Reduction, Recycling, Reuse For Cooling System Makeup

By Colin Frayne

Industry in general, and cooling tower operators specifically, are urged to implement novel strategies to reduce process demands for fresh and potable water, and to expand the use of treated wastewater streams and recycled water as cooling tower makeup.

Cooling systems are generally accepting of a wide diversity of waters and, given some consistency, many industrial streams can be economically recovered and reused as tower makeup. However, recoverable process waters will always require some judicious pretreatment before being recycled for reuse in cooling systems, if only to remove particulates, fats, oils, and greases (FOG), and heavy metals; and provide pH adjustments (say pH 7.0 to 8.5). Suitable candidates may include waters employed for:

• Washing, cleaning, dying, rinsing, melting, quenching, stripping, scrubbing, desalting, plating, surface coatings, fermentation, dust control, process liquors, steam heating and drying, cooking, pasteurization, and domestic purposes.
• Additionally, excess water results from alcohol and spirit distillation, sugar/fish-meal/orange juice evaporator condensates, chemical manufacturing, recovery of fibers and chemicals, straining, filtration, drainage, stormwater storage, etc.

Screening Of Influent Streams At Electric Power Generating Stations, Wastewater Treatment Facilities And Industrial Plant Wastewater Disposal

Since electric power generation stations, wastewater treatment facilities and wastewater disposal at large industrial complexes use such large volumes of water; they are generally located adjacent to a ready supply of substantial amounts of water. If there is not a lake, river or other large water source nearby for such a plant when under construction, a lake or other water source may be built.
  The first, or primary section of a typical wastewater treatment facility will receive the incoming wastewater or influent via a channel or basin, into a screenhouse. It is necessary, initially, to remove from the influent large solid materials or those which are not water soluble.