Register

Homework Help Question and Answers

Submit a new Query

Recent Homework Help Question & Answers


Question 39915

posted 1 years ago

A municipal wastewater treatment plant employs three circular primary clarifiers arranged in parallel, following the bar screen and grit removal chamber. The plant receives 12 MGD. Each clarifier is center-fed (water enters at the center and exists at the perimeter).
The clarifier radius is 42 ft and depth is 10 ft.
What is the hydraulic loading rate (critical velocity) in each clarifier in units of ft.ft2.hr 1?

View answer

Question 39917

posted 1 years ago

Suppose an underground storage tank has been leaking for many years, contaminating the groundwater and causing a contaminant concentration directly beneath the site of 0.30 mg/L. The contamination is flowing at the rate of 1.5 ft per day toward a public drinking water well 2 mile away. The half-life of the contaminant is 10 years. If the PF for the contaminant is 0.02 (mg/kg-day), estimate the cancer risk if a 70-kg person drank 2 L of this water per day for 10years.
If the cancer risk is equal to X in 1 million population, find the X.

View answer

Question 39918

posted 1 years ago

A lake is fed by a polluted stream and a sewage outfall. The stream and sewage wastes have a decay rate coefficient (k) of 0.3/day (1st order units). Assuming complete mixing and no other water losses or gains, what is the steady-state pollutant concentration as mg/L in the lake?
\text { Incoming Stream: } C=10 \mathrm{mg} / \mathrm{L}, Q=55 \mathrm{~m}^{\wedge} 3 / \mathrm{s}
\text { Sewage Outfall: } C=100 \mathrm{ppm}, Q=0.5 \mathrm{~m}^{\wedge} 3 / \mathrm{s}
\text { Lake: V=1,000 m^{ } 3}

View answer

Question 39919

posted 1 years ago

A coal-fired 2100 MW Power Plant has an efficiency of 35%, burns coal with an energy content of10,000 BTU/lb, with 60% carbon content, 1.5% sulfur content. The coal burned produces 10% ash,and of the ash, 70% is fly ash. What are the sulfur emissions if a 70% efficient scrubber is used (inIb S/hr)?

View answer

Question 39916

posted 1 years ago

Find the equilibrium concentration of O, in water (mg/L) at the following temperature and altitude.Sea level is 1atm. Use the Henry's Law Coefficient (KH) from Table 4 (or 2-4).
H: 500 m
T= 20 °C

View answer

Question 40310

posted 1 years ago

1. What is the volume (cf) of a detention pond with:
o Top elevation of 5.0 feet
o Top dimensions of 150 feet by 150 feet
o Bottom elevation of 0.0 feet
o 5:1 H:V Sideslopes
a. < 100,000 cf (b) 100,000 to 200,000 cf (c) 200,000 to 300,000 cf (d) >300,000 cf
\text { Prismoidal formula }-V(c f)=0.333^{*} D Y^{*}\left[A 1+A 2+\left(A 1^{*} A 2\right)^{\wedge} 0.5\right]
DY (ft) is the distance between A1 and A2
A1 (sf) is the area at surface 1
A2 (sf) is the area at surface 2

View answer

Question 40311

posted 1 years ago

2. What is the flowrate (cfs) for a 5 foot wide (length) rectangular weir with an invert of 1.0 feet if the water surface is at elevation 5.0feet? (a) < 50 cfs (b) 50-80 cfs (c) 80-100 cfs (d) > 100 cfs
\text { Rectangular Weir }-\mathrm{Q}(\mathrm{cfs})=\mathrm{C}^{\star} \mathrm{L}^{*} \mathrm{H}^{\wedge} 1.5
L (ft) is the weir length/width
C = 3
H (ft) is the height of the water above the weir invert

View answer

Question 40312

posted 1 years ago

3. What is the flowrate (cfs) for a 1 foot diameter circular orifice with an invert of 0.0 feet if the water surface is at elevation 5.0 feet?(a) < 5cfs (b) 5-10 cfs (c) 10-15 cfs (d) > 15 cfs
Circular Orifice - Q (cfs) = C*A *(2*32.2*H)^0.5%3!
C = 0.6
A (ft2) is pipe area = (3.14*Diameter^2)/4 where Diameter is in ft
where H (ft) is the height of water above the centerline of the orifice

View answer

Question 40313

posted 1 years ago

\text { 4. What is the flowrate (cfs) due to infiltration at elevation } 5.0 \text { feet if } K \text { (ft/day) }=5.0 ? \text { (a) }<0.5 \text { cfs (b) } 0.5-2 \text { cfs (c) } 2-4 \text { cfs (d) }>4 \text { cfs }
\text { Darcy's Law- Q (cfs) }=K^{\star} i^{\star} A
A (sf) is the area at the elevation in question
• i = dH/dL = 1%3D
K (ft/s) is the hydraulic conductivity

View answer

Question 40314

posted 1 years ago

5. What is the value (cfs) at elevation 5.0 feet (top of pond) of the stage-storage-discharge curve (deltat=0.1 hours) assuming a detention pond with volume, weir, orifice, and infiltration as identified in Questions 1 thru 4? (a) < 750 cfs (b) 750-1500 cfs (c)1500-2500 cfs (d) > 2500 cfs
\text { Stage-storage-discharge curve (cfs) }-25 / d t+0
Storage (S) is the total volume (cf) at the elevation in question
Delta time (dt) is the time step (seconds) which is given
Outflow (O) is the total outflow rate (cfs) at the elevation in quêstion

View answer

Questions not Found

Most popular subject

Thermodynamics

Essay/Summary

Mechanics

Complex Analysis

Engineering Economics

Calculus

Modern Physics

General Chemistry

Strength Of Materials

Fluid Mechanics

x