Updated: July 2002
PABIO Mover1. Outline of PABIO MOVER
PABIO MOVER is moving bed type organic wastewater treatment process in aerobic condition, developed through technical tie-up with KALDNES Co. in Norway, in which the specially shaped plastic carriers filled in the aeration basin are moved in the whole basin.
As for the biological treatment for organic wastewater, generally the activated sludge process has been used. But the fixed bed biofilm process has also been introduced for a treatment of higher load, where biofilm is attached on fixed bed media.
While the conventional activated sludge process can cope with BOD volumetric load of approx. 1 kg/m3/d, the fixed bed biofilm process BOD volumetric load of 3-6 kg/m3/d.
However, the effective treatment in the fixed bed biofilm process is often retarded by clogging of media or blockade of biofilm, resulting in insufficient oxygen supply for bacteria or frequent backwashing of fixed bed media.
PABIO MOVER is a process in which such drawback has been solved by the plastic carriers moving in the whole basin.
2. Mechanism of treatment
In PABIO MOVER, the carriers are filled in the multi-basin type reactor in which they are agitated by aeration to give them movement in the whole basin. Hence, it can obtain high contact efficiency of wastewater, oxygen, and microorganisms and also high oxygen supply efficiency, enabling a high load treatment.
In this process, sludge returning is not required. Since proliferated sludge flow out with the treated water, they can be easily removed by coagulo-sedimentation or flotation process.
Moreover, an existing sedimentation basin can be diverted into an advanced treatment facility by remodeling an existing aeration basin.
Carriers used in PABIO MOVER are lighter than water, S.G. 0.95, and are made of polyethylene. It is column shaped with a cross partition inside and wings outside, allowing easily to flow inside the basin.
Moreover, it has a large unit surface area of 500m2/m3, and microorganisms are chiefly living inside the carriers.
3. Features
1) High contact efficiency can be obtained by use of suitable microorganisms and by moving carriers in the basin.
2) Return sludge is not needed since wastewater is treated by microorganisms adhering to the carriers in the reactor.
Excess sludge will flow out in small particles, but bulking phenomena is not worried since they are easy to be removed in sedimentation basins, etc.
3) Various grade of treated water can be obtained according to purposes from discharge to sewage to public waters.
4) It is possible to apply this process to wide range of applications such as food, chemical, pulp and paper industries, and sewage treatment, and also to the nitrogen removal process.
5) Existing aeration tanks or unused basins can be converted for this process. Therefore, the existing facilities are effectively utilized for intensification of performance.
6) There is no possibility of clogging of carriers, backwashing process is not required as in the biocontact filtration or the fixed bed biofilm process.
4. Performance
PABIO MOVER has higher performance of 5-10 times of that in activated sludge methods. The test results using actual wastewater are below:
1) Agricultural chemicals wastewater
BOD removal rate 97% or more at BOD volumetric load up to 3.0kg/m3/d and 80% or more at BOD volumetric load of 9.5kg/m3/d.
2) Recycled paper plants wastewater
BOD removal rate 80% or more at BOD volumetric load of 5.5kg/m3/d.
3) Soybean foodstuff plants wastewater
BOD removal rate 90% or more at BOD volumetric load 7.9kg/m3/d.
4) Beer brewery wastewater
BOD removal rate 92% or more at BOD volumetric load 4.4kg/m3/d.
