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The Environment / Estimating total coliform levels?
« on: 14/09/2009 12:11:18 »
Hey guys and girls,
been on this site a few time but never submitted a question, however Iam really struggling with this one!!.
Basically, I am currently putting together an Environmental Statement as part of my coursework.
It is for a new Materials Recovery Facility which will be using water from the local river for dust suppression during the construction of this development.
The problem is particularly acute with respect to a farm some 2 km upstream, where a dilapidated wastewater collection system permits an average of 50 m3 d –1 of slurry to enter the river.
Given the following data, an estimate of the total coliform level is required.
River flow = 10 000 m3 h–1
20
BOD 5 of river water = 3.5 mg l−1
Background total coliform level in river = 500 per 100 ml
Total coliform level in slurry = 8.0 × 104 per 100 ml
Average river water temperature = 8 °C
River width = 13.5 m
River depth = 2.2 m
Also what impact will the ingress of slurry (BOD 2000 mg 1–1, temperature 18 °C) have on the river? Assuming the river is 85% saturated with oxygen prior to entry of the slurry, and that the BOD decay rate constant of the slurry is 0.12 d–1 at 20 °C.
I have spent a fair few days on this part of the project now and it is just not making any sense at all!!.
Any advice on this question would be most grateful
Gary
been on this site a few time but never submitted a question, however Iam really struggling with this one!!.
Basically, I am currently putting together an Environmental Statement as part of my coursework.
It is for a new Materials Recovery Facility which will be using water from the local river for dust suppression during the construction of this development.
The problem is particularly acute with respect to a farm some 2 km upstream, where a dilapidated wastewater collection system permits an average of 50 m3 d –1 of slurry to enter the river.
Given the following data, an estimate of the total coliform level is required.
River flow = 10 000 m3 h–1
20
BOD 5 of river water = 3.5 mg l−1
Background total coliform level in river = 500 per 100 ml
Total coliform level in slurry = 8.0 × 104 per 100 ml
Average river water temperature = 8 °C
River width = 13.5 m
River depth = 2.2 m
Also what impact will the ingress of slurry (BOD 2000 mg 1–1, temperature 18 °C) have on the river? Assuming the river is 85% saturated with oxygen prior to entry of the slurry, and that the BOD decay rate constant of the slurry is 0.12 d–1 at 20 °C.
I have spent a fair few days on this part of the project now and it is just not making any sense at all!!.
Any advice on this question would be most grateful
Gary