...
After laboratory tests on the filtering capacity of the polyurethane foam material are concluded, we will continue to explore different research areas. This will include determining head loss across the foam over the run time of the filter, the effect of layering different porosities of foam, the effectiveness of an aluminum hydroxide wash to decrease the ripening time of the foam, and the effects of natural organic matter on the foam material
Head Loss Calculation
The amount of headloss that occurs with the build up of particles in the foam will determine how often the filter will require cleaning, and the additional height required for the walls of the filtration unit to accomodate this additional head loss. It is therefore important to measure the change in headloss over the running time of the filter.
Aluminum Hydroxide Wash
Research has shown that the foam material has a fairly long ripening time. In order to reduce this ripening time, it may be useful to prime the filter with an aluminum hydroxide rinse after cleaning. This may reduce the time delay in the filter becoming coated with enough alum to achieve the desired filtration performance. In this test, we will need to determine whether the aluminum hydroxide will result in excess aluminum being washed into the effluent water from the filter. It will then be necessary to determine a washing and foam reinstallation method to reduce this effect.
Effect of Natural Organic Matter
If we conclude from laboratory tests that the foam material provides adequate filtration, it will be necessary to test the effects of natural organic matter on the foam material.
Foam Filtration Unit Design
This filtration unit design should be optimized according to the required surface area and filtration velocity parameters determined through previous laboratory experiments. In addition, it should minimize the required plan area, as well as maximize the ease of maintenance for the operator.
Cleaning Method
After determining the effects of natural organic matter on the foam material, we will propose a standardized method for cleaning and replacing the foam.
Foam Media Upflow Design
An alternative to using the foam simply as a flat sheet which water is filtered through is to design a hybrid upflow filter, which uses small pieces of the foam as the filtering material, as opposed to the traditional upflow sand filter. This idea is based on the technique outlined in this article, Water Filtration- Advantages of Fabric Media