Kasur tanneries waste management agency (ktwma)
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Transcript of Kasur tanneries waste management agency (ktwma)
Institute of Environmental Engineering & Research,
University of Engineering & Technology Lahore.
Introduction to Kasur Tanneries
Waste Management Agency
(KTWMA)
Report Prepared by:
Muhammad Imran Nawaz
Cell No: +92-333-7320747
Email ID: [email protected]
Discipline: Environmental Engineering
Institute: Institute of Environmental Engineering and Research,
University: University of Engineering & Technology Lahore, Pakistan
Submitted to:
Mr. Muhammad Younis Zahid (Deputy District Officer EPD)
Environment Protection Department Lahore, Punjab
1 Introduction to KTWMA
Abstract
This report contains a brief introduction about the city Kasur, about the tanneries, tanning
Pakistan its background and its environmental impacts and the issues created by tanning and a
complete description and Introduction to Kasur Tanneries Waste Management Agency
(KTWMA), its complete processes occurring within it and their details and at the end it also
contains a critical analysis about the effluent treatment plant (ETP) including its demerits and
deficiencies. This report is the result of our visit to the KTWMA during our internship at EPD
(Environment Protection Department) on 26/07/2011 in which we visited whole the plant and
collected information and data from there. At the end I would like to thank Sir Mr. Muhammad
Younis Zahid (Deputy District Officer EPD) for his great love, kind affection, a lot of
cooperation and guidance from all aspects, which lead us to make this report.
2 Introduction to KTWMA
Table of Content:
1. Introduction 4
1.1 The city of Kasur 4
1.2 Industries in Kasur 4
1.3 Tanning in Pakistan 5
1.4 The Environmental Challenge 5
1.5 The Issue 6
1.6 Background 6
2. ETP (Effluent Treatment Plant) Description 7
2.1 Location 7
2.2 Plant Description 7
2.3 Influent Wastewater 7
2.4 Flow measurement on site 7
2.5 Flow control valves 8
3. Bar Screening 9
3.1 Manual Bar Screening 9
3.2 Mechanical Bar Screening 9
4. Aeration Tanks 10
4.1 Tanks description 10
4.2 Distribution of wastewater to the aeration Tanks 11
4.3 Aerators 11
5. Clarifiers 12
5.1 Working of Clarifiers 13
5.2 Pumping System 13
5.3 Distribution channels 14
6. Lagoons 15
6.1 Wastewater Lagoons 15
6.2 Sludge handling lagoons 16
6.3 Waste material dumping site 16
7. Critical analysis 17
3 Introduction to KTWMA
Introduction
The city of Kasur:
Kasur is one of the districts in the province of Punjab, Pakistan It came into existence on 1 July
1976. Kasur city is located at around 55 km from Lahore. Earlier it was part of Lahore
District.The district capital is Kasur city, the birth city of the Sufi poet Bulleh Shah, well known
in that region as well as in the whole of Pakistan. The total area of the district is 3,995 square
kilometres.Kasur is located adjacent to the border of Gunda Singh Wala between Pakistan and
the India, and is a tourist attraction because of the daily occurring Flags lowering ceremony.
Kasur district is surrounded at north by Lahore, at east and south by India, at southern west
Depalpur tehsil of Okara district and at northern west Sheikhupura district. At east-southern
border it is circled by the Sutlej River and at west-northern border of district the river Ravi
flows.The famous man made forest Changa Manga is located at western direction of the city
Kasur about 30 miles away.
Kasur is known for its foods and dishes, e.g. a spicy fried fish, sweet dishes like Andrassay,
Falooda and vegetable (both as fresh and dried) Kasuri Methi.The area is birthplace of many
popular figures e.g. Noor Jehan, the Pakistani singer and actress who gained popularity in the
1950s. The city is also the resting place of Sufi poet Abdullah Shah (Bulleh Shah).
There are different traditions about the name of Kasur.One is that the town was founded by
Kassu the son of King Ram and named after him as Kasur Pur. (One of Kassu's brothers was
Laaho and the City of Lahore was named after him.) According to another tradition the town was
founded by Pashtun families from Kabul (today the capital of Afghanistan) during the period of
Mughal emperor Akbar. The Pashtuns constructed 12 small forts (called as "Qasar" in Persian)
so the city was later on named as Qasoor i.e. city of many Qasar (Forts). There are twelve known
Qasars (Kot-urdu/Punjabi word of Qasar) named after the heads of various families.
