670 likes | 899 Views
Module 5: Disinfection and Chlorination. Wastewater Treatment Plant Operator Certification Training. Unit 1 – Disinfection and Chlorination Principles. Learning Objectives State the purpose of disinfection in wastewater.
E N D
Module 5: Disinfection and Chlorination Wastewater Treatment Plant Operator Certification Training
Unit 1 – Disinfection and Chlorination Principles Learning Objectives • State the purpose of disinfection in wastewater. • Identify the three types of chlorine used as disinfectants in wastewater. • Describe the breakpoint chlorination curve. • Identify alternate feed points and the use of chlorination in wastewater treatment. WB 1-1
Pathogen Removal 3 WB 1-2 & 1-3
Elemental Chlorine (Cl2) Chemistry Chlorine + Water ðHypochlorous Acid + Hydrochloric Acid Cl2 + H2O ðHOCl + H+ Cl- 4 WB 1-4
Distribution of HOCL and OCL- 5 WB 1-5
Sodium Hypochlorite (OCl-) Chemistry Sodium Hypochlorite + Water ðSodium Hydroxide + Hypochlorous Acid + Hypochlorite- + Hydrogen 2NaOCl + 2H2O ð2NaOH + HOCl + OCl- + H+ 6 WB 1-6
Calcium Hypochlorite Chemistry Calcium Hypochlorite + Water ð Calcium Hydroxide + Hypochlorous Acid Ca(OCl)2 + 2H2O ð Ca(OH)2 + 2HOCl 7 WB 1-6
Chlorine Dioxide (ClO2) Chemistry Sodium Chlorite + Chlorine ðSodium Chloride + Chlorine Dioxide 2NaClO2 + Cl2ð 2NaCl + 2ClO2 Chlorine dioxide + Water ð Chlorate Ion + Chlorite Ion + Hydrogen Ion 2ClO2 + H2O ð ClO3-+ ClO2-+2H+ WB 1-7
Chlorine Demand WB 1-8
Chlorine Residual WB 1-9
Establishing Dosages Feed Rate, lbs/day = Flow (MGD) x Dosage (mg/L) x 8.34 lbs/gal WB 1-10 & 1-11
Breakpoint Chlorination Curve WB 1-12
Factors Influencing Disinfection WB 1-13
Relative Effectiveness vs. pH WB 1-14
Application Points • Collection Systems • Pre-chlorination • Plant Chlorination • Chlorination prior to filtration • Post filtration chlorination WB 1-17
Key Points and Exercise • Turn to page 1-18 to summarize the unit key points. • Turn to page 1-19 for exercise
Unit 1 Exercise • kill, inactivate • bacteria, viruses, cysts • screening, grit removal, primary sedimentation • chlorination • All of the above • 6.5 mg/L • Short-circuiting WB 1-19
Unit 1 Exercise con’t • All of the above • A, C, C, B, C, D, D, B
Unit 2 – Chlorination Process Control Learning Objectives • List the ways in which a chlorine feed can be controlled. • Describe chlorine residual and identify the types of chlorine residuals expected to be present during disinfection. • Describe the common methods used for measuring chlorine residual in wastewater operations. WB 2-1
Manual Control WB 2-2
Start Stop Control WB 2-3
Step Rate Control WB 2-4
Timed Program Control WB 2-5
Flow Proportional Control WB 2-6
Chlorine Residual Analyzer WB 2-7
Key Points and Exercise • Turn to page 2-10 to summarize the unit key points. • Turn to page 2-11 for exercise
Unit 2 Exercise • d • e • 93.8 lbs/day • 0.6 mg/L WB 2-11
Unit 3 – Chlorine Safety & Handling Learning Objectives • Describe an effective chlorine safety program. • Describe the handling procedure for each chlorine container and some of the related safety devices provided. • Describe the measures to take in the event of a chlorine leak. WB 3-1
Personnel Safety, Protection & First Aid WB 3-3 & 3-4
Chlorine Cylinder WB 3-5
Ton Container WB 3-6
Trunnions WB 3-7
Excess Flow Valve WB 3-8
Chlorine Leaks & Response WB 3-9
Chlorine Repair Kit WB 3-10
Chlorine Scrubber WB 3-11
Key Points and Exercise • Turn to page 3-12 to summarize the unit key points. • Turn to page 3-13 for exercise
Unit 3 Exercise • a • safety • 10 • Risk Management • 158 to 165 • 6 and 12 • top WB 3-13
Unit 3 Exercise • trunnions • a • railroad tank • ammonia, white smoke
Unit 4 – Chlorination Equipment and Maintenance Learning Objectives • Identify equipment related to a gas feed system. • Identify equipment related to a hypochlorite feed system. • Identify equipment related to a chlorine dioxide feed system, and how it differs from the gas and hypochlorite feed systems. WB 4-1
Gas Feed System 47 WB 4-2
Evaporator WB 4-6
Hypochlorite Generator WB 4-10