Environmental Engineering Reference
In-Depth Information
popular degreasing solvent (Richardson
2007
; Richardson and Ternes
2011
; Lee
et al.
2011
). Siloxanes are widely used in PCPs and in a number of household
products, such as cosmetics, deodorants, soaps, hair conditioners, hair dyes, car
waxes, baby pacifiers, cookware, cleaners, furniture polishes, and water-repellent
windshield coatings (Richardson and Ternes
2011
; Kierkegaard et al.
2011
).
Ammonium perchlorate is used in solid propellants for rockets, missiles, fireworks
and highway flares. It can also be added in drinking water treatment processes as an
impurity of sodium hypochlorite (liquid bleach), and is present as naturally-occuring
perchlorate in fertilizers (e.g., Chilean nitrate). Formation of perchlorate can also take
place upon reaction of chlorine radicals with ozone in the troposphere during the sum-
mer periods (Richardson and Ternes
2011
; Parker
2009
; Furdui and Tomassini
2010
).
Benzotriazoles are complexing agents that are mostly used as anticorrosives or
corrosion inhibitors (e.g., in engine coolants, aircraft deicers and antifreezing liq-
uids), as UV-light stabilizers for plastics, for silver protection in dish-washing liquids,
as anti-foggants in photography, and in aircraft de-icing/anti-icing fluids (ADAFs).
These compounds are responsible for acute Microtox activity (Richardson
2007
;
Lovley
2006
; Cancilla et al.
1997
). They are soluble in water, resistant to biodegrada-
tion, and are only partially removed in wastewater treatment (Richardson
2007
).
Naphthenic acids are a complex mixture of alkylsubstituted acyclic and cyclo-
aliphatic carboxylic acids that dissolve in water at neutral or alkaline pH and have
surfactant-like properties (Richardson and Ternes
2011
). The key sources of naph-
thenic acids are the residual tailing water left over from the extraction of crude
oil from oil sands, coal deposits, and petroleum industries (Richardson
2007
;
Richardson and Ternes
2011
; Headley et al.
2009
; Scott et al.
2009
). PFCs are
widely used in fabrics and carpets, paints, adhesives, waxes, polishes, metals, elec-
tronics, fire-fighting foams and caulks, as well as grease-proof coatings for food
packaging such as microwave popcorn bags, French fry boxes, hamburger wrap-
pers, and so on (Richardson and Ternes
2011
).
Pesticides are generally released from agricultural fields to rivers or nearby waters
by surface runoff, induced by either atmospheric precipitation or overflow and drain-
age of agricultural field waters (Wang et al.
2007
; Guo et al.
2009
; Richards and Baker
1993
; Majewski et al.
2000
; Derbalah et al.
2003
; Qiu et al.
2005
). However, the new
sources of dichlorodiphenyltrichloroethane (DDT) are mostly connected with con-
tinuing illegal applications of technical DDT, use of technical DDT-containing anti-
fouling paint in commercial fishing boat maintenance, and presence of DDT residues
in dicofol, although its use is internationally forbidden (Wang et al.
2007
; Guo et al.
2009
; Qiu et al.
2005
). Nonylphenol polyethoxylates (NPEOs) and alkylphenol eth-
oxylates (AEOs) are non-ionic surfactants, which are widely used in household, clean-
ing products, paints, pesticides, and industrial processes such as paper and petroleum
production (Farré et al.
2008
; Fairchild et al.
1999
; Strynar and Lindstrom
2008
).
Ionic liquids have unique properties including tunable viscosity, miscibility,
and electrolytic conductivity. These properties make them useful for many appli-
cations, such as organic synthesis and catalysis, production of fuel cells, batteries,
coatings, oils, nanoparticles, as well as other chemical engineering and biotechnol-
ogy applications (Richardson and Ternes
2011
).
