Part 2a Wk 5-6 Water Quality and Quantity EENV 101

8/17/2019 Part 2a Wk 5-6 Water Quality and Quantity EENV 101

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Lecture Presentations onEnvironmental Engineering

Course EENV101

Part 2a Wk 5 (Feb 4- Feb 9) Water:Quality and Quantity

Chapter Seven of TextbookBy Engr. Jessica. M. Castillo

Rev. 3T 2015-16


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Week 5 : Learning ObjectivesDescribe the different components of the hydrologic cycle. (CO2)

Identify the different storage of water. (CO2)

Explain why there is a scarcity of water for human use. (CO2)

Calculate the water footprint. (CO2)

Determine Runoff from changes in Land Use (CO2)

Enumerate the most important surface water quality parameters.

(CO2)

Identify the sources of ground water contamination

Identify the pollutants in ground water

Identify the most common pathogens in wastewater. (CO2)

Describe several methods to remediate soil and groundwater

contamination.

(CO2)

Rev. 3T 2015-16


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Rev. 1T 2013-14

Hydrology is the study of the movement, distribution, and

quality of water on Earth and other planets, including the

hydro log ic cycle, water resources and environmental watershed

sustainability. From WIKIpedia

HYDROLOGY

Rev. 3T 2015-16


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Rev. 1T 2013-14

This picture shows the total volume of water and air (formed

into spheres) on Earth compared to the size of the Earth.http://www.abovetopsecret.com/forum/thread341549/pg1


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HYDROLOGIC CYCLE

Precipitation to Land(rain, snow, hail)

Transpirationfrom plants

Runoff

Surface runoff (rapid)

Evaporation

from land Evaporationfrom ocean Precipitation to

ocean

Ocean storage

Surfacerunoff (rapid)

Groundwater movement (slow)

Clouds Condensation

Transpiration

Evaporation

Precipitation(rain, snow,hail)Precipitation

Infiltration andPercolation Watershed

Water in theSoil

Rev. 3T 2015-16


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Watershed

The surface land area that drains water to rivers and lakes.This area has topographical ridges.

Drainage in the watershed is due to gravity.

Precipitation that falls within a watershed must be drained

somewhere.

Rev. 3T 2015-16

Surface Water

Precipitation that falls to the ground are considered

as fresh water and sea water.Surface run-off ends up in reservoir, rivers, lakes, wetlands,

bays, estuaries and flows out to the oceans


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Rev. 3T 2015-16

Aquifer

The underground soil or rock where the water infiltrates

downward through gravity, until it reaches the watertable.

Groundwater

The water that infiltrates the ground’s surface is referred to asgroundwater. It can come out to the surface through artesian wells,

pumps and springs.


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Rev. 1T 2013-14


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Classification of Water

Rev. 1T 2013-14

Inland Water means an interior body of water or watercourse such as

lake, reservoir, river, stream, creek, etc., that has beneficial usages

other than public water supply or primary contact recreation (eg.

Swimming, water skiing). Tidal affected rivers or streams are considered

inland waters.

Coastal Water" means an open body of water along the country'scoastline starting from the shoreline (MLLW) and extending outward up

to the 200-meter isobath or three-kilometer distance, whichever is

farther.

Protected Water" means a watercourse or a body of water, or any

segment thereof, that is classified as a source of public water supply orprimary contact recreation, or that is designated by competent

government authority as a national park or reserve. (As defined in the

Pollution Control Decree of 1976)

Rev. 3T 2015-16


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HUMAN IMPACTS TO WATER CYCLE

1. Water withdrawal from streams, lakes andgroundwater. (salt water intrusion and groundwater

depletion)

2. Clear vegetation from land for agriculture, mining,

road and building construction. (nonpoint sourcerunoff carrying pollutants and reduced recharge of

groundwater)

3. Degrade water quality by adding nutrients(NO2, NO3,

PO4) and destroying wetlands (natural filters).

4. Degrade water clarity by clearing vegetation and

increasing soil erosion.

