Progress Update 4/28/13

Week Four Completed Tasks 

Filter Construction

Fiberglass, rubber hose, and cap were purchased. Cap is too large for filter housing so group will find a new way to seal off the bottom. Filter is mostly assembled. Rusted filings will be added once the rusting is complete. The bottom is temporarily sealed with papertowel.

Progress Update 4/25/13

Week Three Completed Tasks

Preparing for Filter Construction - Obtaining Supplies

1.5 gallons of river water obtained during class today.
http://water.weather.gov/resources/hydrographs/padp1_hg.png
Indicates no flooding or conditions that would worsen water.

Filter housing (1''x3' clear tubing), gravel, and 5.6grams of unrusted iron filings obtained today. Prerusted iron nails will no longer be used. Instead, iron filings will be rusted and placed at the top of filter. Filings will be rusted by moisturizing with water and also appling table salt. Ratio of solution not yet determined. Challenges may include separating the filings from the salt. While water can be evaporated, salt will remain.

Fiberglass insulation, rubber hose, and possibly a bottom cap will be purchased on Friday and filter will be assembled over weekend. Base and sheath to be determined. 

Progress Update 4/14/13

Week Two Completed Tasks

Preparing for Filter Construction

We put nails in a salt water bath on this day and began researching optimal sizes and quantities for the final water filter design.

4/17 Final sizes confirmed, suppliers found - filter housing will be 3' long by 1" diameter clear aquarium tubing with an outer sheath to keep it stabilized and shielded from light. About 2 quarts of fiberglass will be needed, weight unknown, we'll use fiberglass insulation. Hydraulic loading rate for testing is 2 m/h, meaning a flow rate of ~900 ml/h, feeding is to be 1% of this and constant (outflow tube opening will be constricted to achieve this). Final quantity of nails unknown.

4/19 First signs of rust on test nails, larger quantity soaked for use in final design. Final quantity still unknown.

4/22 Water container obtained for sample collection on Thursday, 4/25. One gallon to be used by group

Research Results

Bacterial Hazards 

Most common bacteria: Camplyobacter

• size: minimum below .45 microns (can pass through)
• prevalence: extremely common, even in developed world
• effects: diarrhea for a week or longer, not usually lethal

Most deadly bacteria (untreated): Vibrio cholerae

• size: 1 micron (small dimension)
• prevalence: rare, but can cause epidemics
• effects: diarrhea, nausea, vomiting, shock, death, usually lethal if untreated

E. coli:

• size: .5 microns (small dimension)
• prevalence: extremely common, but pathogenic strains rare
• effects: haemolytic uraemic syndrome, death, deadly strains rare

Shigella:

• size: .5 micron (small dimension)
• prevalence: less common, mainly in children of developing countries
• effects: dysentery, death, not usually lethal
• death is rare for majority

Protozoa:

• typically >2 microns

Chemical Hazards (removable by filtration)

Aldrin and dieldrin

• require coagulation
• chlorinated pesticides
• highly toxic

Arsenic

• generally requires coagulation
• can be deadly

Atrazine

• can be removed by bankside filtration and nanofiltration
• herbicide
• can cause reproductive and immune problems

Chlorpyrifos

• requires coagulation
• insecticide
• inhibition of cholinesterase activity

Chromium

• requires coagulation
• carcinogen

DDT

• requires coagulation
• pesticide
• hazardous

Mercury

• coagulation
• from electronics, industrial waste
• highly toxic

Nickel

• coagulation
• potential allergic reaction

Polynuclear aromatic hydrocarbons

• coagulation
• industrial
• uranium
• coagulation
• radioactive

References

Rollins, David M. "Campylobacter Summary." Life.umd.edu. N.p., Aug. 2000. Web. 07 May 2013. <http://www.life.umd.edu/classroom/bsci424/pathogendescriptions/Campylobacter.htm>.

Formadi, Herman. "Vibrio Cholerae." Cv.vbi.vt.edu. N.p., 5 July 2007. Web. 07 May 2013. <http://ci.vbi.vt.edu/pathinfo/pathogens/V_cholerae_2.html>.

"Shigella." Cdc.gov. Centers for Disease Control and Prevention, 9 Feb. 2011. Web. 07 May 2013. <http://www.cdc.gov/pulsenet/pathogens_pages/shigella.htm>.

"Guidelines for Drinking-water Quality, Fourth Edition." WHO. N.p., n.d. Web. 07 May 2013. <http://www.who.int/water_sanitation_health/publications/2011/dwq_guidelines/en/index.html>.




