I need help to do my outline

Ion Exchange Pilot Plant SOP – From the Archives

Oregon State University, Gleeson 009

Note: This SOP is just a guide. More work can and should be done during the lab periods.

MATERIALS

Equipment (for all three lab periods)

· Safety glasses · Labeling material (tape and marker) · Plastic syringe · Mass balance · 2 Gal plastic bucket (2) · Test tube rack · Test tubes · pH paper · Calcium test kit · 1 L poly graduated beaker · 50 mL poly graduated cylinder · 250 mL poly graduated cylinder · Squirt bottle for rinsing · PVC stir rod

· Ion exchange apparatus with panel, pump, rotometer, and column · Pre-cut tubing · Teflon tape · Ruler · Funnel · Watch or timer Chemicals · Potable water · Hydrochloric acid · Calcium carbonate · Sodium chloride

Lab Period 1: Standard curve and system volume

Standard Curve Preparation

1. All solution preparation will take place in GLSN 003, and the HCl must not leave the fume hood. Determine the weight of CaCO3 required to prepare 7-8 L of a 640 ppm (mass) Ca2+ solution in your plastic bucket. Identify one team member to do the solution preparation in GLS 003.

a. Add water to bucket while waiting to use the fume hood.

b. First, add about 25 mL of 37 percent HCl to drop the pH below 2.0. Measure and add required CaCO3. This concentration (640 ppm) is an order of magnitude higher than very hard water. This allows a reasonable experiment duration. Be sure the CaCO3 is completely dissolved by stirring and checking for cloudiness. Add more acid if necessary.

Note: This is usually where students make errors that result in several hours of extra work.

2. Prepare and label five dilutions to develop a standard curve for calcium concentrations between zero and 640 ppm Ca2+. Run replicates to enable error analysis.

3. You have been provided with calcium test kit. For each test:

a. Shake Bottle 1, and add 10 drops to each test tube.

b. Shake Bottle 2.

c. Add a drop from Bottle 2 and shake the tube. If the color is blue, stop. If the color is pink, add another drop and shake. Continue until a blue color is achieved.

d. Record the number of drops to turn each test tube solution blue. Make the estimate in standard deviation from your replicates.

4. Create a standard curve by plotting ppm versus drops from Bottle 2. The points should lie in a straight line. If they do not, repeat the analysis.

5. Cover your 640 ppm Ca2+ solution with the bucket label the 6 L of 640 ppm Ca2+ solution for the next lab period.

6. Clean up the lab area. All lab stations must be cleaned up before 15 minutes to the hour.

The following is required of your team before you leave the laboratory:

1. Inspect the ion exchange laboratory column. Draw a schematic of the system to scale, from the source/pump to the waste stream.

2. Unscrew and inspect the top and bottom fittings to open the column. Note the screens in the top and bottom fittings to retain the resin.

3. Estimate system component volumes to enable estimation of retention times.

4. Use the resin properties provided by the manufacturer to select 15 sample times you will use to measure exchange capacity during Lab Period 2. The specific times can be adjusted as your experiment progresses. What do you expect to see?

5. Discuss column operating procedure with an Instructor prior to leaving. It is important to minimize air in the system during resin characterization. It may be useful to practice running the column without resin and develop a procedure to avoid entrapping air.

Review these items with an Instructor.

Lab Period 2: Resin characterization

Preparation

1. Measure out 30 mL of ion exchange resin in a graduated cylinder and transfer to a 1 L beaker.

2. Pour potable water into the beaker to cover the resin. Gently agitate for a few minutes to rinse the resin. Pour off the water and replace with new water.

3. Remove exchange column from setup by disconnecting the tubing and releasing the clamp.

4. Transfer the resin into the column. Make sure you use Teflon tape on the threaded seals (ask the TA if unsure). DO NOT OVERTIGHTEN THE FITTINGS.

5. Connect the column and tubing so the direction of flow is up through the column. Push the tubing on only as far as necessary to ensure it is easily removable for later steps. Before reconnecting the top tube, fill the column and tubing with water (as best as possible).

6. Turn on pump, bypass the flow meter, and let water flow for a couple of minutes. (Make sure to eliminate as much air as possible.) Resin will rise in the column. Stop the pump and allow the resin to settle in the column.

7. Turn on the pump, bypass the flow meter, and run 1 L of potable water (without calcium) down through the column. Consider how your flowrate might be verified and also that entrained air and bubbles can affect pumping capability.

Resin Capacity Characterization

1. You are limited to 15 samples, so do a final review of these times with an Instructor. The specific times can be adjusted as your experiment progresses.

2. Stir CaCO3 solution to eliminate gas bubbles that may have formed.

3. Note the time and start your resin characterization process. Pump the 640 ppm Ca2+ solution at 100 ml/min through the column. Execute your sampling and test plan and continue until you have pumped out as much solution as possible. Check your rotometer frequently to ensure constant flow and also check your pump to make sure it stays submerged.

4. Remove the calcium-loaded resin from the column. Store the resin in your labeled bucket covered with any remaining 640 ppm Ca2+ solution.

5. Clean up the lab area. All lab stations must be cleaned up before 15 minutes to the hour.

Before you leave the laboratory review the following with an Instructor:

1. Plot the calcium (Ca2+) concentration against time.

2. Estimate the total calcium (mg Ca2+) removed from the water.

3. Do you feel your surface flow rate was appropriate?

4. Knowing the volume of the resin bed, calculate the exchange capacity of the resin as eq/L of resin volume. Compare this result with information given by the manufacturer, and consider reasons for any difference.

Lab period 3: Regeneration of ion exchange resin

Regeneration

1. Separate the calcium-loaded resin from Lab Period 2 from the 640 ppm Ca2+ solution and transfer it into the column. Remove as much of the 640 ppm Ca2+ solution as possible. Plumb the system for downflow.

2. Rinse your bucket, re-label it, and prepare 6 L of 6000 ppm (mass) salt (NaCl) solution. Decide as a team on the pH level you will use and share that with an Instructor.

3. Limit yourselves to 12 samples and decide on a sampling and testing scheme. Your initial sample(s) may have high concentration, so you should dilute it before testing.

4. Carry out regeneration at 150 ml/min until your salt solution is exhausted (consider this a practical regeneration limit). Collect all of the solution that passes through the bed, record the volume collected, and measure the final concentration.

5. If you feel that you have not yet removed enough calcium, consider recycling your solution through again and again monitoring the effluent.

6. Clean up the lab area. All lab stations must be cleaned up before 15 minutes to the hour.

Before you leave the laboratory review the following with an Instructor:

1. Plot the calcium (Ca2+) concentration against time, assess the total amount of calcium removed from the resin, and estimate the regeneration efficiency.

Be sure to calibrate your rotameter at the beginning and throughout your work to ensure confidence in the reading.

� http://www.caitechnologies.com/images/pdfs/specs/c249.pdf, accessed Oct. 2013