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Published by mahdi.hyari, 2021-04-09 14:37:38

PPT_Reuse Technologies Module 1&2_Eng

ReWater MENA | Reuse Technologies

Wastewater collection technologies (onsite and
conventional)and Treatment technologies (primary,

secondary and tertiary treatment)
Module One and Two

Dr. Maha Halalsheh & Dr. Mohammad Duqqah

Learning objectives

Sewage management:
A Strategy

Pollution Treat and Dispose
Prevention re-use ‘self
purification’

The 3 - Stage Strategic Approach

Gravity collection systems Conventional
collection system

Solids-free
collection system

Simplified
collection system

Conventional wastewater collection system

Advantages Disadvantages

Convenient systems and High investment costs

no attention is needed

by households or users

Abundant experience in

such systems exist in the

region

System is mostly in line Minimum velocity is

with existing national required to flush solids.

codes and standards Accordingly, minimum

slope should be provided

to maintain the

minimum velocity

Requires less Leakages may pose high

maintenance as risk for contamination as

compared to other compared to other

gravity systems systems

Solids-free wastewater collection system

Advantages Disadvantages

Cost savings might be 30 to 50% Space has to be provided for the

as compared to conventional interceptor tank at each

sewer system household. Additionally, access to

the interceptor must also be

provided

No need for continuous Regular de-sludging is crucial for

downward slope and accordingly the a well operated system

the pipes might be installed at

shallow depths

Inspection manholes are not Needs high public awareness as

required public are involved in the

operation and maintenance of

the system

Less environmental risks in case In many cases in the region,

of leaks codes and standards still need to

be developed for such systems

Reduction on the treatment Lack of regional experience in
costs since solids are removed such systems
upstream

Simplified wastewater collection system
Advantages Disadvantages

Shallow depth and flatter Toilets need to be flushed

gradients as compared to with sufficient amount of

conventional systems water to provide flushing

for the system

Pipes are smaller and Grease and grit traps

cheaper as compared to need to be installed at

conventional sewer each household and

system regularly maintained.

Accordingly, community

involvement is crucial

Higher maintenance

requirements as

compared to

conventional system

No sufficient experience

exists so far in the region

regarding such systems

Wastewater treatment

Preliminary treatment Screening

Preliminary treatment Grit removal Unit

Primary treatment sedimentation tank

The purpose is to remove readily
settleable solids and floating materials.
Efficiently designed and operated
primary sedimentation tank removes
50-70% of TSS and 24-40% of the
BOD.

The tank can be rectangular or circular
and equipped with scrapers at the
bottom to remove collect sludge at the
sludge hopper. The clarifier is also
equipped with scum removal
mechanism.

Aerobic Biological processes

Suspended growth Attached growth

Heterotrophic bacteria degrades the organic material and are found
in suspended or attached systems.

Activated Sludge system

Trickling filter system

Rotating biological contactors

Anaerobic treatment
Up Flow anaerobic sludge blanket

Anaerobic treatment
Anaerobic Baffled reactor

Anaerobic treatment: Septic tank

1895, England

Donald Cameron Septic

Tank

Natural Systems
Waste stabilization ponds

Natural Systems
Constructed wetlands

How do we
select the
treatment
system?

Some important factors that must be considered
when selecting unit operations and processes

1. Process Past experience, data from full scale plants, published
applicability data and from pilot plant studies. If new conditions are
encountered, pilot plant studies are essential.
2. Applicable flow
range Example: stabilization ponds are not suitable for
extremely large flow rates in highly populated areas.

3. Influent Affect the type of the process to be used. The
wastewater presence of inhibiting constituents may limit the
characteristics application of biological treatment systems.

4. Climatic Temperature affects the rate of reaction for most
conditions biological and chemical processes.

Some important factors that must be considered

when selecting unit operations and processes

5. Process Reactor sizing is based on the governing
sizing based on reaction kinetics and kinetic coefficients. Data
reaction kinetics on kinetics are obtained experimentally. Data on
or process loading rates are based also on kinetics but can
loading criteria be obtained from pilot studies.

6. Performance Needed effluent quality is important in
determining the required treatment system.

7. Sludge Are there constraints that would make sludge
production and processing and disposal infeasible or
processing expensive.

8. Environmental conditions such as prevailing
Environmental wind direction and proximity to residential areas
constraints may restrict the application of some processes.
Proximity to water bodies may require removal
of some constituents such as nutrients.

Some important factors that must be
considered when selecting unit operations
and processes

9. Chemical What effects might the addition of chemicals have on
requirements or any the characteristics of sludge and what is the cost of the
other resources chemicals.
requirements.
Energy requirements and future energy cost must be
10. Energy known for cost effective treatment systems.
requirements

11. Personnel How many do need for operating the systems and do
requirements they have the skills.

12. Flexibility Can the unit operation be modified when needed to
meet future requirements.

Sustainability criteria for comparing different
options

Please refer to the excel sheets

Outputs of the module

Questions


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