Typical water clarifiers |
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Characteristic DBO |
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rate retained\ verted |
tasa rebose superficial |
|
k 20°C.day-1 |
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treatment water |
|
hours retention |
m3/(m.day) |
m/day |
|
0.3-0.7 |
black water without treatment |
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Pre-sedimentation |
|
3 - 8 |
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|
0.1-0.2 |
grey water treated |
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normal tank |
coag & floculation |
2 - 8 |
250 |
20 - 33 |
|
0.1-0.2 |
contaminated river |
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softening |
4 - 8 |
250 |
20 - 40 |
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Speed DBO (k 20°C / day) |
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ascending clariefier |
coag & floculation |
2 |
175 |
55 |
|
blackwaters without treatment |
0.35-0.70 |
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softening |
1 |
350 |
100 |
|
grey treated waters |
0.12-0.23 |
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sedimentation |
coag & floculation |
0.2 |
|
|
|
contamined river |
0.12-0.23 |
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softening |
0.2 |
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Key Parameters for sludge site |
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|
requirements |
land application |
distribution & marketing |
landfilling |
incineration |
ocean disposal |
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Dewatering of sludge |
moderatly |
very |
very |
very |
not important |
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|
Stabilization of sludge |
very |
very |
moderatly |
not important |
not important |
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Community size |
not important |
moderatly |
not important |
very |
very |
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|
Land availability |
very |
not important |
very |
not important |
not important |
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Hydrogeology |
very |
not important |
very |
not important |
not important |
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Storage |
very |
very |
moderatly |
moderatly |
very |
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|
Good practices |
very |
very |
very |
very |
very |
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|
Sludge pathogens |
very |
very |
not important |
not important |
not important |
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|
Sludge toxic organic chemicals |
moderatly |
moderatly |
moderatly |
moderatly |
moderatly |
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|
metals |
very |
very |
moderatly |
moderatly |
moderatly |
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|
nutrients |
very |
moderatly |
not important |
not important |
not important |
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|
odors aesthetics |
very |
very |
very |
very |
moderatly |
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|
traffic public acceptance |
very |
moderatly |
very |
moderatly |
not important |
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|
transportation requirements |
very |
very |
very |
not important |
moderatly |
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|
energy use |
not important |
moderatly |
not important |
very |
not important |
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|
costs factors |
variable |
|
|
|
low |
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|
regulations |
according |
according |
according |
according |
according |
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Sludge application |
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application |
application frequency |
low loading |
typicalloading |
high loading |
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agriculture application |
apply repeatedly to the same sites ever year |
2 dry mt / ha.year |
15 dry mt / ha.year |
70 dry mt / ha.year |
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forest application |
apply to each site one time every 5 years |
10 dry mt / ha. 5year |
40 dry mt / ha.5year |
220dry mt / ha.5year |
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land reclamation |
apply to a site one time only |
7 dry mt/ ha |
112 dry mt/ha |
450 dry mt/ha |
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dedicated land disposal |
apply repeatedly to the same site |
220 dry mt / ha.year |
227dry mt / ha.year |
900dry mt / ha.year |
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composting |
apply to static piles with 28day extended detention |
4.2 dry mt / ha |
6.7 dry mt/ ha |
11.2 dry mt / ha |
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wide trench landfill |
apply 20% solids content sludge to asite one time only |
1200 dry mt/ha |
3450 dry mt / ha |
5450 dry mt / ha |
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narrow trench landfill |
apply 20% solids content sludge to asite one time only |
460 dry mt/ha |
482 dry mt/ha |
2120 dry mt/ha |
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codisposal |
apply 20% solids content sludge to asite one time only |
900 dry mt/ha |
1800 dry mt/ha |
7900 dry mt/ha |
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