Page History

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Goal: Modify Experimental System to Develop Consistent Supersaturation in Inflow Water
(Changes were made to the sand filter experimental system in order to establish more consistent supersaturation of the influent water flowing into the sand filter. The existing aerator was replaced by a taller aerator that would allow for increased residence time of the bubbles.)

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• June 8-11: Aerator was incorporated into the new system and leaks were fixed. (Adela, Shaina, Tanya)
• June 10-11: The water source of the system was changed from tap water to the white tub in the lab to allow for the removal of the hot and cold water valves. The cold and hot water valves were replaced with a flow control valve after the aerator and a water wasting valve was added to the aerator for better water level control. (Adela, Shaina, Tanya)
• June 11: Process controller methods for the experimental system were rewritten. (Adela, Tanya; Reviewed with Shaina) Adela, Tanya
• June 14 - June 20: Debug experimental system, debug process controller methods, and properly configure the system (determine set points for minimum and maximum water levels, etc). (Adela, Shaina, Tanya)
• June 20 - June 24: Verify that the new aerator functions properly and olds results are replicable. (Adela, Shaina, Tanya)
  
  

EXPERIMENTS

Descriptions of the experiments that will be conducted are available here.

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• June 24 - July 1: Experiment Bed Depth:
  Starting with 10 cm on June 24, experiments will be conducted with varying bed depths. Bed depth will be increased 10 cm daily. Final data analysis will occur on June 29-July 1. (Adela, Shaina, Tanya)
• July 1 - July 8: Experiment Bed Expansion:
  The range of expansions to be tested will be determined after the bed depth experiments are conducted. A bed depth that yields moderate gas removal will likely chosen and the physical limitations of the sand column will govern the expansion range. Like in Bed Depth Experiments, expansion will likely be increased incrementally by a certain percentage daily. (Adela, Shaina, Tanya)
• July 8 - July 15: Experiment DO Concentration:
  Starting with 20 kPa gage pressure on July 8, experiments will be conducted with varying aerator pressure and thus influent dissolved air concentrations. Pressure will be increased 20 kPa daily. Data analysis will begin July 12 - July 15. (Adela, Shaina, Tanya)
  Note: We plan to completely finish experimentation by July 26. This gives us eleven extra days of leeway for these experiments or to devote to any for addressing additional issues that may arise.
  
  

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• July - July 23: Literature searches for MathCAD modeling. After viewing data from each set of experiments, literature searches will be performed as necessary to explain the relationship between variables that are tested.
  July 1 - July 15: Bed Depth Research , (Adela)
  July 5 - July 19: Bed Expansion Research , (Shaina)
  July 9 - July 23: Dissolved Air Concentration Research , (Tanya)

Modeling:

After collecting data, MathCAD models will be developed to quantify the relationship between the parameter of interest and the performance of the sand filter and also to find optimal values for each parameter.

• July 1 - July 26: Model Bed Depth . (Adela, Tanya)
• July 8 - July 26: Model Bed Expansion . (Shaina, Tanya)
• July 15 - July 26: Model Dissolved Air Concentration . (Adela, Shaina)
  
  

REFERENCES:

The articles detailed below were found in Spring 2009. References will be expanded during experiments, data analysis, and MathCAD modeling as the need arises during experiments and data analysis.

Fundamentals of Bubble Formation during Coagulation and Sedimentation Processes

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Akkoyunlu, A. (2003). "Expansion of Granular Water Filters During Backwash."Environmental Engineering Science. 20(6): 655-665, 2003. Available from <http://www.liebertonline.com/doi/pdf/10.1089/109287503770736168>. Accessed 2009 February 27.
References will be expanded as further literature searches are performed for MathCAD modeling.