     Downloads - Reports
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| D12 - MBR fouling control strategies and on-line sensors of fouling indicators | |
| Project | AMEDEUS |
| Date | 11.5.2010 |
| Abstract | The objective of this research work was on the one hand the development of an on-line analysing system in order to determine the organic fouling compounds and on the other hand fouling mitigation by using different chemicals (e.g. flocculants, starch, PAC) in membrane bioreactors. For the first purpose two different sensors have been developed. First a photometrically based sensor, developed by TU Berlin, relies on the direct measurement of fouling active compounds - proteins and polysaccharides - in the mixed liquor. These substances are very important components of EPS/SMP. The second approach, developed by VITO, is a physically based sensor which measures reversible and irreversible filtration resistances of the mixed liquor under welldefined and reproducible conditions – and is thus independent of the current age or fouling state of the MBR plant membrane module. In lab-scale experiments and in technical installations the effectiveness of the measuring instruments was investigated. Good results in terms of reproducibility and sensitivity in different matrices have been obtained for both sensors. A comparison of both sensors is presented. In a comprehensive and impartial screening 30 substances have been investigated. SMP elimination potential, effects on filterability in small scale, respiration, oxygen transfer, nitrification and denitrification, as well as shear stability, dewaterability and costs were taken into account. Also the impact of biomass concentration, calcium concentration and temperature on flocculation and adsorption was tested. To confirm their applicability at technical scale, two identical MBRs were constructed and operated for several months (one for tests, other as reference). Two polymers and a starch have been selected from pre-screening tests and studied in a MBR pilot plant. The tested additives showed no negative impact on the biological performance in terms of COD- and N-elimination. While both polymers showed a positive effect on membrane performance, the starch led to an accelerated fouling behaviour. Furthermore dynamic operation of MBR pilot plant has been conducted by simulating of rain events and of influent peaks. The purpose of this test was to evaluate the impact of dynamic operation on fouling and fouling compounds (proteins, polysaccharides) measured online as well as on biological performance. |
| Pages | 83 |
| Download | pdf (2.00 MB) |
