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Wastewater Treatment. Alexander Adams, Luke Bosse , Elizabeth Kissner , Stephanie Linares, William Major, Gabriel Rivera, Rachel Voss. Introduction. First treatment focused on removal and collection Privies and cesspools Followed by “dry sewage system” Pails
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Wastewater Treatment Alexander Adams, Luke Bosse, Elizabeth Kissner, Stephanie Linares, William Major, Gabriel Rivera, Rachel Voss
Introduction • First treatment focused on removal and collection • Privies and cesspools • Followed by “dry sewage system” • Pails • During industrial revolution sewer pipes were built privately • Many abandoned halfway and dumped into nearby water sources • Medical advances proved polluted water caused diseases • Cholera outbreak
Introduction • Beginning of 20th century plants made with filters, settling tanks, and/or chlorination • 1948 Federal Water Pollution Control Act • Provide federal funding for treatment plants • 1972 the Federal Water Pollution Control Act Amendments • Provide standards on quality of effluent water • Modern trends • Energy efficiency and reusability
Objective • Create an efficient way to treat municipal wastewater that incorporates traditional methods of treatment with new methods that includes algae. • Cultivate algae and bacteria in order to treat municipal water. • Harvest biomass. • Take treated water and process it through a tertiary treatment to achieve potable water.
Raw Materials • Municipal wastewater is a collection of water from households, businesses and small industries by means of a sewer system • Water Supply Considerations • Water Demand Useful Life vs. Design Life Census Data often used • Water Source Evaluation • Water Quality Physical, Chemical and Microbiological, and Radiological • Plant sizing and layout
Inflow/Headworks • Inflow vs. Infiltration • Variability of Flow Rates • Head Works Unit operations placed at the upstream end of the plant • Pumping Station (Lift Station) • Flow Measurement Devices • Preliminary Treatment
Pretreatment • Removes large insolubles • Required because large insolubles can clog later filtration
Bar Screens • Very cheap and easy to manage • Requires regular cleaning of the screens by belts or manual labor Source: http://www.infobarscreens.commanual-bar-screen.htm
Comminutors • Grinds up large insolubles • Later filtered out in primary treatment • Insolubles can recoagulate and clog system later • More expensive but requires less maintenance Source: http://www.franklinmiller.com/comminutors-article.html
Primary Treatment • Equalizing Basins • In-Line • Off-Line • Settling Tanks • Sludge Treatment Clarifier in wastewater treatment plant. Source: http://home.howstuffworks.com/home-improvement/plumbing/sewer3.htm
What is Microalgae? • Microscopic, single-cell organisms that exist in fresh water and marine environment • Thousands of species • Are able to create large amounts of biofuel • Use Carbon Dioxide, Nitrogen, and Phosphorus and expel Oxygen sunchlorella
Algal-Bacterial Cultures • Synergistic Cooperation • Benefits: • Reducing need for aeration • Alleviating the release of green house gasses • Forming flocs that increase settleability
Isolation, Selection and Inoculum Ratios • Specific to the environment • Studies • 5:1 and 1:1 algae to sludge ratios are most efficient
Algal and bacterial inoculum OMEGA Biomass Harvest
OMEGA • Offshore Membrane Enclosure for Growing Algae • Proposed by NASA • Large, flexible, plastic tubes (PBRs) • Remove BOD, Pathogens, Phosphorus, and Nitrogen Lundquist
Photobioreactor TED talks
OMEGA • Pros • Extremely sustainable • Cost efficient, can compete with fossil fuels • Cons • Biomass will rarely settle well, thus possible interference with disinfection • Hasn’t been tried on a large scale • Collection of water
Forward Osmosis: Like reverse osmosis, uses a semi-permeable membrane to separate water from dissolved solutes. The driving force is an osmotic pressure gradient. High “draw” solution(sea water) has a higher concentration than the feed solution (wastewater), thus separating feed water from solutes. NASA Ames
Secondary Treatment Low Rate Facultative Ponds Image from (Ali)
Secondary Treatment Cont. High Rate Algal Ponds Image from (Park, 633-939)
Tertiary Treatment • Determined to be expensive • Highly increased product purity • Processes can vary in extensiveness
Simple vs. Extensive Pressure Regulating Valve Injector http://water.me.vccs.edu/courses/env110/clipart/chlorinator3.gif
Conclusion • Process development from allocation to re-use • Insoluble/Non-treatable removal (Preliminary) Isolate and Purify Product (Primary and Secondary) Polishing of Product (Tertiary) • Product pumped out to reservoir/storage/wetlands
Inquiries? Feel free to ask any questions!