Ayika

INTERVIEW AYIKA 2020

AN INTERVIEW WITH

Dr. KUNDAN LAL SHRESTHA

Dr. Kundan Lal Shrestha is an Assistant Professor at the
Department of Environmental Science and Engineering at
School of Science, Kathmandu University. He has also served
as the Coordinator of Environmental Engineering Program in
the department. He completed his Ph.D. in Engineering and
Master of Engineering (Sustainable Energy and Environmental
Engineering), Osaka University, Japan and Bachelor of
Technology (Chemical Engineering), Aligarh Muslim University,
India. He was also awarded the prestigious JSPS (Japan Society
for the Promotion of Science) Postdoctoral Fellowship for two
years at Osaka University.
He has fifteen years of experience in environmental modeling
with emphasis on air quality modeling, water resource modeling
and integrated air-water coupled modeling. His research includes
assessment of atmospheric transport phenomena, impacts of
climate change on the environment, hydroclimatology, urban
environmental pollution, regional climate modeling, and so on.

You are an environmental engineer and also a environment. So, it was not specifically called
chemical engineer. Could you give us a brief environmental engineering but instead, it was the
account on what your professional life has been application of chemical engineering. So, doing
like? Any personal landmarks that you would specialization in environmental engineering was
like sharing with us? a natural step. So, I did masters as well as Ph.D.
in this field. So, I was more focused on how to
I started with chemical engineering at the bachelor give a solution in Nepalese context using the
level. That time, environmental engineering was current resources. So, you can say that in many
only a specialization. From my perspective, the engineering fields we are very much dependent
environment was one of the main concerns for us on foreign technology that our economy cannot
chemical engineers because we were noted for our handle. Hence, I was more interested in making
industrial applications and many people thought the solutions more sustainable and independent.
that environmental problems started from these And my interest was also in using computational
industries. So, we chemical engineers were thought techniques in engineering. When I started my
to be the culprits. That’s why chemical engineers bachelors in India, chemical engineers were already
were interested in solving these problems. So, the starting to believe that the future of engineering
chemical engineers used the chemical engineering was in using the computational techniques and
principles to solve the environmental problems. data science. If you don’t use these technologies our
Sanitation problem started with urbanization. But, engineering profession will not evolve because of
with time this problem became intensive and toxic the complex problems cropping up in our society
chemicals started coming to the environmental for which we need more sophisticated tools.
media due to industrialization. Then the chemical So, that is why I specialized in comprehensive
engineers could use their expertise in solving environmental modelling specifically in air quality
these problems. When I was doing my chemical and integrated water resource assessment. I also got
engineering, we had special courses on the to do a Ph.D. in Japan from which I was able to gain

74

AYIKA 2020 INTERVIEW

more experience with the novel techniques to solve environmental processes, all these processes are
problems in the environment. I focused on how governed by chemical engineering principles. In
to integrate and use a multidisciplinary approach the future, in order to build sustainable solutions
to any environmental problem. This is also one of for fulfilling our basic or environmental needs,
the unique features of environmental engineering chemical engineering principles will still play an
compared to traditional engineering. indispensable role.

