1 ctc 450 review advanced ww treatment advanced ww treatment removal of nitrogen removal of nitrogen...
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CTC 450 ReviewCTC 450 Review
Advanced WW TreatmentAdvanced WW Treatment Removal of NitrogenRemoval of Nitrogen Removal of phosphorusRemoval of phosphorus Complete removal of pathogensComplete removal of pathogens Removal of other toxicsRemoval of other toxics
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ObjectivesObjectives
Understand the basics with respect Understand the basics with respect to reusing wastewaterto reusing wastewater
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Water ReuseWater Reuse
Reuse is defined as direct application Reuse is defined as direct application of treated WW for agricultural and of treated WW for agricultural and urban irrigation, industrial reuse, urban irrigation, industrial reuse, groundwater recharge, and othersgroundwater recharge, and others
Discharging WW to a receiving water Discharging WW to a receiving water that is ultimately used downstream for that is ultimately used downstream for a water source is not considered reuse a water source is not considered reuse (dilution/separation in time and space)(dilution/separation in time and space)
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Water Reuse - FunctionsWater Reuse - Functions
Treated effluent is used as a water Treated effluent is used as a water resource for beneficial purposesresource for beneficial purposes
Effluent is kept out of streams, lakes Effluent is kept out of streams, lakes and beaches and beaches
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Water Reuse – Main Water Reuse – Main ConcernsConcerns
Reliable treatment of WWReliable treatment of WW Protection of public healthProtection of public health Gaining public acceptanceGaining public acceptance
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Matter of EconomicsMatter of Economics
Water reuse may be less costlyWater reuse may be less costly Use N/P for irrigation instead of Use N/P for irrigation instead of
providing tertiary processes to prevent providing tertiary processes to prevent eutrophicationeutrophication
Water shortages – a future possibility Water shortages – a future possibility (CA/AZ/FL)(CA/AZ/FL)
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Potential DrawbacksPotential Drawbacks
Pathogens via physical contact or Pathogens via physical contact or aerosolsaerosols
Public perceptionPublic perception
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Water StatisticsWater Statistics
Recycled WW Recycled WW 983 MGD (1995)983 MGD (1995) 2% of total wastewater release (41,000 2% of total wastewater release (41,000
mgd)mgd) CA/AZ/FL account for majorityCA/AZ/FL account for majority
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Water Quality Effluent StdsWater Quality Effluent Stds
Dependent upon reuse applicationDependent upon reuse application Agricultural irrigation (restrictedAgricultural irrigation (restricted-with respect to human -with respect to human
activityactivity)) fodder,fiber,seed cropsfodder,fiber,seed crops
Agricultural irrigation (unrestricted)Agricultural irrigation (unrestricted) processed food, food eaten rawprocessed food, food eaten raw
Urban irrigation (restricted)Urban irrigation (restricted) Golf courses, cemeteries, highway mediansGolf courses, cemeteries, highway medians
Urban irrigation (unrestricted)Urban irrigation (unrestricted) Parks, playgrounds, residences, comml landscapingParks, playgrounds, residences, comml landscaping
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Advantages/Disadvantages of Advantages/Disadvantages of Agricultural IrrigationAgricultural Irrigation
Already contains Already contains nutrients and soil nutrients and soil amendmentsamendments
Agricultural areas Agricultural areas may be nearbymay be nearby
Money for cash Money for cash cropscrops
In arid regions, ww In arid regions, ww may be the only may be the only source of watersource of water
Nitrate - Nitrate - groundwatergroundwater
Heavy metals - Heavy metals - soilssoils
Pathogens - farm Pathogens - farm workersworkers
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Agricultural Irrigation Agricultural Irrigation
Storage required to balance Storage required to balance supply/demandsupply/demand
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Design of Irrigation SystemsDesign of Irrigation Systems
Balance water to determine storage Balance water to determine storage requirementsrequirements
Balance nitrogen to prevent Balance nitrogen to prevent migrationmigration
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Urban Irrigation Urban Irrigation
