Application of Bio-eco Engineering to Water Environment

Application of Bio-eco Engineering to Water Environment Restoration
as a Decentralized Wastewater Treatment System
(Joe) Kaiqin XU1,2, Yoshitaka EBIE2 and Yuhei INAMORI3
1) Environmental Technology Assessment Section; 2) Bio-Eco Engineering Section
National Institute for Environmental Studies, 16-2 Onogawa Tsukuba 305-8506, Japan
3) Fukushima University, 1 Kanayagawa Fukushima 960-1296, Japan
The environmental quality standards relating to the protection of human health in Japan were
amended from nine items into twenty six items, and the compliance ratios were more than 99.1% in 2005.
However, the compliance ratios of BOD/COD for rivers, lakes and coastal waters were 87.2%, 53.4% and
76.0% in 2005, respectively, which still remains in low levels for enclosed water areas (Ministry of
Environment, Japan, 2006). Especially in urban rivers, lakes, inland sea and bays, the water bodies are
extremely eutrophic because of the direct discharging of gray water, which represents a substantial portion
of the total household effluents, and the wastewater from the small scale factories. They are almost 70 % of
the total pollutants in public water areas. On the other hand, as for the environmental quality standards
relating to nitrogen and phosphorus in 60 determined lakes and 112 sea areas were 46.6% and 82.2%. The
removal of nitrogen and phosphorus in effluent from domestic and industrial wastewater treatment
facilities is most important to control the eutrophication.
Water environment pollution has been accelerated by point and non-point sources. Consequently,
the abnormal growth of blue-green algae in enclosed water bodies has become a serious environmental
issue. Although the economic and social conditions in Japan, China and other Asian countries differ
substantially, the environment ministers of these countries have been sharing the common task of
combating environmental problems at the domestic, regional and global levels. It is necessary to promote
joint research and development as well as the dissemination of appropriate technologies tailored for each
situation, such as the ‘on-site advanced domestic wastewater treatment systems’ and ‘soil and aquatic plant
purification systems’, based on bio-eco engineering. The extreme growth of poisonous picoplankton and
the occurrence of water bloom even caused the crisis of water supply systems. The control of micro
pollutants such as organochloride and agricultural pesticides is also an urgent problem. Some successful
results have been reached through the cooperative studies of government, companies and research institutes.
Some of the acquired new technologies have been applied to the practical use. At the meantime these
technologies are adopted as advanced treatment methods and begun to spread to different regions. Among
them the application of the eco-technology and bio-technology is one of the important tasks for the
treatment of wastewater and the conservation of water environment.
The removal of nitrogen and phosphorus in effluent from domestic and industrial wastewater
treatment facilities is most important to control the eutrophication. In this presentation, new environmental
problems caused by blue-green algae, necessity and improvement of nitrogen and phosphorus removal
144
technology, and some advanced national projects will be presented. As a cost-effective, energy-saving and
less technique intensive innovation/alternative, eco-technology and biotechnology may be more important
and useful to water environmental conservation. Eco-technology using wetland system, aquatic plant
system, land treatment system, stream purification system, and some biological wastewater treatment
systems should be established. The technical development for the removal of nitrogen and phosphorus by
using the combination of eco-technology and bio-technology, and the efficiency promoting for the
biological water and wastewater treatment must be carried out to prevent eutrophication. Many studies,
both science and engineering, are needed to develop an effective treatment system which provides suitable
habitats of aquatic livings. Furthermore, the importance of international cooperative studies has been
increased because the water pollution of international rivers and oceans become more serious problems and
it is recognized that emission of green house effect gases from deteriorated water environment and
wastewater treatment may cause global environmental problems. The global water environmental issues,
especially the abnormal algal growth and mycrocystin, comprehensive efforts in regard to these issues and
some integrated countermeasures based on bio-eco engineering conducted in the NIES, Japan, are
discussed. The applications of eco-technology and bio-technology to the restoration of water environment
field as a decentralized wastewater treatment system were also discussed.
