assignmentfinal.docx

8/19/2019 assignmentfinal.docx

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Group-D

Section:20

Assignment Title : Pollution of rivers around Dhaka

Submitted b :

! "ahat Perve# !$D: %&2022'()2

! Sinthia Sharin *ho+dhur !$D: %&20,)0()2

! d. /ahad Arafin !$D:%&20,%'0)2

! d. Asadu##aman Sakib !$D: %&2%0&()2

! itu "ani Das !$D:%&%2,1,()2

Submitted to:

$nstructor: Aurchie "ahman 3ecturer

Department of 4iolog 5 *hemistr

Submitted date:22-0,-20%(

!"iver pollution and Dhaka *it


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➢ Ans+ered b "ahat Perve#

!*auses of river pollution

➢ Ans+ered b Sinthia Sharin *ho+dhur

!6ffects of river pollution in Dhaka

➢ Ans+ered b d. /ahad arafin

!7hat should +e do to control river pollution in Dhaka 8

➢ Ans+ered b d. Asadu##aman Sakib

! 9o+ should $ *ontribute to ake the "ivers *lean 8

➢ Ans+ered b itu rani das

##River pollution and Dhaka City

✓ Dhaka, the capital city of Bangladesh has it’s fair share of problems like over

population,traffic jam,load shedding etc.However,the problem of water pollution has

never been contemplated like it has been in recent times,Eperts have epressed their


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concerns over this issue time and again and they are trying their level best to get the

government’s as well as the public’s attention.!he following discussion is to give the

readers a little prospective of this situation.!here are si rivers located around thecapita.Buriganga is the main with !urag canal,balu and "hitalakshya,!hese rivers are

surrounding Dhaka#$ncluding %araynganj city& in a circular path termed as circular water

way.!his path covers a length of almost ''( k.m.Hardly any city in the world has this privilege of having a water way like Dhaka.!his makes this city uni)ue and

phenomenal.Having read this one would imagine this city to be a paradise full of

beauty.$n reality this is about to beome impossible to live in because of it’s rivers chokedwith wastes and the toic air which causes many of the people to be sick.

*round Dhaka, river water has altered from its natural state in terms of physical, chemical

and microbiological composition and lost its suitability for any safe and beneficial use. !he

signs of contamination have become obvious through bad taste, offensive odours, uncheckedgrowth of a)uatic weeds, and decrease in the number of a)uatic animals, floating of oil and

grease, colouration of water and so on. +enerally, rivers surrounding Dhaka are being

polluted by the discharge of untreated industrial effluent, urban wastewater, agrochemicals,sewage water, storm runoff, solid waste dumping, oil spillage, sedimentation and also

encroachment.

ver the last couple of decades major industrialisation has been observed in Dhaka,

especially in dyeing, washing and tetiles sectors. Estimation reveals that there are over -,((( industries in Dhaka metropolitan area located mostly in three clusters, namely,

Haaribagh, !ejgaon, and Dhaka/ %arayanganj/ Demra dam area. However, among all these

the dyeing factories and tanneries are the main polluters of the rivers. 0aste from theseindustries is usually connected to the sewerage system that directly follows to the rivers

around the city. *s a matter of fact, the rivers have become a dumping ground of all kinds of

solid, li)uid and other chemical waste.Dhaka city has been growing without much of plan and the city lacks systematic waste

management system as well. Dhaka generates around (.1 to (.- kilograms of solid waste per

capita per day but the Dhaka 2ity 2orporation #D22&, the main agency responsible for


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collection, transportation and disposal of the waste cannot manage the task properly with its

eisting limited logistics. !he per capita waste collected in Dhaka per day is (.3 kilograms.

!he waste which is not managed by the D22 is dumped into the rivers by the people livingnear the river banks.

