Hydrocarbon Processing - October 2022 - 11

Water
Management
D. WILLIAMS
Contributing Author, Torrance, California, U.S.
Achieve compliance with automated wastewater
treatment for industrial facilities with cooling towers
Industrial facilities with cooling towers in the U.S. must
meet U. S. Environmental Protection Agency (EPA) and local
wastewater requirements for effluent, including those under
the Clean Water Act. Failing to do so can result in severe fines
that quickly escalate.
A wide range of industries utilize cooling towers in their
facilities, such as metal processors and rubber, chemical and
plastic product manufacturers. For industrial facilities with a
cooling tower, a water treatment system is required to ensure
an efficient process and long equipment life. If cooling tower
water is not treated properly, fouling, scaling, corrosion and
organic growth can trigger sizeable EPA and local environmental
agency fines. This can not only cause facility downtime,
but also reduce productivity and necessitate costly, premature
equipment replacement.
A cooling tower water treatment system can consist of
various technologies needed to regulate the level of alkalinity,
chlorides, hardness, iron, organic matter, silica, sulfates, total
dissolved solids (TDS) and total suspended solids (TSS). Although
the type of industry and specific operational practices
determine the type of wastewater generated, most involve suspended
solids, heavy metals, organic compounds or a variety
of other pollutants. Under the Clean Water Act, for example,
the EPA has identified 65 pollutants and classes of pollutants
as " toxic pollutants, " of which 126 specific substances have
been designated " priority " toxic pollutants.
For many plants utilizing cooling towers, this means installing
a wastewater treatment system that effectively separates
the contaminants from the water so it can be legally discharged
into sewer systems or even re-used.
However, traditional wastewater treatment systems can be
complex, often requiring multiple steps, a variety of chemicals
and a considerable amount of labor. Even when the process
is supposedly automated, too often technicians must still
monitor the equipment in person. This usually requires oversight
of mixing and separation, the adding of chemicals, and
other tasks required to keep the process moving. Even then,
the water produced can still fall below mandated requirements
(FIG. 1).
Although paying to have industrial wastewater from a cooling
tower hauled away is also an option, it is extraordinarily
expensive. In contrast, it is much more cost effective to treat
the industrial wastewater at its source, at or near the cooling
tower. This can enable treated water to be reused, effluent to
go into a sewer and treated sludge to pass a toxicity characteristics
leaching procedure (TCLP) test, allowing disposal as
non-hazardous waste in a local landfill.
FIG. 1. Untreated wastewater effluent.
Fortunately, complying with wastewater regulations has
become much easier with more fully automated, wastewater
treatment systems. Such systems not only reliably meet regulatory
wastewater requirements, but also significantly reduce
the cost of treatment, labor and disposal when the proper
separating agentsa
are also used.
Cost-effective, automated wastewater treatment. In
contrast to labor-intensive, multiple-step processes, automated
wastewater treatment can help to streamline production and
cooling tower wastewater treatment-usually with a one-step
process-while lowering costs at manufacturing facilities.
An automated wastewater treatment system for cooling
towers can eliminate the need to monitor equipment in person
while complying with mandated requirements. Such automated
systems separate suspended solids, emulsified oil and heavy
metals, and encapsulate the contaminants, producing an easily
de-waterable sludge in minutes, according to production consultants
at Sabo Industrial Corp., a New York, U.S.-based manufacturer,
distributor and integrator of industrial waste treatment
equipment and solutions, including batch and fully automated
systems, separating agentsa
, bag filters and accessories.
The water is typically then separated using a de-watering
table or bag filters before it is discharged into sewer systems or
further filtered for re-use as process water. Other options for
de-watering include using a filter press or rotary drum vacuum.
The resulting solids are non-leachable and considered nonhazardous,
so they will pass all required testing.
These systems are available as manual batch processors,
semi-automatic or automatic, and can be designed as a closedHydrocarbon
Processing | OCTOBER 2022 11
Hydrocarbon Processing - October 2022

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