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Join Date: Nov 2007
Posts: 3

Sewage disposal

11/25/2007 4:04 AM

is there any formula to calculate the sludge formed in a domestic septic tank?

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Guru
New Zealand - Member - Interested in everything- see my Profile please APIX Pilot Plant Design Project - Member - Member Engineering Fields - Electrical Engineering - Member Engineering Fields - Power Engineering - Member Engineering Fields - Civil Engineering - Member Hobbies - Musician - Autoharp and Harmonica Hobbies - Hunting - Member Hobbies - Fishing - Member

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#1

Re: Sewage disposal

11/25/2007 5:36 AM

Please formulate your question, so it can be answered.

What about the sludge are you actually trying to calculate?

  1. Volume
  2. Specific gravity
  3. Density
  4. Weight
  5. Natural Gas production ability
  6. Smell
  7. Coefficient of friction
  8. Resistance to pumping
  9. Acidity
  10. Corroding ability
  11. Waterproofing ability of sludge when dried
  12. Depth in the tank
  13. Ability to "wet" the walls
  14. Surface tension
  15. Stickiness coefficient
  16. Is the sludge from people - how many, ages, and diets of them all
  17. Is the sludge from animals - give animal types = sheep, cows, goats etc, and ages plus quantities plus diets of same
  18. What proportion of water is flushed into the tank.
  19. The temperature of the tank, incoming water, incoming sewage etc

The list goes on, and on, and on, and on, and on.....

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Guru

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#2

Re: Sewage disposal

11/25/2007 11:18 PM

"is there any formula to calculate the sludge formed in a domestic septic tank?"

"The formula to calculate the sludge" involves leventy-seven variables !

Begin by listing each individual, living in the house, age, weight, color of hair, their calorie intake per day, daily fecal waste production, % fat vs. protiern, special diets, etc.

Take into account the volume of the tank, the type and extent of the drain field, the enzymes added to the tank, amount and frequency.

Forget the formula, excavate the inlet port manhole cover and remove same being carefull to NOT fall in. Not as messy as an old fashioned out house but a foul deed in any event. Measure the depth of the floating mass, the top of the bottom sludge, if any, and total depth of tank. etc. etc.

Oh well just as well call Septic Sam and have the tank pumped and forget about any complicated research.

Septic tanks are fast becoming outlawed as a bio-hazard anyway so why worry.

In plain English, the answer to your original inquiry is simply NO!

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Guru
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#10
In reply to #2

Re: Sewage disposal

11/26/2007 9:03 PM

Hi SS,

You said "Septic tanks are fast becoming outlawed as a bio-hazard anyway so why worry."

Legislators are debating this issue now where I live. I am on a septic system and my house is considerably below street level so to hook on to county sewer line would require pumping up to street level. Easement to a line on lower street is not an option. Even if they pass such legislation, it would be phased in over a period of years so it's not an immediate concern.

I'm just wondering though why a septic system is a bio-hazard if it's nowhere near a stream, etc. Looks like the natural filtering that occurs through soil, sand, rock, etc. would clean the water that came from the leach field. Am I wrong here?


What is the leventy-seventh variable anyway?

-John

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Guru

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#11
In reply to #10

Re: Sewage disposal

11/26/2007 9:20 PM

"What is the leventy-seventh variable anyway? "

Johnjohn The one after the leventy-sixth variable. There are oodles of them. Twomanytocount !

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#3

Re: Sewage disposal

11/25/2007 11:56 PM

NO

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#4

Re: Sewage disposal

11/26/2007 2:14 AM

This is a related topic, perhaps distant

In the British Virgin islands, overboard discharge by charter boats in the bays are one of the causes of death to the local reefs. The BVIs do not have any pumpout stations as they do not have any waste water treatment plants. I cannot solve the waste water treatment plant for the island, but what about a small treatment plant of say 500 gallons per day to manage the holding tanks of the visiting charter boats.