Having the knowledge of both chemical and Have you ever felt that it is difficult to find a good
environmental engineering, what kind of career as an environmental engineer in Nepal?
projects do you think can be established that
uses chemical engineering as a base to improve In Nepalese context, our traditional education
the environment? system usually discourages this kind of
multidisciplinary course. It was also very difficult
Environmental engineering and chemical to get equivalency. In Nepalese education system,
engineering are interlinked with the common this kind of degree is usually integrated or being
theme of always improving the current situation, conducted in the traditional courses itself. But now
whether it is the industry, society or environment. with the changing society we have more access to
Only one field may not give you a sustainable modern technologies and modern concepts. So,
solution. This is only possible if we implement our in the coming days these interdisciplinary and
traditional engineering principles in an integrated multidisciplinary courses will provide diversity
manner along with the emerging fields. in your job opportunities. In a country like Nepal
you have to be prepared to solve not only one but
Currently we try to get sustainable design. a diverse set of problems. So, engineers in Nepal
Traditional engineering dealt with the end-of-the- should be studying more multidisciplinary courses.
pipe solutions just like the control technologies in It is difficult but we can change this into our
drinking water, air pollution, waste-water or solid opportunities. Being an environmental engineer,
waste. So, they try to control the problem once it we can assimilate into nearly all professional
is created. The future lies in creating new products careers.
that will not create the problem in the first place.
Every engineering field is now leaning towards Even with more than 10 years having passed since
sustainability. Also, population is directly linked the establishment of Environmental engineering
with urban design. The design of a sustainable city in Nepal, it is still underrated, and unknown to
will be a major concern. So chemical engineering the governmental sectors. What do you think will
principles are in fact some of the core principles be the state of its scope and opportunities in the
of environmental engineering. If we talk about next 10 years?
drinking water, engineers were more interested in
how to supply these through a network of supply Our scope will be very much interlinked with
systems. But we need to ensure the quality of the growth of the society and the progress of the
water and for that we need many more integration nation. If there is less investment to solve the
of different fields like environment chemistry, environmental problems using different kinds
water chemistry and we need knowledge about of scientific and environmental techniques, I feel
how to remove the water pollutant from drinking that there might still be a problem because of our
water, which are in fact depending on the traditional approach in the education system. So, it
principles of chemical engineering. That’s why needs to be improved and along with that we need
chemical engineering is one of the core engineering to change the perception in the society. So, change
principles in environmental engineering. in the perception will be the key focus to increase
Before environmental engineering became an the opportunity in the future. Environmental
undergraduate program, chemical engineers have engineering is the strong integration of science
been specializing in this field and treating water, and all the major engineering principles. Studying
improving air quality, managing solid waste and so these multiple disciplines in a synergistic way helps
on. to bring out more effective solutions. So, what I
believe is that environmental engineers have to
I think the basic need of our country is clean air, convert all the challenges into opportunities and
clean water and clean soil which can be fulfilled by we can contribute in other different fields besides
using chemical engineering principles. Chemical the government jobs.
engineering is also called 'process engineering'
in many countries. Whenever we talk about the Do you think there will be any changes in the

75

INTERVIEW AYIKA 2020

air quality improvement 15 years from now a cause of pollution as many people might find
with the increasing technologies and which it easier to burn the waste instead of disposing
environmental issues do you think will require of it. Episodic problems may be a challenge. The
the most attention in the next 10 years? improving scenario might be because of reduction
In Nepal there are mainly two types of air quality in both the long-range transboundary and local
problems. One is the indoor air quality especially pollution. Generally, we cannot say that just the
in the rural context and another is the ambient or decrease of transportation has improved air quality.
outdoor air quality. In ambient condition, we have So, scientists are very much working on how air
two aspects. One is the emission of pollutants from quality is being improved. Scientists are having a
the local sources and another is the transboundary unique opportunity to do research on air quality.
pollution. Transboundary is more complex, But from the general public’s perspective, we will
which involves far-away sources. Even in federal have to be more careful in preventing the episodes
structure we will be having the inter-state pollution of air pollution such as open burning.
problems. For example, one of the regions might
have lots of agricultural residue burning that may Following the question, will there be a drastic
contribute to massive pollution to some very far change in the environment once the pandemic
away region because of the long-range transport of ends? And, what factors do you think will bring
the air pollution. Even after fifteen year it may be the most changes?
difficult to assimilate or adapt to these state-of-the-
art technologies. So, the new technologies may give Post pandemic situation is very important. We have
us sophisticated solutions but that may be difficult to predict using robust tools. Prediction is very
in our rural society. We may have to come up with important from the health perspective as well for
more indigenous solutions. the general public. For the general public, technical
people like environmental engineers have to find
Our success in the next fifteen years may depend out what will be the post pandemic situation. For
on how you bring the environmentally friendly example, the first thing might be that after the
fuel/energy and simple yet effective solutions to post pandemic there might be a certain surge or
every household. increase in the use of more applications that release
the pollution just like transportation. So obviously
Now talking about ambient air quality, in Nepal, if there is a surge or increase that will lead to a very
ambient air quality is very much linked with our fatal episode of air pollution. So, there is a chance
urbanization. In Nepal, urbanization is very high that we will see an acute impact on the environment
and haphazard. This is amplifying the air pollution as well as the health of the people.
scenario. So, in fifteen years, even if we change
the process and use good technologies it may not Another scenario might be that the government
be effective in our society without the correct policy may be more diverted towards the
societal perception. For instance, one of the typical COVID-19. In the post pandemic situation, there
problems is open burning in nearly all sectors, is also a risk that a significant portion of the fund,
which is a societal problem and cannot be dealt only time and effort of the people may be diverted
with technology. So ambient air quality very much from the environmental problems towards the
depends on how we tackle it with multidisciplinary COVID-19 response. There is a risk that people
effort along with engineering principles. might be more relaxed in terms of environmental
problems. Having said that, air quality problems are
With the pandemic going on, people are talking long-term problems. In the long-term problems,
about the improvement of air quality. In your the general public may not be aware or highly
opinion, has the air quality differed from before alert. So, in Nepalese context it may be difficult to
the pandemic? convince the stakeholders to invest their time and
money to preserve the environment. Therefore,
Technically speaking, if you stop the sources of the the post-pandemic situation may amplify this
emission of air pollutants, obviously the emission noncommittal behavior of the stakeholders. Thus it
will stop and the impact will reduce. The ambient can be predicted that the environmental conditions
condition may be improving. But the main concern might degrade.
is that it may be temporary. There might be
episodes of high air pollution in some cases which You worked for many years as Environmental
might be due to several reasons, such as natural engineering's coordinator at Kathmandu
wildfire and anthropogenic open burning. During University. What changes have you brought in
the pandemic situation, open burning might be your time? Do you think our current curriculum

