Chemical Engineering September 2023 - 36

opposed to testing for a specific chemical, WET is the
aggregate toxic effect of an effluent. By observing the
effect of a facility's wastewater on living aquatic plants,
vertebrates and invertebrates, it can be established what
the larger impact on an ecosystem and the safety of its
water would be. There are two basic types of WET tests:
acute and chronic.
Acute tests measure the immediate impact (such as
mortality) of effluent on life forms that act as representatives
of a general aquatic setting, and the test duration
is usually 24, 48 or 96 h. The EPA recommends the use
of ≥0.5 dilution factor, five effluent concentrations and a
control for both freshwater and marine/estuarine effluent
(although different organisms are used for freshwater
and marine settings).
Chronic tests measure the longer-term impact of effluent,
such as survivability, growth, mobility, fecundity,
reproduction and teratogenicity (embryonic abnormalities).
For chronic tests in freshwater settings, the EPA
recommends the use of ≥0.5 dilution factor, five effluent
concentrations and a control with a test duration of between
four and eight days. For testing on marine/estuarine
organisms, the test includes five effluent concentrations
and a control, with a duration of between one hour
and nine days.
The required frequency of a WET test is determined by
a facility's discharge permit and can range from monthly
to annually, depending on substances handled by the
facility and their potential risk to surface waters. Only
third-party certified laboratories can perform these tests.
Ref 4. Includes a list of methods and their corresponding
test organisms.
Piloting can minimize risk
Wastewater and water treatment systems are a significant
investment, so it is usually advisable to pilot the
treatment before committing to a permanent installation.
Most reputable suppliers will have a containerized, plugand-play
version of their products (Figure 3) with laboratory-scale
testing that facilities can use for a limited period
of time to confirm that the process will produce the
desired results.
Piloting can overcome the challenges of variability
presented by seasonality, weather and many other factors
that affect water quality over time, as well as provide
the opportunity to adjust certain parameters to design
a system that will deliver the right treatment for the
specific application.
One size most certainly does not fit all when it comes
to water, wastewater and process water treatment, and
the various applications, regulatory requirements, space
allotment and optimal performance of each unique bioprocessing
plant demands a tailored approach. Piloting
will ensure that a plant invests properly and for the
long term.
For bioprocessing facilities seeking to ensure that their
wastewater complies with federal and state regulations
and does not contaminate the surface water into which
it discharges its effluent, the advanced oxidation processes
described here can offer exceptional benefits, including
reducing costs, increasing profitability, lowering
risk and improving reputation.
References
1. U.S. EPA Office
gram,
EPA,
of Wastewater Management, Introduction
June 2011,
program_intro_2011.pdf.
2. U.S. EPA, Industrial Effluent Guidelines, March 2023, www.epa.gov/eg/industrial-effluent-guidelines.
3. U.S.
Spill Prevention,
Control,
stream (Oil Exploration and Production) Sector,
and Countermeasure (SPCC) for the Upwww.epa.gov/
March
2023,
oil-spills-prevention-and-preparedness-regulations/spill-prevention-control-andcountermeasure-19.
4.
U.S. EPA, Whole Effluent Toxicity Methods, August 2020, www.epa.gov/cwa-methods/wholeeffluent-toxicity-methods.
Author
Alex
Bettinardi (Via Leonardo Bistolfi, 35, 20134 Milan Italy;
Phone: +39 02 21291, Email: industriedenora@denora.com) is
the global ozone and AOP product technology manager at De
Nora S.p.A. in Lodi, Lombardy, Italy. He manages the technical
and commercial bidding process, strategy definition, municipal
and industrial market development, technical and sales training
and knowledge transfer and support for representatives and distributors.
Before joining De Nora, Bettinardi was the managing
director at Ozono Elettronica Internazionale. He has a B.S. degree
in biotechnology from Università degli Studi di Milano.
For details visit adlinks.chemengonline.com/84651-18
36
CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM
SEPTEMBER 2023
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Edited by Mary Page Bailey
to the National Pretreatment Prowww.epa.gov/sites/default/files/2015-10/documents/pretreatment_

http://adlinks.chemengonline.com/84651-18 http://www.epa.gov/sites/default/files/2015-10/documents/pretreatment_program_intro_2011.pdf http://www.epa.gov/sites/default/files/2015-10/documents/pretreatment_program_intro_2011.pdf http://www.epa.gov/eg/industrial-effluent-guidelines http://www.epa.gov/oil-spills-prevention-and-preparedness-regulations/spill-prevention-control-and-countermeasure-19 http://www.epa.gov/oil-spills-prevention-and-preparedness-regulations/spill-prevention-control-and-countermeasure-19 http://www.epa.gov/cwa-methods/whole-effluent-toxicity-methods http://www.epa.gov/cwa-methods/whole-effluent-toxicity-methods http://http:// http://WWW.CHEMENGONLINE.COM

Chemical Engineering September 2023

Table of Contents for the Digital Edition of Chemical Engineering September 2023