Waste Water Engineering Questions

• The coagulant widely used for sewage treatment, is
• The gas which may cause explosion in sewers, is
• Assertion (A) : Discharging the effluents from the oxidation ponds just up stream of lakes or reservoirs is undesirable. Reason (R) : The discharged algae get settled in the reservoirs and cause anaerobic decomposition and other water qualities.
• In a fully mechanised composting plant, involves
• In primary sedimentation, the 0.2 mm inorganic solids get separated if specific gravity is
• For non-scouring velocity 5 m/sec, the type of sewers generally preferred to, is
• If D is the diameter of upper circular portion, the overall depth of a standard egg shaped section, is
• When drainage to sewage ratio is 20, the peak dry weather flow is
• A rain sanitary sewer is constructed to carry
• For the COD test of sewage, organic matter is oxidised by K2Cr207 in the presence of
• The sewage is pumped up
• The screens are fixed
• If the over land flow from the critical point to the drain is 8 km and the difference in level is 12.4 m, the inlet time is
• The minimum recommended diameter of sewers, is
• Aerobic bacterias
• A sewer pipe contains 1 mm sand particles of specific gravity 2.65 and 5 mm organic particles of specific gravity 1.2, the minimum velocity required for removing the sewerage, is
• In R.C. sewer pipes, the percentage longitudinal reinforcement to the cross-sectional area of concrete is kept
• The width of a rectangular sewer is twice its depth while discharging 1.5 m/sec. The width of the sewer is
• Chlorination of water is done for the removal of
• The detention time of a circular tank of diameter d and water depth H, for receiving the sewage Q per hour, is