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1

/l

2

c

o o

10

10 100 100

1.0

0.10

0.01

ChlorineConcentration,mg

HOCl

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

Adenovirus3

E.coli

Poliomyelitisvirus1

Coxsackie

virusA2

0.1

0.1

10 100

1.0

0.01

ChlorineasHOCL,mg

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 Environmenta

Engineering. 2nd ed. Boston, MA: PWS Publishing Company, 1996, pp. 742-743.

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Required

C.t or l.tCombined chlorine Free chlorine Chlorine dioxide Ozone UV light

C. parvum

LegionellaMycobacterium

fortuitum

Poliovirus

E. coli

E. coli

E. coli

Adenovirus

Adenovirus

Adenovirus

Adenovirus

Adenovirus

Calicivirus

Calicivirus

Calicivir

Calicivirus

C. parvum

C. parvum

C.parvum

M.fortuitum

Legionella

Legionella

Microsporidium

Microsporidium

Microsporidium

GiordiaPoliovirus

Poliovirus

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

Calicivirus

Giardia

M.fortuitum

Poliovirus

LegionellaGiardia 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.

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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.

dapted from: Binnie, C., M. Kimber, and G. Smethurst. Basic Water Treatment. 3rd ed. Cambridge, UK: Royal Society of Chemistry, 200

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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.

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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

0.25

0.50

0.75

1.00

0.00

0.25

0.50

0.75

1.00

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 whereDNA absorbs UV

Germicidal Range

200 250 300 350 400

1

2

3

Figure by MIT OCW.

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Clements, John, 2004. Ultraviolet Disinfection. Brown and Caldwell Engineers.February 2004. http://www.xaraxone.com/FeaturedArt/jc/html/08.htm Accessed3/13/05

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e by MIT OCW. Adapted from: Mancl, Karen M.. "Bacteria in Drinking Water." The Ohio State University Extension Bulletin.Bulletin 795 (1989).