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A

Presentationon

Oxidation Ponds & Lagoons

By

DEEPAK CHHIMPA

DAVINDER SINGH


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Oxidation Ponds

What are Oxidation Ponds ?

Oxidation Ponds are large earthen basins in which waste water

is treated by natural processes involving bacteria and in many

instances algae.


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Types Of Oxidation ponds

Aerobic Ponds

Anaerobic Ponds

Facultative Ponds

Maturation or Tertiary Ponds


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New

Algae

Algae

O2

Bacteria

CO2, NH3, PO4, H2O

NewBacteria

OrganicBacteria

Solar

Energy

Symbiosis


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Aerobic Ponds

The aerobic pond is shallow pond in which light

penetrates to the bottom there by maintaining active

algal photosynthesis through out the entire system.


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ALGAE

AEROBIC BACTERIA

Light Energy from Sun

New Algal

Biomass

New

Bacterial

Biomass

Organics

from

Waste

Water


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Diurnal Variations in Aerobic Ponds

Diurnal variation in DO concentration

Diurnal variation in pH

Extreme values of these, in either direction may be

detrimental to microbial activity.


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Design Considerations

Parameter Value

Depth in mts. 0.15-.5

Retention time (day) 2-6

BODu loading( lb/acre-day) 100-200

BODu removal(%) 80-90

Algae concentration(mg/l) 100-200Re-circulation ratio 0.2-2.0

Effluent suspended solids

concentration(mg/l)

150-350


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Problems

Nuisance vegetation

Inhibitory temperatures

Oxygen retention

Shock loads


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Anaerobic Ponds

These ponds requires no D.O. for microbial activity

as the organisms use O2 from compounds such asNO3, SO4 as their hydrogen acceptors and give end

product such as methane, carbon dioxide etc.


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Acid producing Bacteria

Methane producing

bacteria

H2O, CO2, CH4

Organic Wastes

H2O, CO2

Bacterial

Cells

Bacterial Cells


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Facultative Ponds

These are neither fully aerobic nor fully anaerobic. They are

often about 1 to 2 m in depth and favor algal growth along

with the growth of aerobic, anaerobic and facultativemicroorganisms. Such ponds are predominantly aerobic

during day light as well as for some hours of the light. In the

few remaining hours the pond bottom may turn anaerobic.


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Wind

CO2

Anaerobi

cZone

A

erobic

Anaerobi

cZone

Facultative

Zone

O2

alga

e

(CO2, NO2, PO4, SO4)

Aerobic

Bacteria

Biomass

Biomass

Anaerobic

Bacteria

Sludge Blanket

Organic acids &

Compounds of C, N, P, S

Im ermeable linin

Sunligh

t


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Maturation / Tertiary Ponds

These are similar to aerobic ponds but are very

lightly loaded with organic wastes. Generally

used for upgrading effluents from conventionalsecondary treatment processes. The principal

purpose is to achieve reduction in fecal colliform

count.


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Applications

Type of Ponds Applications

Aerobic Nutrient removal, treatment of soluble

organic waste & effluents from waste water

treatment plants.Anaerobic Treatment of domestic and industrial wastes.

Facultative Treatment of untreated screened waste waterand industrial wastes.


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Outlet of pond

Oxidation pond

Hamirpur REC Campus


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Reasons For Poor Performance of

Oxidation Pond

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

almost zero.

BOD removal efficiency was only 50-58%

BOD loading rate was 91.20 kg/day as compared to the design

BOD of 81kg/day.

Black effluent was found exerting very high BOD values of

80-110mg/l.


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LAGOONS

Lagoons are deep waste stabilization ponds -like

bodies of water or basins designed to receive, hold,

and treat wastewater for a predetermined period of

time by artificial means of aeration. In the lagoon, wastewater is treated through a

combination of physical, biological, and chemical

processes.


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TYPES OF LAGOONS

According to the microbial activity in the aerated

lagoons-

Aerobic aerated lagoons.

Facultative aerated lagoons.


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AEROBIC AERATED LAGOONS

Dissolved oxygen is present throughout much of the

depth of aerobic lagoons.

They tend to be much shallower than other lagoons.

They are better suited for warm, sunny climates,where they are less likely to freeze.

HRT = 2 to 3 days.


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FACULTATIVE AERATED

LAGOONS

Three types of zones are present

Aerobic Zone.

Anaerobic Zone.Facultative Zone.

HRT is higher than aerobic lagoons because

time requires for the solids to settle and formany pathogens viruses to either die off or

settle out.


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Two, Three, or Four Lagoons Are

Better Than One

Each lagoon cell has a different function to perform,

and a different kind of lagoon design may be used for

each cell.

In SeriesWhen lagoons operate in

series, more of the solid

material in the wastewater,

such as algae, has an

opportunity to settle out

before the effluent is

disposed of.

In ParallelThis system design is

particularly useful in

cold climates or where

lagoons are covered

with ice for parts of the

year


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Factors to consider for transfer of

the oxygen

Alpha factor.

Beta factor.

Theta factor. Atmospheric pressure.


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Misleading Parameters

The first myth is that effluent BOD5measures the

biodegradable carbonaceous material in the effluent

The second myth is that the effluent BOD5, or

CBOD5, is the residual of the BOD5 in the influent to

the lagoon.


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Operation And Maintenance

For 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


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Operation And Maintenance

For 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 devicesmay not be required.

Earthen structures used as impoundments must be inspected

for rodent damage.


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Applicability

Type of Lagoon Application

Aerobic Lagoon Municipal and industrial wastewaters of

low to medium strength.

Facultative Lagoon Treated raw, screened, or primary settled

municipal wastewater and biodegradable

industrial wastewaters.


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LimitationsFor 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 Lagoons

The 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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