Naslov
Membrane filtration-integrated bioreactors in wastewater treatment a way out from the dead-end street

Autori
Horvat, Predrag

Vrsta, podvrsta i kategorija rada
Poglavlja u knjigama, znanstveni

Knjiga
Current studies of Biotechonology, Volume II. - Environment

Urednik/ci
Kniewald, Zlatko

Izdavač
Hrvatsko Društvo za Biotehnologiju

Grad
Zagreb

Godina
2001

Raspon stranica
97-115

ISBN
953-98094-3-6

Ključne riječi
wastewater, cross-flow filtration, hollow-fibre filtration, membrane-integrated bioreactors

Sažetak
In the last years, in communal wastewater treatment circles, the question is frequently raised if the classical approach has exhausted its possibilities or stated otherwise ; -has the classical activated sludge technology (primary clarifier, aerated basins with pre-treatment, cyclic or simultaneous denitrification, and secondary clarifier) reached its maximum performance? There are a number of arguments for these questions! Accepted output concentrations of all compounds according to recently published new legislations, become more eco-friendly, what means, are lower as before. Therefore, a tendency is developing to build greater and greater plants, or to increase the sludge concentration. The latter is possible with enhancing the degree of sludge recirculation, leading to increased growth of filamentous bacteria, which settle slowly or not ("bulking"). A "step before" denitrification, leads necessary to recirculation of bigger and bigger flows of purified water. As a consequence, to achieve 90 % of nitrogen reduction the quantity of purified water in the recirculation should be ten times higher than the incoming water flow. In addition, concentrations of all compounds in such mixed wastewater are decreasing, and therefore, a negative influence on degradation rates is usually observed. The problem described above could be partially solved by cyclic or simultaneous nitrification/denitrification. In this case, the question is how to co-ordinate the different biological reaction rates (COD, BOD, N and P elimination). A classical settler used as an end-clarifier is unable to remove all of the members of life community, especially enteric bacteria and hosts of viruses. Some of those originate from hospitals and some are dangerous. If the water is to be reused (i.e. natural swimming areas), the uncontrolled spreading of diseases and of organisms resistant to antibiotics is possible. This work reports on the possibilities of membrane microfiltration technology integrated in bioreactors, for the solution of the problems enumerated.

Izvorni jezik
Engleski

Znanstvena područja
Biotehnologija, Prehrambena tehnologija

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