References
1)
Y. Inamori, K-Q. Xu and N. Noda: Development of Advanced Water Renovation Systems using
Bio-eco Engineering for Establishing Sound Water Environment, in “Study on Lake Eutrophication
and Its Countermeasure in China”, China Environmental Science Press Edited by State
Environmental Protection Administration of China, 53-71, 2001
2)
P. Hawkins, Y. Inamori et al.: A Review of Analytical Methods for Assessing the Public Health Risk
from Microcystin in the Aquatic Environment, Journal of Water Supply: Research and
Technology-AQUA, 54(8), 509–518, 2005.
3)
R. Inamori, P. Gui, Y. Shimizu, K-Q. Xu, K. Kimura, Y. Inamori: Effect of Constructed Wetland
Structure on Wastewater Treatment and its Evaluation by Algal Growth Potential Test, Japanese
Journal of Water Treatment Biology, 41, 159–170, 2005.
4)
Y. Inamori, Y. Kimochi et al.: Control of Anthropogenic CH4 and N2O Emissions from Several
Industrial Sources and from Daily Human Life, Journal of Chemical Engineering of Japan, 36(4),
449–457, 2003.
5)
T. Saito, N. Sugiura, T. Itayama, Y. Inamori, M. Matsumura: Biodegradation of Microcystis and
Microcystins by Indigenous Nanoflagellates on Biofilm in a Practical Treatment Facility,
Environmental Technology, 24, 143–151, 2003.
6)
R. Sudo and K-Q. Xu: Present status and conservation measures of water environment in Japan, in
“Study on Lake Eutrophication and Its Countermeasure in China”, China Environmental Science
Press, Edited by State Environmental Protection Administration of China, 107-122, 2001.
145
2nd Sino-Japan River Basin
Water Environment Workshop
May 24, 2007
Tshukuba, Japan
Application of Bio-eco Engineering to Water
Environment Restoration as a Decentralized
Wastewater Treatment System
(Joe) Kai-Qin XU*, Yoshitaka EBIE* , and Yuhei INAMORI**
*National Institute for Environmental Studies, Japan
** Fukushima University, Japan
Current conditions of lakes in Japan – problems shared between
countries all over the world
30
25
20
Japan clears 80.9%, 74.9%,
環境基準達成率は,
河川8and
0.9
41.0% of environmental
％,
海域74.
9％,
湖沼41.
0％と
standards
for
rivers,
sea areas,
and lakes, respectively. When it
特に湖沼が低く,
comes to standardsかつ湖沼の
of
concentrations
of nitrogen and
窒素,
リンの環境基準達成率
phosphorus, it clears only
は
4 0 .6
と 極めて低 い　40.6%
for％
lakes.
Teganuma
手賀沼
Inbanuma
印旛沼
Lake
児島湖
Kojima
Kasumi霞ヶ浦
gaura
(西浦)
(Nishiura)
15
The growth of algae originated from nitrogen
窒素,リンに由来する藻類増殖に伴う
and phosphorus increases the ratio of internally
produced COD.
内部生産CODの割合の増大
Lake Suwa
諏訪湖
Nakaumi
中海
10
Lake Shinji
穴道湖
Lake Biwa
琵琶湖
(Lake Nan)
Cell
Cell
(南湖)
5
Kamafusa
釜房ダム
Dam
100µm
Lake Nojiri
野尻湖
0
1988
1989 1990
63 平元
2 1991
3 1992
4 1993
5 1994
6 1995
7 1996
8 199719981999
9 10 11
Year
年度
Water10quality
of 10 designated lakes (average of COD)
ヶ所指定湖沼の水質状況（COD平均値）
100μm
Cell morphology
有毒アオコ
of toxic green
の細胞形態
algae
An accumulation of toxic green algae
有毒アオコの霞ヶ浦における集積部の状況
in Kasumigaura
2
2 定 湖沼 をは じめ 面 積が 1 k m を 越え る淡 水 湖沼 は
湖 沼水
質保
全 計画
定さ れ
てい
る指
Japan
has
more
than の策
100 lakes
over
1 km
in area including those designated in the lake water
1 0 0 ヶ所以
上存在
し、気象
水深、形
川等から
の流入水
特性は地
域ご
quality
protection
project.
