Wastewater Disposal and Reuse

Lab Report # 2

Design of the Disposal System

of Lahore

Muhammad Imran Nawaz

2008-ENV-43

26/03/2012

1

Table of Contents

Chapter 1

Introduction 2

Chapter 2

Preparation o model for existing conditions 4

2.1 Given Data for existing conditions 4

2.2 Constants and Velocities Given 4

2.3 Procedure for Developing the Model 5

2.4 Equations and Formulas used 5

2.5 Representation of the Results for Existing Conditions 6

Chapter 3

Treatment Options and Alternatives 8

3.1 Dilution 9

3.1.1 Applying Dilution to the Model 9

3.2 Treatment 11

3.3 Applying treatment options on the model 14

3.3.1 Trail 1: Using Primary Treatment 14

3.3.2 Trail 2: Applying 70 % DOT 16

3.3.3 Trail 3: Applying 80 % DOT 17

Chapter 4

Recommendations 19

References 20

2

Chapter 1

Introduction

For the section of the River Ravi from the entry point into Pakistan originating from India to

Ravi Siphon after Marala Ravi Link Canal joins, the river keeps a good water quality such as 2.8

to 4.3 mg/L in BOD5, 4.8 to 11.5 mg/L in COD, and 20 to 40 mg/L in SS. (EPA. Punjab Report)

Due to the discharge control at Thein Dam in India, the natural discharge from India is hardly

expected in the River Ravi especially during the dry season

Lahore is located in the upstream most reach of the Ravi River and all the domestic, commercial

and industrial wastewater generated in the almost entire Lahore with a population of 6.5 million

and 2,700 industries is discharged into the river without any treatment in 2008, which

substantially forms the biggest pollution source of its river basin.

At present, the major downstream use of the River Ravi is for irrigation beyond the

BallokiHeadworks. However, the population and economic activities in the immediate areas

along the river from Lahore to BallokiHeadworks (64 km) are affected in different degrees by

pollution in the river. It is estimated that waste water (domestic and industrial) from Lahore will

increase significantly as a proportion of total flow in the river. In a one in twenty year minimum

monthly flow, wastewater from Lahore accounted for about 47 percent of total flow in 1987,

rising to about 68 percent in 2007.(Source: Environment Department, CDGL, “Environmental

Profile of Lahore (2007-08)”

The wide variety of fish that once swam in the Ravi has vanished, as have the tiny minnows and

crabs children used to catch in the shallow waters along the banks. Even the reeds that used to

line the river have gone. The river is virtually dead even when the normally dry bed carries

water, such as after the rains.(Source: Environment Department, CDGL, “Environmental Profile

of Lahore (2007-08)”)

The Environmental Protection Department of the Punjab Provincial Government considers that

the river is under a constant threat of indiscriminate disposal of untreated municipal sewage from

Lahore / industrial sewage from Faisalabad through Maduana Drain and industrial effluent from

industrial units of Kala Shah Kaku along G.T. Road, Sheikhupura Road, Township and Gulberg

Industrial Estate located in Metropolitan of Lahore and untreated industrial wastewater of

District Kasur.(Source: Letter from the Secretary of EPD to the Secretaries of HUD&PHED,

Irrigation Department and Industrial Department, “Installation of Wastewater Treatment Plants

to Save River Ravi from Pollution”, dated 16/09/2009).

Historically, the River Ravi has not been used as a major source of potable water. Most

communities in the area, including Lahore, are dependent on ground water as the major source of

drinking water. In the rural areas of districts which border the river from Lahore to

3

BallokiHeadworks, only 0.3 percent of households are dependent on open surface watercourses

(river, springs and streams) for their drinking water. This represents about 1,700 households and

10,600 people. There are no known plants to use the River Ravi as a major water supply source.

(Source: Environment Department, CDGL, “Environmental Profile of Lahore (2007-08)”,

City of Lahore is discharging its wastes into the Ravi River through various outfalls over a given

length of the city which is polluting the river day by day which is a great threat for the aquatic

life and for the downstream uses of the river water. This report is aimed to construct a

mathematical model which will give the solution at different outfalls or which will give the

better alternatives for the disposal of wastewater. This model will give us the values of BOD and

the DO concentrations at each outfall for the existing conditions and for the proposed alternatives

which will be used to select the most appropriate method or the alternative for disposal. This

model is constructed to meet the DO requirements of 4 mg/l for the aquatic life.

