fundamentals of engineering supplied-reference handbook - Ventech!

Facultative Pond
BOD Loading
Mass (lb/day) = Flow (MGD) × Concentration (mg/L)
× 8.34(lb/MGal)/(mg/L)
Total System ≤ 35 pounds BOD5/acre-day
Minimum = 3 ponds
Depth = 3−8 ft
Minimum t = 90−120 days
WATER TREATMENT TECHNOLOGIES
Activated Carbon Adsorption
Freundlich Isotherm
x 1 n
X = KCe
= , where
m
x = mass of solute adsorbed,
m = mass of adsorbent,
X = mass ratio of the solid phase—that is, the mass of
adsorbed solute per mass of adsorbent,
Ce = equilibrium concentration of solute, mass/volume,
and
K, n = experimental constants.
Linearized Form
x
ln = 1 nlnCe+ lnK
m
For linear isotherm, n = 1
Langmuir Isotherm
x aKCe
= X = , where
m 1+
KC
e
a = mass of adsorbed solute required to saturate
completely a unit mass of adsorbent, and
K = experimental constant.
Linearized Form
m 1 1 1
= +
x a aK Ce
C, ,
mg/l
Cα =
Co
z
161
Depth of Sorption Zone
VZ
ZS
Z
s
(QW, CIN)
(QW, COUT)
⎡
= Z ⎢
⎣V
= VT – VB
T
ENVIRONMENTAL ENGINEERING (continued)
VZ
− 0.
5V
= depth of sorption zone,
Z = total carbon depth,
Z
⎤
⎥ , where
⎦
VolT = total volume treated at
exhaustion (C = 0.95 Co),
VolB = total volume at
breakthrough (C = Cα =
0.05 Co), and
Co = concentration of Ce
contaminant in influent.
Air Stripping
where
(QA, AOUT)
Aout = H′Cin
Qw[Cin] = QA [H′Cin]
Qw = QA[H′]
H′(QA / QW) = 1
(QA, AIN)
Aout = concentration in the effluent air,
H = Henry's Law constant,
H′ = H/RT = dimensionless Henry's Law constant,
T = temperature in units consistent with R
R = universal gas constant, QW
flow rate (m
= water
3 /s),
QA = air flow rate (m 3 /s),
A = concentration of contaminant in air (kmol/m 3 ), and
C = concentration of contaminants in water (kmol/m 3 ).
Stripper Packing Height = Z
Z = HTU × NTU
⎛ R ⎞ ⎛( Cin Cout )( R−
1) + 1⎞
NTU = ⎜ ln
⎝
⎟
R−1⎠ ⎜
R
⎟
⎝ ⎠
NTU = number of transfer units
Z
Zs
Co
Qin
Co
Qout