While条件、
they are
different状、河
from each
other in
weather 量等の
conditions,
water depth,
shape,
and
volume
of
water
inflow
from
rivers,
green
algae
have
been
detected
in
many
of
them.
とに異なるが、これらの多くの湖沼では
有毒アオコが顕在化 している。
オコの効
果的抑制対
策を図る
上では、
有毒アオコ
の発生現状
とともに
各湖沼の
To有毒ア
effectively
prevent
the growth
of green
algae, the
current condition
of their
growth and
the
環 境お よび
地理
的特 性を 調査
解 析し
策と
それ
に基be
づ く新
たな バイInオ･
エコ エン ジ
environment
and
geographical
properties
of、対
these
lakes
should
investigated.
addition,
advanced
technologies
for building
bio-ecosystems
should be developed
introducing化技術
ニアリ ングを活
用した技術
導入による
バイオ ・エコシステ
ム構築のby
ための支援
appropriate
countermeasures 。
and bio-eco engineering.
を充実 させる必要がある
146
Bio-engineering
Technology to take full advantage of the
function of microbes
Advanced combined wastewater treatment system
Eco-engineering
Technology to take full advantage of the
potential function of ecosystems
Water and soil purification by means of aquatic plants and water culture
Combination of bio- and
eco- technologies
Bio-eco engineering
Kasumigaura
Miho-mura,
Ibaraki Prefecture
9
Domestic
wastewater
Miho-mura rural
community
wastewater
treatment system
Water 100
m3/day-1
inflow
1
Multi-purpose
6
7
8
bio-engineering
experimental field
5
1
Treated
water
Constanttemperature facility
for testing private
sewage systems
2
3
Building to analyze
technology transfer
to developing
countries in bioeco engineering
4
Wastewater tank
Approx. 2km
Facility for
evaluating the
effects of reducing
eutrophication
Treated water tank
Approx. 2km
Eco-engineering
experimental field
Water culture purification
experimental facility
y Develop and evaluate bio-eco
engineering
y Transfer technology to developing
countries and give training
y Cooperate with government offices and
conduct international joint research
y Promote the education of the
environment and environmental
safeguards
Soil treatment
experimental facility
The Bio-Eco Engineering Research Laboratory of the National Institute
for Environmental Studies, built as an international central facility
147
Comparison of toxicity between microcystis aeruginosa
(a genus of blue-green algae) and different toxins
Toxin
Botulinus toxin
Ciguatoxin
Tetrodoxin
Saxitoxin
Dioxin
Anatoxin-a(s)
Microcystin-LR
Microcystin-YR
Okadaic acid
Cholera toxin
Microcystin-RR
Potassium cyanide
Toxic Algae
Microcystis aeruginosa)
LD50 (μg/kg-1)
0.00003
0.35
8
10
20
40 - 50
80
100
200
250
600
5,000
* When administered intraabdominally to mice,
The WHO guideline of microcystin LR for drinking
water quality: 1 μg/l
糸状性有毒アオコ（ Anabaena affinis）
Major eutrophic lakes in the Asian region where microcystin
and musty odor substances were detected, including Japan
and tropical, subtropical, temperate, and polar zones
アルハイ湖
Er Hai
玄武湖Hu
Xuanwu
モンゴル
Mongolia
●
Barudanho
八堂湖
日本
Japan
中華人民共和国
China
Afghanistan
アフガニスタン
●●
Most designated
我が国のほとんど
lakes and marshes
の指定湖沼
in Japan
Nepal
ネパール
Pakistan
パキスタン
Bhutan
ブータン
●
クワン・ファヤオ湖
Kwan Phayao
太　湖
Tai Hu
●
●
インド
India
Hong
Feng Hu, Bai Hua Hu
紅楓湖，百花湖
ベトナム
Vietnam
ラオス
Laos
ミャンマー
Myanmar
●
Thailand
タイ
●
●
●
ベトナム
Vietnam
デンチ湖
Dian
Chi Hu
カンボジア
Cambodia
ブン・ボラペット湖
Bun Borapetto
●
フィリピン
Philippines
バン・プラ湖
Bang Pra
ラグナ湖
Laguna
de Bay
●
Indonesia
インドネシア
148
Concentration of microcystin (μg/L-1)
Concentrations of microcystin in eutrophied lakes
in Japan, China, and Thailand
10 5
Microcystin-RR
Microcystin-YR
Microcystin-LR
10 4
10 3
10 2
10 1
10 0
Thai Hu Dian Chi Enhai Bangpra Tega(China) (China) (China) Reservoir numa
(Thailand)
Kasumi- Kojima
gaura
Lake
Lake
Suwa
Lake
Tsukui
Lake
* The concentrations of microcystin above were measured in a large accumulation of green algae.