Fig 1: location of different outfalls along the Ravi River with distances.

4

Chapter 2

Preparation of model for existing conditions

2.1 Given Data for existing conditions:

The data for flow, BOD and the DO is given below in the table for existing conditions along with

the distances of situation of outfalls. Flow (Q) is in m^3/S, BOD and COD in mg/L and the

distance is in meters.

Table 2.1: Given data for flow Q, DOD and DO along with the distances

Pumping Station Q (m^3/S) BOD (mg/L) DO(mg/L) Distance(Km)

Ravi Syphen 11.05 3 8 0

N.E PS 13.5 285 0 26.1

Shahdra 3.7 230 0 27.9

Main outfall 13.4 340 0 34.1

Gulshan Ravi 9 250 0 35.5

Multan Road PS 4.5 225 0 45.3

Hudiara Drain 11.11 130 2 60.3

Deg Drain 91.4 198 5 63

QB link Canal 544 5 8 85

Balloki head works 98.7

2.2 Constants and Velocities Given:

The value of constants like Ks, Kd and Kr and the velocities of the flow in the river are given in

the table below

Table 2.2: value of constants and Velocities in the river

Parameters m/s km/d

U(velocity upto Hudiara Drain m/s) 0.06 5.184

U (velocity after Hudiara Drain m/s) 0.27 23.328

mean Depth (m) 1.02

DO saturation mg/l 8

Kr (per Day) 0.5

Kd (per Day) 0.3

Ka(upto Hudiara Drain per Day) 0.9273

Ka(after Hudiara Drain per Day) 1.9671

5

2.3 Procedure for Developing the Model:

All the given values and the given data is tabulated and arranged then BOD ultimate is

determined and then the mass balance of BOD is made at each and every outfall station and after

every 0.2 km distance. in the same way the mass balance of DO is made and the Deficit and the

DO values are determined at each outfall and after every 0.2 km distance.

After all this process the graph between the BOD and Distance and a graph between the DO and

the distance are plotted and which gives the proper representation of the existing conditions of

the Ravi river at different outfalls.

2.4 Equations and Formulas used:

For BOD model we use the general equation for 1st order reaction i.e.

The following Equation is used for Finding BOD Ultimate from BOD5 in mg/L

L = Lo(1 - 𝑒−𝑘𝑡 ) ……………………………………2.4.1

And the following equation is used to find BOD ultimate for the river conditions

L = Lo𝑒−𝑘𝑡 ……………………………….………….2.4.2

The Equation given below is used to make the BOD Mass Balance at any outfall:

Concentration (mg / L) = 𝑄𝑟 𝑥 𝐶𝑟 + 𝑄 𝑒 𝑥 𝐶𝑒

𝑄𝑟+𝑄𝑒 ……………….………….2.4.3

and

the following Equation is used to find the Deficit for finding DO Concentration in river:

Dx = 𝐾𝑑 𝐿𝑜

𝐾𝑎−𝐾𝑟 (𝑒−𝐾𝑟

𝑋

𝑈 -𝑒−𝐾𝑎 𝑋

𝑈 ) + Do (𝑒−𝐾𝑎

𝑋

𝑈 ) …………………..2.4.4

First of all the equation 2.4.1 is used to find out BODu from the given BOD5 then a mass

balance is made using the equation 2.4.3 at the first outfall for BOD, after that point the equation

2.4.2 is used to find out the BOD at different points from one outfall to the next with a distance

increment of 0.2 km. the equation 2.4.4 is used to find out the deficit for determining the DO

values.

6

2.5 Representation of the Results for Existing Conditions:

After making the mass balance and all of the above calculations the findings of the results are

made which includes the representation of whole of the data. Below is the table which represents

the results of the model for present or existing conditions.

