On Friday, October 21 and again on Wednesday, October 26,  Environmental Engineer Joseph Nattress joined Mr. Fawks's STEM classes to help students better understand the field of Environmental Engineering, especially the process for making water consumable.  Students learned about flocculation, coagulation, sedimentation, clarification, filtration and disinfection as Mr. Nattress walked each class through the entire process.

  

 

 

 

  

Flocculation, in the field of chemistry, is a process wherein colloids come out of suspension in the form of floc or flake; either spontaneously or due to the addition of a clarifying agent.  Due to the clarifying agent, the particles in the water coagulate together forming larger floc.  Coagulation and flocculation are important processes in water treatment. 

   

 

 Sedimentation is a physical water treatment process using gravity to remove suspended solids from water.  Clarifiers are tanks built with mechanical means of continuous removal of solids being deposited by sedimentation.  Sedimentation and clarification are important processes in water treatment. 

Filtration

 

 

 

 

 

As a part of the STEM activity, students built a working prototype filter with the following materials: empty water bottle, rubber band, coffee filter, rocks, sand and anthracite.  Students first ran water through the filter to prepare the filter for actual use.  Once the filters were conditioned, each team ran a sample of the water that had undergone flocculation, coagulation and clarification steps through their filter.  Comparison of the clarified water and the filtered water was a quick means to identify how much cleaner the water had become from the initial dirty water where the process began.