See the rubric that was shared with you earlier in the semester for your Team's grade.

-Thorough explanation of issues (such as the one that Du wrote for Task 2.5) is what we’re looking for! Don’t forget to update progress on each task throughout the week
-Close issues after you complete them (ie: are the issues for February completed? Almost completed?)
-Use Github to ask Monroe and Auggie questions
-Moving forward (I know the group has had problems with Github until recently), utilize Github! Check out High Flow Float Valve as an example of the interaction we would like your team to achieve. Encourage all team members to utilize it as a resource.
-In the future, contact your RA as soon as possible whenever you run into problems or have questions!
-The next Github issues check will be in 2 weeks!

Fix Leaks

The problem that no floc blanket has been forming was discussed with Monroe. Due the to limitation of ProCoDA, our team mix clay and humic acid before putting into the system. However, we haven not seen floc blanket forming in most of our runs. A new hypothesis can be that by adding humic acid with clay together before entering the system, humic acid makes the clay surface more negatively charged (humic acid is strongly negatively charged while clay is slightly negatively charged), which creates more dispersion between the clay particles, and creates more surface area to make the coagulant sticks to the particles.

Present results and findings of our sub-team results to the entire project team. Should have a powerpoint ready and data to hand out to the audience.

input parameter later

input parameter later

April 11, 2018 2-Stage Meeting with graders Research Report Suggestions:

• Meeting in a group settings to work on report (currently 5 hours)

• Should schedule one more hour to meet together to work on the data

• Meet to clarify distribution of work and by rotating different parts of work (lab and typing)

• One person writing one week and then lab the other week Current problem:

• Obstacle in writing the report:

• Miscommunication and fear to put irrelevant information in the report

• Doing report in a group settings can be helpful

• Knowledge (obstacle) --> can add a weekly recap to go over

• Understanding of technical background

• Misunderstanding of current goals of the team this semester (?) Report details:

• Try to understand what is the problem we are trying to solve (why do we have the team set up)

• Abstract: purpose, hypothesis and importance

• Marker of efficiency Current obstacle in experiment:

• Effluent turbidity can never reach under 10, which is not optimal for the experiment as the turbidity should be around 3-5

• Might be problems with translated calculations from MathCAD to Python

• Will meet with Monroe to discuss Suggestion before next grading:

• Read through and try to understand the report before setting up a meeting (should be soon) with the team that goes through the

• Edit together using teletype (in the meeting)

• For final report, submit to graders (graded) and to RA (not graded before final presentation)

• Self-evaluate for each section and then split up work after then

• Switch to slack to improve communication

• Improve technical writing through having more people to read through the report0

The first coagulant pump that has been used since the last semester was proved to have the display problem. Its maximum speed is 100 rpm, but the highest speed it could display is 300rpm, and the increase of pump speed is nonlinear according to our calibration outcome.

New 100 rpm pump was used to replace it, and the pump property was tested, the flow rate per revolution is similar to the second coagulant pump.

We test the pump property by measuring the flow rate per revolution. Unplug the tube fitter, catch the water in a measuring cylinder for 1 minute, then divided the volume we had by pump speed value.

In each single circulation, the coag dosage is: 0.5, 1, 1.5, 2.0, 2.5. Actually this is the value used by Yingda(Author of our reference thesis). My point is that we should add two more data point, one between 1-1.5, and the other between 1.5-2.0. Because usually we generate desirable effluent turbidity around that range, besides, we might don't have to start from 0.5mg/L, for that value is too low to treat the raw water.
My plan is that we run 3 circulation per week, basically that will take 3 days, we use different humic acid between those 3 diff tirals within a week. Thus we can test the impact of both humic acid and coagulant dosage on the flocculate process.

@monroews @caseyching13 Hi Monroe, hi Casey, our group can not find the HA in the lab since yesterday. Can we order some of it?

I was asked to give a talk about the past study on the effect of humic acid on flocculation in AguaClara project team and followed is the abstract. Flocculation is the critical particle removal process in traditional water treatment, it can transform turbid suspension of the tiny particle into a turbid suspension of a big particle so that the turbid can be removed more efficiently in the following process, sedimentation. To optimize our water treatment process, we have to fully understand the physical and chemical process and modeling can help us to make it. However, the model created in the past research only consider of clay and coagulant particle, which is useless in engineering application, because it failed to consider the effect of the NOM in the water. In the recent research of AguaClara project team, we study the effect of HA (humic acid), as the representative of NOM. Bonding mechanism between clay, coagulant, and HA was studied. A model which consider the effect of HA was developed based on the previous version. In last semester, according to the result of modeling, our subteam worked on a new method of coagulant addition, two-stage coagulant addition. Series of experiments was conducted to test the efficiency of two-stage addition and compared with the efficiency one stage addition.