Table 2.3: Results generated the model for EXISTING CONDITIONS:

The graphical representation of the above results is shown below in the form of BOD and DO at

different outfalls

Graph 2.1: BOD Profile for Existing Conditions

0

20

40

60

80

100

120

140

160

180

200

20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

BO

D(m

g/L)

Distance (KM)

BOD Vs Distance

Pumping Stations Q

accumulative Flow BOD (mg/L) DO

DO mass

Balance deficit Distance (Km)

(m^3/S) (m^3/S) BOD5 BOD u Mass

Balance mg/L mg/L

Ravi Syphen 11.05 11.05 3 3.27

8 0

N.E PS 13.5 24.55 285 310.49 172.21 0 3.60 4.40 26.1

Shahdra 3.7 28.25 230 250.57 158.62 0 0 8 27.9

Main outfall 13.4 41.65 340 370.40 178.33 0 0 8 34.1

Gulshan Ravi 9 50.65 250 272.36 176.52 0 0 8 35.5

Multan Rd PS 4.5 55.15 225 245.12 83.00 0 0 8 45.3

Hudiara Drain 11.11 66.26 130 141.63 40.00 2 4.63 3.37 60.3

Deg Drain 91.4 157.66 198 215.71 140.95 5 4.84 3.16 63

QB link Canal 544 701.66 5 5.45 23.99 8 6.87 1.13 85

Balloki Drain 98.7

7

Graph 2.2: DO Profile for Existing Conditions

The existing condition shown in the above graphs gives very worst conditions. The BOD values

are very high that are frequently more than the NEQS values that is 80 mg/L that represents the

unacceptable conditions for the aquatic life and for the downstream use of river water.

The DO values are also lower than the NEQS standard values for the aquatic life of 4 mg/L in

most of the places like from NE pumping station to the mid of the Multan Rd Pumping station

the valves are below zero because the initial values of DO are also zero at these points, the

effluent DO is zero. These are also worst conditions for the aquatic life to survive in this

environment. These values should be greater than or equal to the NEQS of 4 mg/L otherwise the

existence of aquatic life will be impossible. These scenarios make the Ravi River as DEAD

River.

0

1

2

3

4

5

6

7

8

20 30 40 50 60 70 80 90 100

DO

(m

g/l)

Distance (KM)

DO profile

8

Chapter 3

Treatment Options and Alternatives

Treatment or any other alternatives are required for the worst conditions of the River Rave for its

proper water use and to prevent aquatic life. A lot of work is done and also is being done on the

River Rave to improve its existing conditions. A brief summary of these works is given below to

have an idea about the projects that are proposed for the River.

WASA Lahore is responsible for maintaining the water supply sewerage and storm water

drainage system for city of Lahore. The construction of piped water supply system started in

Lahore in 1870 in and around the Walled City of Lahore, whereas sewerage system was

introduced in the central part of the city in 1936-37, mostly in the shape of brick sewers.

Sewerage system in the Central areas of the Lahore started more than 70 years ago. Most of the

system has outlived its life and need replacement. During this period there has been an immense

increase in population, making the system in adequate and under sized.

To address these problems Economic Affair Division (EAD), Government of Pakistan sent

official request to the Government of Japan in July 2008 for loan assistance to

(a) Lahore South East Sewerage Treatment Project and

(b) Lahore Sewerage and Storm Drainage Improvement Project, and another official request

was sent from EAD in September 2008 on technical assistance on

(c) Study/ review of Comprehensive Sewerage and Drainage System in Lahore and

(d) Study for Water Distribution System of Lahore City.

Given the high priority of the Government of Pakistan on Water Supply, Sewerage and Drainage

Improvement in Lahore, JICA(Japan International Cooperation Agency) decided to start “The

Preparatory Study on Lahore Water Supply, Sewerage and Drainage Improvement Project”, The

Study aims to formulate the Project which may be financed by JICA’s loan assistance. The Study

was started in March 2009 and completed by July 2010. The Study aimed to formulate “the

Lahore Water Supply, Sewerage and Drainage Improvement Project” through basic study,

review of vision and strategy on development and management of water supply, sewerage, and

drainage facilities in Lahore and based on this study, preparation of the project plan and of plan

for implementation, operation and maintenance, confirmation of environment, social

considerations, thereby improving efficiency of water supply, improving sanitary environment

and water quality in public water bodies, alleviating flooding and improving management

capacity.

Meanwhile, a renewed official request with eight projects including this Project was submitted

from EAD to the Government of Japan in September 2009. JICA’s Fact Finding Mission (“F/F

9

Mission”) aimed to confirm the progress of the important institutional improvement action

agendas, which were agreed to be progressed by appraisal mission between Pakistani side

(WASA, HUD&PHED, and P&D) and JICA agreed in the previous F/F Mission, and to carry out

fact-finding for the Project. The Pakistani side and the JICA Mission agreed to take necessary

actions on the basis of the framework agreed in this Minutes of Discussion.