Piping systems color-codedPiping systems color-coded Cross-connections prohibitedCross-connections prohibited Warning signsWarning signs Reuse water pipes placed 3’ below Reuse water pipes placed 3’ below
potable water pipespotable water pipes
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Groundwater RechargeGroundwater Recharge
Surface infiltration (surface spreading)Surface infiltration (surface spreading) Direct injectionDirect injection
IssuesIssues Fate of particulatesFate of particulates Fate of bacteria/virusesFate of bacteria/viruses Fate of dissolved organic/inorganic Fate of dissolved organic/inorganic
constituents (particularly toxics)constituents (particularly toxics)
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Groundwater RechargeGroundwater Recharge
US federal requirements/standards US federal requirements/standards have not been establishedhave not been established
Currently regulated by state Currently regulated by state agenciesagencies
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Storage IssuesStorage Issues
Need for storageNeed for storage Type (open or closed)Type (open or closed) Discharge requirements Discharge requirements Problems:Problems:
Odors, loss of chlorine residual, low DOOdors, loss of chlorine residual, low DO Temperature stratification, bird/rodentsTemperature stratification, bird/rodents Algal blooms, regrowth of Algal blooms, regrowth of
microorganismamicroorganisma
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Agricultural Irrigation-ExampleAgricultural Irrigation-ExampleTallahassee, FLTallahassee, FL
2000 acres; 2000 acres; 16 pivot irrigators16 pivot irrigators
irrigators controlled by computerirrigators controlled by computer low-drift nozzleslow-drift nozzles
Vegetation-canola, corn, sorghum, grassVegetation-canola, corn, sorghum, grass Monitoring wells Monitoring wells Capacity-23 mgdCapacity-23 mgd Four parallel treatment plants (fig 14-4) Four parallel treatment plants (fig 14-4)
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Residential Lawn WateringResidential Lawn WateringEl Dorado Hills, CAEl Dorado Hills, CA
Dual plumbed distribution systemDual plumbed distribution system 66 mg reservoir66 mg reservoir Drip irrigators-no restriction timesDrip irrigators-no restriction times Spray irrigators-restricted to 9pm-6amSpray irrigators-restricted to 9pm-6am Back-up: potable lake waterBack-up: potable lake water
Plant doesn’t meet required water qualityPlant doesn’t meet required water quality System can’t meet peak irrigation System can’t meet peak irrigation
demandsdemands
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Urban ReuseUrban ReuseSt. Petersburg, FLSt. Petersburg, FL
Irrigation of parks, school, golf Irrigation of parks, school, golf courses, comm’l and residential courses, comm’l and residential irrigationirrigation
Some water injected into deep-well Some water injected into deep-well systemsystem
Effluent requirements:Effluent requirements: SS-5 mg/l (in practice 1-3 mgl/l)SS-5 mg/l (in practice 1-3 mgl/l) Chlorine residual-1 mg/l after 15 min Chlorine residual-1 mg/l after 15 min
(in practice 4 mg/l)(in practice 4 mg/l)
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Industrial ReuseIndustrial ReuseLos Medanos Energy Center, Los Medanos Energy Center,
CACA WW treatment plant provided recycled WW treatment plant provided recycled
water to the energy centerwater to the energy center Water is used for the heat recovery steam Water is used for the heat recovery steam
generator make-up and water for the generator make-up and water for the evaporative cooling systemevaporative cooling system
Treatment processes:Treatment processes: Dual-media, ultra- and activated carbon Dual-media, ultra- and activated carbon
filtration for TOC removalfiltration for TOC removal Antiscalant chemical added for evaporative Antiscalant chemical added for evaporative
systemsystem Reverse osmosis for evaporative coolingReverse osmosis for evaporative cooling
Final Exam ReviewFinal Exam Review
Water Processing-Clarifier following Water Processing-Clarifier following Coagulation (25 pts)Coagulation (25 pts)
Wastewater Processing-Trickling Filter Wastewater Processing-Trickling Filter (25 pts)(25 pts)
Wastewater Processing-Clarifier (25 Wastewater Processing-Clarifier (25 pts)pts)
25 pts – will cover material presented 25 pts – will cover material presented after the midterm after the midterm
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Final Exam ReviewFinal Exam Review
Open book/open notes/Open book/open notes/ Can use computer Can use computer (but monitored)(but monitored)
No cell phones; no old testsNo cell phones; no old tests Show all work Show all work Know the standardsKnow the standards Don’t forget unitsDon’t forget units Conversions-concentration to massConversions-concentration to mass
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