Lime Softening, Ion Exchange, Activated Carbons, Taste and Odor - Intro Treatment (1.5 Contact Hours)

Module 1: Understanding Water Hardness

• Define total, carbonate, and non-carbonate hardness and their impact on water systems.

• Explain how hardness causes scaling, staining, and soap precipitation in domestic and industrial systems.

Module 2: Lime Softening Chemistry and Principles

• Describe the chemical reactions that occur during lime softening, including precipitation of calcium carbonate and magnesium hydroxide.

• Identify key pH thresholds for calcium and magnesium removal and explain the role of recarbonation.

Module 3: Lime Types and Slaking Process

• Distinguish between quicklime and hydrated lime, and explain the lime slaking process including safety and equipment concerns.

• Identify challenges in lime feed systems such as dust control and caking.

Module 4: Softening Process Variants

• Compare partial lime, excess lime, lime-soda ash, caustic soda, and combined lime/caustic soda processes.

• Describe when to apply each process based on source water quality and operational goals.

Module 5: Process Flow and pH Stabilization

• Outline single-stage, double-stage, and split treatment lime softening designs.

• Explain the role of carbon dioxide in recarbonation and the need for pH adjustment post-softening.

Module 6: Ion Exchange Softening

• Explain how ion exchange (IX) works using sodium zeolite resins to replace calcium and magnesium with sodium ions.

• Describe the regeneration process using brine solution and identify the stages of IX operation (service, backwash, brine, rinse).

Module 7: Ion Exchange System Design

• Calculate resin capacity in grains per cubic foot and determine flow rates and resin bed requirements.

• Identify applications of IX systems including blending, fluoride saturator supply, and nitrate removal.

Module 8: Membrane and Brine Management

• Compare membrane softening with IX and lime softening in terms of pressure requirements and waste stream.

• Explain brine management strategies, environmental concerns, and regional solutions like the Santa Ana River brine line.

Activated Carbon Fundamentals

• • Principles of adsorption and contaminant removal
  • Types of activated carbon: powdered (PAC) and granular (GAC)
  • Sources of carbon (coconut shell, coal, wood) and performance differences
• Contaminants & Removal Targets
  • Inorganic contaminants: arsenic, fluoride, selenium, uranium
  • Organic contaminants: natural organic matter (NOM), disinfection byproduct (DBP) precursors, pesticides, herbicides, VOCs, SOCs
  • Taste- and odor-causing compounds: geosmin and MIB from algae blooms
• Powdered Activated Carbon (PAC)
  • Application methods, slurry preparation, and safety precautions
  • Dosage determination using jar tests
  • Best practices for applying PAC ahead of chlorination
• Granular Activated Carbon (GAC)
  • Operation in filters and contactors
  • Empty Bed Contact Time (EBCT) requirements (e.g., GAC10 standard)
  • Breakthrough curves, media replacement, and regeneration options
• Taste and Odor Control
  • Seasonal algae blooms and environmental causes of odor
  • Treatment options: PAC, GAC, copper sulfate, ozone, chlorine dioxide
  • Best practices for lake aeration and reservoir mixing to prevent odor events
• Operational Considerations
  • Safety precautions for PAC/GAC storage and handling (dust control, fire hazards, PPE)
  • Recordkeeping requirements for dosage, filter performance, and breakthrough monitoring
  • Cost and maintenance considerations for PAC vs. GAC systems