Guheswori Waste Water Treatment Plant, P963+FXH, Bagmati Rd, Kathmandu 44600, Nepal Guheshwori waste water treatment plant is located at the bank of the Bagmati River on the northeastern part of Kathmandu City. It is constructed at the initiative of the government to clean up the Bagmati River.But it is managed by nongovernment organization “VA Tech WayBag LIMITED”. The plant treats the untreated wastewater generated by the household, industries and other institutions of Gaurighat,Gokarna,Chabahil, Bouddha and Kharibot. The main aim of the guheswori waste water treatment plant are: 1. To improve quality of wastewater 2. Elimination of pollutants, toxicants and many such 3. Preservation of water quality of natural water resources 4. To make wastewater usable for other purposes 5. Prevention of harmful diseases

1. Purbanchal University
Himalayan White House International College
College of Science and Technology
B.tech in Biotechnology
Ramshahpath, Putalisadak, Kathmandu
Field Visit Report
Guheswori Waste Water Treatment Plant,
P963+FXH, Bagmati Rd, Kathmandu 44600, Nepal
22nd
December, 2022
Prepared by: Dewaka Poudel Submitted to: Astha Sakya
Semester: 7th
Department of Biotechnology

2. Aims and Objective:
The motive of this visit is to provide practical insights on the waste water
treatment process to the students which includes:
1. To learn the process of waste water treatment.
2. To know the environmental and management aspect of Guheswori waste
water treatment plant.
3. To observe the current status of guheswori waste water treatment plant in
Nepal .
4. To know the potential role of guheswori waste water treatment plant .
5. To understand how guheswori waste water treatment plant performs.
6. To be aware of problems seen during the process.
Introduction:
The Field visit was held on 22nd
December,2022/ 7th
Poush, 2079. The field visit
was organized by Mr.Annon Chaulagain, HOD, Department of Biotechnology of
HWIC for the students of 2018th
Batch. Department of Biotechnology at HWIC,
established in 2007, has been providing knowledge on genetics, microbiology,
molecular biology, biochemistry, embryology and cell biology with technical
disciplines like chemical engineering, informational technology and robotics to
develop product and technology for plant, animal and human welfare.
Guheshwori waste water treatment plant is located at the bank of the Bagmati
River on the northeastern part of Kathmandu City. It is constructed at the initiative
of the government to clean up the Bagmati River.But it is managed by non-
government organization “VA Tech WayBag LIMITED”. The plant treats the
untreated wastewater generated by the household, industries and other institutions
of Gaurighat,Gokarna,Chabahil, Bouddha and Kharibot.
The main aim of the guheswori waste water treatment plant are:
1. To improve quality of wastewater
2. Elimination of pollutants, toxicants and many such
3. Preservation of water quality of natural water resources
4. To make wastewater usable for other purposes
5. Prevention of harmful diseases
All the students from 2018th
batch along with teachers Astha Shakya and
Shristy Tamrakar were present in the field visit. We were welcomed by the
chemist of guheswori waste water treatment plant.

3. Field Observation:
The treatment plant site covers an area of five (5) hectares. A chain of interceptor
drains along the river corridor to check haphazard disposal of the raw sewage was
installed. It had a design capacity of 32.4 ml/D. Guheswori WWTP was three (3)
Arab project.
Procedure for Waste water treatment at Guheswori waste water treatment
plant :
A.Preliminary Treatment of Wastewater:
This is the first step in guheswori wastewater treatment process and its objective
was to remove large debris, coarse solids and heavy inorganic material contained
in the wastewater flow. It consisted of physical operations such as:
1. Screening: About 40 mm diameter of bar rack was used for screening to
removes heavy solids in wastewater such as rags, paper, plastics, sticks and
metals to prevent damage and clogging of downstream equipment. The
obtained residues were manually removed with the help of labor. The removed
waste was transferred to solid waste management process. The working Principle
was based on Gravity.
2.Coarse manual screening:
About 20 mm diameter bar rack was used to removes solid particles of size above
20mm. The obtained residue was removed manually and transferred for further
solid waste treatment. The working Principle was based on Gravity.
3. Grit removal:
Here, grit chambers was used to slow down the flow so that solids such as sand,
ash, cinder and eggshells will settle out of the water and it can be removed
manually or mechanically. Different settling time was differentiated for different
sand particle under velocity and conveyer shape.The working Principle was
based on Gravity.
B. Primary Treatment of Wastewater:
Large debris and grit removed in the preliminary treatment was directed to
primary treatment operations and it’s objective was the removal of settleable
organic and inorganic solids by sedimentation and the removal of materials that
will float (scum) by skimming. It involves physical and /or chemical operations
for treatment of wastewater. The retention time of the tank was 2 hrs.
1. It involved a more sophisticated tank called sedimentation tank or primary