High concentrations of microcystin are detected in many eutrophic lakes in the Asian
region, indicating that a measure to prevent increases in the toxic substance is required.
Others
10%
Wastewater
from
stockbreeding
22%
Domestic
wastewater
Others
51%
Domestic
wastewater
33%
Ratios of domestic
wastewater in other Asian
countries
68%
Wastewater from
stockbreeding
12%
Pollution loads in Tokyo Bay
Others
31%
Domestic
wastewater
63%
4%
Pollution loads
by source in Kasumigaura
Others
39%
Domestic
wastewater
28%
Wastewater
from
stockbreeding
Industrial
wastewater
Industrial
wastewater
Industrial
wastewater
Indonesia
70%
Thailand
75%
Philippines
55%
Malaysia
77%
South Korea
54%
China
53%
20%
13%
6%
Pollution loads
by source in Teganuma
Pollution loads
by source in Lake Biwa
Ratio of domestic wastewater to the entire pollution load
in Japan and other Asian countries
149
Microbes that contribute to the normalization
of the aquatic environment
Small biomass
Low pollution load
Birds
Predation
Fishes
Predation
Advanced
wastewater
treatment
Large biomass
Protozoans, metazoans,
insects, shellfishes
Predation
Algae, bacteria
(decompose organic substances,
consume nitrogen and phosphorus)
High pollution load
Food-chains and their cleaning effect in natural and artificial ecosystems
Predation of green algae by aquatic earthworms
Aquatic earthworm
Aeolosoma hemprichi
Consumption of a flock
Dispersion
Flock of green algae
Microcystis
150
Amoeba
Amoeba that consumes
filamentous green algae
Thecamoeba sp.
Filamentous
green algae
Special
mouth
structure
Filamentous green
algae taken into a ciliate
Ciliate that consumes
filamentous green algae
Trithigmostoma cucullulus
Ciliate
Filamentous
green algae
Ciliate
Ciliate that consumes
filamentous green algae
Furgasonia sp.
Filamentous green
algae taken into a ciliate
Water purification and sludge reduction system using food-chains
Domestic and industrial
organic wastewater
High concentration of BOD,
COD, T-N, T-P, and SS
Activated sludge treatment
system using suspended
microbes
Predation and decomposition by protozoans
including ciliates and sarcodinians, and
micro-metazoans including rotifers,
oligochaeta, and crustaceans
Aeration tank
Activation of
animalcules at a high
temperature
Conversion
ratio
0.5
BOD, N, P
Bacteria
Settling tank
Takes advantage of food-chains
of fishes including guppies and
catfishes to reduce the amount
of sludge and make water clear
0.5
0.2
0.1
Sludge tank
Dried solids on the
surface are recycled for
use in green farms.
0.1
MicroGuppies
Catfish
metazoans
Water becomes clear, green algae aggregates,
and the amount of sludge is reduced.
Protozoans
Anaerobic nitrification,
aerobic denitrification
151
Johkasou System that removes nitrogen and phosphorus
– an application of bio-engineering
Installation of a small
compact combined
wastewater treatment tank
Installation of a medium
size compact combined
wastewater treatment tank
Circulatory biological filtering system with anaerobic filter
bed for advanced wastewater treatment (flow adjustable)
Inflow
Domestic wastewater
Back wash drain pipe
Baffle board
Aeration pipe
Flow shift gate
Outfall
First chamber of aerobic
filter bed tank
Circulation unit Sterilizing tank
Second chamber of
aerobic filter bed tank
Treated water tank
{ Flow can be adjusted to cover
increases in water volume in the
morning and evening.
