Sulfate (SO4^2-) concentration is 10 mg SO4^2-/L and
monohydrogen sulfide (HS-) concentration is 2 mg HS-/L....
Sulfate (SO4^2-) concentration is 10 mg SO4^2-/L and
monohydrogen sulfide (HS-) concentration is 2 mg HS-/L. What is the
total inorganic sulfur concentration in mg S/L?
If a ground water contains H2S at concentration of 2 mg/L,
determine the concentration of H2S in head space of a closed tank
containing the ground water at at 20 oC. Given that for
H2S, Henry’s constant (H) is equal to 5.15×102 atm at 20
oC.
An unknown solution containing iron at a concentration between
10 and 50 mg/L is now to be analyzed. 5 mL of this unknown solution
is diluted to 100 mL with the appropriate reagents to form the
ferrous - phenanthroline complex. The diluted solution has an
absorption of 0.614. A. What is the concentration in (mg/L) of
ferrous ion in the diluted solution? B. What is the concentration
of iron in the unknown solution (before it was diluted), in mg L-1...
A surface water is coagulated with a dosage of 30 mg/L ferrous
sulfate and an equivalent dosage of hydrated lime (Ca(OH)2).
2FeSO4*7H2O + 2Ca(OH)2 +
0.5O2 -> 2Fe(OH)3 + 2CaSO4 + 13
H2O
A ) How many pounds of ferrous sulfate are needed per MGD of
water treated.
B) How many pounds/mil of hydrated lime are required assuming, a
purity of 70% CaO?
C) Determine the pounds of Fe(OH)3 sludge are produced per MGD
of water treated.
A wastewater contains 8 mg/L O2, 10-3 mol/L NO3 - , and 10-2
mol/L organic matter [CH2O] (no significant exchanges with
atmosphere occur) After bacterial metabolism is complete, which of
the following statements will be true? a) No [CH2O] remains b) Some
O2 remains c) Some NO3 - remains d) Denitrification consumed more
[CH2O] than respiration e) The composition of water remains
unchanged
A river is contaminated with 0.65 mg/L of dichloroethylene
(C2H2Cl2). What is the concentration (in ng/L) of dichloroethylene
at 21 C in the air breathed by a person swimming in the river (kH
for C2H2Cl2 in water is 0.033 mol/L * atm)
If hydrogen sulfide concentrations are greater than 0.15 mg S/L,
it is harmful to fish health, calculate the minimum safe pH, if the
total sulfide concentration is determined to be 20 micrometers.
Assume this is a closed system and there is no H2S
transfer with the atmosphere. pKa1= 7, pKa2=
12 for H2S. Molar mass for sulfur is 32g/mol