocity and
(ii) Non scouring velocity
(b) A 2 m deep trickling filter with a diameter of 18 m is operated with a recirculation ratio of 1.5. The raw wastewater flow rate is 2.5 ML/d and the 5-day BOD of the raw wastewater is 210 mg/L. Assuming that the primary tank BOD removal efficiency is 30%, compute the hydraulic filter. as well as organic load on the trickling
Q.8 (a) FIDE do you understand by sludge volume index? Discuss in brief
(b) Design an oxidation pond using the following data:
Population 5000
Sewage generation 120 L/c/d
BOD5 of sewage 300 mg/l.
Organic loading 300 kg/ha/d
Q. 9 Write short notes on any four of the following:
(a) National river cleaning plans
(b) Roles of Govt. authorities in water supply
(c) Biomedical waste
(d) Recycling of Sewage
(e) 3R
(f) Roles of government authorities in control of environmental pollution