Page 417 - Industrial Wastewater Treatment, Recycling and Reuse

An Introduction to Biological Treatment and Membrane Filtration 389

9.9.2 Selection Criteria
The treatment objective of the effluent in present the study is to achieve dis-
charge limits in the secondary/tertiary process and to achieve water of a
quality lying in the recyclable range with advanced treatment.
Following are the Criteria for Selection of Treatment Technology
➢ BOD removal efficiency: Because the objective of treatment is to achieve
water quality in the discharge, the selected technology should have the
ability to remove biodegradable organic compounds.
➢ COD removal efficiency: If the wastewater has a high COD content, the
COD has to be reduced to the discharge limit or even lower. Thus,
the technology selected should be capable of operating at higher SRT
and also reducing chemically oxidizable substances.
➢ Footprint: The land area required for the plant should be as small as
possible.
➢ O & M cost: The cost of operation and maintenance should be low.
➢ Sludge disposal cost: The cost of sludge collection and dewatering should
be low.
➢ Ease of installation and commissioning: The total amount of time required
for the installation and commissioning should be minimized.
➢ Ease of operation: The technology selected should be easy to operate
without the need for constant adjustment once the system becomes
stabilized at certain feed conditions.
➢ Energy efficiency: The technology provided should be energy efficient.
➢ Nitrification efficiency: As wastewater contains excess nitrogen, the pro-
cess should be capable of nitrifying ammonia.
➢ Reliability of technology: The process should preferably be stable against
shock loading. For example, it should be able to continue operation and
to produce an acceptable effluent under unusual conditions.
Considering the above factors and based on experience in treating such
industrial wastewater, Aquatech proposed its own innovative Aqua EMBR
technology to treat such complex wastewater.

9.10 SCHEME AND PROCESS DESCRIPTION
2
A module having 42 m membrane area was used for solid/liquid separation.
Wastewater with the characteristics shown in Table 9.4 was fed to the bio-
reactor after primary screening. During startup the bioreactor with a volume
3
of 20 m was seeded with activated sludge from the local municipal waste-
water treatment plant. The sludge had been acclimated with the same feed