In every single circulation, the coag dosage is: 1.1-2.6mg/L, increase 7 times by using the increment function, in which values are derived based on those used by Yingda(Author of our reference thesis). We should add two more data point, one between 1-1.5, and the other between 1.5-2.0. Because usually we generate desirable effluent turbidity around that range, besides, we don't have to start from 0.5mg/L, for that value is too low to treat the raw water.

My plan is that we run 3 circulations per week, basically, that will take 3 days, we use different humic acid between those 3 diff trials within a week. Thus we can test the impact of both humic acid and coagulant dosage on the flocculating process.

In the experiment of May, we finally fixed every problem we could find in our apparatus (leak, aged tube, clogged tube, wrong pump), and calculation. And now we are able to observe the formation of floc blanket in 10mins, the lowest effluent turbidity is now 1.9 for two stage and 2.5 for one stage, both can meet the requirement of filtration system. The coagulant we apply, compared to the dosage we used in this semester, improved about 20%, from 2.3ml/L water to 3ml/L water. But the effluent turbidity achieved the lowest in the history of two-stage subteam.

Have the final report done. Should include: detailed literature of our subteam, data we collected throughout the semester, improvements that can be done, and ideally a final conclusion on whether two stage addition is more effective than one stage addition

Creating the plot and compare the treatment efficiency between 1 stage and 2 stage.
The original data collected by ProCoDA should contain seven, and they are day fraction, 7Kpa, effluent turbidity, influent turbidity, pump control(clay), the increment function, coag pump control. Among them, only day fraction and effluent turbidity, influent turbidity and coag pump control will be used to create the plot.

Before creating the figure, we first need to transform the day fraction to hours of operation, by multiplying 24hr to the day fraction then we can have a column in hour unit. We also need to transform the coagulant pump control to coagulant dosage, the pump control column was displayed in the fraction of the maximum pump speed, it is confusing for the outsider to understand our plot if we keep using this value while coagulant dosage is more comfortable for people to understand and compare with other experimental data.

When drawing the plot, use the operation time in hour unit as the independent variable and use other three column we mentioned before as the dependent variable, eventually we can have a time series of coagulant concentration and effluent turbidity.

study the mechanism behind the experiment, namely how water flows through an AguaClara water treatment plant. Understand the theory of flocculation, sedimentation, etc.

We met with Auggie to go through our report, and how to make it more clear and concise. The minutes of the meeting have been uploaded in the comments in this issue.

Carry on series of control experiment for 2 stages addition, find the most effective portion of coagulant allocation. Then compare with data generated from 1 stage experiment.

Two-stage coagulant addition experiment should base on the data we generate on the first week, the total amount coag addition can be the least dosage which can achieve the effluent requirement, and then we add two more circulations for comparison, vary the total amount, +-0.5 on the basis of the first trial. During those weeks we conduct two stages addition, we won’t test the effect of humic acid on flocculation because the mechanism of this part should be similar between one and two stage.

We found that the lowest turbidity never reach below 3, and we suspect that might be because the flush state is not enough to clean both SedTank and Flocculator. The coagulant might have stuck to the wall of the Flocculator and SedTank, making it difficult to remove turbidity with regular water pump speed. Therefore, we manually did flush state, increasing the water pump speed to 160 RPM for around 3 to 5 minutes in between each coagulant dosage.

In these weeks, we had the maual flush every Tuesday, Thursday and Friday, team members came to the lab every two hours and turn the tap water pump to a high speed then get the flocculator and sed tank washed.

After applied the manual flush, our experiment outcomes inproved a lot, we got rid of the coag wall loss over time and the increasing in effluent turbidity over time. We can now compare the effluent turbidity directly between different trials conducted on different days.

Leaks appeared in our apparatus, and the flow rate of leaking is relatively high so we can not ignore it. We checked the apparatus. It was the gaps between microbore and tube fitter caused the leak. To seal the gap, we used microbore with a larger diameter to replace the old one. Besides, most of the apparatus was kept since it was completed in last semester, the ends of microbore aged after soaked in the fluid for a long time and their inner diameter decreased due to the wall loss of coagulant. We cut the length which was aged, and water came out of the microbore more smoothly.

Currently, no leak was found in our apparatus.

Reflection: when conducting control experiment, it is necessary to control the experiment condition, and make sure the parameters other than control variable stay the same in every trial. However, minor problems such as clogged tubing, nano-aggregant on the tube wall could happen as time went on, and those problem, unlike a leak in the appartus, is more intangible. So it requires the team members to check the apparatus in deep frequently and make atteintion to every unusual experiment outcome.

Fix all the leak in the apparatus, remeasure the pump property, calibrate the turbidity meter.

Creating the plot and compare the treatment efficiency between 1 stage and 2 stage.
The original data collected by ProCoDA should contain seven, and they are day fraction, 7Kpa, effluent turbidity, influent turbidity, pump control(clay), the increment function, coag pump control. Among them, only day fraction and effluent turbidity, influent turbidity and coag pump control will be used to create the plot.

