GATE Questions & Answers of Primary and secondary treatment

What is the Weightage of Primary and secondary treatment in GATE Exam?

Total 2 Questions have been asked from Primary and secondary treatment topic of Water and Waste Water subject in previous GATE papers. Average marks 2.00.

Ultimate BOD of a river water sample is 20 mg/L. BOD rate constant (natural log) is 0.15 day-1. The respective values of BOD (in %) exerted and remaining after 7 days are :

In a wastewater treatment plant, primary sedimentation tank (PST) designed at an overflow rate of 32.5 m3/day/m2 is 32.5 m long, 8.0 m wide and liquid depth of 2.25 m. If the length of the weir is 75 m, the weir loading rate (in m3/day/m) is _________.