A meeting was held between Pakistani Mission and JICA Mission on December 9, 2010 and in

this meeting the JICA Mission strongly requested the Pakistani side to get the PC-I approval

from CDWP by the timing of Pledge (Prior-notification) from Government of Japan to

Government of Pakistan in the same way as past JICA-financed projects. Accordingly this PC-I

has been prepared and submitted to government for approval.

Treatment options and Alternatives:

To maintain the river water in favorable conditions or to avoid the worst conditions like the

existing ones, two options can be done

Dilution

Treatment

1. Dilution

Dilution is a reduction in the concentration of the chemical or the waste loads in the river usually

by adding or mixing with more liquid/water in the river flows. In this way the waste loads can be

reduced to larger limits. In dilution we add water into the river flows allowing it to mix the

wastes thoroughly which reduces their concentration.

Dilution can be done from the initial point i.e. adding a maximum amount of water to the river or

it can also be done at the different outfalls by adding water in larger quantities to reduce the

waste concentrations.

Applying Dilution to the Model

Now we will apply the dilution to our model, for this we will require a larger amount of water to

dilute the river flow, for this we will also have to make dilution to each of the outfall for

improving the DO levels. We will consider a DO value of 3 mg/l at each of the outfall and an

initial dilution is made four times of the existing flow at Ravi Syphen and also adding a dilution

of 2 m^3/S at each outfall, we will have these results.

10

Table 3.1: Results generated the model for DILUTION

Graph 3.1: BOD Profile for DILUTION Conditions

0

20

40

60

80

100

120

20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

BO

D

Distance (KM)

BOD Vs Distance

Pumping St. Q Addition of Flow

acc. Flow BOD (mg/L) DO

DO mass Balance deficit

Distance (Km)

m^3/s (m^3/S) (m^3/S) BOD5 BOD u Mass

Balance mg/L mg/L

Ravi Syphen 45 2 47 3 3.27

8 0

N.E PS 13.5 2 62.5 285 310.49 69.42 3 6.41 1.59 26.1

Shahdra 3.7 2 68.2 230 250.57 67.07 3 2.084892 5.91511 27.9

Main outfall 13.4 2 83.6 340 370.40 89.46 3 0.767053 7.23295 34.1

Gulshan Ravi 9 2 94.6 250 272.36 94.98 3 0.285412 7.71459 35.5

Multan Rd PS 4.5 2 101.1 225 245.12 45.45 3 1.146964 6.85304 45.3

Hudiara Drain 11.11 2 114.21 130 141.63 23.24 3 5.85 2.15 60.3

Deg Drain 91.4 2 207.61 198 215.71 107.06 5 5.43 2.57 63

QB link Canal 544 751.61 5 5.45 22.40 8 6.92 1.08 85

Balloki Drain 98.7

11

Graph 3.2: DO Profile for DILUTION Conditions

Findings for Trail 1 of Dilution:

For increasing the initial flow to four times of the existing and adding a flow of 2 m^3/S at each

outfall in the river as dilution makes the river conditioned for BOD as satisfactory that is , the

BOD is almost reached the NEQS of 80 mg/l at most of the outfalls,

But for DO the results are still not acceptable even we have added the initial DO of 3 mg/l at

each outfall but the results are not meeting the NEQS

Now we will have to install any treatment facility for the outfalls to reduce their BOD levels to

acceptable limits, by installing the treatment facilities we will have better conditions for both

BOD and the DO even without increasing the flow or making any dilution.

2. Treatment

Sewage treatment, or domestic wastewater treatment, is the process of removing contaminants

from wastewater and household sewage, both runoff (effluents) and domestic. It includes

physical, chemical, and biological processes to remove physical, chemical and biological

contaminants. Its objective is to produce an environmentally-safe fluid waste stream (or treated

effluent) and a solid waste (or treated sludge) suitable for disposal or reuse (usually as farm

fertilizer). Using advanced technology it is now possible to re-use sewage effluent for drinking

water, although Singapore is the only country to implement such technology.