!he rivers, which perform the task of natural drainage for the city are also being polluted as

rain water sweeps into them all the waste dumped here and there of the city. 4urthermore,li)uid waste produced in the city is being poured in the rivers untreated. f the discharged

untreated li)uid waste, 5' percent is industrial and 67 percent domestic. However, the lone

"ewerage !reatment 8lant #"08& situated in 8agla of %arayanganj can treat only '( percentof the industrial waste. 9oreover, Dhaka 0*"* utilies the eisting canals and sewerage

pipes to collect waste water from different residential areas and depose, most of it, into

surrounding rivers without any treatment. *part from domestic and industrial waste, oil and

other chemicals which are spilled into the rivers from launches, steamers, and trawlers arealso polluting river water. Besides in Dhaka contamination of water is occurring from human

ecreta as well, as -( percent of the population of the city does not have access to improved

sanitation facilities.

Encroachment on rivers is a common practice in Bangladesh. 9ost of the natural drainagesof Dhaka 2ity disappeared or are in way to due to illegal encroachment. Encroachment on

the rivers through unauthoried construction and dumping of solid waste in clearence of regulations to prevent encroachment making it difficult to drain out the runoff and the

pollutants i.e., added particles remaining in the rivers keep polluting the environment.

8olluted water of Buriganga, !urag, Dhaleshwari, Balu, and %arai flowing around the greater Dhaka city is posing serious threats to public life as it is unfit for human use #$nstitute for

Environment and Development "tudies, 3((6&. 8eople living near the rivers, having no other

alternative, are forced to use polluted river water. "ome also use the water because they are

unaware of the health risks. !his causes spread of water borne and skin diseases. "olid wasteand different effluents dumped into the rivers make it difficult for fishes and other sub/

a)uatic organisms to live. 0hen solid waste and effluents run into the river, the Biological

ygen Demand #BD& in the water rises, creating oygen crisis for the sub a)ueous life. *sthe dissolved oygen #D& content of the river water is decreased below the critical level of

four milligrams per liter it is posing threats to bio/diversity in and around the rivers.

8ollution is so severe in the Buriganga, "hitalakhya and Balu rivers that it is almostimpossible to treat the water for making it suitable for human use. !he 0ater and "ewerage

*uthority #0*"*& is supplying stinky water purified by chlorine and ammonia sulfate.

9oreover, due to river encroachment and dumping of solid waste into the rivers the rivers are

loosing their natural flow. !hus, the waterways are shrinking and the alternative way of communication around Dhaka city through rivers turned unsuccessful.

!ame : "ahat Perve#


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!$D : %&2022'()2

##Causes of river pollution

✓ !here is no sign of river pollution being stopped. $t is increasing day by day.

!here are several sources of water pollution, which work together to reduce overall

river water )uality. $ndustries discharge their li)uid waste products into rivers. ur

agriculture practice that uses chemical fertiliers and pesticides also contribute to river

pollution as rainwater drains these chemicals into the rivers. Domestic wastes that we

throw into rivers adds to pollution levels. *s population grows, the sie of towns and

cities also grows. 0ith that the amount of domestic wastes that we throw into river

increases. $n most of the towns and cities, the municipal drains carry our wastes to rivers.

!here are eamples of rivers catching fire because of high pollution levels. !his shows

how seriously polluted our rivers are. $n our everyday life we can easily see symptoms of

river pollution.


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!he floating dead fishes in our river, any coloured water in the river, or a bad smell from

the river point towards river pollution. $f you see or feel any of these things in a

river be sure that the river is a victim of pollution. :iver pollution can be due to the

causes below;

!acid rain::ain falling through polluted air absorbs some of the pollutants. 8olluted air contains

many poisonous gases such as sulphur di/oide #"3&, oide of nitrogen #%&

etc. that react with rainwater to form acids. 0e call this acid rain. n reaching the ground

the acidic rain water has many effects. $t can release harmful substances such as

aluminium and heavy metals from the soil.!hese are normally present chemicals or li)uid manure enter rivers, the amount of oygen in the water reduces. 0ithout

sufficient oygen no life form can survive in a water body. $t also permanently changes

the nature of river.

!;il Pollution:2areless people can also pollute rivers and harm wildlife by pouring things like used car

oil and paint into drains. $f oil enters a slow/moving river it forms a rainbow/coloured

film over the entire surface preventing oygen from entering the water. *s mentioned

above, without oygen the river is biologically dead.

