File Name: Chlorine.pptFeb 2001

Chlorine & Chlorine Dioxide

Overview

File Name: Chlorine.pptFeb 2001

Free Chlorine

Free Chlorine exists as • Hypochlorite Ions

OCl• Hypochlorous Acid

(HOCl)

File Name: Chlorine.pptFeb 2001

Free Chlorine Sensor

ORP Reaction• HOCl diffuses through

the membrane and is reduced at the gold cathode to chloride ions and hydroxide ions.

• Silver is oxidized to silver chloride at the anode.

The current flow is directly proportional to the free chlorine concentration.

File Name: Chlorine.pptFeb 2001

Guide to Chlorine Requirements

Application Probable Chlorine Requirement mg/l

Algae Control 3 to 5

Bacterial Slime Prevention 3 to 5

BOD Reduction 10 to 20

Color Removal 5 to 100

Cyanide

Oxidation to Cyanate 2.7 Times Cyanide content as CN

Complete Destruction 6.8 times Cyanide content as CN

Hydrogen Sulf ide

Odor Control 2.1 times H2S content

Oxidation to Sulfate 8.4 times H2S content

Iron Bacteria Control 2 to 10

Iron Precipitation 0.63 times Fe content

Manganese Precipitation 1.3 times Mn content

Sew age

Raw (including odor control) 10 to 30

Primary Sedimentation Effluent 8 to 15

Trickling Filter Eff luent 3 to 10

Activated Sludge Effluent 2 to 8

Sand Filtered Effluent 2 to 5

Septic Tank Effluent 30 to 45

Water

Cooling (once through) 5 to 15 (intermittent)

Cooling (open recirculation) 3 to 5

Chilling 20

Washdow n 50

Disinfectation of Mains and Tanks 10 to 50

File Name: Chlorine.pptFeb 2001

Chorine and Chlorine Dioxide

Free Chlorine Sensors• Model 140

• 0.05 to 20 mg/l (ppm)

• Model 141 Trace• 0.01 to 5 mg/l (ppm)

Chlorine Dioxide Sensors• Model 240

• 0.05 to 20 mg/l (ppm)

• Model 241 Trace• 0.01 to 5 mg/l (ppm)