{ Nitrification and denitrification by
anaerobic and aerobic circulation
remove nitrogen.
{ Sludge can be recycled into ceramics.
Biological slime
filtering tank
Outflow
Sophisticatedly treated water
Back wash pump
Biological filtering tank
Bowls made from ceramics
recycled from sludge
φ 5 – 9 mm
152
Flow of an advanced combined wastewater treatment tank
BOD 200 mg/l-1
T-N 50 mg/l-1
T-P
5 mg/l-1
Adsorptive
吸着脱リン装置
dephosphorization
unit
Miscellaneous
生活雑排水
domestic
wastewater
し尿
Human
waste
Sterilization
消毒
Circula循環
tion
HWL
Discharge
放流
LWL
First chamber of
嫌気ろ床第1室
anaerobic
filter bed
BOD
T-N
T-P
Treated
処理水槽
Biological
Second chamber of 生物ろ過槽
filtering tank
嫌気ろ床第2室
anaerobic
filter bed
10 mg/l-1
10 mg/l-1
1 mg/l-1
water tank
P
Nitrogen
Phosphorus
Domestic
wastewater
Recycling of phosphorus
Crops
Returned to
Fertilizer agricultural
lands
Recycled into
fertilizers or
industrial
chemicals
P
Maintenance company
Advanced combined
Adsorbent recycling station wastewater treatment tank
Recovery of
phosphorus
(Sewage treatment system)
Adsorptive
dephosphorization system
Building of ecosystems to recover
phosphorus resources in short
supply, a strategic material banned
from being exported in the United
States.
Carbon
Prevention of the eutrophication of
public water areas
Human life
Advanced treatment of nutritive salts
Introduction of an advanced combined wastewater treatment
tank to build a system that recovers phosphorus resources
153
The effect of an advanced combined wastewater treatment tank
against domestic wastewater – an Application of Bio-Engineering
A Pump-up toilet
B Separate sewage treatment tank
Conventional combined
C wastewater treatment tank
Treat only
human waste
Discharge of
miscellaneous
domestic
wastewater
Pumpup toilet
Discharge of
miscellaneous
domestic
wastewater
Treat both human
waste and
miscellaneous
domestic wastewater
Final discharge Advanced combined Final discharge
BOD 90 mg/l-1 wastewater treatment BOD 20 mg/l-1
Sent to a human waste
treatment facility
D
Advanced combined wastewater treatment tank
Retain a high, stable concentration of
microbes to remove BOD and N
Physico-chemical removal of phosphorus
Advanced removal of
BOD, nitrogen, and
phosphorus
Circulation
system
Final discharge
BOD: 10 mg/l-1 or below
T-N: 10 mg/l-1 or below
T-P: 1 mg/l-1 or below
P
Human waste and miscellaneous
domestic wastewater
Advanced treatment of water
Point sources
Domestic/industrial
Non-point sources
Agricultural, forest. natural, rainfall
Livestocks/fishery
（fertilizer, manure ）
（Sewer system, regulations）
＜Inflow from outside＞
Pollutant load from PS
Water Quality
Pollutant load from non-PS
Lake/reservoir
Water supply
problems
Lake reproduction
Safety
＜Internal＞
Internal load （ 1 mg Algae=0.5 mg COD )
Sediment / algae
Reproduction by diversion, circulation,
dredging, harvesting etc.
Natural and socio
factors
Water pollution mechanism
mechanism and watershed management in Lake and reservoir
154
Lake Taihu Aquatic
Environment Restoration
Modeling Project
Global transmission
of information
Introduce a new model of
Tai Hu to the entire China
Send that information to the Beijing
global network base
Technological transfer
in China
Promotion of education
on the environment
Technological transfer of
water purification systems
using soil
Nanjing
Wuxi
Chao Hu
Er Hai
Tai Hu
Technological transfer of
advanced wastewater
treatment Johkasous
Technological transfer of
water purification systems
using aquatic plants and water
culture
Shanghai
Japan
Dian Chi Hu
China
Japan International Cooperation Agency (JICA)
National Institute for Environmental Studies (NIES)
Public Works Research Institute (PWRI)
Joint research projects in
cooperation with government
offices
Transfer of technologies for
removing nitrogen and
phosphorus in consideration of
efforts to improve the
environment in Japan
Relation between throughput of water purification systems
using aquatic plants and coexistent microbes
Absorption of O2 in the air
Removal
rate of BOD
85%
Trapping of
suspended
solids
Aerobic
(nitrification)
Removal
rate of T-N
85%
Water purification
by biomembranes
in rhizomes
Anaerobic
(denitrification)
Removal
rate of T-P
85%
Food-chains
reduce the
amount of sludge.