0

1

2

3

4

5

6

7

8

20 30 40 50 60 70 80 90 100

DO

(m

g/l)

Distance (KM)

DO Profile

12

There are different methods, techniques and processes to treat the wastewate that are used now

days. Some of them are listed and a brief description is given below that are mainly and

frequently used.

Activated sludge process

Aerated lagoons

Trickling Filters

Waste Stabilization Ponds

And many others

I. Activated sludge process

The most common suspended growth process used for municipal wastewater treatment is the

activated sludge process.

Activated sludge plant involves:

1. wastewater aeration in the presence of a microbial suspension,

2. solid-liquid separation following aeration,

3. discharge of clarified effluent,

4. wasting of excess biomass, and

5. return of remaining biomass to the aeration tank.

In activated sludge process wastewater containing organic matter is aerated in an aeration basin in

which micro-organisms metabolize the suspended and soluble organic matter. Part of organic matter

is synthesized into new cells and part is oxidized to CO2 and water to derive energy. In activated

sludge systems the new cells formed in the reaction are removed from the liquid stream in the form of

a flocculent sludge in settling tanks. A part of this settled biomass, described as activated sludge is

returned to the aeration tank and the remaining forms waste or excess sludge.

II. Aerated lagoon

Aerated lagoons are relatively shallow lagoons in which wastewater is added at a single point

either at the edge or middle of the lagoon and the effluent is removed from another point. The

retention time is a function of the percent removal of BOD. The retention time may vary from 6

to 18 days as the removal of BOD from domestic wastewater varies from 75 to 90 percent.

Oxygen is supplied by means of surface aerators or by diffused aeration units. The action of the

aerators also maintains the solids of the lagoon in suspension. Depending on the degree of

mixing, lagoons may be operated as either aerobic or as aerobic-anaerobic systems.

13

In aerobic lagoons all biological solids are in continual suspension and stabilization of the

rganics occurs under aerobic conditions. In the case of the aerobic-anaerobic lagoon a large

portion of the solids settles to the bottom of the lagoon. As the solids build up, a portion will

undergo anaerobic decomposition. Therefore, stabilization in this case occurs partly under

aerobic conditions and partially in anaerobic conditions

III. Trickling filter

A trickling filter consists of a fixed bed of rocks, lava, coke, gravel, slag, polyurethane foam,

sphagnum peat moss, ceramic, or plastic media over which sewage or other wastewater flows

downward and causes a layer of microbial slime (biofilm) to grow, covering the bed of media.

Aerobic conditions are maintained by splashing, diffusion, and either by forced air flowing

through the bed or natural convection of air if the filter medium is porous.

The terms trickle filter, trickling biofilter, biofilter, biological filter and biological trickling filter

are often used to refer to a trickling filter. These systems have also been described as roughing

filters, intermittent filters, packed media bed filters, alternative septic systems, percolating filters,

attached growth processes, and fixed film processes.

IV. Stabilization Ponds

A stabilization pond or "oxidation pond" as it is often called, is usually a shallow earthen basin

of controlled shape, which is designed for treating wastewaters from small communities or

industrial plants. The ponds are usually 2 to 4 feet deep, although much deeper ponds have been

used quite successfully. Stabilization ponds have been applied singly as part of a treatment

scheme or as the sole process, providing complete treatment.

The process involves two major steps in the decomposition of organic matter in wastewater. The

carbonaceous matter is first oxidized by the aerobic microorganisms with the formation of

carbon dioxide and the inorganic forms of nitrogen and phosphorous. These inorganic forms are

then used by algae in their photosynthetic reactions. Photosynthesis is a natural process carried

on by green plants in the presence of light. One of the end products of photosynthesis is oxygen

which becomes available to the aerobic microorganisms. As a result of the reactions in the

ponds, the organics in wastewater are partly oxidized and partly converted to algae cells. Algae

has been harvested in some of the locations and used for animal feed as a protein source.

Therefore, treatment of wastewater with the production of a useful by-product is possible in

stabilization ponds.

Most stabilization ponds are designed for loadings of one acre per 400 persons, 50 pounds of

BOD per acre per day or 15 pounds of BOD per acre foot per day with detention periods

generally greater than 30 days. The natural soil in which they are located should be fairly

14

impervious so that seepage will not materially affect the surface level of the wastewater in the

pond.

