Q / 2: A city discharges 115000 m³/d of wastewater into a stream whose minimum rate of flow is 8.5 m/s. The velocity of the stream is about 3.2Km/hr, the temperature of the wastewater is 20 °C and that of the stream is 15 °C. The BOD5 at 20 °C of the wastewater is 200mg/l and that of the stream is 1mg/l. The wastewater contains no dissolved oxygen but the stream is 90% saturated upstream of the discharge. At 20 °C kj is estimated to be 0.3 day", and ký is 0.7 day". Determine the critical oxygen deficit and its location, also estimate BOD5 at 20 °C of the sample taken at the critical point. Use temperature coefficient of 1.135 for ki and 1.025 for k2, also plot the dissolved oxygen sag curve.

Q / 2: A city discharges 115000 m³/d of wastewater into a stream whose minimum rate of flow is 8.5 m/s. The velocity of the stream is about 3.2Km/hr, the temperature of the wastewater is 20 °C and that of the stream is 15 °C. The BOD5 at 20 °C of the wastewater is 200mg/l and that of the stream is 1mg/l. The wastewater contains no dissolved oxygen but the stream is 90% saturated upstream of the discharge. At 20 °C kj is estimated to be 0.3 day", and ký is 0.7 day". Determine the critical oxygen deficit and its location, also estimate BOD5 at 20 °C of the sample taken at the critical point. Use temperature coefficient of 1.135 for ki and 1.025 for k2, also plot the dissolved oxygen sag curve.

Sustainable Energy

2nd Edition

ISBN:9781337551663

Author:DUNLAP, Richard A.

Publisher:DUNLAP, Richard A.

