1. Catalina M. Rodríguez Sergio A. Blanco Carlos A. Arias
SOLAR DISINFECTION
OF CONSTRUCTED WETLAND EFFLUENT
IN TROPICAL COUNTRIES
Catalina M. Rodríguez
Sergio A. Blanco
Carlos A. Arias
Tatiana R. Chaparro
3rd Wetland Pollutant Dynamics and Control Symposium WETPOL 2009
September 20-24, 2009
Barcelona, Spain

2. Introduction.... Domestic Sewage Treatment Public Health
(DST)
Public Health
(e.g pathogens)
Economical accessibility
(e.g low-cost)
Resource recovery
(e.g sequestering CO2)
Environmental protection
(e.g Organic matter removal)

3. Constructed wetlands as a core technology for sustainable
Introduction....
Solar Disinfection
(SODIS)
Constructed wetlands as a core technology for sustainable
DST!!!!!
Turbidity < 30 N.T.U 3

4. Theoretical solar radiation in Bogota
Introduction....
Theoretical solar radiation in Bogota
425W/m2
Solar Disinfection
(SODIS) 4

5. Objective
Assessment of the E. coli inactivation in an integrated system comprised with a vertical flow constructed wetland (CWFV) and a solar disinfection unit treating a domestic wastewater in Bogota (Colombia).

6. Vertical flow constructed wetland
Material and methods :
Vertical flow constructed wetland
VFCW
Hydraulic load = 29cm/d
24 pulses/day 6

7. Solar disinfection unit
Material and methods :
Solar disinfection unit
SODIS 7

8. Dark reactivation of E.coli
Material and methods :
Experimental design
Domestic sewage
(Septic tank)
VCFW Treatment
SODIS of VFCW effluent
Dark reactivation of E.coli
4 PET bottles
V = 1500 mL
Solar radiation time exposure = 6 hours pH
Conductivity
Turbidity
Color
E.coli
1 PET bottle was kept in a dark place for 10 days. 8

9. raw wastewater characteristics
Results:
raw wastewater characteristics
Parameter
Unit
Mean ± Sd pH
6,7±0,3
Conductivty µS
414±55
Turbidity
T.U
27± 5
Color
C.U
56± 8
E.coli
FCU/100mL
1,70E-05± 1,88E-04

10. Results: removal efficiencies10

11. Results: comparison with reuse guidelines
Class
Limit (FCU/100 ml)*
E.Coli in final effluent (FCU/100mL)*
World Health Organization W H O A
<1000
229±87 B NS C NA
Food and Agriculture Organization F A O (CETESB)
< 200
< 10E+05
Enviromental Protection Agency E P A D ND E F G H I J
* Geometric mean 11

12. Results: dark reactivation SODIS effluent after 10 days
Bottles
SODIS effluent
(FCU/100mL)
SODIS effluent after 10 days 1
200 2 3 4
500 5
300 6 12

13. Complementary studies...
CWFV + SODIS
Kinetic of E.coli inactivation.
Reuse of CW effluent in aquaculture.
Inactivation at different solar radiation time exposure. 13

14. Conclusions
It was observed further correlation between temperature increased and E.coli inactivation.
The integrated system (CWFV + SODIS) resulted very efficient for water disinfection. Total inactivation of E.coli was observed without bacterial regrowth. This should be considered in near future to develop environmental sustainable technologies to water treatment in tropical countries.

15. Acknoweledgments Military University – for the financial support.
Laboratory of Water Quality – for the technical support.

16. Thanks for your kind attention!!