A completely mixed activated sludge process is to be used to treat a flow rate of 2.5 MGD. Design a rectangular activated sludge reactor with a 4:1 ratio of length to width. (design only 1 reactor for all flow). The effluent from the plant must not exceed 15 mg/L of BOD5. Use the following design criteria:

a. BOD5 influent = 250.0 mg/L

b. MLVSS (X) = 3500 mg/L

c. Reactor depth = 11 ft

d. Effluent BOD5 must be less than 20 mg/L

e. Y = 0.6 mg VSS/mg BOD5

f. K = 6 day-1

g. KS = 65 mg/L BOD5

h. Kd = 0.08 day -1

i. MLVSS/MLTSS = 0.75

Determine the following: a. Determine the minimum solids retention time (SRT) in days to meet discharge criteria

b. If the actual solids retention time is 4 days, what would be the volume of the activated sludge basin if the wasting flow rate is 40,000 gpd containing 6,400 mg/L of solids.

c. Using the volume of aeration basin in question (b) determine the dimensions of the basin, if the depth is 11 feet, to the nearest even foot

d. What is the hydraulic retention time (HRT) in hours, in the activated sludge basin?

4. Which chemical bond is involved in each of the following? Explain your answer. Justify
each answer with a reason.                                                                                                            []
a. Copper
b. Salt (Nacl).
c. Plastic cup.

* Please answer in clear and readable writing or by typing. The solution is with all the right steps.

The stratigraphy in a site from top to bottom are (1) 4.5 m thick sand; (2) 4.5 m thick clay; (3) impermeable shale. The water table is at a depth of 2 m below ground. The sand above the water table has a void ratio of 0.52 and a saturation degree of 37%. The clay has a moisture content of 42%. The specific gravity of both the sand and clay is 2.65. If constructing a foundation whose bottom is at a depth of 3m, resulting in the extra stress at the top and the bottom of the clay layer is 100 kPa and 40 kPa, respectively. According to the consolidation test, the void ratio of the clay corresponding to 50, 100 and 200 kPa are 1.02, 0.922 and 0.828, respectively. The settlement of the clay layer will be_____________(mm). (One-dimensional settlement is applicable. The density of water is 1000 kg/m³)

1. You suspect that a railroad embankment is unstable and exhibiting a slip failure. To confirm this and to monitor the conditions, what instrumentation and testing do you consider using and why? What soil exploration would you consider?

i need a research about the main usage of reinforced concrete structure including it's applications and primary advantages and disadvantages additionally , discuss the main types of each structural elements such slaps, beams , columns and foots

#1 Parts

a). Identify and explain at least three factors that contribute to sprawl.
b). Identify and explain at least three strategies that are intended to counteract sprawl.
c). Identify and explain at least three different BMPs for low-impact development.

A rectangular cross section beam (A) made of steel constructed in an industrial building
between two columns which are “X” m apart. The beam is acting as a support for one end of a pair of crane wheel (B). The distance b/w wheels are “Y” m. The crane is used to lift max. of Z tonnes of load which is having hook at the centre of crane. Draw shear force and B.M of all types of beam
diagram of the beam.
Case i) If the crane wheels are positioned at equal distances from centre of the beam.
Case ii) If one of the crane wheels is exactly at the centre.
Case iii) If one of the crane wheels comes exactly over a column.
Also find the max. bending stresses in the beam for the first case considering the depth (d) as twice the width of the beam.
X =6m,Y =1m ,Z=15 tonnes, Depth (d)=500mm

Please provide step be step solution

At a depth of 7km in the ocean,the pressure is 71.6Mpa assume a specific weight at the surface 10.03kn/m3 and average bulk modulus of elasticity of 2.34Gpa for that pressure range find (a) the change in specific volume between the surface and 7km (b) specific volume at 7km (c) the specific weight at 7km

A groundwater contains the following constituents to be treated by the lime-soda process to the minimum hardness possible has the following characteristics:

CO2 = 62.0 mg/L HCO3- = 250.0 mg/L as CaCO3

Ca2+ = 80.00 mg/L Cl- = 35 mg/L

Mg2+ = 36.6 mg/L SO42- = 96.0 mg/L

Na+ = 23.0 mg/L

The facility is to treat 50 x 106 L/day of water from this source using lime-soda ash to reduce the hardness.

a) Determine the total hardness, carbonate hardness, and non-carbonate hardness in mg/L as CaCO3.

b) Determine the lime and soda-ash dosages for softening (units of kg/day). Assume that the lime is 90 percent CaO by weight and the soda ash is pure sodium carbonate.

Explain why ‘Discovery’ is not carried out in criminal court cases.

Explain the differences between Hot Extrusion, Hot Forging, and Swaging in detail. Define the spring-back and mention how spring-back effects can be taken into consideration in bending process?

What does the word "slew" mean with regard to tower cranes? what are two different ways a tower crane can slew?

List dynamic factors that affect crane capacity.

(6 pts) List the seven rules for pumping concrete. What are the three rolling steps when paving asphalt? What is TMPH? What is the possible consequence for not considering TMPH?

Why are cycle times typically larger for a hoe than a shovel?

(4 pts) Define the term of “windrow” in grader operations. How can you minimize spillage from the blade?

(3 pts) In what soils is a vibratory pile driver/hammer effective?

(7 pts) List major factors that should be considered when laying out a construction site.

List 4 functions that required to process and produce suitable aggregate materials