Is this totally rediculous or would it be affordable to a small private contractor and how big might such an operation have to be. How big would the footprint of such a plant be?

I'm also thinking about selling carbon credits to pay for the plant.

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Member

Join Date: Nov 2007
Location: Gulfport, Ms
Posts: 9
#8
In reply to #4

Re: Sewage disposal

11/26/2007 9:44 AM

Several years ago I designed and built a floating sewage treatment plant for boats. It is a horizontal Composite or plastic tank designed for the amount of water to be cleaned. Perforated Baffles on the inside break up the solids and pass the water. A Chlorine (swimming pool tablets) mixing tank for the discharge is on the end of the tank to kill the bacteria before it reaches the bay water. This tank can be located close to the boat with a gentle wave motion to move the water against the baffles inside. I will be happy to discus this design. My email is thrasmussen@yahoo.com

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Raz
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#14
In reply to #8

Re: Sewage disposal

12/03/2007 7:26 AM

sent you an email with no response. Did you lose interest?

I'm interested in your design. Do you have any pictures? Does it have any approvals from governing bodies? I would have to sell the concept to the BVI gov so any supporting approvals would make it more reasonable for them. thanks

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Member

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Location: Gulfport, Ms
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#15
In reply to #14

Re: Sewage disposal

12/03/2007 9:37 AM

Sorry, i have not read my emails in a few days. I have some pictures and drawings that I will have to dig up. I didn't have the money to get the required approvals so it will be up to you. The one I built worked fine for my application which was small but it should work for a larger volumn of water. I will send what i have.

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Join Date: Oct 2007
Location: Thailand
Posts: 58
#12
In reply to #4

Re: Sewage disposal

12/03/2007 7:12 AM

Hi,

Take a look at our blog which is a temporary home for our waste water technology until we have the website built. Our systems start at 70,000 litres per day. I would be happy to answer any questions about the technology, cost, delivery and installation

Cheers,

TC

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Commentator

Join Date: Oct 2007
Location: Thailand
Posts: 58
#5

Re: Sewage disposal

11/26/2007 4:22 AM

Hi,

Of course your answer depends upon local factors. We are manufacturers of continuous aerobic sytsems and if you can be more specific, I can give you reasonable "ballpark" figures.

Q1: In which country/province is the tank located?

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#6
In reply to #5

Re: Sewage disposal

11/26/2007 5:12 AM

it is located in maldives

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Commentator

Join Date: Oct 2007
Location: Thailand
Posts: 58
#13
In reply to #6

Re: Sewage disposal

12/03/2007 7:16 AM

Hi,

sorry to be so tardy, the posts got caught in an overzealous spam filter. Take a look at our blog and we can talk about technology, cost and performance,


Cheers,

TC

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Power-User

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#7
In reply to #5

Re: Sewage disposal

11/26/2007 7:28 AM

British Virgin Islands thanks

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Commentator

Join Date: Oct 2007
Location: Thailand
Posts: 58
#16
In reply to #7

Re: Sewage disposal

12/03/2007 2:03 PM

Hi sail4evr,

Take a look at our blog. It provides information on the aerobic barch reactors we manufacture. I'll be hapyy tp get down to answering any speciifc questions on their operation in particular and wate water treatment in general,

Regards,

TC

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Power-User

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#9

Re: Sewage disposal

11/26/2007 12:44 PM

hi everyone,

when i was "metacrawler"ing, to the research for my methane digester. i was doing a search for septic systems, and ran across a chart for how often a septic tank should be pumped out. which is the really relevant info. going by memory, it was with a 1500 gal septic tank, with 1 person using it, it needed to be pumped out once every 15 years. with 4 or 5 people using it, it needed to be pumped out every 3 or 4 years.

the reason for pumping it out, is to prevent the solids from getting into the leach field (old style) which meant that you had to dig and install a new leach field (very expensive). nowadays with the new infiltrators, it is not so much of a problem, as the infiltrators are only set about 12 below the surface, and are easy to get to, plus have tremendous surface area for leaching.

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