These ponds are low cost in construction and require a minimum of operation. The requirement

that large, fairly isolated areas be provided limits their use to relatively small populations in areas

where land is available.

Using the model and applying treatment:

Using any of the process for the outfalls the value of BOD is decreased to a maximum level and

then the wastewater is disposed off into the river. Using these processes for treatment we will

now use the reduced BOD values for our model and will predict the downstream concentration

levels and we will later on use any of these options to treat the river water for acceptable values

of the BOD and that of DO.

Trail 1: Using Primary Treatment

Using the trail 1 that is to treat the wastewater at each outfall to the primary level that is DOT

degree of treatment is 40 % and maintaining the initial DO level to 5 mg/l at each outfall.

Table 3.2: Results generated the model for PRIMARY TREATMENT (TRAIL 1)

Pumping Stations Q Acc Flow BOD (mg/L) DO

DO mass

Balance deficit Distance (Km)

(m^3/S) (m^3/S) BOD5 BOD u Mass

Balance mg/L mg/l

Ravi Syphen 11.05 11.05 3 3.27 8 0

N.E PS 13.5 24.55 171 186.29 103.91 5 6.350 1.650 26.1

Shahdra 3.7 28.25 138 150.34 95.60 5 0.655 7.345 27.9

Main outfall 13.4 41.65 204 222.24 107.16 5 1.609 6.391 34.1

Gulshan Ravi 9 50.65 150 163.41 106.03 5 0.888 7.112 35.5

Multan Rd PS 4.5 55.15 135 147.07 49.84 5 0.903 7.097 45.3

Hudiara Drain 11.11 66.26 78 84.98 24.01 5 5.949 2.051 60.3

Deg Drain 91.4 157.66 118.8 129.42 84.57 5 5.398 2.602 63

QB link Canal 544 701.66 5 5.45 16.08 8 7.254 0.746 85

Balloki Drain 98.7

15

Graph 3.3: BOD Profile for PIMARY TREATMENT (TRAIL 1)

Graph 3.4: DO Profile for PIMARY TREATMENT (TRAIL 1)

The above results shows that applying the primary treatment with 40 % DOT the BOD removal

is very much significant but the DO value are still not meeting the required standards of 4 mg/l

although applying the initial DO values of 5 mg/l at each outfall.

This trail is not acceptable for DO values so we will take another trail.

0

20

40

60

80

100

120

20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

BO

D(m

g/L)

Distance (KM)

BOD Vs Distance

0

1

2

3

4

5

6

7

8

20 30 40 50 60 70 80 90 100

DO

(m

g/l)

Distance (KM)

DO Profile

16

Trail 2: Applying 70 % DOT

Using the trail 2 that is to treat the wastewater at each outfall to the DOT degree of treatment of

70 % and maintaining the initial DO level to 5 mg/l at each outfall.

Table 3.3: Results generated the model for DOT OF 70 % (TRAIL 2)

Pumping Stations Q Acc Flow BOD (mg/L) DO

DO mass Balance Deficit

Distance (Km)

(m^3/S) (m^3/S) BOD5 BOD u Mass

Balance mg/L mg/l

Ravi Syphen 11.05 11.05 3 3.27 8 0

N.E PS 13.5 24.55 85.5 93.15 52.69 0 3.601 4.399 26.1

Shahdra 3.7 28.25 69 75.17 48.34 0 1.049 6.951 27.9

Main outfall 13.4 41.65 102 111.12 53.78 0 1.086 6.914 34.1

Gulshan Ravi 9 50.65 75 81.71 53.16 0 0.000 8.000 35.5

Multan Rd PS 4.5 55.15 67.5 73.54 24.97 0 3.206 4.794 45.3

Hudiara Drain 11.11 66.26 39 42.49 12.02 2 6.148 1.852 60.3

Deg Drain 91.4 157.66 59.4 64.71 42.29 5 5.516 2.484 63

QB link Canal 544 701.66 5 5.45 10.15 8 7.516 0.484 85

Balloki Drain 98.7

Graph 3.5: BOD Profile for DOT OF 70 % (TRAIL 2)

0

10

20

30

40

50

60

20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

BO

D(m

g/L)

Distance (KM)

BOD Vs Distance

17

Graph 3.6: DO Profile for DOT OF 70 % (TRAIL 2)

The above results shows that applying the secondary treatment with 70 % DOT the BOD

concentration in the river is now in the standard values but the DO value are still not meeting the

required standards of 4 mg/l in the start at starting outfalls, although applying the initial DO

values of 5 mg/l at each outfall. This trail is not acceptable for DO, we will take another trail

Trail 3: Applying 80 % DOT

Using the trail 3 that is to treat the wastewater at each outfall to the DOT degree of treatment of

80 % and maintaining the initial DO level to 5 mg/l at each outfall.

