Coal seams are commonly associated with poor quality water that requires treatment. Water treatment can be very expensive and can severely affect the profitability of mining projects. This study investigated the potential cultivation of Arthrospira maxima (Spirulina) in coal seam water to beneficiate coal seam water in order to effectively offset the water treatment cost. The study was conducted in Northern South Africa and formed part of a larger Coal Seam Water Beneficiation Project (CSWBP). The study consisted of laboratory based Flask Studies and outdoor High Rate Algal Pond Studies. The Flask Studies that were carried out in the on-site field laboratory, found that the coal seam water could provide a suitable medium for Spirulina cultivation. In addition, it was found that the optimal pH for the selected strain ranged between 9 - 10.5 and that the addition of excess iron, up to 100 times the concentration found in defined growth media such as Schlösser’s, to the culture media could enhance productivity. The High Rate Algal Pond Studies (HRAP) were carried out over a period of 18 months. The studies showed that the coal seam water at the CSWBP is a valuable resource that can reduce media costs by 50% without affecting productivity. In a study encompassing 334 days it was shown that heating the culture through plate heat exchangers would result in a significant increase in productivity and a heated productivity of 19.86 g/m2/day was recorded. An unheated productivity of 14.11 g/m2/day was recorded. Therefore, it was found that it would be economically feasible to beneficiate coal seam water found at the CSWBP through the cultivation of Arthrospira maxima (Spirulina). / Environmental Sciences / M. Sc. (Environmental Science)

Coal seams are commonly associated with poor quality water that requires treatment. Water treatment can be very expensive and can severely affect the profitability of mining projects. This study investigated the potential cultivation of Arthrospira maxima (Spirulina) in coal seam water to beneficiate coal seam water in order to effectively offset the water treatment cost. The study was conducted in Northern South Africa and formed part of a larger Coal Seam Water Beneficiation Project (CSWBP). The study consisted of laboratory based Flask Studies and outdoor High Rate Algal Pond Studies. The Flask Studies that were carried out in the on-site field laboratory, found that the coal seam water could provide a suitable medium for Spirulina cultivation. In addition, it was found that the optimal pH for the selected strain ranged between 9 - 10.5 and that the addition of excess iron, up to 100 times the concentration found in defined growth media such as Schlösser’s, to the culture media could enhance productivity. The High Rate Algal Pond Studies (HRAP) were carried out over a period of 18 months. The studies showed that the coal seam water at the CSWBP is a valuable resource that can reduce media costs by 50% without affecting productivity. In a study encompassing 334 days it was shown that heating the culture through plate heat exchangers would result in a significant increase in productivity and a heated productivity of 19.86 g/m2/day was recorded. An unheated productivity of 14.11 g/m2/day was recorded. Therefore, it was found that it would be economically feasible to beneficiate coal seam water found at the CSWBP through the cultivation of Arthrospira maxima (Spirulina). / Environmental Sciences / M. Sc. (Environmental Science)

MESHWR / Department of Hydrology and Water Resources / In South Africa, inland aquaculture is on the increase, especially among the rural communities. Thus aquaculture is able to provide a source of employment and improve rural incomes. This study assessed algae species and their cyanotoxins in small holder production in Vhembe district, Limpopo, South Africa. Thirteen study sites were selected to assess the algae species and their cyanotoxins. The water samples were collected in four quarters and analysed for water temperature, pH, total dissolved solids, Electrical conductivity, phosphates, nitrates, chlorophyll, cyanobacteria, cyanotoxins, metal species and quality of the water in the fish ponds. In the 1st quarter of the year there was variation in Water Temperature (23.7oC-31.4oC), pH (5.5-9.6), EC (3.82-46.8μS/cm), TDS (2.4-45 mg/L), Phosphate (0.0-1.09mgL-1), Nitrates (0.0-1.00mgL-1), Chlorophyll-a (5.8-11.5mg/m-3). In the 2nd quarter there was variation inwater temperature (22.4-25.0oC), pH (6.6-8.8.9), EC (19.23-21.47μS/cm), TDS (12.5-17.9 mg/L), Phosphate (1.64-1.84mgL-1), Nitrates (1.02-1.88mgL-1), Chlorophyll-a (4.6-15.6mg/m-3). In the 3rd quarter there was variation for water temperature (22.9-25.0oC), pH (7.5-9.1), EC (7.91-293.3μS/cm), TDS (11.7-180.9 mg/L), Phosphate (1.10-1.80mgL-1), Nitrates (1.28-1.84mgL-1),Chlorophyll-a (6.8-15.6mg/m-3). In the 4th quarter there was variation forwater temperature (23.5-30.3), pH (7.1-9.3), EC (18.24-623μS/cm), TDS (23.7-136.4 mg/L), Phosphate (1.45-1.99mgL-1), Nitrates (1.43-1.68mgL-1), Chlorophyll-a (6.6-25.9mg/m-3). The metal content of the fish pond water was variable throughout the year but with moderate levels of Al, Cd, Cr, Mn, Fe, Cu, Zn and Ba were found. The metal Fe, exceeded the DWAF guideline values during this first quarter. The presence of Cd in the fish pond water could be attributed to rainfall eroding the earthen embankments of the fish pond. The results of physico-chemical parameters promotes the growth of cyanobacteria in the fish ponds. Flow cam and SEM were used to identify the cyanobacteria species and most cyanobacteria identified are hazard to human health, fish and other aquatic organisms. Molecular technologies were used to identify cyanotoxins and there was no cyanotoxins detected which was concluded that during collection of water samples no cyanobacteria produced toxins. / NRF