10mg/L HA Test

[VanessaQi]

1 Repeat the same procedure but instead of using 5 mg/L HA, the team will start using 10mg/L HA.

2 The choice of coagulant concentrations will be decided later based on results gained from Task #1. But the rough range should be 0.5mg/L - 2.5mg/L.

3 The team expects the peak of optimal coag dosage vs coag concentration graph will shift to the right. If the experiment could not verify the hypothesis, the team will consult Monroe.

[VanessaQi]

Result for 10mg/L HA, 0.3mg/L coag: The lowest effluent turbidity is around 4.3 NTU but didn't last for long time. Compared to 5mg/L HA, 0.3mg/L coag, this result is actually much better. A diluted floc blanket formed.

[VanessaQi]

Result for 10mg/L HA, 0.8mg/L coag: The lowest effluent turbidity is around 3.1 NTU. The floc blanket is formed but we believe the optimal coag dosage hasn't occurred yet.

[VanessaQi]

Result for 10mg/L HA, 1.3 mg/L coag: The lowest effluent turbidity is around 0.62 NTU. Even though the plot doesn't look very pretty, the result is great! We think that may be our optimal coag dosage for 10mg/L HA.

[VanessaQi]

Result for 10mg/L HA, 1 mg/L coag: The lowest effluent turbidity is around 3.9 NTU. This result is similar to the result of 0.8mg/L coag trial. We will keep increasing the coag dosage to see if anything happen.

[VanessaQi]

Result for 10mg/L HA, 1.5 mg/L coag: The lowest effluent turbidity is around 5.7 NTU. We repeated the same experiment for three times but still get very high effluent turbidity. Therefore, we know after 1.3mg/L coag, the increasing in coag dosage makes the performance worse.

[VanessaQi]

As we have found the optimal coag dosage for 10mg/L HA, we will not spend time on testing higher coag dosage so we move on to 15mg/L HA test.