NUI Galway – UL Alliance First Annual ENGINEERING AND - ARAN ...

Air Suction Bio-flow Reactor.
Eoghan Clifford 1 , Paul Forde 1,* , Edmond O Reilly 1 , Salvador McNamara 1 .
Abstract
The research project involves the development of a
new bio-film reactor technology, an Air Suction
Bio-flow Reactor (ASB-FR), for the removal of
organic carbon, solids, nitrogen, phosphorus,
odours and greenhouse gases from municipal,
industrial and agricultural wastewaters.
1. Introduction.
Existing wastewater treatment facilities have to
improve operating performance and provide
effluent of higher quality, conforming to more
stringent regulation [1].
2. Materials.
A laboratory unit has been setup within the
Environmental Engineering Laboratory, at NUI
Galway for the treatment of high strength
wastewater and is currently in the second phase of
testing.
The technology comprises a treatment system
of two identical closed cylindrical reactor which
can become air-tight when process requires,
connected in series through a pipe-connected to a
motorised valve. Each tank has an air suction
device, plastic bio-film media, influent and effluent
pipes with motorised valves, level switches, and is
operated and controlled through a programmable
logic controller (PLC).
Heterotrophic, autotrophic, anammox and
phosphorus accumulating micro-organisms develop
on the plastic media to treat the wastewater under
suitable aerobic, anoxic and anaerobic conditions
by using the PLC to control the movement of
wastewater and air in the enclosed tanks. During
the aerobic phase the bio-film is passively aerated
which removes the need for inefficient mechanical
aeration.
The wastewater is moved from one tank to
the other by atmospheric pressure and reducing the
air pressure in the other tank by the air suction
device (ASD). Furthermore, the gases exiting from
the tanks through the ASD e.g., N2O contained in
the air from the denitrification process, can be
1 Civil Engineering, NUI Galway
* Corresponding author: p.forde2@nuigalway.ie
146
captured and cleaned in scrubbing filters before
exhausting to the atmosphere.
3. Results.
During phase 1 of the study, which lasted 166
days, the organic loading rate was 2.84g COD/m 2
media/day and 0.26g NH4-N/m 2 media/day
achieved removals of 97% COD, 96% ammonium
and 60% phosphorus.
During phase 2, which is ongoing the same
organic loading rate was maintained but the
wastewater was retained in each reactor for longer
periods this reducing the energy costs of operating
the vacuum pump by 60%. Removals to date
during this phase were 97%, 93% and 78%, filtered
COD, ammonium and filtered phosphorus
respectively.
A third phase is due to start in the coming
weeks.
A pilot scale unit is currently being
commissioned at a local landfill site where the
treatment of high strength landfill leachate using
the ASB-FR treatment unit will be investigated.
4. Conclusion.
Results to date have shown that the treatment
unit is capable of complying with both national and
international discharge requirements while having a
lower operating cost.
The ASB-FR treatment unit is currently
undergoing an international patent application.
5. Acknowledgments and References.
Funded by Entreprise Ireland.
[1] Galil, N.I., Levinsky, Y., 2006. Sustainable
reclamation and reuse of industrial wastewater
including membrane bioreactor technologies: case
studies, Presented at the conference on Wastewater
Reclamation and Reuse for Sustainability
(WWRS2005), November 8–11, 2005, Jeju, Korea.