Activated sludge process: F/M ratio, MLSS, SRT and SVI
How the most common sewage treatment process works, and the four numbers operators watch every day.
Ujjwal Infra
Civil engineering, made clear.
Clear notes, exam preparation and practice for every civil engineering subject, from structures and geotechnics to transportation, water and construction.
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All notes →Atterberg limits and plasticity index in plain words
Liquid limit, plastic limit and shrinkage limit, what the plasticity index tells you, and how the A-line classifies fine soils.
Bernoulli's equation and the venturimeter
Energy along a streamline as pressure head, velocity head and datum head, and how a venturimeter turns a pressure drop into a flow rate.
Bitumen tests and VG grades, explained for exams and site
Penetration, softening point, ductility and viscosity tests, and how India moved to VG-10, VG-30 and VG-40 grading.
BOD: what it measures and how to calculate it
Biochemical oxygen demand, the first-order BOD curve, the dilution test, and the effect of temperature on the rate constant.
Curvature and refraction corrections in levelling
Why long sights read too high, the 0.0785 d² and 0.0112 d² corrections, and the distance to the visible horizon.