Chapter14: Ocean Thermal Energy Conversion And Ocean Salinity Gradient Energy

Section: Chapter Questions

Problem 14P

See similar textbooks

Similar questions

The town of Pittsburgh discharges 0.126 m3/s of treated wastewater intoCherry Creek. The BOD5 of the wastewater is 34 mg/L. Cherry Creek hasa 10-year, 7-day low flow of 0.126 m3/s. Upstream of the wastewater outfallfrom Pittsburgh, the BOD5 is 1.2 mg/L. The BOD rate constants k are0.222 d21 and 0.090 d21 for the wastewater and creek respectively. Thetemperature of both the creek and the municipal wastewater is 208C. Calculatethe initial ultimate BOD after mixing.
At the point of mixing of a river and a wastewater point discharge, DO is 5.5 mg/L and DOs is 10.1 mg/L. Upstream, the BODu of the river is 3.2 mg/L and its volumetric flow rate is 3.2 m3/s.a) Calculate the maximum allowable volumetric flow rate of the wastewater dischargeif the maximum allowable BODu at the mixing point is 20.0 mg/L. The BODu of the wastewater is 250.1 mg/L.b) For a water temperature of 15 ℃, calculate kd and kr. At 20 ℃, kd is 0.30 per day. The combined stream and wastewater velocity and depth are 2.0 m/s and is 4.0 m.c) Calculate the critical time in days and critical distance in km.d) Calculate the maximum deficit and minimum DO in mg/L
A tannery with a wastewater flow of 0.011 m½ and a BOD; of 590 mg/L discharges into a creek. The creek has a 10-year, 7-day low flow of 1.7 m^3/s. Upstream of the tannery, the BOD5 of the creek is 0.65 mg/L. The BOD rate constant k is 0.115 d-^1for the tannery and 3.7 d-^1 for the creek. The temperature of both the creek and the tannery is 20°C. Calculate the initial ultimate BOD after mixing.
A tannery of processing plant with a wastewater flow of 0.011 cu.m/s and a BOD5 of 590 mg/L discharges into the river. The river has a 10 year, 7-day low flow of 1.7 cu.m./s. Upstream of the tannery, the BOD5 of the river is 0.6 mg/L. The BOD rate constants (k) are 0.115 day-1 for the tannery and 3.7 day-1 for the river. Calculate the ultimate BOD of the tannery wastewater, in mg/L. a. 1,972 mg/L b. 2,155 mg/Lc. 1,350 mg/L d. 1,264 mg/Le. None of these
a) A city discharges 1.5 m3/sec of wastewater into a river whose flow rate is 10m3/sec. The velocity of the river is 1.0 km/hr. The temperature of the wastewater is 20oC, while that of the river is 15 oC. The 20oC BOD5 of the i) wastewater is 200 mg/L, while that of the river is 1.0mg/L. The wastewater contains no dissolved oxygen (DO), but the river’s DO is 90% saturated upstream of the discharge. At 20oC, BOD decay coefficient is estimated to be 0.3/day, while re-aeration rate coefficient is 0.7/day. Using temperature coefficients of 1.135for BOD decay coefficient and 1.024 for re-aeration, answer the following questions i. Determine the DO of the river before discharging the wastewater (saturation concentration of DO at 15oC is 10.1 mg/L)ii. Determine the temperature, DO and BOD of the mixture.iii. Determine the ultimate BOD5 of the mixture b) In a water treatment plant the responsible sanitary engineer designed a cone aerator for aeration of…
Assume that DLSUD lake is 100m2 and its average height is 5ft. Wastewater that flows into the lake are the following: Food square kitchen waste 7 m3/sec; Total Dissolved Solids (TDS) is 25,000 mg/L which operates 8hrs per day CIH 5m3 /hr kitchen waste; TDS is 20mg/L which operates 4hrs per day PCH 20m3 /day diluted laboratory waste ; TDS = 40mg/L (1)Determine the volumetric flow rate of the lake water can still accommodate prior to rainfall.
A rectangular channel of width 550 mm has a discharge of 0.1 m3/s and a uniform flow depth of 250 mm. The channel has an adjustable bottom slope with the value of C equal to 55. Calculate the slope of the channel and the convenience of fume.
A stream with a flow of 1.7 m3/s and BOD 3.4 mg/l is saturated with DO (9.27 mg/l at 20oC). It receives a treated effluent discharge from a cocoa processing factory of BOD 6780 kg/day and DO of 5.0 mg/l. The BOD of the stream immediately after mixing is 7.6 mg/l. The DO at a point 36 km downstream is 7.20 mg/l. The average velocity of the stream flow is 0.2 m/s. Determine the flow and the BOD in mg/l of the treated effluent discharged from the cocoa processing factory into the stream. Assume the temperature is 20oC throughout, k1 for effluent/water mixture is 0.1/day, k2 for stream is 0.4/day.
The flow rates measured during a precipitation at the outlet of a basin with an area of 32400 hectares are given below. It is assumed that the precipitation intensity is constant 60 mm/hr and the infiltration index of the basin is 10 mm/hr. Determine the duration of the unit hydrograph and obtain the 60-minute unit hydrograph of the basin. You can take the base flow as 100 m³/s.
Problem 5: Design a aerated grit chamber for a wastewater treatment plant where the incoming average flow rate is 0.8m3/s. Assume • a peak factor of 2.5. • Detention time = 225 sec • Width to Depth ratio = 1.5:1 • Width = 3 m • Aeration requirement is 0.3 m3/min/m • Sludge generation 40L/103 m3
A manufacturing facility that manufactures printed circuit boards puts washwater that was used to wash solvents from the circuit boards into a septic tankwhich discharges into ground water. The wash water contains 7.34 mg/L of dissolved trichloroethylene (TCE). The daily rate of discharge is 13.6 m'/day. Theunderlying aquifer has an average linear groundwater velocity of 0.34 m/day.The discharge has been going on long enough so that steady state conditionshave been reached. Assuming no degradation of the TCE, what is the concentation at a monitoring well located 22 meters downgradient of the septic tankdischarge (* = 22 m, y = 0 m)? Assume a value for b.
Wastewater of 30ft3/s with a biochemical oxygen demand (BOD) of 55mg/l, and dissolved oxygen (DO) of 3.3mg/l enters a river where the flow is 125ft3/s with an ultimate BOD of 7.0 mg/l, and DO of 6.8mg/l. The downstream has an average velocity of 0.8ft/s. i . Calculate the minimum DO level and its distance in miles downstream using the oxygen sag equation. Assume k1 = 0.046 per day and k2 = 0.304 per day. The saturation DO = 8.5mg/l. (1 mile = 5280ft) ii. At what distance downstream would the DO level of the river be equal to 6.10 mg/l? iii. How much should the wastewater DO be increased to maintain a minimum DO of 4.8mg/l anywhere along the river. Assuming that the BOD of the wastewater and the river flow remains the same?