Recycling Treated Municipal Wastewater for Industrial Water Use

Section 2
Implementation Considerations
Craddock Consulting Engineers
In Association with CDM & James Crook 2-21
TM1-Sec2_0707.doc
reclaimed water. However, some contaminants may occur in higher concentrations in
reclaimed water, and will vary highly with the water source, the industrial and
domestic wastewater influent characteristics, and wastewater treatment processes.
Table 2.11 demonstrates the variability in reclaimed water quality for constituents of
concern for many industries.
Treatment Processes
Cooling and Process Water. The overview of industrial water quality concerns in the
preceding subsection identified treatment practices for industrial water use for
cooling water and boiler feed water. The treatment processes commonly used for
industrial cooling water are shown in Figure 2.1. Nitrification is usually used to
remove ammonia that causes stress in copper based alloy pipes. Ferric chloride or
alum is used to precipitate phosphorus to levels less than 0.6 mg/L, to avoid
precipitation and scale formation.
Table 2.11. Florida and California Reclaimed Water Quality – Industrial
Constituents of Concern
Water Constituent Orlando Tampa Los Angeles San
(mg/L)
Francisco
Conductivity, umho/m 1200-1800 600-1500 2000-2700 800-1200
Calcium Hardness 180-200 100-120 260-450 50-180
Total Alkalinity 150-200 60-100 140-280 30-120
Chlorides 20-40 30-80 250-350 40-200
Phosphate 18-25 10-20 300-400 20-70
Ammonia 10-15 5-15 4-20 2-8
Total Suspended Solids 3-5 3-5 10-45 2-10
Source: U.S. EPA Guidelines for Water Reuse [2004]
Secondary
Effluent
Nitrification
Flocculation Clarification
Filtration
Figure 2.1. Typical Treatment Train of Reclaimed Water for Power Plant Cooling Water
Disinfection