Table 3.4: Results generated the model for DOT OF 70 % (TRAIL 2)

0

1

2

3

4

5

6

7

8

9

20 30 40 50 60 70 80 90 100

DO

(m

g/l)

Distance (KM)

DO Profile

Pumping Stations Q Acc Flow BOD (mg/L) DO

DO mass

Balance deficit Distance (Km)

(m^3/S) (m^3/S) BOD5 BOD u Mass Balance mg/L mg/l

Ravi Syphen 11.5 11.5 3 3.27 8 0

N.E PS 13.5 25 57 62.097 35.036 5 6.380 1.620 26.1

Shahdra 3.7 28.7 46 50.114 32.116 5 4.503 3.497 27.9

Main outfall 13.4 42.1 68 74.081 35.619 5 4.399 3.601 34.1

Gulshan Ravi 9 51.1 50 54.471 35.233 5 3.448 4.552 35.5

Multan Rd PS 4.5 55.6 45 49.024 16.551 5 5.130 2.870 45.3

Hudiara Drain 11.11 66.71 26 28.325 7.964 5 6.956 1.044 60.3

Deg Drain 91.4 158.11 39.6 43.141 28.117 5 5.840 2.160 63

QB link Canal 544 702.11 5 5.447 8.172 8 7.630 0.370 85

18

Graph 3.7: BOD Profile for DOT OF 80 % (TRAIL 3)

Graph 3.8: DO Profile for DOT OF 80 % (TRAIL 3)

The trail 3 is somehow very reasonable trail also for the DO concentration that most of the times

meet the standards and the BOD is completely within the standard.

0

5

10

15

20

25

30

35

40

20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

BO

D(m

g/L)

Distance (KM)

BOD Vs Distance

0

1

2

3

4

5

6

7

8

9

20 30 40 50 60 70 80 90 100

DO

(m

g/l)

Distance (KM)

DO Profile

19

Chapter 4:

Recommendations

Lahore is a main city of Pakistan and which is recognized internationally and it should have the

basic facilities of road infrastructure, sanitation, clean drinking water and sewerage. This

crowded city generates a huge amount of the waste produced daily now it is the need to properly

dispose it off, for this different treatment plants at different outfalls are running in spite of this

the Ravi river is going polluted day by day, because the condition of these treatment plants is

worth seeing, and also due to the direct disposal of waste to the River without any treatment.

Now the need is to properly handle the waste produced and dispose it off.

At source treatment:

We can control the worst conditions of the Ravi River by individual awareness; each and every

individual citizen of the city can play its role,

Every house of any community of a colony should have a septic tank instead of disposing the

waste directly to the sewers and they can also make dilution to the waste, this will reduce the

BOD concentrations to a very low values so the treatment starts from the point of generation of

the waste, this awareness should be created to the public so that the worst conditions of the

disposal of the wastewater in Lahore can be controlled.

Making a collector Drain along the River:

If a collector drain is made all along the Ravi River so that it will collect all of the wastewater

from all of the outfalls and will eventually dispose it to the end of the city at Baloki Head Works

where a lot of dilution to the river is available, or at that point a treatment plant should be

installed which will treat the wastewater before disposing it into the Ravi River.

If this collector channel is made all along the River Ravi then the River water will be pure all

along the city and all the recreational facilities like fishing and boating can be made alive, and

also the aquatic life will sustain in that environment which will be an healthy activity.

20

References:

Environment Department, CDGL, “Environmental Profile of Lahore (2007-08)”

EPA. Punjab Report

http://water.me.vccs.edu/courses/ENV149/stabilization.htm

http://nptel.iitm.ac.in/courses/Webcourse-contents/IIT-

KANPUR/wasteWater/Lecture%2024.htm

http://nptel.iitm.ac.in/courses/Webcourse-contents/IIT-

KANPUR/wasteWater/Lecture%2024.htm