Industries in Kasur
Kasur is famous for raw leather produce which is sent within country and exported for further
cutting, polishing etc. Hand looms, which arenow replaced by machine looms, have been another
big industry of kasur. Shoe making industry for sale within and outside the country has also
flourished in last two decades and is a major cause of economic well being of lower class of area.
Chemical production is also a good business in the city. Whereas many textile, food, iron, light
machinery industries are located within the district. Kites and strings manufacturing has been a
business of the poor prior the ban on kite flying and use of chemical/steel string some years ago.
A very famous paper mill, Packages Ltd. has also erected its new mill in vicinity of the main
city. Some sugar mills are also located in Chunian and pattoki tehsils. Kasur is also well-
knowned as the city of foods, there are so many foods industries are working with the best
quality like: Kasuri Methi, Rice, Corn, Potatoes and many other vegetable & fruits products.
4 Introduction to KTWMA
Tanning in Pakistan
Leather refers to animal skin that has been fully tanned. Tanning is a process that chemically
alters animal skins, making them supple, strong and resistant to rotting. The leather and leather
products sector now represents one of the most important industrial sectors in Pakistan,
significantly contributing to the national economy. There are around 600 tanneries located
mainly on the eastern fringes of Pakistan and it is estimated that over one million people,
including small-scale enterprises, depend on this sector for their livelihood. Yet concerns over
the expansion of the leather sector have resulted in considerable pressures on the environment
and pollution that affects the local people.
Tanning is an integral part of the process of converting raw hides and skins into finished leather.
Tanning is a complicated and laborious process which can involve over 130 different chemicals,
depending on the type of raw material used and the finished product. In Pakistan, animal skins
are obtained from the provinces of the Punjab and Sindh, with limited quantities of imported
hides also used. The season of peak activity lasts for two to three months, during which time
production levels can reach twice the normal level.
The chrome (also known as chromium) tanning method is the most widely used process in
Pakistan's leather sector. However, the vegetable tanning method, considered to be more
environmentally friendly, and a combination of chrome and vegetable tanning are also used. The
process includes a number of steps during which large quantities of water and chemicals are
applied to the skins. These steps can be divided into four major classes: pertaining chemicals,
tanning chemicals, wet finishing chemicals and finishing chemicals. Groundwater is used as the
major source of water.
The Environmental Challenge
The uncontrolled discharge of untreated effluent from tanneries is a growing problem in
Pakistan's leather industry. With exports of tanned leather increasing as a consequence of more
stringent environmental controls curtailing the process in Western countries, severe
environmental degradation is occurring as untreated effluent is released into nearby water
reservoirs and the sea. With scarce land resources, pollution also affects large numbers of people
who live close to the tanneries. The effluent contaminates the sea as well as the inland water
supply, and pollution of the water supply in turn affects the food supply for the population.
Moreover, much of the country is subjected to the air pollution caused by burning tannery
residuals into the atmosphere. All these forms of pollution have detrimental effects on the health
of the Pakistan population.
Leather tanneries in Pakistan produce three categories of waste: wastewater, solid waste and air
emissions, of which wastewater is by far the most important environmental challenge.
5 Introduction to KTWMA
The Issue
The leather sector in Pakistan is one of the largest foreign exchange earned generating some Rs.
13,000 million in FY 95/96. The tanning industry is concentrated in korangi (near Karachi),
Kasur, Lahore, Sahiwal, Multan, Gujranwala and Sialkoat. The town of Kasur is located 55
kilometers southeast of Lahore near the India border in the province of Punjab and has become
well known for the pollution problems caused by the discharge of large volumes of untreated
tannery waste. In Kasur the tannery industry is mainly responsible for bread and butter for the
major portion of the local population which is now estimated to about 0.3 millions. Originally
there were about 180 tanneries; the figure has now gone up to over 300.
As a result of tanning activities about 9,000 cubic meter of heavily pollution waste water is being
discharged besides dumping of about 150 tons solid tannery waste here and there on daily basis.
