A A Presentation Presentation

onon Oxidation Ponds & Oxidation Ponds &

LagoonsLagoons

Oxidation PondsOxidation Ponds

What are Oxidation Ponds ?What are Oxidation Ponds ?

Oxidation Ponds are large earthen basins in which waste waterOxidation Ponds are large earthen basins in which waste water

is treated by natural processes involving bacteria and in manyis treated by natural processes involving bacteria and in many

instances algae.instances algae.

Types Of Oxidation Types Of Oxidation pondsponds

Aerobic PondsAerobic Ponds

Anaerobic PondsAnaerobic Ponds

Facultative PondsFacultative Ponds

Maturation or Tertiary PondsMaturation or Tertiary Ponds

New Algae

Algae

O2

Bacteria

CO2, NH3, PO4, H2O

New Bacteria

Organic Bacteria

Solar Energy

Symbiosis

Aerobic PondsAerobic Ponds

The aerobic pond is shallow pond in which light The aerobic pond is shallow pond in which light penetrates to the bottom there by maintaining activepenetrates to the bottom there by maintaining active

algal photosynthesis through out the entire system.algal photosynthesis through out the entire system.

ALGAE

AEROBIC BACTERIA

Light Energy from Sun

New Algal Biomass

New Bacterial Biomass

Organics from Waste Water

Diurnal Variations in Aerobic Ponds

Diurnal variation in DO concentrationDiurnal variation in DO concentration

Diurnal variation in pHDiurnal variation in pH

Extreme values of these, in either direction may beExtreme values of these, in either direction may be

detrimental to microbial activity.detrimental to microbial activity.

Design ConsiderationsParameterParameter ValueValue

Depth in mts.Depth in mts. 0.15-.5 0.15-.5

Retention time (day)Retention time (day) 2-62-6

BODBODu u loading( lb/acre-day)loading( lb/acre-day) 100-200100-200

BODBODuu removal(%) removal(%) 80-9080-90

Algae concentration(mg/l)Algae concentration(mg/l) 100-200100-200

Re-circulation ratioRe-circulation ratio 0.2-2.00.2-2.0

Effluent suspended solids Effluent suspended solids concentration(mg/l)concentration(mg/l)

150-350150-350

ProblemsProblemsNuisance vegetationNuisance vegetation

Inhibitory temperaturesInhibitory temperatures

Oxygen retentionOxygen retention

Shock loadsShock loads

Anaerobic PondsAnaerobic Ponds

These ponds requires no D.O. for microbial activity These ponds requires no D.O. for microbial activity as the organisms use Oas the organisms use O2 2 from compounds such as from compounds such as

NONO33, SO, SO44 as their hydrogen acceptors and give end as their hydrogen acceptors and give end

product such as methane, carbon dioxide etc.product such as methane, carbon dioxide etc.

Acid producing Bacteria

Methane producing bacteria

H2O, CO2, CH4

Organic Wastes

H2O, CO2

Bacterial Cells

Bacterial Cells

Facultative PondsFacultative Ponds

These are neither fully aerobic nor fully anaerobic. They are These are neither fully aerobic nor fully anaerobic. They are often about 1 to 2 m in depth and favor algal growth along often about 1 to 2 m in depth and favor algal growth along with the growth of aerobic, anaerobic and facultative with the growth of aerobic, anaerobic and facultative microorganisms. Such ponds are predominantly aerobic microorganisms. Such ponds are predominantly aerobic during day light as well as for some hours of the light. In the during day light as well as for some hours of the light. In the few remaining hours the pond bottom may turn anaerobic.few remaining hours the pond bottom may turn anaerobic.

Wind

CO2

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An

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Fac

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O2

algae

(CO2, NO2, PO4, SO4)

Aerobic Bacteria

Biomass

Biomass

Anaerobic Bacteria

Sludge Blanket

Organic acids & Compounds of C, N, P, S

Impermeable lining

Sunlight

Maturation / Tertiary Maturation / Tertiary PondsPonds

These are similar to aerobic ponds but are very These are similar to aerobic ponds but are very lightly loaded with organic wastes. Generally lightly loaded with organic wastes. Generally used for upgrading effluents from conventional used for upgrading effluents from conventional secondary treatment processes. The principal secondary treatment processes. The principal purpose is to achieve reduction in fecal colliform purpose is to achieve reduction in fecal colliform count.count.

ApplicationsApplicationsType of PondsType of Ponds ApplicationsApplications

AerobicAerobic Nutrient removal, treatment of soluble Nutrient removal, treatment of soluble organic waste & effluents from waste water organic waste & effluents from waste water treatment plants.treatment plants.

Anaerobic Anaerobic Treatment of domestic and industrial wastes.Treatment of domestic and industrial wastes.

Facultative Facultative Treatment of untreated screened waste water Treatment of untreated screened waste water and industrial wastes.and industrial wastes.

Outlet of pond

Oxidation pond

Salashi Nalla

Hamirpur REC Campus

Reasons For Poor Reasons For Poor Performance of Oxidation Performance of Oxidation

PondPond

DO level in the pond during night & early morning hours was DO level in the pond during night & early morning hours was almost zero.almost zero.

BOD removal efficiency was only 50-58%BOD removal efficiency was only 50-58% BOD loading rate was 91.20 kg/day as compared to the design BOD loading rate was 91.20 kg/day as compared to the design

BOD of 81kg/day.BOD of 81kg/day. Black effluent was found exerting very high BOD values of Black effluent was found exerting very high BOD values of

80-110mg/l80-110mg/l..

