Water supply equipment minimum |
and = yn (Q/Qn)exp(m) |
Water treatment calculus volumes m3 per day |
|||||
|
minimum value |
liters/sec |
White waters 3000 a 350 000 m3 per day |
y = yn (Q / (Qn)) exp(0.67) |
|||
well or tap |
1 / 200 persons |
0.6 |
primary treatment small digestor 300 a 3500 m3 per day |
y = yn (Q / (Qn)) exp(0.55) |
|||
pipe |
5 cms |
1 |
primary large digestor 2000 a 3500 m3 per day |
y = yn (Q / (Qn)) exp(0.75) |
|||
drill diameter |
15 - 20 cms |
Waters recycling and spilling options |
slow filtration(300 a 700 m3 per day) |
y = yn (Q / (Qn)) exp(0.6) |
|||
water pressure |
0.15 kg/cm2 |
wetlands artificials discharge water bodies |
free flow |
bioactivaded mud 300 a 3500 m3 per day |
y = yn (Q / (Qn)) exp(0.77) |
||
Served population / sewer km |
overground system |
stabilization pound 2000 a 3500 m3 per day |
y = yn (Q / (Qn)) exp(0.57) |
||||
US town |
eighties |
according type |
Method of residual waters analysis |
||||
< 10000 |
144 |
observation and measure |
|
micrometer range of use |
|||
10000 - 50000 |
181 |
Systems of evaporation applied in soil |
evapo transpiration beds |
microscope |
light |
0.2 a > 100 |
|
50000 - 100000 |
222 |
evapo transpiration pounds |
electrons transmission |
0.2 a > 100 |
|||
100000 - 500000 |
275 |
Superficial drops dispersion |
electronic scattering |
0.002 a 50 |
|||
> 500000 |
393 |
image analysis |
0.2 a > 100 |
||||
Aerobic digestion design |
particles numbering |
differntial conductivity |
0.2 a > 100 |
||||
retention hidraullic |
15 - 20 day |
reuse applied |
agriculture irrigation |
equivalent sparsed light |
0.005 a > 100 |
||
needs oxigen |
2 (/l VBS destroyed) |
Green areas irrigation |
light's dispersion |
0.2 a > 100 |
|||
air need |
0.71 - 1.1 sca/m3 |
Aquifer reload |
separation and analysis |
centrifugation |
0.08 a > 100 |
||
Scale of turbidity value |
natural wetlands |
fraction of flow field |
0.09 a > 100 |
||||
NTU < 5 |
colourless, can be directly disinfected or fitlered |
non potable water supply |
gel filtering chromatography |
< 0.0001 a > 100 |
|||
industrial supply |
sedimentation |
0.05 a > 100 |
|||||
5 < NTU < 30 |
slightly turbid, some treatment: floculation, sedimentatin, filtration, before disinfection |
leisure lakes |
membrane filtration |
0.0001 a > 1 |
|||
increase of water supply |
Residual waters treatments speeds & retention |
||||||
NTU > 50 |
turbid water, treat before disinfection: floculation, sedimentatin, filtration |
availability in soil |
absorption systems |
|
time |
m3 / sec |
|
passive infiltration field |
common mixing operation |
10 - 30 sec |
0.13 - 0.4 |
||||
Chlorine generating products |
active infiltration fields |
chemical filtration rapid contact mixing |
< 1 sec |
0.4 - 1.6 |
|||
Calcium hypochlorite |
70% powder for collective treatments |
drops irrgation |
chemical filtration rapid contact mixing |
< 1 sec |
0.66 - 1.98 |
||
Sodium dichloro-isocyanurate |
60% powder; 1.5g/tablet (household distribution) |
infiltration beds |
Common floculation |
30 - 60 min |
0.01 - 0.02 |
||
sodium hypochlorite |
4 - 5% liquid stay not for long after opened |
infiltration landfill |
direct filtration floculation |
2 - 10 min |
0.005-0.03 |
||
chloramine T |
25% tablets (for individual use) |
filling system |
Contact floculation / filtration |
2 - 5 min |
0.005-0.04 |
||
|
|
grade system |
|
|
|
||
Disinfection Treatment Methods |
|||||||
|
Chlorination |
Ozonation |
ultraviolet |
heating |
halogens (bromine, iodine) |
metal ions (silver, mercury, copper |
|
required dosage ppm |
1 - 3 or 2 - 5 |
1.5 - 4 or 2.5 - 5 |
- |
- |
- |
- |
|
minutes contact time |
10 - 30 |
5 - 10 |
minimum |
15 - 20 |
10 - 30 |
120 |
|
effectiveness/ bacteria |
yes |
yes |
yes |
yes |
yes |
yes |
|
effectiveness/ virus |
some |
yes |
some |
yes |
some |
no |
|
effectiveness/ spores |
no |
yes |
no |
no |
no |
no |
|
advantages |
inexpansives; well developped, lasting |
rapid,complete, non toxic products |
fast, no chemical |
no special equipment |
similar to chlorine less irritating to eye |
long lasting bactericidal effect |
|
disadvantages |
no effective on spores & viruses toxic at high concentration |
more expansive, less developed, does not leave protecting residue |
leaves no protective residue, expansive, small scale |
slow& expeansive |
slow & more expansive thanchlorine |
slow &expansive, amines &others interfere |
|
Water Treatment Methods Effectivity |
|||||||
|
|
BOD |
Grease |
Color |
Alkalinity |
suspended solids |
|
Grease recovery |
acid cracking |
0.35 |
0.45 |
0 |
0 |
0.25 |
|
centrifuge |
0.35 |
0.35 |
0 |
0 |
0.45 |
||
evaporation |
0.95 |
0.95 |
0 |
0 |
0.45 |
||
Screening |
|
0.05 |
0 |
0 |
0 |
0.2 |
|
Sedimentation |
|
0.4 |
0.85 |
0.35 |
0.15 |
0.55 |
|
Flotation |
|
0.4 |
0.96 |
0.15 |
0.15 |
0.55 |
|
Chemical coagulation |
CaCl2 |
0.55 |
- |
- |
- |
0.85 |
|
lime + CaCl2 |
0.6 |
0.97 |
- |
- |
0.85 |
||
CO2 + CaCl2 |
0.35 |
- |
- |
- |
0.85 |
||
Alum |
0.4 |
- |
0.75 |
|
|
||
Copperas |
0.2 |
|
|
|
|
||
activated sludge |
0.85 |
0.1 |
0.2 |
0.2 |
0.92 |
||
tricklig fimtration |
0.85 |
0.05 |
0.2 |
0.2 |
0.9 |
||
lagoons |
0.5 |
0.05 |
0.2 |
0.15 |
0.50 |
||