Tratamento de água por sistema SODIS com utilização de Moringa oleifera

Abstract

The sharp growth of the world population has led to a considerable increase in drinking water consumption, but a significant portion of this population lives in locations where sanitation is poor or even non-existent. In this context, the use of the Solar Water Desinfection (SODIS) system associated with organic coagulant has become an attractive alternative for water disinfection, due to its high efficiency and sustainability. The objective of this work is to evaluate the efficiency of water disinfection with the use of solar radiation associated with the use of Moringa oleifera organic coagulant. Thus, 75 liters of water from Ribeirão Três Bocas was collected for the coagulation, flocculation, sedimentation, filtration and disinfection tests. The tests were conducted in 3 days in duplicate, and two solar concentrators were constructed using low cost material, where 1 L PET bottles were placed inside the concentrators and the following treatments were used: 100% painted bottle (G1), Bottle 50% horizontally painted face up (G2), Bottle 50% horizontally painted face down (G3) and Bottle without paint application (G4) and after 4 hours of exposure to the sun, water and Temperature, pH, electrical conductivity, apparent color, true color, turbidity, total coliforms and Escherichia coli parameters were analyzed for each assay. After disinfection, the temperature increased between treatments due to solar radiation, maintaining an average of 29 ° C. For pH there was no significant variation in values between treatments, maintaining a mean of 7. In electrical conductivity values between treatments did not show a significant variation, occurring only in test 1 where electrical conductivity showed a mean value. 300 μScm-1 compared to assay 2 and 3 which had an average value of 200 μScm-1. The apparent color removal was quite significant with an efficiency above 89% in the treatments after sun exposure, showing a good functioning of the SODIS system. True color showed 100% removal efficiency after disinfection. For turbidity the achieved efficiency values were above 96% with satisfactory results for all treatments. For total coliforms and E coli. The solar concentrator was very efficient, showing 100% elimination for all treatments for trials 1 and 3, which occurred on sunny days with temperatures above 60 ° C. For test 2 there was not enough elimination due to the weather conditions on the day, however there was a decrease in its values, demonstrating that the complete water treatment using the SODIS system at the end of the process was not satisfactory. Regarding the analysis of variance between tests 1 and 3, there was no significant difference between treatments for all parameters. The action of SODIS showed a 100% efficiency of coliform removal on days of high solar radiation, and for days with cloudiness had a reduction in the number of coliforms, but there was no elimination, being an effective, alternative and cheap process for disinfection from water.