Effects of harvesting cell density, medium depth and environmental factors on biomass and lipid productivities of Chlorella vulgaris grown in swine wastewater

Abstract

A regression model was developed to determine the growth rate of C.vulgaris that is affected by the environmental factors of temperature, light intensity and pH value. The optimum environmental condition for growing C.vulgaris was experimentally determined at light intensity of 240 µEm −2 s −1 , 24 • C and pH of 7.4. At the optimum environmental condition, the growth rate of C.vulgaris in swine wastewater with 102 mg N/l and 76 mg P/l was 0.160 g/l/day, compared to 0.191 g/l/day for its growth on a modified Bold's medium with 100 mg N/l and 53 mg P/l. The regression model was further integrated with a light and heat transfer model to estimate the biomass productivity of C.vulgaris grown on the swine wastewater in an open raceway pond

Enhancing Stability of Microalgae Biocathode by a Partially Submerged Carbon Cloth Electrode for Bioenergy Production from Wastewater

“…The associated average productivity of lipid in the three batches of culture was 25 ± 7 mg/(L•d). The lipid content obtained in this study was higher than that from previous studies on algal lipid production from swine farm anaerobic effluents, in which lipid content of dry biomass ranged from 22% to 27% [14,15,24,25]. Negligible presences of bacteria cells (Figure 3d) could be a possible reason for the relatively high lipid content achieved under the non-septic open conditions.…”

Evaluation of the removal of total phosphorus from sanitary effluent by Chlorella vulgaris in a small batch photobioreactor

“…The two samples prepared (from pure or diluted) effluent showed lower biomass growth than that observed for the synthetic medium, during the observed period. This can be explained by the higher concentration of nutrients present in the synthetic medium, and the higher turbidity of the nature effluent, since according Amini et al (2016) [4] the efficient growth of microalgae depends on environmental variables and the concentrations of essential nutrients such as N and P, the optimal temperature, light intensity and pH for maximum algal growth rate vary among algal. After the 17 th day, it is possible to observe a decrease of growth in the diluted medium (50%) due to the agglomeration of microalgae cells.…”

“…Microalgae are a satisfactory alternative in this scenario. The main attribute of algae culture in wastewater is its ability to efficiently assimilate organic carbon and inorganic nutrients from the waters, leading to biomass production, efficient nutrient removal and lipid accumulation, which can be converted into biodiesel [4]. Assuming the important role of photosynthetic, CO2 fixation, which helps to mitigate the alarming effects of releases of greenhouse gases into the atmosphere [5].…”

“…It is well established that biofuels derived from microalgae have the potential to make a significant contribution to the fuel market. However, this is still not feasible due to the high costs, which can be significantly reduced by using domestic, agricultural and industrial effluents as a source of nutrients for the cultivation of microalgae [4].…”

“…Amini et al (2016) [4] studied the influence of environmental conditions on the growth rate of microalgae and proposed a model to describe this behavior. They observed that the depth of the medium is a very important factor for the growth rate, as well as the luminous intensity.…”