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The final trial was carried out was using distilled water and the old brand of lime. The apparatus was kept the same as that of the previous three trials with the exception that the tank in which the distilled water had been stored was cleaned up thoroughly.
The purpose of this trial was to confirm if the failure of the previous trial (trial-3) was because of the carbon dioxide (in the air) which the water had been exposed to or the presence of carbonate impurities in the container. Another objective was to verify if the lime feeder performance was grossly affected by the change in lime brands.
For this trial the pH remained stable at 12 for 11hrs, which was by far the maximum duration achieved and very close to our goal of 12 hours.
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