Rev. 3T 2015-16


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Sample Problem

Rational Method to determine Runoff from Land Use

Page 305 from textbook


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Rev. 1T 2013-14


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Pollutants/Contaminants in

Water Solid wastes/Particles

Oil and grease

Decayed matter/animals

(Flood water containing too much heavy metals)

Excessive level of natural elements like

Phosphorus and Nitrogen

Chemicals (acids and alkaline)

Hazardous Chemicals like insecticides

Pathogens /Microbes such as E-coli bacteria

Rev. 3T 2015-16


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Surface Water Quality

Degradation

Rev. 3T 2015-16


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Causes of Water contamination

Rev. 3T 2015-16

Domestic Wastes:

Inappropriate Solid Waste management

Poor Sewage System

Agricultural

Poor waste management, Inappropriate practices

Aquaculture:

Inappropriate practices

Air pollution:

Acid rain, cloud seeding

Water Run off from Land use:

Land conversion, mining etc.


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Specific sources/origins:

Domestic waste (48%) – bathing, laundry,sanitation, cleaning, cooking, washing andother kitchen activities

Agricultural runoff (37%) – organic wastessuch as decayed plants, livestock manureand dead animals, pesticides, etc.

Industrial (15%) – may be organic orinorganic depending on the nature of the

industry


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Taal Lake fishkill 2011

http://sanfrancisco.ibtimes.com/articles/154627/20110530/philippine-fishermen-struggle-with-

massive-number-of-dead-fish-photos.htm


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What caused the fishkill?

Fishkills may be caused by:

Oxygen depletion

Toxins, man-made and naturalNatural changes in water

currents that bring about any

one or both of the above


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The Taal Fishkill

Countdown The period of November to April, lake

and air currents are cold which allowsbetter dissolution of oxygen into the

water. During this period, the strong winds

create strong water currents which stirthe lake water and bring down oxygen-

rich surface water to the deeper partsof the lake.Note that Taal lake is around 172 meters at itsdeepest point.


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The Taal Fishkill

Countdown Starting April, the wind velocity slows, currents weaken

and dissolved oxygen (DO) stratifies by depth.

Summer heat kicks in which drastically reduces the

solubility of oxygen at the surface.


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The Taal Fishkill

CountdownOxygen is depleted at the bottom of

the lake due to the heat and lack of

strong water currents.Aquatic organisms and

microorganisms that thrived onuneaten fish feeds and fish waste

during the period of good mixingnow have to contend withinsufficient DO.


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The Taal Fishkill

Countdown The summer heat continues and

further depletes the lakes DO

until the bottom layers cannotsupport fish.

To make matters worse, theanoxic water may create an

opportunity for anaerobicmicrobes to produce toxins suchas hydrogen sulfide.


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The Taal Fishkill

Countdown A strong downpour signifying the start

of the rainy season brings in coldrainwater which is more dense than

the warm lake water causing aninversion.

The inversion brings up warm anoxicwater from the bottom of the lake to

the surface thereby suffocating thefish, and possibly poisoning them thrubiologically-produced toxins producedat the bottom of the lake.


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Taal: The aftermath of a

fishkill Uncollected fish breakup and decay in the water surface

supporting a new population of bacteria supported by

the putrid water.

DO is reduced even further and the fishkill progresses.


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Untreated water and the

BOD/COD ratioCase 1: BOD/COD ratio is close to 0.7, the

water tested is considered very

biodegradable. This is usually the casefor domestic wastewater and food

industry wastewater.

Case 2: BOD/COD ratio is less than 0.3, thewater is considered non-biodegradable.

http://www.allskull.com/wp-content/uploads/2010/08/wateragriculture.jpghttp://www.allskull.com/wp-content/uploads/2010/08/wateragriculture.jpg


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Rev. 1T 2013-14

http://www.allskull.com/wp-content/uploads/2010/08/waterpollution.jpghttp://www.allskull.com/wp-content/uploads/2010/08/waterpollution.jpghttp://www.allskull.com/wp-content/uploads/2010/08/waterpollution.jpghttp://www.allskull.com/wp-content/uploads/2010/08/wateragriculture.jpghttp://www.allskull.com/wp-content/uploads/2010/08/wateragriculture.jpg


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Surface Water Quality

ParametersDO – Dissolved oxygen

BOD – Biochemical oxygen demand

COD – Chemical oxygen demand


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Dissolved Oxygen (DO)

Dissolved oxygen is required to maintain a balanced community of

organisms in lakes, rivers, and ocean.

