Material and Method
For testing the effectiveness of SODIS the material that was used were a sola reflector, 9 clean 500ml PET water bottles, and Versoix River Water from La Batie. The method used to conduct eh experiment is as elaborated bellow.
First, the nine 500 ml PET water bottles were each filled with Versoix River water from La Batie. Each of the bottles was filled up to its ¾ marks and shake for twenty seconds. After the shaking, all the bottles were completely filled and sealed. Then one of the nine bottles was drawn and taken to the lab of for the initial E.Coil count of the raw water sample. The rest of the bottles were able with a number, and a number and a letter as follows; 1. 1F, 2, 2F, 3, 3F, 4, 4F. The numbers indicate the numbers of days the bottle were exposed to sunlight and heat. F stand for the foil, in which the bottles labelled F were wrapped to prevent exposure of its contents from sunlight, but only expose them to the heat. The bottles were drawn in correspondence with the labelled number of days, one at a time from the first day to the fourth day. After the first day of exposure, the bottles labelled 1 and 1F were drawn and taken to the lab for E.Coil analysis. This was repeated on the second day 2 and 2F, on the third day 3 and 3F and the fourth day for 4 and 4F. There were two control treatments. The first control treatment was the water in the first bottle with raw water that was not exposed to sunlight or heat and the second was water without exposure to sunlight but exposure to heat through the solar reflector. They offered a difference from the bottle that were exposed to both the suns UV-A and heat which had the condition necessary for SODIS to work
Results
Observation from the SODIS experiments
On the first day the experiment was conducted outside for 2h 13min (from 12:17pm to 2:30pm.) They sky was cloudy and with light snow furies. There was the sun albeit limited. From 1pm to 1:40 pm, the opening was covered with a cling wrap to prevent to inhibit snow from getting into the sola reflector. The cling wrap was removed after its interior surface steamed. This day had snow furies.
On the second day the experiment was conducted behind glass in a house, since it was snowy outside. It was conducted for 2h 12mins between 12:28pm and 4:40pm. On this day it was snowing and there was no direct sunlight.
On the third day the experiment was conducted behind glass, in a car. From 11am to 1pm, the sky was cloudy and the experiment did not face direct sunlight since the direction of the sun could not be determined. From 1pm to 1:30pm, the sun came out briefly and the experiment was adjusted to face direct sun. At 3:30 the experiment was stopped since it was raining heavily. The whether was cloudy, then sunny and then rainy.
On the fourth day, the experiment was conducted between 12:30 pm to 4: 30pm behind glass in the houses because it was lightly snowy outside. There was a lot of snow on the ground and although it was bright, there was no direct sunlight. The bottle had a brown/green sediment, which was denser than water, but did not adhere to the bottle. This day was snowy.
Lab results
Days 1 & 1F 2 & 2F 3 & 3F 4 & 4F
E.Coli Experiment UFC/100ml 202 95 96 18
Contrôle UFC/100ml 427 418 205 241
EMBED Excel.Chart.8 s
