Section Four Analysis and Design

accumulations (delta s)=

input - output + reaction

if 0= input - output then the reaction is ______

steady

when n = 1 the reaction is considered a _____ order reaction

first order

rate of loss of the substance is _______ to the amount of substance present at any given time for the first order reaction

proportional (not exponential) (r=-kC)

rate of loss of the substance is _______ to the amount of substance present at any given time zero order reaction

independent (linear) (r=-k)

rate of loss of the substance is _______ to the amount of substance present at any given time second order reaction

proportional to concentration squared (r=-kC²)

single phase, ex: BOD by bacteria during bio treatment of WW, chemical rxn between aqueous chlorine and pathogens during disinfection of drinking water

homogeneous reaction

two phases, ex: air water interface or solid water interface… transfer of o2 into water or ww to increase DO concentration and the adsorption of organic contaminants in activated carbon

heterogeneous reaction

overflow rate/ surface loading = Q/ ( X )

LXW

horizontal velocity = Q/ ( X )

WXH

in a storage tank , flow in - flow out =

change in storage volume , unsteady

closed conduit measures pressure (5)

piezometer, manometer, pressure transducer, barometer

closed conduit measures velocity (2)

pitot tube, current meter

closed conduit measure flow (3)

oriface, nozzle, venturi meter

open conduit measures flow by changes area of stream and then changes water level (5)

weirs , flumes, oriface, sluice gate, spillway

barrier in an open channel over which water flows, useful only as means of measuring flowing water which type specifially

sharp crested weir

weir with not sharp crested, all other weirs classified

broad crested

weir type used in small rivers and canals

sharp crested, rectangular

weir type measure low flows, used in clarifiers

v- notch

weir type large rivers or canals

broad crested

weir type highest flows measured, irrigation canals

trapezoidal

discharge over an ogee spillway remains the same as that of (sharp crested weir, or sluice gate)

sharp crested weir

which of the weirs are used to measure low flow in an open channel (v notch, sharp, broad)

v notch