76

AYIKA 2020 INTERVIEW

will prepare us sufficiently for the professional It is very important that the curriculum is updated
practice after graduation? with new concepts and techniques. Regarding the
engineering principles, it may not change quite
As a Coordinator there are two aspects of the often, but the tools and techniques need improving
job. One is the operational aspect and another is every year. So, it is a very rapid development process
how we enhance the program in the long run. In and I think that I have tried to incorporate that in
the operational duties as a coordinator, I could the current and proposed curricula.
streamline the day to day operation. From the
perspective of how we have improved the scope In the current time, after graduation in
of environmental engineering, one of the most Environmental engineering, which subjects can
important things is how you make your education be a suitable pathway for the students to pursue?
system more inclusive of the requisite courses and If instead, they are looking into a professional
exposure to more learning and research resources life, then what career steps do you suggest?
for the students. It is very important that in the
current age of information, along with the challenges Of course, core engineering is dealing with the
of dealing with the international competition, I feel end-of-the-pipe solutions. So, if you like it, it
that students need to be exposed to a level of offline is always possible to go into these engineering
and online resources that any global engineer is fields. Environmental engineering is traditionally
exposed to. So, I tried to incorporate them. dealing with environmental problems like how to
improve the water, air and soil and many other
For the research materials or professional tools, I related aspects. Or else you could go for sustainable
tried to incorporate a more sustainable approach engineering. If you are going to contribute to Nepal,
which is applicable in Nepalese context. It is then understand how your knowledge of tools and
very important for Nepalese engineers to not be techniques will be sustainable in the Nepalese
dependent on closed systems. Tools might be very context. You might be learning very sophisticated
expensive and they might not be available to us and expensive methods outside Nepal and after
in a very flexible way. So, we may not be able to coming here, if you cannot use that knowledge it
afford this tool in the future as well. But if we go will be a big loss to you as well as to the Nepalese
towards the open systems, it might be beneficial for society. So you may go for conventional applications
all. I have tried to improve that situation as well or without being constrained by those traditional
as the professional communication techniques like approaches, you can contribute to other fields like
publications and technical writing. urban engineering and sustainable engineering.

Refreshment | Meme

77

PROJECT AYIKA 2020

FIRST-YEAR PROJECTS

(Demonstrative Model)(Batch-2017)

SLUDGE DEWATERING UNIT OF GUHESHWORI AERATION TANK
WASTEWATER TREATMENT PLANT. MGroonuipkaMGeumrubnegrs, A: NakerlsitoinGGyauwruanli,gS, aPbiyinasa GGuyrauwnagli,
Supervisor : Er. Subodh Luitel and Er. Nirmal Babu Aryal
Group Members : Lakisha Shrestha, Sophie Shrees,
Yutshu Shrestha, Dewasis Dahal, Sophiya Shrestha, Shruti
Shrestha
Supervisor : Er. Subodh Luitel and Er. Nirmal Babu Aryal

This project deals with the study and development Aeration tank is where air (or oxygen) is injected in the
of physical model of Sludge Dewatering Unit of mixed liquor. In municipal and industrial wastewater
Guheshwori Wastewater Treatment Plant. Wastewater treatment, aeration is part of the stage known as
treatment is the process of converting wastewater the secondary treatment process. Aeration in an
into bilge water that can be discharged back into activated sludge process is based on pumping air into
environment. The main objective of this project to a tank, which promotes the microbial growth in the
fabricate a physical model of the Sludge Dewatering wastewater.
Unit. This project aims at gaining thorough knowledge The main objective of this project is to develop the
on the working mechanism of the Guheshwori physical model of an Aeration Tank of Guheshwari
Wastewater Treatment Plant, specifically on the topic WWTP and to understand the working mechanism
of sludge dewatering unit. Sludge management is and importance of Aeration Tank. The physical model
required for the proper disposal of generated sludge of an aeration tank was constructed with an aerator
from the WWTP and application to land. Estimated which replicates the original model of GWWTP
60% of biosolids are used for the land application and the working mechanism of the GWWTP was
whereas the remaining 40% are disposed in most understood. The dimension of the physical model is
WWTP. With the reduction of weight and volume 17cm*17cm*18cm.
of sludge through sludge dewatering, the disposal
cost including transportation are kept minimal. The
centrifuge dewatering requires lesser area and widely
accepted sludge management process.

