Chapter 6.3 Biological treatment
Notes on this chapter
This chapter looks at biological treatment processes, which are used in hazardous waste
treatment, both alone and in combination with other treatment methods such as physical
and chemical treatment.
Biological treatment methods are well-developed and understood. This chapter is not
aimed at teaching the fundamental principles, which are well-covered elsewhere.
While it is more commonly used for non-hazardous wastes, biological treatment can be a
cost-effective and efficient treatment method for certain organic hazardous wastes in low
concentration. For example, biological treatment can be used to remove hazardous waste
constituents from wastewater. The focus in this manual is on ‘new’ wastes, but it is worth
noting that biological processes are used to treat contaminated soils.
The chapter gives some examples of the most common techniques and hazardous waste
applications.
List of slides
Title slide
Slide 2 Application of biological treatment
Slide 3 Factors influencing biological treatment
Slide 4 Process conditions
Slide 5 Advantages of biological waste treatment
Slide 6 Scope of treatment application
Slide 7 On-site vs off-site treatment
Slide 8 Typical wastewater treatment process
Slide 9 Wastewater treatment - liquid phase
Slide 10 Wastewater treatment example 1 – Bacterial filter beds
Slide 11 Wastewater treatment example 2 – Activated sludge
Slide 12 Wastewater treatment example 2 – Lagoons
Slide 13 Slurry phase treatment
Slide 14 Land treatment – solid phase
Slide 15 Co-composting – solid phase
Slide 16 In-situ bio-remediation
Slide 17 Soil heaping - solid phase
Slide 18 Emerging applications for biological treatment
Slide 19 Key considerations
Slide 20 Summary
TRP Chapter 6.3
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Background notes
1 Biological treatment processes are widely used throughout the world for a variety of
purposes, from treating wastewater to cleaning up contaminated soils.
2 Biological treatment may be suitable for organic hazardous wastes at low
concentrations. Biological processes are never 100% efficient and this limits their
application.
3 Biological processes rely on the natural actions of living organisms, but for their
effective harnessing, clearly defined conditions must be present. Where conditions are
outside the required range, the process will fail.
4 Biological processes may take months to reach goal concentrations of microbes – the
required conditions for good microbial activity will vary according to individual
organisms – and treatment may therefore take a long time.
5 Biological treatments may be used after physical or physico-chemical processes, to
further refine waste streams. This is often the case with wastewater treatment processes.
Industrial wastewater can seldom be treated solely by biological means.
Sources of further information
Batstone, R; Smith, JE & Wilson, DC editors (1989) The safe disposal of hazardous
wastes: The special needs and problems of developing countries World Bank,
Washington, Technical paper No 93 Vol 2 ISBN 0-8213-1144-1 (available as pdf files
from www.worldbank.org/publications/)
Dean, RB & Wilson, DC (Editors) (1990) Adapting hazardous waste management to the
needs of developing countries, Waste Management & Research Vol 8 No 2
Guyer, Howard H (1998) Industrial processes and waste stream management Wiley
ISBN 0-4712-9984-7
LaGrega, MD; Buckingham, PL; Evans, JC & ERM Group (1994) Hazardous Waste
Management McGraw Hill, New York ISBN 0-07-019552-8
Lewandowski, GA & DeFilippi, LJ (1997) Biological treatment of hazardous wastes
Wiley ISBN 0-471-04861-5
Technical guidelines from the Secretariat of the Basel Convention www.basel.int
TRP Chapter 6.3
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