When levels drop below 4-5 mg O2/L (measured by BOD test)

reproduction by fish and macro invertebrates is impaired.

Biochemical Oxygen Demand (BOD)

The amount of oxygen utilized by microorganisms in oxidizing

carbonaceous and nitrogenous organic matter.

BOD Reflects the amount of oxygen necessary for aerobic bacteria

to digest organic pollutants in water.

Reported in mg oxygen per liter of water (mg O2/L)


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Dissolved Oxygen (DO)

Dissolved oxygen is required to maintain a balanced community of

organisms in lakes, rivers, and ocean.

When levels drop below 4-5 mg O2/L (measured by BOD test)

reproduction by fish and macro invertebrates is impaired.

Biochemical Oxygen Demand (BOD)

The amount of oxygen utilized by microorganisms in oxidizing

carbonaceous and nitrogenous organic matter.

BOD Reflects the amount of oxygen necessary for aerobic bacteria

to digest organic pollutants in water.

Reported in mg oxygen per liter of water (mg O2/L)


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A water sample is allowed to be aerobicallydigested by bacteria, and the difference of

dissolved oxygen concentration before and after

digestion is measured.

Only biologically degradable compounds arereported

The test takes 5 days to complete (for a 5 day

BOD test)

Several dilutions of the unknown wastewater

sample must be done in order to assure that the

analysis is valid.

BOD test


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The COD test is used to measure the content of

organic matter of both wastewater and surface

water using chemical oxidation.

Chemical Oxygen Demand (COD)

Note: COD should not be confused with CBOD (Carbonaceous biochemical demand)


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Ground Water Pollution

SourcesStorage tanks

Septic Systems

Large Industrial facilities

Fertilizer Applications

Spills

Pesticide Applications

Hazardous waste sites

Animal feedlots

Agricultural chemical facilities

Salt water intrusions

Shallow Injection Wells

Unlined landfill

Irrigation practices etc.


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Types of pollutantsPathogens

Inorganic chemicals

Metals

Nitrates

Radionuclides e.g. uranium

Pharmaceutical products Organic chemicals

Fuel products

Solvents

Pesticides herbicides

Saltwater intrusionIt occurs from over pumping of freshwater from

coastal areas.


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Affects fresh, marine andgroundwater resources

also affects the adjacent

terrestrial areas by depositionand accumulation of pollutants

Limits the productivity of

agricultural lands that aredependent on the water supplyfor irrigation

Effects of Water Pollution


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Animal mutationScientific studies have

linked abnormalmutations in marine

creatures, like intersex,

to exposure to chemical

compounds that mimic

or imitate natural

hormones in the body.These chemicals are

called endocrine

disrupters.

Please realize by using non-organic household cleaners, shampoos,toothpaste, soaps, lawn care, etc you are contributing to the

contamination of America’s water ways and our water supply, destroying

ecosystems and causing horrible mutations in our fish and amphibians. Inthe long term, this will effect the health of humans.

Rev. 4T 2013-14Source : http://www.allskull.com/wp-content/uploads/2010/08/waterpollution.jpg

http://en.wikipedia.org/wiki/Endocrine_disruptorhttp://en.wikipedia.org/wiki/Endocrine_disruptorhttp://en.wikipedia.org/wiki/Endocrine_disruptorhttp://en.wikipedia.org/wiki/Endocrine_disruptorhttp://www.google.com.ph/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&uact=8&docid=p6Yrhtkog57XlM&tbnid=bzIRcd-5bfjNAM:&ved=0CAUQjRw&url=http%3A%2F%2Feschooltoday.com%2Fpollution%2Fwater-pollution%2Fwhat-is-water-pollution.html&ei=uPhVU-SpBMa4iQec6oDYDg&bvm=bv.65177938,d.dGc&psig=AFQjCNF_BD-cIDyMzWw0RfpuyOvPN99VMA&ust=1398227483237853http://www.google.com.ph/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&uact=8&docid=p6Yrhtkog57XlM&tbnid=bzIRcd-5bfjNAM:&ved=0CAUQjRw&url=http%3A%2F%2Feschooltoday.com%2Fpollution%2Fwater-pollution%2Fwhat-is-water-pollution.html&ei=uPhVU-SpBMa4iQec6oDYDg&bvm=bv.65177938,d.dGc&psig=AFQjCNF_BD-cIDyMzWw0RfpuyOvPN99VMA&ust=1398227483237853http://en.wikipedia.org/wiki/Endocrine_disruptor


