Environmental Engineering FOURTH EDITION

458 ENVIRONMENTLENGINEERING

D(t)
D ord
D
D
DO
DOT
d
d'
dc
dB
Ds
DP
dd4Y

E

E

E

E

EL4

EIS

Em

EPA

EQI

e

esu

eV

F

F

FONSI

FB

FD

Fg

f

F'

G

GL

G

GY

g

Horh

H

H

oxygen deficit at time (t), in mg/L.

diameter, in m or ft or in.

deficit in DO, in mgL

dilution (volume of sampldtotal volume) (Chap. 4)

initial DO deficit, in mgL

U.S. Department of Transportation

depth of flow in a pipe, in m or in. (Chap. 7)

geometric mean diameter between sieve sizes, m or ft

cut diameter, in m

decibel

oxygen deficit upstream from wastewater discharge, mgL

oxygen deficit in wastewater effluent, mg/L

rate of shear, or slope of the velocity @)-depth b) profile

rainfall energy, ft-tondacre inch

efficiency of materials separation

evaporation, mm

symbol for exponent sometimes used in place of 10.

environmental impact assessment

environmental impact statement

environmental impact unit

U.S. Environmental Protection Agency

environmental quality index

porosity fraction of open spaces in sand

electrostatic unit of charge

electron volt = 1.60 x joule

final BOD of sample, mg/L

food (BOD), in mgL

finding of no significant (environmental) impact

buoyant force, in N

drag force, in N

gravitational force, in N

friction factor

final BOD of seeded dilution water, mgL

flow in a thickener, kg/m2 x s (Chap. 9)

limiting flux in a thickener, kg/m2 x s

velocity gradient, in s-l (Chap. 6)

gray: unit of absorbed energy; 1 joulekg

acceleration due to gravity, in m/s2 or Ws2

height, m

depth of stream flow, in m (Chap. 3)

effective stack height, m (Chap. 19)