The outcome was stagnant pools covering an area of 327 acres on the permanent basis with about
311 acres of fertile land affected during the monsoon period. This resulted in overall degradation
of the environment of the area posing serious threat to human health being directly exposed to
unhygienic conditions, drinking contaminated ground water and indirectly through the effects of
the chemically polluted water on growth of crops, yield output from the animals and their health.
The environmental conditions in Kasur hence were detrimental to the health and well being of
the inhabitants, the tanneries workers, and the formers. Considering the importance of the
environmental and health hazards and the occupational health and safety problems in Kasur,
UNDP initiated the Kasur Tanneries Pollution Control Project in collaboration with the
Government of Pakistan, Government of Punjab and the operators of tanneries.
Background of KTWMA:
The government of Pakistan and United Nations Development Program (UNDP) signed the
Kasur Tannery Pollution Control Project document in January 1996 with the United Nations
Industrial Development Organization (UNIDO) being the implementing agency for technical
assistance. UNDP allocated US$ 2.5 million, whereas the local input was Rs. 199 million. The
Project intended to contain and reduce the environmental degradation caused by tannery waste;
to improve the tanner’s technical and managerial skills; to promote environmental awareness
among the pollution, thus improving their overall living, working conditions and creating an
environmentally sustainable tanning industry in Kasur. The project was conceived to deal with
stagnant polls evacuation, providing effluent drainage and collection system, constructing
common effluent pre treatment plant and sanitary landfill for solid waste disposal, and
incorporating in-house waste minimizing measures such as low-waste leather processing,
chromium recovery and occupational health improvement.
6 Introduction to KTWMA
2. Effluent Treatment Plant (ETP) Description
2.1 Location:
Kasur treatment plant is constructed in 1994 in District Kasur. This treatment plant was built on
the area of Railway Pakistan area which was leading to District Ferozpur this land was useless
since after the war of 1971 so Government decided to construct a treatment plant on that useless
area.
2.2 Plant Description:
This treatment plant is treating on the waste produced by the Leather tanneries and it is doing
only primary treatment and the type of treatment plant is aerated lagoon. In the ETP after passing
manual & mechanical screening, the effluent enters the equalization tanks, which are fitted with
the aerators for homogenization. The homogenized effluent is pumped into the settling tanks,
which are equipped with the sludge and scum scrapers to throw sludge into the sludge pit. The
settled sludge so collected into the sludge pumping pit where lime dosing prepared in the
concrete tanks is added by pumps for sludge stabilization, preventing the sludge anaerobic
decomposition and helping emission of noxious gases. From sludge pumping pit, the sludge is
occasionally pumped to the permanent sludge lagoons. The sludge after 5 – 10 years will be
either left as it is or removed from the sludge lagoons and shifted to solid waste disposal site
located at far end of the plant.
The clarified effluent from settling tanks flows through the measurement zone, which has
facilities to measure flow, pH, temperature etc. The clarified effluent further travels through
effluent treatment lagoons in a zig zag pattern. After zig sagging through the lagoons, the
clarified effluent is transmitted through a 36” Dia RCC pipe line into the outfall and then into the
Pandoki Drain and ultimately into the Sutlej River.
2.3 Influent Wastewater:
The influent is entering the treatment plant through two drains and in treatment plant there are
gate vales to control the flow into the treatment plant.
2.31.Flow measurement on site:
• Drain 1 :
Width = 145 cm = 1.45 m
Depth = 54 cm = 0.54 m
Velocity of wastewater = 0.13933 m/s
Flow = 0.1091 m3/s
7 Introduction to KTWMA
= 392.76 m3/hr
= 9426.32 m3/d
• Drain 2 :
Width = 90 cm = 0.9 m
Depth = 54 cm = 0.54 m
Velocity of wastewater = 0.28575 m/s
Flow = 0.1388 m3/s
= 499.94 m3/hr
= 11998.75 m3/d
• The total discharge coming towards treatment plant is:
• From Drain 1 ( Q ) = 9426.32 m3/d
• From Drain 2 ( Q ) = 11998.75 m3/d
= 9426.32 + 11998.75
Total Discharge = 21425.07 m3/d
So the total influent in treatment plant becomes about 892.70 m3 /hr or 21425 m
3 /d
2.5 Flow Control Valves:
There are gate valves that control the flow to the treatment plant. Butterfly wedge type check
valves are installed. The valves are suitable for submerged installation and are 100 % shut-off
type. Check valves are of double disc type, arrows are marked for water flow directions.
