Module 5: Animal Manure and ProcessGenerated Wastewater Treatment

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Module 5 Animal Manure and Process-Generated
Wastewater Treatment

• By Saqib Mukhtar

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Introduction

• The purpose of this module is
• To describe principles of manure and wastewater
  treatment.
• To discuss current and emerging technologies that
  treat and stabilize manure and wastewater.

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Waste Stabilization

• The physical and/or chemical process of
  breaking down and converting waste constituents
  to homogeneous and reusable end products, with
  reduced odors and volatilization of organic
  compounds

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Principles Used in Manure Treatment

• Gravity settling
• Mechanical separation
• Flocculation
• Aeration
• Anaerobic processes
• Natural systems

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Gravity Settling

• One of the first processes used to treat
  wastewater
• Removes larger solids (mineral particles and
  biomass) by reducing flow velocity
• Consists of shallow settling tanks or basin with
  sloped access area
• Handles large amounts of solid and organic matter

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Settling Tank
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Settling Basin
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Gravity Settling

• Advantages
• Load reductionfor subsequent treatment
  processes
• Reduction of clogging in pumps and pipes

• Disadvantages
• Large size requirements
• High construction and operating costs

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Mechanical Separation

• Process consists of solids removal by
• Inclined screens, self-cleaning screens, presses,
  centrifuge processes, and rapid sand filters
• Used for animal manure treatment
• Reduction in carbon, nitrogen, and phosphorous
  and heavy metals loads to subsequent treatment
  units

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Mechanical Inclined Screen Separator
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Mechanical Press Separator
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Mechanical Separation

• Advantages
• Odor control
• Easy removal and disposal of solids
• Separated solids have many end uses.

• Disadvantages
• High initial set-up cost
• Proper maintenance required

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Flocculation

• Removal of solids and suspended particles by
  adding flocculating agents
• Treated particles removed by filtering or
  settling
• Alum and lime are commonly used flocculating
  agents.

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Flocculation

• Advantages
• Removal of very fine particles
• Increase in the agronomic valueof the sludge

• Disadvantages
• Process is expensive
• Additional manage-ment of large amounts of
  removed sludge

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Aeration

• Used to reduce the biological oxygen demand (BOD)
  in water
• Used in waste storage and treatment structures to
  reduce odor
• Aerators are used to provide continuous or
  partial aeration.

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Complete Aerating Unit
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Floating Aerator Unit
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Aeration

• Advantages
• Odor control
• Satisfies high oxygen demands

• Disadvantages
• High energy requirement
• Frequent cleaning required due to enhanced sludge
  accumulation

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Anaerobic Processes

• Natural processes of degradation in the absence
  of oxygen
• Take place in deep lagoons or closed digesters
• Used in the treatment of livestock and poultry
  waste

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Anaerobic Processes

• Advantages
• BOD and solids reduction
• Reduced sludge production
• Methane byproduct can be used as fuel.

• Disadvantages
• Slow process
• Sensitive to temperature and pH changes
• Odor problems

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Natural Systems

• Use natural mechanisms to reduce BOD and
  suspended soils
• Treatment systems include
• Constructed wetland systems
• Vegetative filter strips
• Overflow plots

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Advantages and Disadvantages

• Advantages
• Reduction in nitrogen levels
• Odor reduction

• Disadvantages
• Large area requirement

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Vegetative Filter Strip
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Manure Utilization and Treatment Technologies

• Land applications
• Anaerobic lagoons
• Anaerobic digesters
• Composting
• Vermicomposting

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Manure Utilization and Treatment Technologies
(continued)

• Mortality composting
• By-product recovery
• Energy conservation
• Constructed wetland systems

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Land Application

• Terminal receiver of treated and untreated manure
  and wastewater
• Effective disposal option for livestock and
  poultry producers
• Given proper practices and application
  guidelines, effective plant nutrient supply

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Land Application

• Advantages
• Reduction in fertilizer costs
• Better soil quality
• Low cost

• Disadvantages
• Odor problems
• Large land area required
• Nutrient regulations

