Theme: Our Water Environment
Learning and Teaching Activities
Application of biotechnology in wastewater treatment
Teaching Tips
Action images can impress students and sometimes are a better presentation for memory.
This exercise asks students to view relevant information on waste treatment and enables
students to appreciate the advancement of science and technology benefiting our society.
Objective: To enable students understand what is biotechnology and its role in waste
treatment.
Introduction
Wastewater treatment is a complicated process, consisting of a number of treatment stages.
Throughout the years, treatment methods have expanded to include chemical, physical and
biological means. Biological method in wastewater treatment is widely adopted, as it is more
environmental friendly. The development in biotechnology enhances its role in waste
treatment.
Students need to view and examine the information on biotechnology applied in wastewater
treatment.
Title of the CD-ROM
Funding Agent
Producer
To promote Biotechnology Quality Education Fund
2001, Hong Kong Education
Education
Institute
Biotechnology
Department
of
Biology,
The 2000, Department of Biology,
Chinese University of Hong Kong The Chinese University of
Hong Kong
Biotechnology
Education
Department,
Kong Government
Hong 1999, City University of Hong
Kong
A(E)-T3-7-1
The content supplements the lecture and explains the idea of using biotechnology for
wastewater treatment purpose.
Students’ work
After you have gone through the section, you will find that it gives the information about the
kinds of microbes capable of performing degradation of pollutants, description of the
biodegradation process, sewage treatment procedures, the advantage and actual application of
biotechnology and the relation to environmental protection.
Your group is now going to discuss and summarize important details as mentioned in the CD.
Try to answer the following questions:

What are the principle of degradation using microbes and the procedure for wastewater
treatment process?

What are the functions of biodegrading agent in wastewater treatment? (e.g. treat color,
organic pollutant)

What types of wastes are most suitable for biological treatment?

Discuss the pros and cons of using biotechnology in treatment process.

Instead of waste treatment, propose another waste management strategy.
A(E)-T3-7-2
Suggested Answers (Accept alternative and correct answers)

What are the principle of degradation using microbes and the procedure for wastewater
treatment process?
Under suitable conditions included temperature, oxygen and pH; microbes degrade the
biodegradable substances to carbon dioxide, water and other metabolic by – products.
Procedures of wastewater treatment processes including: preliminary treatment (screening
and removal of grit), primary treatment (primary sedimentation process), secondary
treatment (biological treatment processes) and final sedimentation of sludge (to remove
and regenerate activated sludge).

What are the functions of biodegrading agent in wastewater treatment? (e.g. treat color,
organic pollutant)
The biodegrading agent degrade the waste (e.g. dye and organic pollutant) to substances
such as carbon dioxide, water and other metabolic by – products.

What types of wastes are most suitable for biological treatment?
Biodegradable substances that made up of organic molecules and contain inorganic
nutrients; and also with few/no toxicity to the microbes.

Discuss the pros and cons of using biotechnology in treatment process.
Pros: less toxic products and by – products, more environmental friendly, generate fuel
such as methane, any appropriate answers.
Cons: advanced technology required, problems of handling microbes (as they may be
toxic), any appropriate answers.

Instead of waste treatment, propose another waste management strategy.
Waste reduction or waste recycling.
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