University of Natural Resources and Life Sciences, Vienna (BOKU) - Research portal
Gewählte Master / Diploma Thesis:
Nomundari Erdene
(2018):
Assessment of the water quality by means of fouling indexes.
Master / Diploma Thesis - Institut für Siedlungswasserbau, Industriewasserwirtschaft und Gewässerschutz (SIG),
BOKU-Universität für Bodenkultur,
pp 134.
UB BOKU
obvsg
FullText
- Abstract:
- Silt density index and modified fouling index are extensively employed as a fouling indication in membrane systems. However, there are several disadvantages in terms of reliability and accuracy. The exact relation between two indexes and other water quality parameters is still uncertain. The results from different measuring instruments show incomparable results. Lastly, it is under question whether the indexes can accurately predict the membrane system performance. The objective of this master thesis is to compare the MFI and SDI values with each other and with other water quality parameters and to assess performance and the chemical removal rates in a reverse osmosis pilot plant. For this a reverse osmosis membrane pilot plant was constructed to run experiments with different water matrices, where pollutant removal rates are examined for Zn, Cu, diurone, atrazine and nitrate. In addition, experiments were conducted with a biocide. SDI and MFI measuring unit was arranged at BOKU and compared with the INSPECTOR apparatus. Calculation of the MFI from the BOKU instrument, show that the system requires at least 45 seconds to reach the cake filtration. SDI15 values are on average 1.7 times higher than the MFI values. Experiments with filters with different pore sizes approve that the main mechanism of the filtration process is size exclusion. SDI and MFI have high correlation to turbidity, conductivity and TDS. The comparison of MFI generated from 2 different instruments show statistically significant differences (p=0.28). The removal rate of the pollutants is not lower than 87%. Rejection rate is highest for the heavy metals (>98.9%). The biocide efficiency depends on the fouling of the membrane. The new membrane has higher efficiency (99.5%) than old membrane (88%) in terms of live microbial cells.
- Beurteilende(r): Fürhacker Maria