! $ndustrial pollution:


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illegally dumping chemicals at places where they think they will not be caught. !hese

dumped wastes then runs off into river alongwith rain water.

! ;ther sources of pollution:

=8hosphorus from household waste water and sewage is another powerful pollutant. $tcomes from detergents and stays in rivers for a long time where it takes up

valuable oygen. nly few sewage systems are e)uipped to remove phosphates.

=Disposal of solid waste, plastic bags and flower garlands into rivers. 8eople defecating

in open and near rivers contribute to river pollution.

=*nimals washing and wallowing in the river

=!he practice of dumping human remains in the river also poses health threats because of

the unsustainable rate at which partially burned bodies are dumped. !he dumped dead

bodies of people suffering from certain infectious diseases spread pollution and

epidemics.$n an inert and harmless state, but acidic conditions result into many

compounds poisonous to plant and animal life. 0hen washed into rivers, lakes and

streams they can kill small water creatures and fish.

!ame: Sinthia Sharin *ho+dhur

!$D: %&20,)0()2

##Effects of river pollution in Dhaka

✓ !here is little flow of water in the rivers around the Dhaka,!hey are filled human

and industrial wastes.>arious kinds of virus and bacteria are mied in the water that cancause deadly diseases."ounds surprising,but some of the rivers are in worse condition

than the sewerage lines.!he flowing water in sewerage lines helps wash out most

f the wastes before they start to decay.!his is not the case in rivers."pecially,the rivers

!urag,Buriganga,!ongi canal and balu do not flow in dry season.*s a result,these riversact a septic tank containing the wastes that are piling up every day.!hese wastes

decomposed in the river water are making the surrounding environment polluted and also

filling the river bed with full of sludge.!he water in these rivers cannot be used for washing,bathing,drinking and various purposes.%ot even animanls can drink the water.

!he amount of oygen is decreasing in the river water making it hard for the a)uatic

animals and fishes to live in the water.*t ( centigrade the amount of oygen in sweet

water is '1.53 mg?l,at 6(( it is -.56 mg?l.But in the four rivers mentioned before,theamount of oygen was found almost (m.g. at various points during 9arch to 9ay.0ater

is taken from Buriganga and "hitalakshya and delivered to the city dwellers of

chadnighat and demra by 0*"*.But the amount of dissolved oygen and

BD#Biological ygen Demand& in the water should be at a rate that is good enough to


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treat this water conventionally and make it ready for supply.$n dry season the amount of

oygen is too less and the amount of BD is too high than the necessary rate in these two

rivers.!his makes the water nothing but poison which is nearly impossible to be used for supply.*stonishingly,the water is being delivered to the citiens of Dhaka every day.

**(polluted water of rivers)**

!a


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!$D: %&20,%'0)2

!!7hat should +e do to control river pollution in =

Dhaka 8

✓ *ccording to eperts, the population of Dhaka in '77( was 5 million and the

BD load of the rivers were '3' mega tons per day. !he projected population and BD

load of Dhaka in 3('( is '3.5 million and 6(A mega tons per day. But during this time thecapacity of the 0*"*’s water treatment plant situated in pagla, %aryanganj has not been

increased much. *s a result of the damage of the sewerage lines in different places, thetreatment plant at pagla receives only one/third of its 2apacity in dry season. !he projected population of Dhaka in 3(3A is around 3( million and the projected BD load

is 11 mega tons per day. nly a small amount of this huge load can be treated at pagla’s

water treatment plant. :est of almost 1-( mega tons will be spread around the rivers of

Dhaka. !his very much sums up the enormity of this terrible situation.

Eperts have suggested two possible ways to get out of this problem. 4irstly, to create a

number of small water treatment plants spreading around the city. !he "aidabad water

treatment plant produces 33.A million liters of water per day which covers only ' ofthe total demand. :est ( percent of the drinking water supply comes from

ground water. +overnment has plans to increase it’s capacity by another 33.A million literswhich will then cover around 6( of the total demand.


