Japan's Experience in Decentralized Sanitation - Japan Sanitation ...

14 downloads 34 Views 4MB Size Report
28 Feb 2012 ... Japan Education Center of Environmental Sanitation. Aizawl, INDIA ... Night Soil and Domestic Wastewater Treatment Systems in Japan. 2 ...

Japan’s Experience  in  Decentralized Sanitation (Johkasou) Decentralized Sanitation (Johkasou) Xinbi Yang Japan Education Center of Environmental Sanitation

Aizawl, INDIA 28 Feb. 2012 1

Night Soil and Domestic Wastewater Treatment Systems  in Japan

2

Population Served by Different Systems Population Served by Different Systems

14%

Sewerage system Rural sewerage system Johkasou system Night soil treatment

9% 74%

3%

(as of the end of FY 2009)

100 90

(as of the end of FY 2009)

99.4

90.3

88.9

84.5

80

Perrcentage, %

70

78.0 71 0 71.0

S off major Sum j domestic d ti wastewater t t ttreatment t t systems t

60 50 40 30 20 10

0.5

5.9

7.5

9.6

300-500

100-300

16.9

13.9

Johkasou system

0 More than 1,000

500-1,000

50-100

Less than 50

Size of municipalities, thousand people 3

Number of Installed Johkasou Johkasou:2.9 million units Tandoku-shori johkasou:5.45 million units (as of the end of FY 2009)

65.3% 34.7%

A small-scale johkasou 4

Advantages Ad t off JJohkasou hk System S t for f Decentralized Treatment  Low initial investment cost  Little topographic limitation, short installation time and early realization of the effects  Invaluable contribution to maintaining sufficient water in small rivers and aquatic environments near inhabited areas  Johkasou-treated water and sludge are easy to reuse  Less vulnerable to earthquakes and other disasters

5

Pollutant Loads for Johkasou Design

Determination of Johkasou Size in Buildings Classified by Purpose of Use (Examples) JIS A 3302 2000

Structure and Treatment Performance of Johkasou

Treatment Principles of Johkasou

9

A small small-scale scale Johkasou (FRP)

Diffusion pipe

Effluent water quality BOD