1. SNU RRC
6th
World Water Forum
KSU
RFA
M.T. Amin, M.Y. Han
Socially and economically acceptable drinking water supply from rooftop rainwater and improved solar disinfection

2. Results and Discussion
Contents 1
Introduction 2
Materials and Methods 3
Results and Discussion 4
Conclusions

3. Introduction

4. Background < Tailand > < Uganda > 6th World Water Forum
Lots of countries have water shortage problems over the world
Rainwater harvesting (RWH) can be alternative water resource to these countries
Because RWH system is simple to install and manage, this system has been spread to water shortage areas.
Sited from “ELLIAS SAIDIN and AMINUDDIN BAKI, RAINWATER HARVESTING: POTENTIAL ALTERNATIVE WATER RESOURCES IN MALAYSIA, WATER MALAYSIA 2009”
6th
World Water Forum
SNU RRC
KSU
RFA

5. What is rainwater harvesting system?
Drinking
Cleaning
1- I think, “only non-potable purposes” can be deleted because purpose of SODIS and related is to treat it for potable purposes.
2- Instead of Sewage pipe it could be drain pipe.
Emergency
Gardening
6th
World Water Forum
SNU RRC
KSU
RFA

6. Rainwater as drinking water ?
At least one-third of the population in developing countries has no access to safe drinking water
Rainwater can be used as drinking water if microbial contamination is controlled.
Simple disinfection method can make and supply safe drinking water by rainwater
6th
World Water Forum
SNU RRC
KSU
RFA

7. Solar Disinfection (SODIS)
Inactivation of microorganisms by UV-A-radiation and thermal treatment
Suited for providing safe drinking water in rural and semi-urban communities in developing countries
Promoted by the World Health Organization (WHO)
Solar and Longwave
Radiation UV
Infrared
Reflection and
Back-Radiation
DO/pH
Temp.
Used PET
bottle
Attenuation
By Plastic?
Pasteurization
Cellular
Breakdown
Conduction
6th
World Water Forum
SNU RRC
KSU
RFA

8. Developing Solar Disinfection
a. SODIS
b. W-SODIS
c. SOCODIS
d. W-SOCODIS
e. I-SOCODIS
6th
World Water Forum
SNU RRC
KSU
RFA

9. Limitation of SODIS 6th World Water Forum
Few scientific and engineering data for rainwater disinfection
Only strong sunlight radiation for about 6~8 h daily is adequate for the complete disinfection
W-SODIS (Wrapping Solar Disinfection) system
SOCO-DIS (Solar Collector Disinfection) system
Improving SODIS to achieve more concentrated temperature effects
Improving SODIS to achieve more concentrated sunlight radiation
6th
World Water Forum
SNU RRC
KSU
RFA

10. Limitation of SOCO-DIS
Sunlight radiation for about 6~8 h daily is not adequate for the complete disinfection in the weak weather
W-SOCO-DIS (Wrapping Solar Collector Disinfection) system
I-SOCO-DIS (Improved Solar Collector Disinfection) system
Improving SOCO-DIS to achieve more concentrated temperature effects and sunlight radiation
Improving SOCO-DIS to achieve more high pH
6th
World Water Forum
SNU RRC
KSU
RFA

11. Materials and Methods

12. Sample collection site
Completion date
Roof area
3,892 ㎡
Green roof area
935 ㎡
residence
about 1,000 persons
RWH
Beginning date
A kind of catchment
concrete, terrace, green roof
Catchment area
3,652㎡
Tank volume
250 ton
Consumed
60~90 ton/day
Uses
toilet
* RWH : Rainwater harvesting system
6th
World Water Forum
SNU RRC
KSU
RFA

13. Outline of experiment 6th World Water Forum SNU RRC KSU RFA a. SODIS
b. W-SODIS
Seoul, Republic od Korea,
Seoul University Engineering Building
(37° N, 126° E)
c. SOCODIS
d. W-SOCODIS
e. I-SOCODIS
Rain Water Tank
6th
World Water Forum
SNU RRC
KSU
RFA

14. The quality of rainwater samples
PHYSIOCHEMICAL PARAMETERS
MICROBIAL PARAMETERS
Initial Temp. 0C pH EC
μS/cm DO
mg/l
Turbidity
NTU TC
CFU/100ml
E-Coli
23-25
7-9
5-9
1-5
Main target
Samples were always collected from the same outlet point, about 1.35 m from the base of the tank
The reason for the different initial values of all the parameters is the effect of the season and residential time in the tank
These are used as the standard initial values for the rainwater samples in this study.
6th
World Water Forum
SNU RRC
KSU
RFA

15. Weather conditions 6th World Water Forum
Weak Weather
Moderate Weather
Radiation
Temperature
Radiation
Temperature
Weather is categorized into three different types, depending upon weak, moderate sunlight radiations.
The temperature difference is about 2~10 0C, with the great temperature rise in the SOCO-DIS & W-SOCO-DIS system.
6th
World Water Forum
SNU RRC
KSU
RFA

16. Results and Discussion

17. The effects of weather condition
In case of SODIS, No parameter met the potable guideline values
The difference of disinfection efficiency of SOCO-DIS & W- SOCO-DIS system is about 20-40% with that of simple SODIS mostly because of the enhanced effects of concentrated radiations and heat.
Weak Weather
Moderate Weather

18. The effects of initial pH
Rainwater using lemon and vinegar as catalysts(for acidic pH) offered best disinfection efficiency for SOCO-DIS system for all microbial parameters without any exception.
Overall disinfection efficiency increased from 10 to 20% by decreasing pH values from basic to neutral and then acidic states, respectively.
SODIS
SOCODIS

19. Conclusions

20. Conclusions
Disinfection efficiency of the W-SOCO-DIS or I-SOCO-DIS is 20~40 % better than SODIS and it managed complete disinfection under moderate weather condition
Developed SODIS system - SOCODIS : disinfection efficiency of SOCODIS system is better than SODIS about 20-40% because of the enhanced effects of concentrated radiations. - W-SOCODIS : The maximum temperature increase due to wrapping with plastic bags was about 4-7 C°, which enhanced the disinfection efficiency by about 5-8%. - I-SOCODIS : using lemon and vinegar as catalysts makes low pH improving the efficiency from 10 to 20 %
6th
World Water Forum
SNU RRC
KSU
RFA

21. Conclusions
this method can be easily applied to any place to gain acceptable water in the world, especially where the centralized water supply system is not affordable in a short time period, eventually contribute to achieve the MDGs.
6th
World Water Forum
SNU RRC
KSU
RFA

22. Thank you