Field tests of the solar water detoxification SOLWATER reactor in Los Pereyra, Tucumán, Argentina.

C. NAVNTOFT,; P. ARAUJO; M. I. LITTER; M.C. APELLA; D. FERNÁNDEZ; M. E. PUCHULU; M. DEL V. HIDALGO; M.A. BLESA

JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME

ASME-AMER SOC MECHANICAL ENG

Lugar: New York; Año: 2007 vol. 129 p. 127 - 134

0199-6231

The SOLWATER reactor prototype is composed of two tubes containing a supportedheterogeneous photocatalyst (Ahlstrom© paper impregnated with titanium dioxide), andtwo tubes containing a supported photosensitizer (designed and provided by G. Orellana,Universidad Complutense, Madrid, Spain). The tubes are placed on a CPC collector andrun in series. Electricity is provided by a solar panel, and the recirculation rate is ca13 L min−1. Total volume in the feed tank plus tubes is 20 L. The reactor was designedand constructed by the consortium of a European research project whose objective is onthe development of a fully autonomous solar reactor system to purify drinking water inremote locations of developing countries. The prototype was placed in the yard of ashanty house in Los Pereyra, Tucumán, Argentina. Water to feed the reactor is taken fromthe shallow aquifer through an open well. This water is contaminated with high counts ofcoliforms and Enterococcus faecalis. It also contains widely variable levels of Pseudomonasaeruginosa. The chemical composition of the water shows high levels of naturalorganic matter and of various inorganic pollutants. The reactor has been running sinceFebruary 22, 2005. This paper presents the results collected in three months of operation.Around 4 hr operation on a sunny day, and 5–6 hr on a cloudy day are required to totallydestroy fecal coliforms and Ent. faecalis. Even 24 h after the experiment is concluded, nocultivable bacteria are seen by the membrane filtration method (measured colony formingunits after 24 hr=0). On the other hand, a small number of total coliforms remain (a fewpercent or less of the original count) at the end of some of the latest experiments.Possible explanations for this result are the drop in ambient temperature, the decrease insolar irradiance, and the exhaustion of the catalyst and sensitizer. P. aeruginosa is muchmore resistant, and only partial destruction is observed in those time intervals. Theevolution of chemical parameters is also presented and discussed.