ANC CONTROL
DISTILLED WATER, CHANGE IN LIME BRAND
OVERVIEW
Despite the performance of the apparatus was the expected, the pH couldn't stay twelve hours at 12 units during the second trial. From the analysis of results, the team decided to determine the influence that carbonates in tape water could have. In addition, the team had proposed to evaluate if the lime that was being used for the experiments was not enough pure. With the third trial, those possible causes of the pH performance will be analyzed and discussed.
INTRODUCTION
The design of experiment 3 continued the same, taking into account that the particles movement and effluent characteristics were according the design. However, tap water was replaced by distilled water, trying to figure out the performance with pure water. In this way it is possible to evaluate the influence of the carbonate system, and the influence of other characteristics of the tap water at AguaClara lab.
In addition, the lime was changed, looking for a better quality of the compound. This change will allow evaluate if the performance is different with a new lime brand. It is also important taking into account that in Honduras, the operators have to deal with the brands that they can find on the local market.
OBJECTIVES
• Confirm if the quality characteristics of tap water, have any influence in the lime feeder performance.
• Evaluate the apparatus performance with a different brand of lime.
• Determine some improvements for future experiments.
RESULTS
It was observed a change into the apparatus performance. The new lime is more soluble in water; it diminishes the amount of big particles floating into the water flow, and avoids the accumulation of lime at the bottom of the apparatus. However, that result made a new challenge for the team, because all the design was made assuming the particles movement as flocs movement. That means that the team calculated the upflow velocity and the capture velocity for particles movement, and with the new kind of lime, no particles were observed. The team has to evaluate if the design and the calculations are still acceptable for water without visible suspended particles.
On the other hand, the pH remains in 12 units for 3 hours and a half. The time was less than with the second trial. With these results it seems that the quality of the tap water doesn't have a strong influence on the pH behavior.
CONCLUSIONS
The information obtained with this trial was not enough to probe the influence of the two considered variables. To confirm the results, it is necessary to run one more time the experiment with the new lime but with tap water; that will be the objective of the next challenge.