Magister Scientiae - MSc (Biotechnology) / The treatment of mine water at the eMalahleni Water Reclamation Plant (EWRP) results in the
production of large volumes of brine. Different brine management methods have been applied
to dispose the brine but the evaporation pond method is regarded as the cheaper, most effective
and less laborious method for brine disposal. Brine wastewater is pumped into the pond where
it evaporates resulting in the mixture of salts. The rate at which evaporation occurs is influenced
by many factors such as temperature, salinity, humidity and wind. Due to high salinities in
brine the EWRP is currently experiencing a challenge with low evaporation rate. Here, a
comparative study was done to determine the efficiency of using a chemical and a biological
approach to enhance the evaporation rate of reject brine. The chemical approach involved the
addition of various concentrations of methylene blue dye (100 to 300 ppm with 50 ppm
increments) to 1L volumes of brine, and measuring the evaporation rate. On the other hand, the
biological approach involved the isolation of pigmented halophilic bacteria from eMalahleni
brine and Cerebos salt samples. Isolated bacterial strains were characterised based on their
morphology, biochemical and salt tolerance characteristics. Furthermore, the strains were
identified using 16S rRNA gene sequence analysis. Among the isolated halophilic bacterial
strains, EP-3, an Arthobacter agilis isolated from the eMalahleni brine produced a darker
pigment compared to the other strains. Therefore, EP-3 was evaluated for its effect on the
evaporation of brine using a culture inoculum or the addition pigment extracted from an EP-3
culture. The addition of MB above 100 ppm overcame the effect of salt precipitation and
resulted in higher evaporation (41%) rate. Addition of pigmented bacteria or bacterial extracted
pigment to the brine respectively resulted in 18% and 24% increase in the evaporation rate.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uwc/oai:etd.uwc.ac.za:11394/6353 |
| Date | January 2018 |
| Creators | Khumalo, Londiwe Thandeka Precious |
| Contributors | Trindade, Marla, Petrik, Leslie |
| Publisher | University of the Western Cape |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Rights | University of the Western Cape |
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