4. clarifier removed most of the suspended solids that will float or settle.
2. Sedimentation often used chemicals like flocculants and coagulants.
3. Sludge that settled to the bottom of the clarifier was called as primary sludge
and it was collected for further treatment called sludge treatment.
4. In this treatment about 50-70% of suspended solids, 35% of BOD got
reduced and it removed very few toxic chemicals.
C. Secondary Treatment of Wastewater:
This treatment involved a biological process and it’s objective was the further
treatment of the effluent from primary treatment to remove the residual organics
and suspended solids. It used bacteria, fungi and protozoa to remove organic
matter. The most common method that they used for secondary treatment were:
1.Activated sludge processing
The activated sludge process is a type of biological wastewater treatment process
for treating sewage or industrial wastewaters using aeration and a
biological floc composed of bacteria and protozoa. It used air (or oxygen)
and microorganisms to biologically oxidize organic pollutants, producing a
waste sludge (or floc) containing the oxidized material. It consisted of an aeration
tank with open upper part exposed to atmospheric air. A sedimentation tank
which allowed the biological flocs to separate . The settled sludge was recycled
for maximum utilization.
Two sedimentation tank was used A and B, A for sedimentation of sludge at the
bottom and another sedimentation tank B attached with chain scraper mechanism.
At first ,waste water from primary tank was passed to sedimentation tank A and
then further treated water was transferred to sedimentation tank B. The secondary
sedimentation B used Chain scraper mechanisms.
Chain scraper mechanism are mechanical sludge removal systems. The scraper
arms drive along the basin floor and continuously carry the sludge with them. In
rectangular basins, the sludge will be carried to a ditch and the removed with
sludge pumps. This mechanisms need a motor for sludge movement. Scraper
arms in rectangular basins are connected via chain links to the motor whereas
scraper arms in round tanks are attached to a center located shaft which is
connected to a motor on a service bridge.
After this treatment, It generally removed 80-90% of all the pollutants and
large proportion of toxic chemicals.
D. Tertiary/Advanced Treatment of Wastewater:
It was the final treatment stage of wastewater processing and its main objective
was the removal of specific wastewater constituents which cannot be removed

5. in previous stages and thereby increase the quality of the effluent to higher
degree. They used chemical disinfection method for the tertiary treatment of
wastewater by using chlorine. For this they had three larger tank.
1. Preparation tank for chlorine
2. Chlorination tank : Exposing chlorine and treated waste water
3. Dechlorination tank
Chlorination: This process injects chlorine into the headworks of a serpentine
effluent detention chamber. Chlorination in wastewater treatment kills bacteria
and viruses, and eliminates parasites such as Giardia and Cryptosporidium, which
can cause very serious illnesses. In summary, this process disinfects water so that
it is safe to reuse or recycle.
Dichlorination: The final stage of the tertiary wastewater treatment process
involves removing the chlorine that was used to disinfect the water. This step is
very important because chlorine is harmful to aquatic life. Chlorine also
reduces biological water quality when it is present in high concentrations. To
remove the chlorine, a compound called sodium bisulfite is added to the water.
Chlorine ions in the water react with this chemical and are removed. Once the
chlorine concentration has been reduced to a safe level, the treated water is now
considered clean enough to be safely released into the environment. This process
significant percentage of pathogenic organisms are killed or controlled.
E. Final Testing
Final test was done :
1. To check residual chlorine ( assumed to be 6 ppm)
2. To check fecal coliform
3. To check pH ( around 6-8)
4. To check total soluble solid(TSS)- (not greater than 10)
5. To check BOD ( not more than 10)
F. Clarifier Tank
A disc filter about size of 10 micrometer particle size or a nylon fiber cloth was
used in clarifier tank for the final cleaning of the treated water. Here, pH was
maintained by using lime.Daily sampling in inlet and outlet was performed.

6. PROCEDURE FOR BIOFUEL PRODUCTION/ BIOGAS PRODUCTION
USING SLUDGE OBTAINED FROM WASTE WATER TREATMENT;
Dome shaped digestor tank was used for collection of sludge obtained from
primary and secondary treatment plant. The height of tank was about 1.73m. The
sludge was maintained in an anaerobic condition at temperature 35C .The
digestion of municipal sewage sludge (MSS) occurs in these basic steps:
acidogenesis, methanogenesis, acetogenesis and hydrolysis. The biogas obtained
from digester was used for producing electricity which was obviously used to run
guheswori waste water treatment plant.
PREPARATION OF BIOFERTILIZER AND MANURE:
Remaining sludge obtained as residue from biogas was transferred to centrifuge
for processing. After centrifugation, resultant product was used as biofertilizer
and manure in an agricultural land.
ADVANTAGES:
1.Prevent waterborne disease
2.Increase by product recovery
3. Minimize waste
4.Avoid industrial equipment damage
5.Clean and safe processed water
CONCLUSION
Through this visit, we learned followings:
1. Method of waste water treatment
2. Mangement and Environmental aspect of waste water treatment of
guheshwori
3. Science behind aerobic digestion of sludge and waste water.
Visit was fruitful. The way,chemist at Guheshwori WWTP explained each and
every process performed were lucid to comprehend. We really enjoyed her
honest clear explaination. This visit is a huge learning curve for us in terms of
waste water treatment process. And we are grateful to the college for providing
this opportunity.

7. LIMITATION OF THE VISIT:
Limitation was hard to point out. Everything was managed as per plan. Skilled
manpower were employed to perform different task.
FUTURE ASPECT:
This type of waste water treatment process showed be adopted in each municipal
to reduce water pollution. Individual and community can tribute nature and
environment by following different types of waste water treatment process to
make their areas water pollution free.
Some pictured clicked during visit:
1. Gate of Guheswori WWTP 2.3. Preliminary waste water treatment
4. 20 mm screener 5. 20 mm screener 6. Secondary WWT

8. 7.Secondary WWT 8. Clean water obtained from secondary treatment
9. Tertiary Treatment : Chlorine treatment 10. Laboratory
11. Laboratory at Guheswori WWTP

9. 12. Outstanding view of Guheswori WWTP captured
13. Student of HWIC (2018th
Batch),B.tech in Biotechnology

10. 14.15. Happy Faces😊 after visit (student enjoying the visit)
Thank You !