Pre-treatment (coagulant, algaecide) and filter resistance.

Filamentous diatom :Melosira

Scale of midge, midge are abundant.

In long filter run,filamentousgreen algae are found. Cladophora, Spirogyra, Hydrodictyon,

Mollusk is also found.

Short filter run : filamentous diatom :pioneer of succesion.

0

5

10

15

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25

30

N D J F M A M J J A S O N D J F

水温（

Inflow water temperature: from Dec, 2003 to Dec.2004.

Wakata plant., Takasaki city.℃）

Dominant algaeMidge larvae is a grazing animal of Melosira.

12月

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APR

FEB MARJAN

MAY JUN

JUN AUG SEP

OCT NOV DEC

Filter does not clog in all the year.

NH

L, c

m

Filter run days

Observed head loss and Normalized head loss（ＮＨＬ）

2月

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10

20

30

4 0

5 0

0 1 0 2 0 3 0

8月

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10

20

3 0

4 0

5 0

0 1 0 2 0 3 0

8月

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10

20

30

4 0

5 0

0 1 0 2 0 3 0

2月

0

10

20

30

40

50

0 10 20 30

（ｃｍ）

（ｃｍ）

Filter run in days Filter run in days

Observed HL

Observed HL

ＮＨＬ

ＮＨＬ

＋0.59

＋0.18

＋0.50

－0.07

Observed Head Loss gradually increases. It is due to increase of flow rate. Real resistance of NHL is almost same or it becomes slightly small resistance in warm period (August). These resistance change is influenced with the biological activity.

Sum of turbid matter (load of SS to filter bed) and NHL

8月

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10

20

3 0

4 0

5 0

0 1 0 0 2 0 0 3 0 0

2月

0

10

20

3 0

4 0

5 0

0 1 0 0 2 0 0 3 0 0

FEB

AUG

Load of SS to the filter.

ＮＨＬ（ｃｍ）

ＮＨＬ（ｃｍ）

FEB (Cold season)

Low Biological Activity

Filter Resistance (NHL) increases.

AUG (Warm season)

High Biological Activity

Filter Resistance (NHL) does not increase.

Development of Algal Mat as Chl. a.

8月

1

10

100

1000

0 10 20 30

2月

1

10

100

1000

0 10 20 30

Chl‐a（ｍｇ/㎡）

2月

8月

Run Days

Growth rate 0.054

Melosira varians 2.5E＋09cells/㎡

Growth rate 0.174

Chl‐a（ｍｇ/㎡）

Melosira varians 2.6E＋10cells/㎡

0

50

1 00

0 1 0 2 0 30

0

50

100

0 10 20 30

Health Index (%) of Algae:Chl.a/(Chl.a+Phe.a)

（％）

（％）

2月

8月

Run Days

Active algae M.varians

Chironomide midge larvae graze diatom.

Dead algae of fecal pellet M.varians

Algal development in summer. Filamentous diatom of Melosira grew rapidly and decreased after 10 days. It was caused by the grazing activity. This phenomena is clear in warm period.

DAYS OF FILTER RUN

Chl

orop

hyll

a，

mg

m -2

1

10

100

1000

0 10 20 30

％

0

50

100

0 10 20 30

A

B

A

B

A ; Active algae

B ; In-active algae

Alg

al B

iom

ass

Hea

lth In

dex

1

10

100

1000

0 10 20 30

Comparison of Load of SS and Filter Resistance, and Algal Development in Winter (FEB) and in Summer (AUG).

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10

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0 100 200 300

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0 100 200 300

FEB

AUG

Load of SS (mg/m2) along the filter run

1

10

100

1000

0 10 20 30A

lgal

Bio

mas

s：C

hlor

ophy

ll a，

mg

m -2

Filter Run in Days

AUG

FEB

Low Biomass: Easily Clog in Cold Season.

Low growth rate of algae

High Biological Activity: High Temperature: No Clog in warm period.

Rapid growth of algae, then rapid decrease.Fi

lter

Res

ista

nce ＮＨＬ：

Nor

mal

ize

Hea

d L

oss (

cm)

Filter resistance is related with temperature. This is due to biological activity.

2001: Deep depth, large scrap of upper sand layer.