Absorption of N
and P into roots
Because of their
cleaning ability,
plants and microbes
can be used to
decontaminate the
environment.
Reduced consumption
of energy
Food-chains reduce
the amount of biomass.
Control of emissions of
CH4, N2O, and other
greenhouse gases
Roots supply O2.
155
Bio-park’s role in water purification and development
into environmental education activities
Overview of a water purification
system in a bio-park
Field trip activities in a bio-park
Giving children opportunities to work in a water treatment
system raises their awareness of the importance of
environmental preservation
Microsystin Remaining (%)
Resolving power of the bacterium that resolves microcystin
100
LR
YR
RR
80
60
40
20
0
0
1
2
3
Time (Hour)
4
5
Decomposition of microcystin by Sphingomonas sp.
When added to 1 mg/L-1 of microsystin at a bacterial concentration of
0.3 O.D. and put under a shake culture condition at a temperature of
30℃, the bacterium decomposed over 90% of microcyctin LR, YR, and
RR in 5 hours.
156
Decomposition of microcystin by crude enzyme liquid extracted
from Sphingomonas sp.
Survival rate of microcystin LR (%)
Preparation of crude enzyme
liquid from bacteria
100
Culture and concentration of
Sphingomonas sp.
(O.D. 660 = 6.0)
Ultrasonic disintegration and
removal of disintegrated pieces
Crude enzyme liquid
35% ammonium sulfate fraction
Concentration and recovery
micocystin LR
Initial concentration (1mg/l-1)
80
60
40
20
0
0
10
20
30
40
Reaction time
Decomposition of microcystin LR by crude
enzyme liquid (treated with ammonium sulfate)
(Protein concentration = 8.0 mg/l-1)
The enzyme is high in resolving power before separated into
enzyme liquid. The crude enzyme liquid treated with ammonium
sulfate also decomposed the toxin to the minimum detectable level
in 12 minutes after the reaction started.
Artificial solar
system
0 - 70,000 Lux
Major characteristics
Temperature
temperature stratifications
can be formed.
●Cultured green algae and
other organisms can be
concentrated and recovered.
● An analysis of a system
Control
temperature
5 - 35℃
loaded with bottom mud can
be made.
Formation of
thermoclines and
etc.
temperature stratification
Concentration
and recovery
system
System to
culture a large
quantity of
microbes
Water depth:
4.0 m
Capacity:
2.5 m3
Disinfecting
filter
●Thermoclines and
Control panel
Sampling
and animalcules that prey
on them can be cultured.
High
Stratification
● Green algae and other algae
Shallow
along the length of the tower.
Water depth
● Samples can be extracted
Low
Deep
● It can simulate natural light.
Thermocline
● The tank can be sterilized.
Bottom mud
Body
Compressor
unit
Structure of the system
Overview of a large freshwater microcosm that helps develop environment
recovery technologies based on bio-eco engineering research
157
Inte
eraction between
n organisms in eco-eng
e
ineering
g that pla
ays
an important ro
ole in de
ecompos
sing toxiic green algae
Aeollosoma hempri
richi (ologochae
eta)
Diispersed into se
eparate cells
eparate microcys
stis cells
Se
Micro
ocystis that
forms
s a flock of toxic
c
blue--green algae
Preda
ation
Predation an
nd dispersion
Elution
Enhanced
resolving power
Elution
Bactteria
Aeration in water
w
Microcystin RR
Philodina
P
e
erythrophthalm
ma
(
(rotifer)
M
Monas
guttula (fflagellate)
Org
ganisms in
nteract with
h each oth
her to com
mpletely decompose microcystin.