8 Introduction to KTWMA
3. Bar Screening:
Screening is done in both ways manually and 2 mechanically automatic screens compactor. The
basic purpose of screening is to separate the grit i.e. shoppers, bags, wrappers etc.
2.61 Manual Bar Screening
In manual screening the suspended particles are removed by labors. The opening size of the bars
is 60 mm and a total width of 1200 mm and these are inclined at an angle of 70°.
2.62 Mechanical bar screening:
Mechanical or automatic bar screen is installed in the screen house over an open type concrete
channel. The screen is installed to collect the trash from tannery effluent, which is already passed
through the manually cleaned screens (with bar spacing of 60 mm installed outside the screen
house). The particles to be collected by automatic screens are definitely lesser than 60 mm size.
Screen spacing of these automatic screens is 6 mm and these are inclined at an angle of 350. The
efficiency of screening is more than 95 %.
9 Introduction to KTWMA
Characteristics:
The two automatic screens compactors have following characteristics
• Maximum Flow = 980 m3 / h
• Opening diameter = 6 mm
• Gradient = 35 degrees
• Width = 1200 mm
• Length = 4800 mm
• Wiper motor power = 0.18 kW
• Main screen motor power = 3.0 kW
4. Aeration Tanks:
4.1 Tanks description
There are two aeration tanks that mix the air in the wastewater. There are 2 concrete aeration
tanks in which 8 surface aerators are being installed. These aerators take the air from atmosphere
and mix to the wastewater for aeration.
Following are the characteristics of each aeration tanks.
• Depth = 4.7 m
• Width = 32.5 m
• Length = 65 m
• Water depth = 3 m
• Volume = 6337.5 m3
• Retention time = 1 day
10 Introduction to KTWMA
• Total Volume of 2 tanks = 12675 m3
4.2 Distribution of wastewater to the aeration Tanks
The channel shown in the figure below is used to separate and distribute the wastewater to both
of the aeration tanks.
4.3 Aerators
There are 16 surface aerators in both of the aeration tanks, 8 on each aeration tank. These
aerators are of aspirator type, suitable for surface mounting in water; these are capable to draw
air from atmosphere and mix with the wastewater.
Characteristics of Surface aerators are:
• Power = 30 kW
• Oxygen transfer = 1.6 kg O2 / kWh
11 Introduction to KTWMA
5. Clarifiers:
The clarifiers consist of half span bridge, scum collecting and sludge scrappers are fitted in 18
m of diameter. The equalized effluent is entered to the clarifier for settling under gravity and
settled sludge is scrapped from the bottom of the tank with the help of the sludge scrapper.
The clarifier consists of:
Half span bridge with pivot bearing, a walk way to reach center of the clarifier.
Drive system including electromechanical motor and gearbox travelling bogey and
wheels.
Rake mechanism including feed-well, scrapper blades, dolly wheels and arms, squeegees,
tie lines and underflow cone scraper etc.
Center column including center column pipe with ports, holding down bolts and
templates.
Internals: including overflow weirs, scum-baffle, rotating scum-boom & scum collection
system, including launder plastic wiping brushes.
The terminal limits for electrical system is terminal slip ring assembly.
Characteristics of Clarifier:
Maximum inflow = 700 m3 / h
Sludge incoming = 0.2 – 0.7 %
Center ring dia = 4 m
Tanks diameter = 18 m
12 Introduction to KTWMA
Height of tank side walls = 3 m
Free board = 0.6 m
Floor slope = 1 : 1.5
Feed well diameter = 3 m
Feed well Depth = 2 m
Over flow weir width = 0.6 m
5.1 Working of Clarifier:
Center column supports the bridge as well as inlet feed pipe of 500 mm diameter. The feed to the
tank is through the center column and comes out into the feed well through the ports. The center
column is bolted on a concrete slab. The slip ring assembly through the wheels moves slowly
over the tank wall.