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Anaerobic Lagoons

• Waste stabilization through anaerobic biological
  activity
• Used to store large amounts of wastewater
• Efficiency depends on lagoon design and climatic
  conditions

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Anaerobic Lagoon
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Anaerobic Lagoon

• Advantages
• Can store large amounts of waste
• Recycles flush water
• Removes large amounts of nitrogen

• Disadvantages
• Large land area required
• Odor problems
• Safety concerns
• Sludge management

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Anaerobic Digesters

• Similar to anaerobic lagoons but smaller in size
• Normal operating temperatures between 95F- 165F
• Methane and carbon dioxide byproducts

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Anaerobic Digester
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Anaerobic Digestion

• Advantages
• Methane as an alternative fuel
• Increases solid decomposition
• Small land area required
• Odor control

• Disadvantages
• Careful management required
• Safety concerns methane is explosive
• High costs
• Does not reduce nutrients such as N, P, and K

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Composting

• Aerobic process used to stabilize organic matter
• Volume reduction of between 25-50
• Stabilized end product (humus) is high in organic
  matter and nutrients

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Aerated Composting Containers
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Composting

• Advantages
• Odor control
• Controls pests, pathogens, and weed seeds
• Increases soil quality
• Marketable by-product

• Disadvantages
• Careful management required
• Additional costs
• Space requirements

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Vermicomposting

• Process uses earthworms and microorganisms in the
  conversion of organic wastes to humus
• End product used as fertilizer for plants
• Techniques include boxed and outdoor windrows and
  automatic systems

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Vermicomposting

• Advantages
• Reduces lagoon loading
• Odor control
• Nutrient reduction
• Worms used as animal and aqua-culture feed

• Disadvantages
• Careful management required
• Space requirements
• Additional costs

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Mortality Composting

• Described by the Ohio State University Extension
  as above ground burial in abio-mass filter with
  pathogen kill by high temperature
• Process used to dispose of dead livestock and
  poultry
• Additional materials added to increase porosity
  and as a carbon source

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LargeCarcass Composting
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Mortality Composting

• Advantages
• Disposal of dead animals
• Odor control
• Kills pathogens
• Marketable byproduct

• Disadvantages
• Careful management required
• Regulatory concerns
• Initial setup can be expensive

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By-product Recovery

• Processing the end products into value-added
  material
• End products include spent biomass, sludge, and
  composted manure
• Products rich in C, N, P, and minerals

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Nursery Crops Raised on Treated Animal Manure
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By-product Recovery

• Advantages
• Marketable byproduct
• Feed supplements
• Improve soil quality

• Disadvantages
• Careful management required
• Time and space constraints

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Energy Conservation

• Use of alternative treatment methods to derive
  energy as a byproduct
• Combustion of manure and coal, methane gas
  produced from anaerobic digestion

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Advantages and Disadvantages

• Advantages
• Marketable byproduct
• Use as an alternative fuel
• Used with other manure treatment facilities

• Disadvantages
• Careful management required
• Safety risk

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Constructed Wetland Systems

• Similar to natural wetland systems
• Waste pretreated to reduce organic loads and
  solids content
• Typical wetland systems include surface flow
  systems and subsurface systems.

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Constructed Wetland System
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Constructed Wetland Systems

• Advantages
• Inexpensive
• Low maintenance
• Aesthetically pleasing

• Disadvantages
• Large area requirements
• High monitoring requirements

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State of the Art

• Current technologies being developed include
• Addition of polymers to improve solids separation
  from a liquid stream
• Aerated treatment basins as an alternative to
  anaerobic lagoons
• Artificial floating layers for odor control

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Electrocoagulation

• Destabilization of suspended, dissolved particles
  by passage of electrical current between
  electrodes
• Causes contaminants to form precipitates
• Removed by secondary separation techniques

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Advantages and Disadvantages

• Advantages
• Removes complex organics
• Can process multiple contaminants
• Can destroy harmful bacteria and viruses
• Lesser sludge production

• Disadvantages
• Disposal challenges due to aggregation of
  precipitated solids
• Initial setup expensive and operating costs can
  be high
• Careful, specialized management required