EQUALIZATION TANK
Group Members : Prerana Chand, Salina Shrestha, Prajwol Thapa, Sandip Rana Magar, Subash Duwal,
Kushal Khatiwoda
Supervisor : Er. Subodh Luitel and Er. Nirmal Babu Aryal

Equalization tank is one of the major unit required for chemicals utilized, maintain the appropriate PH level,
this treatment process which collects the incoming reduce the impact of inhibiting constituents, balance
raw effluent that comes of widely fluctuating rates levels of organic composites, and equalize the rate of
and passes to the rest of treatment plant at steady movement.
flow rate. During the peak hours effluent comes at
high rate which the equalization tank stores and lets
out during the non peak time which acts as buffer
to improve sedimentation efficiency. Wastewater
Treatment Plants are forced to deal with varying rates
of biodegradable and inhibiting constituents, along
with toxic constituents and other waste flow to their
water treatment facilities. Under such conditions,
equalization tanks are used to reduce the amount of

78

AYIKA 2020 PROJECT

PRIMARY SEDIMENTATION TANK ANAEROBIC DIGESTER
Group Members : Ashish Dhakal, Bipul Bhandari,
Sudeeksha Basyal, Surath Ghimire, Bishesh Gautam Group Members : Prabhat Rai,Meghna Rajbhandari,
Supervisor : Er. Subodh Luitel and Er. Nirmal Babu Aryal Rojina Shahi, Aakriti Sharma, Ashim Sharma, Sandeep
Mahara
Supervisor : Er. Subodh Luitel and Er. Nirmal Babu Aryal

The Primary Settlement or sedimentation tanks are Anaerobic digestion is the fermentation process
designed to reduce the velocity of the wastewater flow, in which organic material is degraded and biogas
allowing heavier organic solids (called raw sludge) to (composed of mainly methane and carbon dioxide)
settle. They are the first stage of treatment after the is produced. This process takes place in an Anaerobic
removal of rags and grit in the inlet works. Scrapers Digester. It is an airtight cylindrical compartment ideal
present in the tank move continuously along the floor for the biological process to takes place. The process
of the tank to deposit the raw sludge in hoppers for is much more economical than aerobic digestion. The
removal. The scum which floats to the surface is directed process of Biogas formation is a result of linked process
by water jets or scum boards to the sludge sump. The steps, in which the initial material is continuously
raw, settled sludge is removed by pump or gravity feed broken down into smaller units. Specific groups of
to a sludge treatment process. This project is done microorganisms are involved in each individual step.
in order to learn about the Primary Sedimentation These organisms successively decompose the products
Tank of GWWTP. As Primary Sedimentation Tank is of the previous step. The main aim of this project is
one of the important component of WWTP. Primary to construct a model representing the actual anaerobic
Sedimentation Tank works by the action of gravity. digester at the Guheshwori Wastewater treatment
Heavy matters coming from grit chamber gets settled plant.
down and removed as sludge. The output of this tank is
sent for the forther treatment.

SECONDARY SEDIMENTATION TANK
Group Members : Mandip Kafle, Pratik Kushwaha, Roshani Mainali, Rajesh Poudel, Sneha Pradhananga
Supervisor : Er. Subodh Luitel and Er. Nirmal Babu Aryal

In wastewater treatment plant, primary and Materials like 20L water jar, PVC pipes, tee-joints were
secondary treatment of wastewater is done. Secondary used in the making of the physical model.
sedimentation tank is one of the units which come
under secondary treatment. Secondary sedimentation
tank provides some degree of purification allowing
suspended particles to settle out. The secondary
sedimentation tanks or settling basins or clarifiers
allow the microorganisms and other solids to settle
after secondary or biological treatment. This sludge
is pumped back into the inlet end of the primary
sedimentation tanks and settles with the raw sludge.
This project is conducted to design the physical model
of secondary sedimentation tank in reference to that
of Guheshwori Wastewater Treatment Plant. A design
of circular secondary sedimentation tank was made.

79