Sustainable Environmental Engineering

12Treatment

Mineralization is a better strategy than phase transfer.

OBJECTIVES

• To provide technical support of the UV disinfection to replace chlorination to comply with regulatory requirements
• To quantify UV dose for inactivating Cryptosporidium and Giardia
• To design high efficient UV reactor for disinfection
• To define and apply virus or bacteria sensitivity index of UV disinfection for engineering applications
• To provide simplified mathematical model quantifying bacteria shoulder effect during UV disinfection
• To present advanced oxidation processes such as UV/TiO₂ to replace phase transfer process
• To use the Hammett plot to differentiate the hole versus hydroxyl radical oxidation in UV/TiO₂
• To assess and select different advanced oxidation processes (AOPs)

12.1 Principle 9

To meet the US EPA long‐term regulation (LTR) and disinfection by‐product (DBP) Stage 2 rules simultaneously, ultraviolet (UV) disinfection is the key enabling technology, because UV process could not only disinfect all the pathogenic microorganisms but also degrade micropollutants in water or wastewater.

Principle 9 Treatment should avoid adding chemicals or use minimal nontoxic chemicals and renewable energy to reduce footprints.

1. No toxic chemicals such as chlorine or aluminum should be added to drinking water.
2. Destructive technologies such as AOPs should be the first choice versus phase transfer technologies such as activated carbon.
3. Waste such as sludge produced per unit water produced ...