LAGOONSLAGOONSLAGOONSLAGOONS

Lagoons are deep waste stabilization ponds -like Lagoons are deep waste stabilization ponds -like bodies of water or basins designed to receive, hold, bodies of water or basins designed to receive, hold, and treat wastewater for a predetermined period of and treat wastewater for a predetermined period of time by artificial means of aeration. time by artificial means of aeration.

In the lagoon, wastewater is treated through a In the lagoon, wastewater is treated through a combination of physical, biological, and chemical combination of physical, biological, and chemical processes. processes.

TYPES OF LAGOONSTYPES OF LAGOONSTYPES OF LAGOONSTYPES OF LAGOONS

According to the microbial activity in the aerated According to the microbial activity in the aerated lagoons-lagoons-

Aerobic aerated lagoons.Aerobic aerated lagoons.

Facultative aerated lagoons.Facultative aerated lagoons.

AEROBIC AERATED LAGOONSAEROBIC AERATED LAGOONSAEROBIC AERATED LAGOONSAEROBIC AERATED LAGOONS

Dissolved oxygen is present throughout much of the Dissolved oxygen is present throughout much of the depth of aerobic lagoons. depth of aerobic lagoons.

They tend to be much shallower than other lagoons.They tend to be much shallower than other lagoons. They are better suited for warm, sunny climates, They are better suited for warm, sunny climates,

where they are less likely to freeze. where they are less likely to freeze. HRT = 2 to 3 days.HRT = 2 to 3 days.

FACULTATIVE AERATED FACULTATIVE AERATED LAGOONSLAGOONS

FACULTATIVE AERATED FACULTATIVE AERATED LAGOONSLAGOONS

Three types of zones are presentThree types of zones are present

Aerobic Zone.Aerobic Zone.

Anaerobic Zone.Anaerobic Zone.

Facultative Zone.Facultative Zone. HRT is higher than aerobic lagoons because HRT is higher than aerobic lagoons because

time requires for the solids to settle and for time requires for the solids to settle and for many pathogens viruses to either die off or many pathogens viruses to either die off or settle out.settle out.

Two, Three, or Four Lagoons Are Two, Three, or Four Lagoons Are Better Than OneBetter Than One

Two, Three, or Four Lagoons Are Two, Three, or Four Lagoons Are Better Than OneBetter Than One

Each lagoon cell has a different function to perform, Each lagoon cell has a different function to perform, and a different kind of lagoon design may be used for and a different kind of lagoon design may be used for each cell.each cell.

In SeriesIn SeriesWhen lagoons operate in When lagoons operate in series, more of the solid series, more of the solid material in the wastewater, material in the wastewater, such as algae, has an such as algae, has an opportunity to settle out opportunity to settle out before the effluent is before the effluent is disposed of.disposed of.

In ParallelIn ParallelThis system design is This system design is particularly useful in particularly useful in cold climates or where cold climates or where lagoons are covered lagoons are covered with ice for parts of the with ice for parts of the yearyear

Factors to consider for transfer of Factors to consider for transfer of the oxygenthe oxygen

Alpha factor.Alpha factor. Beta factor.Beta factor. Theta factor.Theta factor. Atmospheric pressure.Atmospheric pressure.

Misleading ParametersMisleading Parameters

The first myth is that effluent BOD5The first myth is that effluent BOD5 measures the measures the biodegradable carbonaceous material in the effluent biodegradable carbonaceous material in the effluent

The second myth is that the effluent BOD5, or The second myth is that the effluent BOD5, or CBOD5, is the residual of the BOD5 in the influent to CBOD5, is the residual of the BOD5 in the influent to the lagoon. the lagoon.

Operation And MaintenanceOperation And MaintenanceOperation And MaintenanceOperation And MaintenanceFor Aerobic Lagoons

Any earthen structures used as impoundments must be periodically inspected. If left unchecked, rodent damage can cause severe weakening of lagoon embankments.

In submerged diffused aeration, the routine application of HCl gas in the system is used to dissolve accumulated material on the diffuser units

The use of submerged perforated tubing for diffused aeration requires maintenance and cleaning on a routine basis to maintain design aeration rates

Operation And MaintenanceOperation And MaintenanceFor Facultative Lagoons

Most facultative lagoons are designed to operate by gravity flow. The system is not maintenance intensive and power costs are minimal because pumps and other electrically operated devices may not be required.

Earthen structures used as impoundments must be inspected for rodent damage.

ApplicabilityApplicabilityApplicabilityApplicability

Type of LagoonType of Lagoon ApplicationApplication

Aerobic LagoonAerobic Lagoon Municipal and industrial wastewaters of Municipal and industrial wastewaters of low to medium strength.low to medium strength.

Facultative LagoonFacultative Lagoon Treated raw, screened, or primary settled Treated raw, screened, or primary settled municipal wastewater and biodegradable municipal wastewater and biodegradable industrial wastewaters.industrial wastewaters.

LimitationsLimitationsFor Aerated Lagoons

Aerated lagoons may experience ice formation on the water surface during cold weather periods

Reduced rates of biological activity also occur during cold weatherFormation of ice on Floating Aerators.

For facultative LagoonsThe inability of the process to meet a 30 mg/L limit for TSS

due to the presence of algae in the effluent.

Odors may be a problem in the spring and fall during periods of excessive algal blooms and unfavorable weather conditions

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