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Water-relatedhealth

costs


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The cost of polluted water

The Philippines Environment Monitor2003, a World Bank publicationreported that: “The annual economic

losses caused by water pollution areestimated at PhP67 billion…”

3 billion for health

17 billion for fisheriesproduction

47 billion for tourism


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pH

A measure of the acidity/basicity of

water/wastewater/effluents.

Must be measured immediately afteracquiring the sample

Glass electrode or by pH paper


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Turbidity is a measure of thedegree to whichthe water loses itstransparency due to thepresence of suspendedparticulates.

The more total suspendedsolids in the water, themurkier it seems and thehigher the turbidity.

Turbidity is considered as agood measure of the qualityof water.NTU: Nephelometric Turbidity Units.

www.lenntech.com/turbidity.htm

Turbidity


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In water quality, solids

are divided into adissolved or suspendedfraction.

This is determined by acombination of filtration

(0.45 micron) andevaporation (103-105deg C) procedures.

TS = TDS + TSS

Total Solids (TS)


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Total Suspended Solids (TSS)

TSS is a measure of the amount of solids

suspended in wastewater. These are

particles greater than 2 microns.The

wastewater sample is passed thru filter

media such glass fiber which retains thesolids. This is dried to remove moisture

and the weight gain of the filter is

recorded in milligrams per liter.


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Color

A highly colored wastewater prevents thetransmission of light thru water effectively

reducing or worse eliminating altogether

the photosynthetic activity beneath the

water surface.

Color is usually measured either by visual

comparison with standard solutions or by

light transmission in a spectrophotometer Measured in PCUs or platinum cobalt units


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Oil and Grease

Oil and grease in wastewater are a concern forboth the recipient water bodies and designers ofwastewater treatment plants.

In waterways, it impedes oxygen transfer into

the water. In biological treatment plants, it creates an

imbalance in the biological fora and results inthe of non-biodegradable compounds

Oil pertains to the liquid portion while greasepertains to the solidified floating mass


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Water Lilies on Pasig River

Rev. 1T 2013-14

High TSS (Ex.Phosphates) may also

enhance the growth of

water plants on the

surface thereby limiting

the amount of sunlight

reaching the other

plant organismsunderneath.


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Oil spill

Rev. 1T 2013-14


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Rev. 1T 2013-14


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Sample wastewater test result:

Test

parameter

Result Units Regulatory

limits*BOD5 12 mg/L 50

COD 58 mg/L 100

TSS 2.1 mg/L 70Color 30 PCU 150

pH 6.6 None 6.5-9.0

Oil andgrease

1.1 mg/L 5

* For Class C inland Water, NPI


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Rev. 1T 2013-14

The maximum amount of dissolved oxygen present in a receiving water

is a function of temperature, atmospheric pressure, elevation, the solids

content of the water, and salinity (Cl).


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Week 6 : Learning ObjectivesIdentify the physical characteristics of untreated water

Identify the various biological water treatment processes used fordomestic wastewater. (CO2)

Discuss briefly the various chemical treatment methods and their

applicability. (CO3, CO4)

Discuss the most common treatment plant designs for domestic and

industrial wastewater. (CO2, CO4}

Discuss important sections of the Clean Water Act of the Philippines

of 2004 (R.A. 9275) (CO3)

Rev. 3T 2015-16


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Rev. 1T 2013-14

Part 2a Wk 6

(Feb 11- Feb 16) Water Treatment

Chapter Eight and Nine of Textbook


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Turbidity

Number and type of particles

Dissolved (TDS) Suspended Color (TSS)

Taste and Odor

Temperature

Physical Characteristics of

Untreated or Raw Water


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Unit processes for Surface

Water and Brackish Water

Rev. 3T 2015-16

Turbidity and Particles:Coagulation/Flocculation, Sedimentation, granular filtration

Major Dissolved Inorganics:

Softening, aeration, membranes

Minor Dissolved Inorganics:

Membranes

Pathogens:

Sedimentation, filtration,disinfection

Major dissolved organics:

Membranes, Adsorption


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Purpose of Natural Water

Treatment

Rev. 1T 2013-14

• Provide potable water that is palatable

Potable water

“ water that is healthy for human consumption,

free from harmful microorganisms and organic

and inorganic compounds, that either adversephysiological effects or do not taste good.”