Additional Research


Optimal Biofilm Growth Conditions

• higher temperature is better, as long as it is not too high to kill the microbes
• optimal hyduaulic loading ~3m/h
• *note, figures for sand filter
• **3 m/h is for testing, corresponds to ~900 ml/h flow rate

Filter Dimensions and the Use of Iron

According to one study, this group used 5kg iron nails to remove arsenic in a filter of 30'' diameter and 61 cm height. They put the iron nails in the top of the filter separated in a 'diffusion box'

Relative to our dimensions we would need ~7g scaled for radius and height. Scaled for only radius we need 6g - a study later showed the iron did not propagate very far through the filter, accounting for the full height may be unnecessary 

References

Fengbing Tang, et al. "Effects of Bio-Sand Filter on Improving the Bio-Stability and Health Security of Drinking Water". Mechanic Automation and Control Engineering (MACE), 2010 International Conference on. 2010. 1878-1881. Print.

"Effects of Bio-Sand Filter on Improving the Bio-Stability and Health Security of Drinking Water". Mechanic Automation and Control Engineering (MACE), 2010 International Conference on. 2010. 1878-1881. Print.

Ngai, Tommy, and Sophie Walewijk. "THE ARSENIC BIOSAND FILTER (ABF) PROJECT: DESIGN OF AN APPROPRIATE HOUSEHOLD DRINKING WATER FILTER FOR RURAL NEPAL." N.p., 2003. Web. 8 May 2013. <http://web.mit.edu/watsan/Docs/Other%20Documents/KAF/NgaiWalewijk-%20ABF%20Report2003.pdf>.

Gantt Chart, Master Task List

Tasks to be completed:
1. Create tasks to be completed list/schedule
2. Create master task list

http://bit.ly/10OZ4Nz Gantt Chart
http://bit.ly/10P30he Master Task List

3. Update daily

Literature Study

Information Sought:

-fiberglass density? can biofilm grow inside if of lower density?
-filtration capability w/o biofilm
-fiberglass water retention
-iron nails + fiberglass - does the iron stick? Arsenic-removing filters*
-encourage a biofilm that's better at filtration/eating microbes

General Resources:
World Health Organization website http://www.who.int/en/
Web of Science website http://thomsonreuters.com/products_services/science/science_products/a-z/web_of_science/


Specific Resources:


Wound Fiberglass Depth Filters as a Less Expensive Approach for the Concentration of Viruses from Water

Abstract
http://www.ncbi.nlm.nih.gov/pubmed/2843272
Article about fiberglass-based filters, reference for packing factor, pore size, etc. These cartridges specifically were used for concentration of viruses.

Citation
Payment, Pierre, and Michel Trudel. "Wound Fiberglass Depth Filters as a Less Expensive Approach for the Concentration of Viruses from Water." Canadian Journal of Microbiology 34.3 (1988): 271-72. Print.



Glass Fiber Filter

PDF
http://www.membrane-solutions.com/download/Glass_Fiber_Filter.pdf
Product spec sheet for glass fiber membranes (very thin), qualitative description of filtration ability plus mass and thickness can give us an idea of what density should be

Citation
"Glass Fiber Filter." Membrane Solutions, LLC., n.d. Web. <http://www.membrane-solutions.com/download/Glass_Fiber_Filter.pdf>.



Water safety plan manual (WSP manual): Step-by-step risk management for drinking-water suppliers

Abstract, PDF download
http://www.who.int/water_sanitation_health/dwq/en/
WHO, drinking water quality, links to information about potential hazardous drinking water contaminants

Citation
Water Safety Plan Manual Step-by-step Risk Management for Drinking-water Suppliers. Geneva: World Health Organization, 2009. Print.



Effects of Bio-Sand Filter on Improving the Bio-Stability and Health Security of Drinking Water

Abstract
http://bit.ly/ZlQ7gv
I'm having trouble finding articles about fiberglass filters + biofilms, this is about sand+biofilms, this may have some useful information about biofilms

Citation
Fengbing Tang, et al. "Effects of Bio-Sand Filter on Improving the Bio-Stability and Health Security of Drinking Water". Mechanic Automation and Control Engineering (MACE), 2010 International Conference on. 2010. 1878-1881. Print.




Effects of Hydraulic Loading Rate and Filter Length on the Performance of Lateral Flow Sand Filters for On-Site Waste Water Treatment 

Abstract
http://ascelibrary.org/action/showAbstract?page=639&volume=16&issue=8&journalCode=jhyeff&

Citation
Wilson, Janice, Leah Boutilier, Rob Jamieson, Peter Havard, and Craig Lake. "Effects of Hydraulic Loading Rate and Filter Length on the Performance of Lateral Flow Sand Filters for On-Site Wastewater Treatment." Journal of Hydrologic Engineering 16.8 (2011): 639. Print.

Progress Update 4/10/13

Week One Completed Tasks

Literary Study and Proposal

The group assembled to write the proposal. Previous lab findings were reviewed to determine the best way to go about constructing a water filter that would be effective at removing turbidity. In addition, supplies were assessed in order to gain a rough estimate of the finances needed. Then a timeline was created to ensure that parts of the project would be completed weekly. The information gathered was combined in the proposal.