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#"indabad 0ater !reatment 8lant in Dhalpur&

"econdly, there is a proposal of cutting a '5(k.m. canal which will connect the Camuna

:iver to the other rivers to increase the flow of these polluted rivers. !hese two projects

can be accomplished technologically. But economically and socially these are veryepensive and etremely difficult to overcome. *n easier alternative is to transport the

unrefined waste water of pagla’s water treatment plant to 8adma or 9eghna. $t is also

technologically easier.

0ith these there are many ways we can protect the river from pollution. "ome

immediate ways to control pollution are;

▪ $ndustries should install machineries to remove con/

taminants from their effluents and wastewater. ne way

to do so is installation of Effluent !reatment 8lant #E!8&.!his way we can control pollution at the source itself.

▪ !he towns and cities should also have facilities to clean

the sewage effluent. *ll towns and cities must have

"ewage !reatment 8lants #"!8s& that clean up thesewage.

▪ 4armers should give up chemicals and pesticides in

farming and should instead adopt organic methods of

farming thus reducing chemical pollution of rivers.

▪ 8roper drainage and sewage systems should be adopted


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that will not allow the polluted water to mi with river

water.

Hopefully the +overnment will weigh in all of its options and work together with the people to once again make Dhaka city free from pollution and to create a safe water

supply system for the citiens.

!ame: d. Asadu##aman Sakib

!$D: %&2%0&()2

!! 9o+ should $ *ontribute to ake

the "ivers *lean 8

✓ *s pointed out above, it is our duty to protect our environment. *n individual

effort may not be sufficient to clean our rivers, but when all of us contribute towards this

goal it becomes a big effort. !hus it can help in cleaning up our rivers. !here are many

ways you can contribute towards a clean river in your locality;

!At 9ome:

● %ever dump used motor oil, paint or household chemicals on the ground or in a

storm drain.

● DonFt pour household chemicals down the sink or flush them down the toilet.

● Gse non/toic alternatives to home cleaning chemicals.

● DonFt buy more of a household cleaner or other chemical than you need for the

job.

●

:ead and follow directions on the use of household chemicals and disposal of containers.

● "weep driveways and patios clean instead hosing them down.

● 2heck for leaky faucets and turn off the water when brushing teeth to conserve

water.

● 8re/cycle. Buy products with less packaging and keep your recycling and refuse

bucket lids closed.


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● 8ick up pet waste and put it in the garbage can or flush it down the toilet.

● !alking to our family and friends for spreading aware/● ness on the importance of good water )uality and clean

● rivers

●

!$n >ard:

● 8reserve established trees in my yard and neighborhood.

● DonFt overuse fertiliers and pesticides.

● 8lant trees, shrubs and ground covers that filter pollutants and reduce stormwater

runoff.

● $ donFt cut my grass too short. *djust my lawnmower to the proper height to

reduce runoff from lawns, and evaporation before infiltration.● 8lant native vegetation and choose plants that re)uire little or no fertilier.

● 0hen i water my plants and lawn, make sure water doesnFt wash over streets and

sidewalks.

● :ecycle yard debris, or use it to make compost, instead of raking it into streets

where it can wash into storm sewers.

● Gse compost or mulch to hold moisture in the soil and control weeds.

! *ar:

● $ drive my car less to reduce automotive fluid leaks on roadways.

● +ot drips$ Gse kitty litter or other absorbent material to pick up drips before rain

washes them into the storm drain and river.

● :ecycle used motor oil at appropriate business locations for haardous waste pick

ups.

● 0hen $ wash my car, park it on the grass instead of on the street or driveway.

! 4oat:

●

DonFt dump trash or sewage from my boat.● 0atch for fuel spills when i fill my tank.

● Gse soap without phosphate to wash my boat.

● Gse steel sinkers or washers instead of lead sinkers when i go fishing.

● 2lean, Drain, and DryI don’t be a transporter of invasive a)uatic species .


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!ame: itu rani das

!$D: %&%2,1,()2

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assignmentfinal.docx