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

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)

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

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

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).

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

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

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

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

Results: removal efficiencies 10

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

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

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

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.

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

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