l12 disinfection - MIT OpenCourseWare · Microsporidium Microsporidium Giordia Poliovirus...
17
Transcript of l12 disinfection - MIT OpenCourseWare · Microsporidium Microsporidium Giordia Poliovirus...
1
/l
2
c
o o
10
10 100 100
1.0
0.10
0.01
Chlo
rine
Conce
ntr
atio
n, m
gHOCl
OCl-1
NH Cl
Minutes, t
Concentration versus contact time for 99% kill of E. coil by various forms
of chlorine at 2 C to 6 C.
Figure by MIT OCW.
Figure by MIT OCW.
1
/l
c
o o
Adenovirus
3
E.coli
Poliomyelitis
virus1
Coxsackie
virus A2
0.1
0.1
10 100
1.0
0.01
Chlo
rine
as H
OC
L, m
g
Minutes, t
Concentration versus contact time for 99% kill of E. coil and three enteric
viruses by HOCl at 0 C to 6 C.
Adapted from: Reynolds, T. D., and P. A. Richards. Unit Operations and Processes in Environmental
Engineering. 2nd ed. Boston, MA: PWS Publishing Company, 1996, pp. 742-743.
Required
C.t or l.t Combined chlorine Free chlorine Chlorine dioxide Ozone UV light
C. parvum
LegionellaMycobacterium
fortuitum
Poliovirus
E. coli
E. coli
E. coli
Aden
ovir
us
Aden
ovir
us
Adenovirus
Adenovirus
Adenovirus
Cal
iciv
irus
Cal
iciv
irus
Calicivirus
Cal
iciv
iru
s
C. parvum
C. parvum
C.parvum
M.fortuitum
Legionella
Legionella
Microsporidium
Microsporidium
Microsporidium
GiordiaPoliovirus
Poli
ovir
us
Poliovirus
M.fortuitum
Hepatitis A
Rotavirus
0.01
0.10
1.0
10
100
1,000
10,000
Giardia
E. coli
E. coli Legionella
pnuemophila
Cal
iciv
irus
Giardia
M.f
ort
uit
um
Poliovirus
Legionella Giardia Giardia
ReovirusMS-2
C.parvum
Overview of disinfection requirements for 99 percent inactivation.
Figure by MIT OCW.
Adapted from: MWH, J. C. Crittenden, R. R. Trussell, D. W. Hand, K. J. Howe, and G. Tchobanoglous.
Water Treatment: Principles and Design. 2nd ed. Hoboken, NJ: John Wiley & Sons, 2005, p. 1063.
2 j
Sensor
Cl In ection
Sulfite Diffuser
Chlorination - Dechlorination
Controller
Alternate Locations for Sensor
Typical contact chamber for chlorination. Baffles are provided to promote plug flow. When chlorine has been
applied at elevated concentrations, sulfite is added to reduce chlorine to levels that will not cause consumer
reaction to chlorine taste and odor.
Figure by MIT OCW.
Adapted from: Binnie, C., M. Kimber, and G. Smethurst. Basic Water Treatment. 3rd ed. Cambridge, UK: Royal Society of Chemistry, 2002.
Figure by MIT OCW.
Adapted from: MWH, J. C. Crittenden, R. R. Trussell, D. W. Hand, K. J. Howe, and G. Tchobanoglous.
Water Treatment: Principles and Design. 2nd ed. Hoboken, NJ: John Wiley & Sons, 2005, p. 1121.
100 150
200
0.00200 220 240
Wavelength, nm
Ultraviolet sources and germicidal range: 1) Ultraviolet portion of electromagnetic spectrum, 2) Output from low-pressure UV lamp, and 3) Output from medium-pressure UV lamp.
260 280 900
0.250.500.751.00
0.000.250.500.751.00
Relative lamp output
Relative lamp output
Wavelength, nm
Medium-pressure UV
Low-pressure UV
220 240 260 280 300
Region where UV is absorbed by water
Region where neither DNA nor water absorb UV
Region where DNA absorbs UV
Germicidal Range
200 250 300 350 400
1
2
3
Figure by MIT OCW.
Clements, John, 2004. Ultraviolet Disinfection. Brown and Caldwell Engineers.February 2004. http://www.xaraxone.com/FeaturedArt/jc/html/08.htm Accessed 3/13/05
Figure by MIT OCW. Adapted from: Mancl, Karen M.. "Bacteria in Drinking Water." The Ohio State University Extension Bulletin. Bulletin 795 (1989).