Palatable

free from turbidity, color, odor, and objectionable taste.

note however that palatable water may not be safe.

DDT (dichlorodiphenyltrichloroethane) is a colorless, crystalline, tasteless andalmost odorless organochloride known for its insecticidal properties.

Bottled water are made potable and palatable.

Natural water is referred to as raw or untreated water.


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Purpose of Waste water biological

treatment

Transform dissolved and particulatebiodegradable constutuents into acceptableend products

Capture and incorporate suspended andnon-settleable solids into a biological flocor biofilm

Transform or remove nutrients such as

nitrogen and phosphorous

In some cases, remove specific tracenutrients and compounds


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Microorganisms in WastewaterTreatment Systems Bacteria: primary and secondary degraders of

organic substances, N and P removal, S cycle

Archaebacteria – can grow in extreme

environment Algae – photosynthetic production of oxygen,

symbiotic relation with bacteria

Protozoa – prey on bacteria, fungi, algae Fungi – degradation of organic matter for

some industrial wastewater

16. Identify the most common pathogens in wastewater.


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Common Disinfection Agents

Rev. 1T 2013-14

• Chloramines

• Free Chlorine

• Ozone

• UV light

Bi l i l W t t T t t


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Biological Wastewater Treatment

Rev. 1T 2013-14

Basic categories of treatment:

Aerobic (with oxygen) may follow some form of pretreatmentsuch as oil removal, involves contacting wastewater with

microbes and oxygen in a reactor to optimize the growth and

efficiency of the biomass. The microorganisms act to

catalyze the oxidation of biodegradable organics and other

contaminants such as ammonia, generating innocuous byproducts such as carbon dioxide, water, and excess

biomass (sludge).

Anaerobic (without oxygen) and anoxic (oxygen deficient)

treatments are similar to aerobic treatment, but usemicroorganisms that do not require the addition of oxygen.

These microorganisms use the compounds other than

oxygen to catalyze the oxidation of biodegradable organics

and other contaminants, result ing in innocuous by-products.

B i S i A bi


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Basic Stages in Aerobic

Treatment System

Rev. 1T 2013-14

1. Pre-treatment or Separation stage removelarge solids and other undesirable substances

from the wastewater

2. Aeration Stage where the aerobic bacteria

digest the biological wastes in the wastewater.(SBR or Sequential Batch Reactor)

3. Settling stage allow any undigested solids to

settle and form into sludge which must be

periodically removed from the system.

4. Disinfecting stage where chlorine or similar

disinfectant is mixed in the water.

Source: Wikipedia

http://www.google.com.ph/url?sa=i&rct=j&q=biological+water+treatment&source=images&cd=&cad=rja&docid=pK50LIJc2wSI2M&tbnid=xn-xqeGt0M5HtM:&ved=0CAUQjRw&url=http%3A%2F%2Fwww.enko.pl%2Fen%2Foffer%2F21%2FBiological-waste-water-treatment-plants.html&ei=9-DLUZjLAc-jiAfagoGABg&bvm=bv.48340889,d.aGc&psig=AFQjCNEt_OofcFQvbiyRCLDTCvbsh0CQUA&ust=1372402250963274http://www.google.com.ph/url?sa=i&rct=j&q=biological+water+treatment&source=images&cd=&cad=rja&docid=pK50LIJc2wSI2M&tbnid=xn-xqeGt0M5HtM:&ved=0CAUQjRw&url=http%3A%2F%2Fwww.enko.pl%2Fen%2Foffer%2F21%2FBiological-waste-water-treatment-plants.html&ei=9-DLUZjLAc-jiAfagoGABg&bvm=bv.48340889,d.aGc&psig=AFQjCNEt_OofcFQvbiyRCLDTCvbsh0CQUA&ust=1372402250963274


