I think I saw a thing on tv about how they can treat the liquid part of sewer enough to put it in the lakes rivers, etc, but the solids? Where would they go? I know this is a strange question!
2007-05-25 10:26:46 · 6 answers · asked by en tu cabeza 4 in Science & Mathematics ➔ Engineering
Depends on which solids it is... The stuff off the bar screen (Paper products which don't dissolve) just go in a dumpster, ugh. Other solids are recovered in a vessel with large enough cross sectional area to slow down flow enough to settle out the corn, rice, etc. An auger in a v-shaped channel in the floor moves them all to one end. They are pumped off as a slurry, and dewatered before going into said dumpster.
The remaining dissolved solids are now called sludge, which goes through many steps to settle it out, concentrate it, and eventually decant it off the bottom of the vessels where it's pumped into the anaerobic digester. The organisms in the digester further break it down until it can be dewatered in a centrifuge. The final product can either be used as fertilizer, incinerated, or disposed of in a landfill.
2007-05-25 11:13:00 · answer #1 · answered by Dave O 3 · 3⤊ 0⤋
There are three main types of solids present. Two types come from the sewers and the third is grown at the wastewater plant.
What comes from the sewer is divided into large materials that can be screened out with a bar screen (looks sort of like a jail cell door, alittle narrower between bars). This includes wood, toys, diapers, and other very large things, with some toilet paper. This material is separated and landfilled.
The majority of the toilet paper and human waste goes into the treatment plant, is broken down into the soluble form, and turned into harmless materials that are soluble in the water by the bacteria in the treatment plant. Some will just stick to the bacteria.
These bacteria that grow naturally in the treatment plant are the third type of solids. The oldest are cycled out and collected. The amount can be reduced by several digestion methods. The remains can be landfilled, incinerated, or used as fertilizer.
It is much more complicated than this simple summary. For more info, see the references.
2007-05-26 00:49:58 · answer #2 · answered by Peter Boiter Woods 7 · 0⤊ 0⤋
Trash is screened out in primary processing plant. Organic content is treated further to concentrate those solids.
In the metro Boston area they take the sludge (high percentage organic solids in horrible liquid) and send it through an under harbor pipeline to a fertilizer plant. There they put it in a centrifuge that spins it (like a washing machine spin cycle) to extract the liquid. The solids go into dryers that tumble them under high heat to form little pellets of organic matter. The fumes from that are burnt off in a catalytic furnace and discharged to the outside air. The pellets, which are now germ free and odor free) are cooled and dropped into railroad cars to be sold as organic fertilizer.
2007-05-25 21:42:12 · answer #3 · answered by Rich Z 7 · 0⤊ 0⤋
Somewhere in California a coastal city built a massive enviro-freindly sewage waste treatment facility. Everything is processed for use in some other way. Nothing regarding harmful waste is pumped back into the ocean.
2007-05-25 17:36:21 · answer #4 · answered by JOHNNY D 3 · 0⤊ 0⤋
The heaviest precipitates down the ponds, the lightest float over the water and are separated.
Both are separated from the water and deposited in yards to recover the utilizable ones.
2007-05-25 18:09:36 · answer #5 · answered by Anonymous · 0⤊ 0⤋
In some places, they get incinerated.
2007-05-25 17:43:28 · answer #6 · answered by Stan the Rocker 5 · 0⤊ 0⤋