158
Water purification by artificial wetlands using aquatic plants
Gas Chamber
Inflow
Inflow
Surface flow
Surface of water
Surface of sand
Surface flow
system
Outflow
Outflow
Infiltration flow
Surface of sand
Surface of water
Infiltration
flow system
The infiltration flow system provides higher throughput and is higher
in stability than the surface flow system. It also effectively controls
emissions of methane, a greenhouse gas.
Letting wastewater run through a special
device allows effective water treatment.
Results
BOD removal ratio (%)
Calla
Umbrella
Plant
-Organic matter removal characteristics-
Typa
Purple
Bulrush
Latiforia Loosestrife
Ruush
Zizania Canna
Latiforia
Pragmites
Australia
Control
100
80
60
40
20
0
Above 10 degrees
Below 10 degrees
BOD removal ＞ 80％ in planted systems
NO significant difference of BOD removal from the plant species
BOD removal was affected temperature
Planted system can avoid clogging and maintain a good condition.
Organic matter removal can be achieved with enough HRT in planted systems.
159
Nitrification and T-N removal ratio (%)
Results
Calla
Umbrella
Plant
-Nitrogen removal characteristics-
Typa
Purple
Bulrush
Latiforia Loosestrife
100 Above 10 degrees
80
60
40
20
0
100
Nitrification
80 Below 10 degrees
60
40
20
0
Ruush
Zizania Canna
Latiforia
Pragmites Control
Australia
Nitrogen removal
> 80% removals were obtained in the systems with Canna, Manchurian Wild rice,
Bulrush, Purple loosestrife, and Common reed.
Nitrification/dinitrification was affected by water temperature.
Wastewater purification system in a soil trench
N2O
CO2 Wastewater
Aerobic bacteria
O2
Absorption
of N and P
Org-C
NH4
Nitrifying
bacteria
NO3
Small animals and insects
prevent soil to decompose
organic substances from
clogging.
Water flow
Gas flow
Aerobic zone
N2O
N2
Trench
Organic
substance
CH4
PO4
Physical adsorption by
Al and Fe
Anaerobic bacteria,
methane bacteria
Treated water
Recharge of groundwater
with treated water
Anaerobic zone
160
Process flow of a powerless anaerobic/aerobic
soil treatment system
Water inflow (domestic wastewater)
Soil composition
BOD 220 mg/l-1
SS 370 mg/l-1
Red clay
Sawdust
Water quality
Inflow ratio
Load 1 m3/d-1
First
stage
5
COD 150 mg/l-1
T-N 50 mg/l-1
(Wastewater is fed into the system every 4
hours 5 times, starting at 8 a.m.)
Anaerobic
filter bed
(Turned into
nitrogen gas)
Second
stage
Third
stage
3
2
Anaerobic
filter bed
Anaerobic
filter bed
70 - 80％
20 - 30％
Wind driven fan
Air
Soil trench
(Nitrification and
phosphorus adsorption)
Wind driven fan
Air
Soil trench
BOD 1 mg/l-1
T-N
3 mg/l-1
T-N 0.1 mg/l-1
Outflow
Soil trench
No energy is required because wastewater naturally flows downward.
Establishment of a global network that develops technologies for efficiently
introducing bio-ecosystems and analyzes resultant improvements
Technology for using bio-ecosystems to prevent eutrophication
Bio-engineering
system
Eco-engineering
system
Control of the
source of problems
Purification
(direct measures)
Load inflow (Current
conditions, standards)
zLoad of point source
zLoad of plane source
Technological
introduction
Conditions, climates, lifestyles, and economy different between countries
Technological
development and
introduction
support system
Analyze the cost-effectiveness of countermeasures against sources and
direct purification measures
Propose guidelines for appropriate plane maintenance plans
Establishment of a global network to efficiently introduce
eutrophication prevention systems that prevent the growth of
toxic green algae as well as to raise public awareness of the
environment in international society.
161
好 沈 メタン
気 殿 発酵槽
槽 槽
原料
貯留槽
槽
水素
発酵
槽
162