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Rev. 1T 2013-14

http://www.enko.pl/en/offer/21/Biological-waste-water-treatment-plants.html

http://www.google.com.ph/url?sa=i&rct=j&q=biological+water+treatment&source=images&cd=&cad=rja&docid=pK50LIJc2wSI2M&tbnid=xn-xqeGt0M5HtM:&ved=0CAUQjRw&url=http%3A%2F%2Fwww.enko.pl%2Fen%2Foffer%2F21%2FBiological-waste-water-treatment-plants.html&ei=9-DLUZjLAc-jiAfagoGABg&bvm=bv.48340889,d.aGc&psig=AFQjCNEt_OofcFQvbiyRCLDTCvbsh0CQUA&ust=1372402250963274http://www.google.com.ph/url?sa=i&rct=j&q=biological+water+treatment&source=images&cd=&cad=rja&docid=pK50LIJc2wSI2M&tbnid=xn-xqeGt0M5HtM:&ved=0CAUQjRw&url=http%3A%2F%2Fwww.enko.pl%2Fen%2Foffer%2F21%2FBiological-waste-water-treatment-plants.html&ei=9-DLUZjLAc-jiAfagoGABg&bvm=bv.48340889,d.aGc&psig=AFQjCNEt_OofcFQvbiyRCLDTCvbsh0CQUA&ust=1372402250963274http://www.google.com.ph/url?sa=i&rct=j&q=biological+water+treatment&source=images&cd=&cad=rja&docid=pK50LIJc2wSI2M&tbnid=xn-xqeGt0M5HtM:&ved=0CAUQjRw&url=http%3A%2F%2Fwww.enko.pl%2Fen%2Foffer%2F21%2FBiological-waste-water-treatment-plants.html&ei=9-DLUZjLAc-jiAfagoGABg&bvm=bv.48340889,d.aGc&psig=AFQjCNEt_OofcFQvbiyRCLDTCvbsh0CQUA&ust=1372402250963274


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Biological waste water

treatment of Sewage

ENKOSYSTEM is an entirelybiological household waste water

treatment system working all year

long with no chemical additives

and little demand for outside

energy. This system can replaceexisting three-chamber septic

tanks and systems that infiltrate

waste water into the soil. System

provides complete possibility of

purified water qualitymeasurement at any seasons.

Rev. 1T 2013-14


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Rev. 1T 2013-14

The Activated – Sludgeprocess is a biological method of waste water treatment

that is performed by a variable and mixed community ofmicroorganisms in an aerobic aquatic environment. These

microorganisms derive energy from carbonaceous organic

matter in aerated wastewater for the production of new

cells in a process known as synthesis, whilesimultaneously releasing energy through the conversion of

this organic matter into compounds that contain lower

energy, such as carbon dioxide and water, in a process

called respiration. This consortium of microorganisms, the

biological component of the process,is known collectively

as activated sludge. The MLVSS is maintained as 2500 –

3000 mg/L.


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Rev. 1T 2013-14

Trickling filter

a bed of crushed rock or other coarse media roughly 2

metres (6 feet) deep and up to 60 metres (200 feet) in

diameter. Settled sewage is sprayed over the bedsurface and is further purified as it trickles downward,

coming in contact with filmy layers of microorganisms

(slime) attached to the media. The microorganisms

absorb the organic matter in the sewage and stabilize

it by aerobic metabolism, thereby removing oxygen-

demanding substances from the sewage. Trickling

filters remove up to 85 percent of organic pollutant

from sewage.

http://www.britannica.com/EBchecked/topic/605008/trickling-filter

Chemical Precipitation

http://www.britannica.com/EBchecked/topic/505970/rockhttp://www.britannica.com/EBchecked/topic/505970/rock


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Chemical Precipitation

Chemical precipitation is the most common method for

removing dissolved metals from wastewater solution

containing toxic metals. To convert the dissolved metals

into solid particle form, a precipitation reagent is added

to the mixture. A chemical reaction, triggered by the

reagent, causes the dissolved metals to form solid particles.

