JAEA-Review-2010-065.pdf:15.99MB - 日本原子力研究開発機構

2-03
Decolorization of Secondary Treated Water from
Livestock Urine Waste
M. Takigami a) , N. Nagasawa b) , A. Hiroki b) , N. Kasai b) , F. Yoshii b) , M. Tamada b) ,
S. Takigami c) , T. Shibata d) , Y. Aketagawa d) and M. Ozaki e)
a) Gunma Industry Support Organization, b) Environment and Industrial Materials Research Division,
QuBS, JAEA, c) Gunma University, d) Weegl Co., e) Maebashi Institute of Technology
Rivers in Gunma Prefecture are the sources of water
supply to the Metropolitan area. There are many swine
farmers near the rivers and the treated waste water from the
farmers comes into the river. There is no regulation of
color of the drainage, however, one of the biggest concerns
of the farmers is the color of the waste water. They have
1-3)
removed the colored substances using coagulant ,
absorption by activated carbon 4) or soil 5) , decomposition
using ozone or hydrogen peroxide 6) and decomposition by
specific microorganisms 7) . They are effective,however, an
easier and cheaper method is expected to reduce the color in
the secondary treated water.
The color is thought to be a metabolite of
microorganisms and not easy to be removed. Reducing the
color of the waste water is expected by the farmers and local
governments. Gunma Prefecture started a project,
“Prefecture Collaboration of Regional Entities for the
Advancement of Technological Excellence” sponsored by
Japan Science and Technology Agency (JST). We
collaborate to develop a material and a system to reduce the
color in drainage from the farmers.
The colored substances caused by the metabolites of
microorganisms are thought to include humic substances
such as humic acid and fulvic acid. As acids are expected
to be absorbed on anion exchange resins, we decided to
develop an absorbent which is cationic, easy to desorb
absorbed materials, durable for repeated use, easy to handle
and not expensive. To develop an absorbent which fulfills
the conditions mentioned above, we targeted a
radiation-induced graft polymerization onto fabric materials.
Poly(vinyl alcohol) fabric mesh was irradiated with
-rays at 60 kGy under reduced pressure and grafted with
N-[3-(dimethylamino) propyl] acrylamide. The degree of
grafting is expressed as a ratio of weight increase (%) by
graft polymerization to the initial weight of the fabric mesh.
The grafted material with degree of grafting exceeding
100% was used as an absorbent to remove color in
secondary treated water. The color was effectively
removed by immersing the absorbent in the secondary
treated water as shown in Fig. 1. Chemical oxygen
demand (COD) of the treated water decreased to 30% of the
initial secondary treated water. The absorbent was
effective to reduce the chromaticity and COD of the
secondary treated water.
The colored materials on the absorbent were easily
removed using salt solution. The absorbent after
desorption was washed with water and used repeatedly for
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the decolorization of the secondary treated water. The
colored materials were precipitated adding acid to the
desorbent (salt solution). The precipitation was collected
and used as a fertilizer. Leaves and roots of plants such as
rice, spinach and buckwheat grew well using the fertilizer.
The desorbent after removing precipitation and adjusting pH
to neutral could be used repeatedly.
As mentioned above, a new system which can be
attached to the present waste water purification system was
proposed to treat secondary treated water from livestock
urine waste without discarding usable materials.
Acknowledgment
The authors are grateful for the financial support of JST
to perform the research.
References
1) I. Kobayashi, Treatment method of organic matter-
containing sewage, 2005-319448A, Japan, Sep. 7, 2004.
2) N. Ozaki, Colored waste water treatment method,
2004-098042A, Japan, Sep., 6, 2002.
3) T. Suzuki, Method for Decolorizing colored waste water,
2003-181491A, Japan, Dec. 14, 2001.
4) Y. Yabuki, et al., Nihon Chikusan Gakkaiho, 78(3)
(2007) 339-344.
5) R. Suzuki, et al., Res. Bull. Aichi. Agric. Res. Ctr., 38
(2006) 181-185.
6) H. Lee et al., J. Hazard. Mater. 153 (2008) 1314-1319.
7) Y. Sakamoto, et al., Method for treating colored waste
water, H06-39392A, Japan, Apr. 17, 1992.
Fig. 1 Secondary treated water (left) and decolorized
water using absorbent prepared by radiation-induced
graft polymerization (right).