South Africa obtains over 80% of its energy needs from fossil fuels. Latest research indicate that South Africa emits over 500 million tons of carbon dioxide (CO 2 ) per year and is therefore ranked number eight as the world's CO 2 emitter. Unabated or controlled emission of CO 2 and other green house gases has largely contributed to detrimental global warming and adverse climatic change. Microalgae are capable of converting hazardous CO 2 into valuable biomass. A high CO 2 tolerating microalgae was collected from Johannesburg Zoo Lake and identified as Desmodemus sp. Batch cultures were grown in 1000 mL. Erlenmeyer flasks. CO 2 was bubbled into the microalgae culture media. The media contained optimal nutrients, an optimal photoperiod and light intensity and controlled pH. CO 2 concentrations of 100%, 50%, 25%, 10%, and 5% and total gas flow rates of 20, 50 and 100 mL/min were used. The aim of this study was to determine the effective flow rate and CO 2 concentration that gave optimal microalgae growth. Microalgae dry mass contain 50% carbon and carbon is known to be a limiting factor when all other nutrients and environmental conditions are presents. When atmospheric air was supplied at 50 mL/min the growth rate was 0.1151 per day and it increased drastically by almost 5 folds when 100% CO 2 was supplied at 50 mL/min. Using a gas flow rate of 20 mL/min and 10% CO 2 , growth rate increased to 1.42 per day with a dry biomass yield of 809.96 mg/L after 12 days of growth. At a gas flow rate of 50 mL/min, 5% CO 2 and the highest growth rate was 1.993 per day and an overall biomass yield of 1200 mg/L and the average pH was 6.36. At 100% CO 2 the growth rate was 1.265 per day and dry biomass yield obtained was 469.81 mg/L while the average pH was 5.12. When gas flow rate was increased to 100 mL/min using 5% CO 2 the growth rate slightly reduced to 1.30 per day with a dry biomass yield of 1000 mg/L. A growth rate was 0.34 and dry biomass yield of 279.47 mg/L at an average pH of 5.09 were achieved at 100% CO 2 . Higher flow rates and higher concentrations resulted in slightly reduced growth due to low pH. These investigations indicate that the species under study is CO 2 tolerant and it presents a viable CO 2 abatement strategy.
School feeding schemes have been implemented in various schools across the globe to improve the nutritional welfare of learners. The purpose of this study was to identify possible nutritional benefits or deficiencies of the foodstuffs served in the South African National School Nutrition Programme in the Free State Province (South Africa). Representative meal samples were collected from randomly selected schools and the nutrient content of meals was determined. The results were measured against nutrient-based standards for an average school lunch for individuals aged 7-10 and 11-18 years. The meals did not meet the nutrient standards for carbohydrate and energy contents for either age group. Protein standards were met by 90% of meals for individuals aged 7-10 years and by 40% for those aged 11-18 years. Only 10% of meals met the standards for calcium and zinc, while 80% and 30% met the iron standards for those aged 7-10 years and 11-18 years, respectively. The lipid and vitamin C contents were within standards. The implementation of proper storage and food preparation procedures may assist in preserving the quality of nutrients.
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