Filtration can then be used to remove the particles fromthe mixture. How well the process works is dependent upon

the kind of metal present, the concentration of the metal,

and the kind of reagent used. In hydroxide precipitation, a

commonly used chemical precipitation process, calcium orsodium hydroxide is used as the reagent to create solid

metal hydroxides. However, it can be difficult to create

hydroxides from dissolved metal particles in wastewater

because many wastewater solutions contain mixed metals.

Chemical Coagulation


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This chemical process involves destabilizing wastewater

particles so that they aggregate during chemical

flocculation. Fine solid particles dispersed in wastewatercarry negative electric surface charges (in their normal stable

state), which prevent them from forming larger groups and

settling. Chemical coagulation destabilizes these particles by

introducing positively charged coagulants that then reducethe negative particles’ charge. Once the charge is reduced,

the particles freely form larger groups. Next, an anionic

flocculant is introduced to the mixture. Because the flocculant

reacts against the positively charged mixture, it either

neutralizes the particle groups or creates bridges betweenthem to bind the particles into larger groups. After larger

particle groups are formed, sedimentation can be used to

remove the particles from the mixture.

Chemical Oxidation and Advanced Oxidation


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Chemical Oxidation and Advanced Oxidation

With the introduction of an oxidizing agent during

chemical oxidation, electrons move from the oxidant to thepollutants in wastewater. The pollutants then undergo

structural modification, becoming less destructive

compounds. Alkaline chlorination uses chlorine as an

oxidant against cyanide. However, alkaline chlorination

as a chemical oxidation process can lead to the creation of

toxic chlorinated compounds, and additional steps may be

required. Advanced oxidation can help remove any organic

compounds that are produced as a byproduct of chemical

oxidation, through processes such as steam stripping, airstripping, or activated carbon adsorption.


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Ion Exchange

When water is too hard, it is difficult to use to clean and oftenleaves a grey residue. (This is why clothing washed in hard

water often retains a dingy tint.) An ion exchange process

can be used to soften the water. Calcium and magnesium are

common ions that lead to water hardness. To soften the

water, positively charged sodium ions are introduced inthe form of dissolved sodium chloride salt, or brine. Hard

calcium and magnesium ions exchange places with sodium

ions, and free sodium ions are simply released in the water.

However, after softening a large amount of water, thesoftening solution may fill with excess calcium and

magnesium ions, requiring the solution be recharged with

sodium ions.


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Chemical Stabilization

This process works in a similar fashion as chemical

oxidation. Sludge is treated with a large amount of a

given oxidant, such as chlorine. The introduction of theoxidant slows down the rate of biological growth within the

sludge, and also helps deodorize the mixture. The water

is then removed from the sludge. Hydrogen peroxide can

also be used as an oxidant, and may be a more cost-effective choice.

Republic Act 9275


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Republic Act 9275Philippine Clean Water Act of 2004

Share in the responsibility in managing a designatedWater Quality Management Area (WQMA) by being

a member of the water Quality Management Area

(WQMA) Governing Board, implementing a WQMA

Action Plan and preparing it's status-report.

Share in the management of non- attainment areas

by implementing contingency plans and othermeasures for the protection of health and welfare of

residents in potentially affected areas.


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Implement National Sewerage and Septage

Management Program by appropriating the

necessary land, including rights-of-way/road

access to the land for the construction of the

sewage and/or septage treatment facility operating

in their area of jurisdiction.

Promote proper domestic sewage collection,

treatment and disposal by giving sanctions to

those who refuse connection of sewage lines toavailable sewerage systems or to employ septage

management system and other sanitation

programs.


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Incorporate Programmatic Environmental Impact Assessment into the preparation, updating or

revision of local land use plans and area

development plans.

Manage and improve water quality within their

territorial jurisdiction by actively participating in all

efforts related to water quality protection and

rehabilitation.


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Homework 4

Discuss the different steps of waste

water treatment used in

MCL’s SEWAGE TREATMENT PLANT


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Rev 1T 2013 14

Part 2a Wk 5-6 Water Quality and Quantity EENV 101

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Transcript of Part 2a Wk 5-6 Water Quality and Quantity EENV 101