Before creating the figure, we first need to transform the day fraction to hours of operation, by multiplying 24hr to the day fraction then we can have a column in hour unit. We also need to transform the coagulant pump control to coagulant dosage, the pump control column was displayed in the fraction of the maximum pump speed, it is confusing for the outsider to understand our plot if we keep using this value while coagulant dosage is more comfortable for people to understand and compare with other experimental data.

When drawing the plot, use the operation time in hour unit as the independent variable and use other three column we mentioned before as the dependent variable, eventually we can have a time series of coagulant concentration and effluent turbidity.

Carry on series of control experiment for 2 stages addition, find the most effective portion of coagulant allocation. Then compare with data generated from 1 stage experiment.

Two-stage coagulant addition experiment should base on the data we generate on the first week, the total amount coag addition can be the least dosage which can achieve the effluent requirement, and then we add two more circulations for comparison, vary the total amount, +-0.5 on the basis of the first trial. During those weeks we conduct two stages addition, we won’t test the effect of humic acid on flocculation because the mechanism of this part should be similar between one and two stage.

circu1: coag_2: start from 0.5, max=total -0.5
circu2: coag_2: same as above
circu3: coag_2: same as above

Read through the thesis of Yingda, which is our theoretical basis. Use other articles online as reference .

In this week and last week, we conducted several trials of 1 stage addition experiment. Several problems happened and remain unsolved. First, it's the high effluent turbidity, the effluent turbidity in last semester was usually between 5-10NTU, but this semester, we actually used a higher coag dosage but the lowest NTU only reached around 11, and for other trials, it was around 12-15. Second, this problem might relate to the first one, our coagulant solution is cloudy since last week, even we have already washed and refilled it for several times. This might require us to make some new lab concentration PAC. The last issue is about the CC, after last Sunday the system was shut down for a while, the water level in CC kept low in this week, lower than the past few weeks.

We will meet up and discuss how we will divide the powerpoint for the final presentation that is on May 18th.

When 2-stage experiment was run on Apr 24, minor leak was found at the connection between coagulant pump 2 and contact chamber. Container was placed under the leak temporarily. The connection needed to be fixed by glue or ordering new parts.

Coagulant pump 1 was switched out to a new one because the previous one was working at a much slower speed on Apr 27. The leaks were also fixed by switching out the plugs and microtubing. However, when we tried to run an one-stage experiment with 7.6 ml of PAC/2L, 17g of clay and 0.2 g of HA/ 5L, the effluent turbidity remained at a level of 90 NTU with the fixed apparatus (4/30/2018).

When we tried to decrease the PAC to 4.0 mL/2L, the effluent turbidity still remained at 90 NTU (5/1/2018). We suspected that there might be problems within the apparatus. We also observed that the level of coagulant in the tank did not change much after the experiment. Therefore, we are trying to see if the larger diameter microtubing has caused a problem in the pressure that prohibits the PAC from flowing through.

des later

Hi 2 Stage,
I did an Issues check for your team today, but since no significant Issues has been added since the previous check, your team will not be graded for this check. (I am giving the team the benefit of the doubt.) For clarification, other teams are getting grades for this check, but your team will not. 2 Stage will have a total of 4 checks before the end of the semester, whereas most other teams will have received 5 checks.

Please remember to update your Issues before the next check!

-Next Issues check will be in 2 weeks!
-Feel free to contact me with questions!

1. according to the experiment result of HighG group, seems like the hydrophobic tube did not solve the wall loss problem of the coag and there is also a fact that the coag would decrease over time/ the experiment process.
   So how to track the amount of the coag which actually take effect and reduce the wall loss as well?

2. Because of the limit port of our system, ProCoDA can only control two pumps, which has to be the Clay pump and one of the coag pump, so we can not conduct a real two-stage experiment. We applied a simplification: use the second coag pump to drain from the first one. And I wonder if there is any way to control two coag pumps separately?

Please create a task list in the projects tab by friday 2/23 at the very latest. Here is an example.

See the rubric that was shared with you earlier in the semester for your Team's grade.

-Progress visible through Issues
-Nice incorporation of picture for demonstration of the fixed problem
-Can the team frame the question/hypothesis being tested for each step?
-The team can close Issues after they have been addressed/no longer needed (example: Issues check1; there’s a Task2.1 in Issues that I don’t know if the team is using?)
-Don’t forget to document meetings with Monroe/RA through Issues

-Next Issues check will be after Spring Break
-Feel free to contact me with questions!

Three leaks in the apparatus. We believe that we should order new tube fittings from McMaster Carr
(Plug with 1/4" Stem OD for Push-to-Connect Fitting for Drinking Water)