Sludge rakes are provided with a number of blades mounted on a rake arm and supported from
the bridge. The arm is pivoted on the bridge to reduce the torque on the bridge. The scrapper
blades are fitted with the rubber squeegees to prevent the built up solids on the clarifier bottom
surface.
The upper scrapper is used to collect the scum that
floats on the surface of wastewater and collected in a
side way to sludge collector. Weir plates are 3 mm
thick with V – notches of minimum 75 mm depth
and evenly space made.
Baffle plates are 3 mm thick and are supported by
brackets from the tank wall to prevent the floating
scum from entering the launder. The scum arm and box is provided to skim off the floating scum
from the surface of the settling tanks.
A safety system for automatic and manual emergency stop is provided in the drive. An
emergency stop button is provided adjacent to the drive.
5.2 Pumping System:
Wastewater is pumped from aeration tanks to the clarifiers through pumps and this system is
called pumping system. Three pumps are installed from which two pumps are working and one
pump is used as backup. As shown in picture below.
13 Introduction to KTWMA
Characteristics of three submersible pumps:
• Flow, Q (each pump) = 350 m3 / h
• Head = 12 m
• Power (2 working pumps) = 18 kW
• One stand by pump = 24 kW
5.3 Distribution Channel:
The wastewater is distributed to clarifiers through the distribution channel as shown in figure the
wastewater after pumped from the aerators enter to these two channel from which it will
distributed to the two clarifiers.
14 Introduction to KTWMA
6. Lagoons:
6.1. Wastewater Lagoons
Water from clarifiers goes to the wastewater lagoons. There are 32 lagoons, 16 on each side. The
lagoons are totally natural process in which the water is placed in the lagoon more 5 days and
during this time period many inorganic and biological reactions will take place in the lagoons.
The detention time period of lagoons is 5 – 7 days.
The organic layer is laid on the bedding and then water is placed on it the function of geo layer is
that wastewater will not seep through the soil.
The water after completing its detention time is collected through sewage system that is used
only for this purpose for the treatment plant.
15 Introduction to KTWMA
6.2. Sludge handling lagoons
Sludge from the sludge pumping pit is taken to the permanent sludge drying lagoons through a
pipe line, and the sludge is left to dry in these lagoons for its permanents disposal as sludge
collected from the clarifier is very toxic because of toxic chemicals and concentration of
Chromium (VI) in it so it is not used further for any use like fertilizer.
The desludging time period of Clarifiers is 1 – 1.5 years. The sludge is dried in open area near
the treatment plant which is also useless area and after drying of sludge it is transferred to
dumping site.
6.3. Dumping site
A dumping site is provided at the end of all the lagoons where all the solid waste produced by
the KTWMA is dumped and also the sludge from the sludge drying lagoons when it is
completely dry and the lagoons are filled is either left as it is in these lagoons or is dumped to the
sludge dumping site.
16 Introduction to KTWMA
7. Critical analysis
The KTWMA is a blessing for the city of Kasur which is used to treat the tanneries waste that is
very toxic and hazardous to dispose off in the environment. But the plant is only beneficial for
the region when it is in working condition and treats all the waste produced by the tanneries.
This is the bad luck of the region that the plant is not working properly and its efficiency is not
meeting the requirements. The plant is often closed and is not used to run properly which is a big
flaw of the authorities of the Kasur. It is also not cleaned properly and the maintenance is not
done properly.
The most alarming fact is that the whole of the waste coming from the tanneries is not sent for
the treatment to the plant but one full drain of wastewater out of two drains coming from the
tanneries is used to by pass into the Pandoki Drain without any treatment directly which is
further going to the Sutlej river.
Wastewater being by pass in Pandoki Drain Pandoki Drain
A lot of solid waste is put over the drain upto the point where the treated water comes to the
drain, but under that solid waste whole of the drain of wastewater coming from the tanneries is
flowing to pandoki drain,
The authorities should take a serious action against the plant management that why the plant is
not working well and the main thing is that why they are using bypass way of the disposal of one
whole wastewater drain to the pandoki drain without any treatment, which is polluting the
pandoki drain and afterall the Sutluj River.