A large stream has a reoxygenation constant of 0.4 per day. At a velocity of 0.85 m/s; and at the point at which an organic pollutant is discharged, it is saturated with oxygen at 10 mg/L (D, = 0). Below the outfall, the ultimate demand for oxygen is found to be 20 mg/L and the deoxygenation constant is 0.2 per day. What is the dissolved oxygen 48.3 km downstream?

A large stream has a reoxygenation constant of 0.4 per day. At a velocity of 0.85 m/s; and at the point at which an organic pollutant is discharged, it is saturated with oxygen at 10 mg/L (D, = 0). Below the outfall, the ultimate demand for oxygen is found to be 20 mg/L and the deoxygenation constant is 0.2 per day. What is the dissolved oxygen 48.3 km downstream?

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

A lake is fed by a polluted stream and a sewage outfall. The stream and sewage wastes have a decay rate coefficient (k) of 0.9/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?Incoming Stream: C = 10 mg/L, Q = 90 m^3/sSewage Outfall: C = 300 ppm, Q = 0.5 m^3/sLake: V= 10,000 m^3
A small coal-fired power plant sends 2.4 m3/s of flue gas through itselectrostatic precipitation (ESP). The particle migration velocity is knownto be 10 cm/s. Calculate the collection area if the overall ESP efficiency is95%.
Lake Taal has a volume of 458 cubic km, and its rate of inflow and outflow are both 175 cubic km/year. Suppose that the time t=0 (years), its pollutant concentration is 0.06 %, and that thereafter the concentration of pollutants in the inflowing water is 0.01 %. Assuming that the outflow is perfectly mixed lake water, find the initial-value problem and how long will it take to reduce the pollution concentration in the lake at 0.03 %? Show illustrations Use 3 decimals
Discharge of waste water from a pulp mill results in an oxygen sag minimum value of 3.2 mg/L. At the point of discharge the river has a saturated DO value of 9 mg/L. The pulp mill isthe only source of BOD to the river. Given a river velocity of 2 m/s, an average depth of 5 m and kd of 0.22/day, calculate: the percent reduction of the BOD in the waste water to ensure a healthy river with > 5mg / L everywhere. the downstream distance that the DO minimum occurs the ultimate BOD of the river waste water mixture at discharge point so that DO minimum si 5 mg/L.
A small town discharges its sewage effluent in a nearby river. The river has an initial background BOD of 23.5 mg/L.The oxygen deficit just upstream from the point of discharge of the sewerage is 4 mg/L. The river is flowing at aspeed of 43 km/day. You have been asked to determine the impact of this town’s sewerage discharge on the rivergiven that the deoxygenation rate coefficient kd is 0.3/day, and the reaeration rate coefficient kr is 0.5/day.a) A sensitive fish species inhabits the river 120 km from the point of discharge. Determine if the impact of theBOD will have led to the minimum DO before or after the location of the fish species.b) Find the minimum DO due to the effluent discharge.c) Discuss the oxygen deficit in relation to the location of the fish species and whether the fish are at risk due tothe discharge upstream.
Dissolved chloride in a concentration of 500 mg/L is being advected with flowing groundwater at a seepage velocity of 0.3 m/d in an aquifer with a porosity of 0.25. Groundwater from the aquifer discharges into a river. a. What is the mass flux of chloride into the river (in g/(m2d))? b. How long does it take the chloride to travel 100 m through the aquifer (i.e., the travel time for a 100 m distance)?
Flow rate: 1.5 m3/s Pollution: pesticide permethrin Lake size: 100m x100m x 2.5m Steady state concentration of permethrin leaving the lake is 1.4 ppm Average cross-sectional area of the river is 2.7 m2. Half-life of permethrin in this environment is 19 hrs. What is the concentration of permethrin entering the lake and what distance downstream of the outlet would the concentration be less than 1 ppm?
The width of the channel is reduced in the downstream. Upstream flow is subcritical. Please can you explain possible changes to the flow of the channel, and show how this would look on the specific energy diagram? Thanks for any help! Ive attached a picture of the specific energy diagram.
H2. Consider the treatment of a wastewater with the following characteristics: T = 25°C, total flow 650 m3/d, wastewater composition: sucrose (C12H22O11): C = 400 mg/L, Q = 250 m3/d, acetic acid (C2H4O2): C =940 mg/L, Q = 350 m3/d a) Estimate the methane production, from the anaerobic degradation of the discharge using the Buswell equation, in m3/d b) Calculate the total concentration of the residual water in terms of COD, the total mass flow of COD in the residual water (kg/d) and estimate from this last data the production of methane, in m3/d.
A well‐mixed sewage lagoon is receiving 430 m^3/d of untreated sewage. The lagoon has a surface area of 10 hectares and a depth of 1.0 m. The pollutant concentration in the sewage discharging into the lagoon is 180 mg/L. The pollutants degrades in the lagoon according to first‐order kinetics with a reaction rate constant of 0.70 d^‐1. Assuming no other water losses or gains and that the lagoon is completely mixed, find the steady‐state concentration of the pollutant in the lagoon effluent.
Draw DO Sag curves (2) for high BOD and low BOD effluent input for the same river and under same conditions. Also list 4 parameters that influence Oxygen sag curve. What is the best way to make sure that there is adequate DO in a river where treated wastewater is released.
Reportedly one of the shortest rivers in the world at 30 m in length, the Ombla River watershed hasan area of about 600 km2 and receives 1020.8 mm of precipitation annually. The regional averageannual evapotranspiration is 150 mm. Measured at its Adriatic Sea terminus, the average flowrateof the Ombla River is 24.1 m3/s.How much runoff reached the river as discharge for the year (in cm)? What annual volume is removed in vapour form (in m3)?Considering the climatic variables reported, what volume remains unclassified in the waterbalance (in ha∙m/yr), and what could this volume reasonably represent in the hydrologic cycle?