Logo Module 5: Animal Manure and Process-Generated Wastewater Treatment By Saqib Mukhtar.

Logo

Module 5: Animal Manure and Process-Generated Wastewater Treatment

By Saqib Mukhtar

Certified Nutrient Management Planning 5-2Logo

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.


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


Principles Used in Manure Treatment Gravity settling Mechanical separation Flocculation Aeration Anaerobic processes Natural systems


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


Settling Tank


Settling Basin


Gravity Settling

Advantages Load reduction

for subsequent treatment processes

Reduction of clogging in pumps and pipes

Disadvantages Large size

requirements

High construction and operating costs


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


Mechanical Inclined Screen Separator


Mechanical Press Separator


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


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.


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


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.


Complete Aerating Unit


Floating Aerator Unit


Aeration

Advantages Odor control

Satisfies high oxygen demands

Disadvantages High energy

requirement

Frequent cleaning required due to enhanced sludge accumulation


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


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


Natural Systems Use natural mechanisms to reduce BOD and

suspended soils

Treatment systems include: Constructed wetland systems Vegetative filter strips Overflow plots


Advantages and Disadvantages

Advantages Reduction in

nitrogen levels

Odor reduction

Disadvantages Large area

requirement


Vegetative Filter Strip


Manure Utilization and Treatment Technologies

Land applications Anaerobic lagoons Anaerobic digesters Composting Vermicomposting


Manure Utilization and Treatment Technologies (continued)

Mortality composting By-product recovery Energy conservation Constructed wetland systems


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


Land Application

Advantages Reduction in fertilizer

costs

Better soil quality

Low cost

Disadvantages Odor problems

Large land area required

Nutrient regulations


Anaerobic Lagoons

Waste stabilization through anaerobic biological activity

Used to store large amounts of wastewater

Efficiency depends on lagoon design and climatic conditions


Anaerobic Lagoon


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


Anaerobic Digesters Similar to anaerobic lagoons but smaller in size

Normal operating temperatures between 95°F- 165°F

Methane and carbon dioxide byproducts


Anaerobic Digester


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


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


Aerated Composting Containers


Composting

Advantages Odor control Controls pests,

pathogens, and weed seeds

Increases soil quality Marketable by-

product


required Additional costs Space requirements


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


Vermicomposting

Advantages Reduces lagoon

loading Odor control Nutrient reduction Worms used as

animal and aqua-culture feed


required Space requirements Additional costs


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


Large–Carcass Composting


Mortality Composting

Advantages Disposal of dead

animals Odor control Kills pathogens Marketable byproduct


required Regulatory concerns Initial setup can be

expensive


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


Nursery Crops Raised on Treated Animal Manure


By-product Recovery

Advantages Marketable

byproduct Feed supplements Improve soil quality


required Time and space

constraints


Energy Conservation Use of alternative treatment methods to derive

energy as a byproduct

Combustion of manure and coal, methane gas produced from anaerobic digestion


Advantages and Disadvantages

Advantages Marketable byproduct Use as an alternative

fuel Used with other

manure treatment facilities


required Safety risk


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.


Constructed Wetland System


Constructed Wetland Systems

Advantages Inexpensive Low maintenance Aesthetically pleasing

Disadvantages Large area

requirements High monitoring

requirements


State of the ArtCurrent 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


Electrocoagulation Destabilization of suspended, dissolved particles

by passage of electrical current between electrodes

Causes contaminants to form precipitates

Removed by secondary separation techniques


Advantages and DisadvantagesAdvantages 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

Logo Module 5: Animal Manure and Process-Generated Wastewater Treatment By Saqib Mukhtar.

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