Naked Science Forum
Life Sciences => Cells, Microbes & Viruses => Topic started by: tangoblue on 10/01/2012 16:27:39
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hi there! :)
Ehm, well i'm trying to do a 5000 word report on sewage treatment and the public health benefit... i know.
Problem being, i can't seem to find any desent info on sewage treatment like:
- bacteria used
- old treatment methods
- technology involved
etc.
I was wondering if anybody would happen to know any good sorces of information on the subject? or if you know anything useful yourself that would be great too.
THANK YOU!
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oh and btw if you tell me anything that you know i'll be sure to reference you if i use it [:o]
Thanks again
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I'm sure a lot of information is available on the WWW.
Wikipedia has a lot of good information. Don't forget to check out some of the references and links at the bottom of the page.
http://en.wikipedia.org/wiki/Sewage_treatment
Do they use some type of "super bug"? Or, is much of the bacteria used just that bacteria that grows from naturally occurring gut flora, or otherwise naturally grows in the sewage systems?
Alternative methods would include...
Rural Areas often use septic systems. Basically it is a big tank where some of the waste is digested, but solids collect at the bottom. Liquids float and seep into a drainfield. Periodically the tank is pumped, and sent elsewhere for treatment.
I've also seen cistern systems. Similar, except no drainfield, and thus requiring more frequent emptying.
Outhouses have been used. Often simply dig a deep hole. Set the outhouse on top. Once the hole fills up, cover, and dig another hole. Lime is often used to reduce scent. Historically, some high-rise buildings had associated high-rise outhouses.
Rural China may use troughs.
In some areas the human excrement is collected and used as fertilizer. Other areas discourage this practice. If one is growing one's own crops for personal consumption or otherwise use, then it probably isn't bad to use one's personal waste as fertilizer. Risk of disease would occur when it gets mixed up among a whole community, as many diseases are transmitted with what is called "fecal-oral transmission".
If camping in a remote area, one might choose a method to keep human excrement from getting overly concentrated in a single place, then just let it decay naturally. Some people recommend collecting and burning the Toilet Paper.
Sorry, I don't have a lot of info about actual sewage treatment plants. My guess is that you could see a variety of treatment methods by looking at large installations that might serve a whole city, vs small installations that might serve a rural college campus, or a small town. Is there any relation to sedimentation ponds often used for livestock?
After treatment, there usually is some type of "sludge" left over, which can be used as fertilizer, or other uses.
There is also debate about using anaerobic digestion, and recovering methane for use as a fuel elsewhere.
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thank you