1992: Shallow depth, small amount of scrap.

Scrap

↓

鋤取り（取り除く厚みが大きい）

汚泥（汚砂）：生物群集を取り除く

Biomass and Run days

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10

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60

0 5 10 15 20 25 30

生体量（㎎/㎝

２）

0

5

10

15

20

25

30

0 5 10 15 20 25 30ろ過日数（日）

生体量（μg/㎝

２)

Algal Biomass

Animal Biomass

：１００cm～１４０cm：１４０cm～２００cm

▲：Less than 7 daysBiomass: Bio-volume as weight : Specific gravidity = 1.

Growth rate of algae was low in deeper filter. Algal biomass still grew even on 24 days and it did not reach the stationary phase.

Population of small animals (ciliate, rotifer, midge etc.) grew with filter run.

Difference of biomass of algae and animals are 1000 times.

Run Days

Bio

mas

s, m

g/cm

2B

iom

ass,

mic

ro-g

/cm

2

September, Takasaki, Gumma

100

120

140

160

180

200

0 5 10 15 20 25 30生体量（μg/㎝２）

水深（㎝）

100

120

140

160

180

200

0 10 20 30 40 50 60生体量（㎎/㎝２）

水深（㎝）

Depth and Biomass

Algal Biomass

Animal Biomass

：１００cm～１４０cm：１４０cm～２００cm

After 7 days of filter run, algal biomass is related with depth. Shallow: large biomass Deep: small biomass.

Algae and animals are abundant in shallow depth filter.

Active diatom is abundant in shallow filter

Dead and empty diatom is abundant in deep filter.

Biomass, mg/cm2

Biomass, micro-g/cm2

Dep

th, c

m2

Dep

th, c

m2

SSF is not mechanical filter.It is really ecological purification system. This system is similar with the ecosystem of soil in the natural forest. Microbial organisms and small animals are active in the forest soil.

Shallow depth for active algal growth. Small animals are necessary. Long filter run is better. Large size of sand particle. Faster filter rate gives better condition of aerobic condition for small animals. Less amount of removal of upper sand is necessary to keep heterotrophic organisms in the filter.

There are so many bacteria.→Medical doctor touches with patient.→Doctor is safe.

１０６ １０４１０５

Logarithmic bacteria number in 1 ml

１０７１０８

Risk of germ bacteria in water.

１０-１ １０-2 １０-3 １０-４ １０-５１０３ １０２ １０１ １００

.....

....

....

....

....

water

RSF

EPS (SSF)

Dust in air

Wash hand

100 years ago, when the number of general bacteria was less than 100 colonies in 1 ml, Cholera patient did not appear.

Coli-form bacteria are abundant in soil and are not germ bacteria.

Please compare the size and number of Cryptosporidium with bacteria in water. Risk?

100 1101,000 0.1 0.0110,000 0.001 0.0001

soil

0.00001100,0001,000,000

10,000,000100,000,000

Sterilize by chlorine

Toxicity of chlorine?

Gen

eral

ba

cter

ia

Gen

eral

ba

cter

ia

Gen

eral

ba

cter

ia

Gen

eral

ba

cter

iaG

ener

al

bact

eria

Col

i-for

m

bact

eria

Col

i-for

m

bact

eria

Col

i-for

m

bact

eria

Col

i-for

m

bact

eria

Col

i-for

m

bact

eria

Feca

l C

oli-f

orm

Feca

l C

oli-f

orm

Feca

l C

oli-f

orm

Feca

l C

oli-f

orm

Feca

l C

oli-f

orm

Ger

m :

Cho

lera

Ger

m :

Cho

lera

Ger

m :

Cho

lera

Ger

m :

Cho

lera

Ger

m :

Cho

lera

Elimination by chemical

Elimination by biological community

Acceptable risk is essential for practical life.

100 % safe is not good for practical life.

This is natural ecological sense.

SSF(Ecological Purification System) is the suitable environment for filamentous algae.

Filamentous algal growth experiment by use of natural stream water: the best food for animal

Roughing filter experiment for SSF system and algal culture to reduce suspended matter from the surface water of a stream.

Sapporo

Ueda

Tokyo

Tokyo

NaganoSuzaka

Suwa

JICA excursion, Summer, 2007