Page 419 - Book Hosokawa Nanoparticle Technology Handbook

7.2 NANOPARTICLES AND ENVIRONMENT FUNDAMENTALS
significantly affect the behavior of some pollutants treatment of such chemical contaminants at low level
in natural environments, such as trace metal specia- becomes increasingly important.
tion and toxicity, solubilization and adsorption of As mentioned above, the removal of nanoparticles
hydrophobic organic compounds, and disinfection contained in wastewater is stringently required to
by-product formation [8]. recycle the reclaimed wastewater in a wide variety of
Melanoidins are natural polymeric compounds of industries such as chemical industry, textile industry,
dark brown color, and they are closely related to pulp and papermaking industry, food-processing
humic substances. They are produced by a set of con- industry, dairy products industry, and pharmaceutical
secutive and parallel nonenzymatic reactions taking industry. Also for domestic wastewater, the reuse of
place between amino compounds and carbohydrates the reclaimed wastewater for nonpotable purposes is
during a Maillard reaction [9]. They are contained in becoming more and more important, and this is
the molasses wastewater from alcohol distillery, sugar expected to raise awareness of the behaviors of
processing and refinery industry, and glutamate pro- nanoparticles contained in wastewater in order to
cessing industry. Such wastewater containing upgrade the water treatment processes.
melanoidins has frequently caused a coloration prob-
lem of water environment, and thus the suitable decol-
orization treatment is required in many fermentation References
and sugar industries using molasses. Treatments by
flocculation, ozonation, and electrolysis are promis- [1] J.R. Pan, C. Huang, W. Jiang and C. Chen:
ing in color removal [10]. Desalination, 179, 31–40 (2005).
Food-processing wastewater usually contains a [2] H. Umezawa, M. Iseki, D. Takaoka, M. Tsuihiji and
variety of organic materials in varying degree of con- T. Kasahara: Sanyo Tech. Rev., 35(2), 22–30 (2003).
centration. In cheese-making in the dairy products [3] M. Moriya: J. Jpn. Soc. Water Environ., 22, 346–351
industry, only 10% of the initial milk volume (1999).
becomes product, cheese, and the other 90% [4] L. Skipperud, B. Salbu and E. Hagebø: Sci. Total
becomes by-product, liquid cheese whey. Since Environ., 217, 251–256 (1998).
cheese whey is a protein- and lactose-rich by-product [5] K. Karakulski, A.W. Morawski: Desalination, 149,
of cheese production, its cost-effective utilization is
becoming increasingly important. Recent develop- 163–167 (2002).
ments in membrane technology have provided excit- [6] S.K. Kang, K.H. Choo: J. Membr. Sci., 223, 89–103
ing new opportunities for large-scale protein and (2003).
lactose fractionation in whey treatment [11]. In tex- [7] K. Higashi: J. Jpn. Soc. Water Environ., 20, 210–214
tile industry, typically it takes over 100 L of water to (1997).
process just 1 kg of textile material. Not only the [8] N. Shinozuka: J. Jpn. Soc. Water Environ., 18,
washing water must be treated to recover important 261–265 (1995).
by-products such as lanolin, but bleaching and dye- [9] S. Homma: Denpun Kagaku, 38, 73–79 (1991).
ing chemicals must also be removed before discharge [10] A. Nagano, C. Nakamoto and M. Suzuki: J. Jpn. Soc.
back to the rivers [12]. Water Environ., 22, 498–504 (1999).
Surfactants are a primary constituent of the deter-
gent used in the household routinely, and also they are [11] A. Rektor, G. Vatai: Desalination, 162, 279–286
widely used in industry and agriculture because they (2004).
have several functions such as washing, emulsifica- [12] G. Rideal: Filtr. Sep., 42(7), 30–33 (2005).
tion, and dispersion. The surfactants are usually pres- [13] K. Yoshimura: J. Jpn. Soc. Water Environ., 16,
ent in the solution in the form of the micelle, and large 294–301 (1993).
amounts of surfactant wastewater are discharged in [14] Y. Kiso, H.-D. Li and T. Kitao: J. Jpn. Soc. Water
the rivers [13]. Pesticides whose molecular weight Environ., 19, 648–656 (1996).
ranged from 200 to 400 Da ( 1 nm) have been used [15] S.S. Madaeni, A.G. Fane and G.S. Grohmann:
in great quantities not only for agricultural use but J. Membr. Sci., 102, 65–75 (1995).
also in golf links and resort. Therefore, the wastewater [16] T. Urase, K. Sato: J. Jpn. Soc. Water Environ., 28,
and effluent treatments have become an important
issue, and pesticide separation by NF membranes is 657–662 (2005).
found to be very efficient [14]. [17] S. Kim, Y. Suzuki: J. Jpn. Soc. Water Environ., 25,
The potential reclamation of high-quality water pro- 349–354 (2002).
duced by the advanced treatment of the secondary
effluent of the municipal sewage has come a long way 7.2.5 Indoor environments and nanoparticles
in recent years. The sewage contains various compo-
nents such as virus [15], pharmaceutical substances In recent urbanized lifestyles people tend to spend
[16], and endocrine disrupting compounds derived more time in enclosed buildings or residences than
from zoonotic excretory substances [17]. The advanced outdoors. Therefore, it is of great importance to

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