Influence of elevated CO2 concentrations on growth, nutrient removal, and CO2 biofixation using Chlorella kessleri cultivation

Sultana

Intl J of Energy Research

et al. 2021

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This study investigates the influences of light-dark cycles and NaNO 3 dose on Chlorella kessleri microalgal-specific growth rate (SGR), biomass productivity (P), and intracellular lipid productivity (LP) by using central composite design with desirability function. A single-objective optimization showed that the maximum SGR, P, and LP can be achieved as 0.487 day −1 , 58.718 g/L day −1 , and 14.252 mg/L day −1 , respectively. The corresponding optimized light-dark cycle and NaNO 3 loading were determined as 11.6/8.4 (h/h) and 15.54 g/L, 12/12 (h/h) and 16.23 g/L, and 12/12 (h/h) and 6.63 g/L, respectively. The multiresponse optimization showed that the highest SGR of 0.359 day −1 , biomass productivity of 50.663 g/L day −1 and LP of 14.114 mg/L day −1 can be accomplished at culture environments of 12/12 (h/h) light-dark cycles and 10.38 g/L NaNO 3 . These results suggest that the central composite design with desirability function-based technique is useful for design and operation of photobioreactors to produce lipid from microalgae. Analysis of variance was employed to explore the significance of the factors affecting microalgal growth as well as biomass and lipid productivities. The predicted optimized culture conditions were experimentally confirmed (error < 6%) indicating the process is robust and reliable.

Section: Methodsmentioning

confidence: 88%

“…These light intensity and CO 2 mixture conditions gives maximum biomass productivities in recent findings. 51 Microalgae were cultured in 10 days, however, lipid contents were carried out using the data collected on day 8.…”

Section: Microalgae and Its Growth Environmentmentioning

confidence: 99%

Optimization of microalgal biomass and lipid productivities for bioenergy production using central composite design with desirability function

Sultana

Intl J of Energy Research

et al. 2021

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Int. J. Environ. Sci. Technol.

“…The term 'phycoremediation' refers to remediation by algae (John 2003), or specifically the removal or transformation of organic and inorganic pollutants from wastewater (Rawat et al 2011), and CO 2 from atmospheric emissions, using either terrestrial or aquatic macro-or microalgae (Olguín 2003). Algae are used to remove toxic and non-toxic substances from solid, liquid or gaseous wastes by metabolic uptake, accumulation or biotransformation processes, and subsequently harvested for valuable biomass (Rao et al 2019;Faruque et al 2021). Phycoremediation has been used in wastewater treatment for the last 60 years, with one of the first descriptions of its application being reported by Oswald and Gotaas (1957).…”

Section: Phycoremediation Of Pomementioning

confidence: 99%

“…The process utilises the natural ability of algae to uptake and assimilate the nutrients, accumulate toxic metals, and degrade organic contaminants via symbiotic interaction with aerobic bacteria (Ahmad et al 2020). It has a low environmental impact due to the suitability of the biomass byproduct for biofuel which allows efficient nutrient recycling (Olguín 2003;Faruque et al 2021). Using microalgae to remediate wastewater is also cost effective because less freshwater is consumed by the process, and nutrients levels are reduced by microalgae assimilation for the synthesis of proteins, nucleic acids and phospholipids (Rao et al 2019).…”

Section: Phycoremediation Of Pomementioning

confidence: 99%

Advances in POME treatment methods: potentials of phycoremediation, with a focus on South East Asia

Tan

Maznah

Morad

et al. 2021

The discharge of palm oil mill effluent (POME) without effective treatment is highly toxic to the environment and receiving waters due to its high chemical oxygen demand , biochemical oxygen demand and increased levels of suspended solids. The ponding system is regarded as a conventional method for the treatment of POME but requires long retention time and extensive treatment areas. Other processes, such as physicochemical treatment, have also been applied as tertiary steps to ensure lower toxicity of the POME discharge. More recently, phycoremediation, a new biological treatment method using microalgae, has been reported as having great potential in being a highly efficient method of reducing the environmental impact of POME. This paper discusses the feasibility of the above treatment methods of POME, including the potential of phycoremediation, with a focus on their application in South East Asia.

“…Various biological, chemical, and physical techniques are available for tertiary wastewater treatment [9]. Although there are numerous techniques for tertiary wastewater treatment, the microalgae-driven biological tertiary wastewater treatment process is in high demand since it is eco-friendly, cost-effective, and does not require any additional energy [10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Phototrophic Bioremediation of Municipal Tertiary Wastewater Coupling with Lipid Biosynthesis Using Scenedesmus dimorphus: Effect of Nitrogen to Phosphorous Ratio with/without CO2 Supplementation

et al. 2023

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Scenedesmus dimorphus was utilized for the tertiary treatment of municipal wastewater in an effort to remove nutrients from secondary treated wastewater. In addition to the concurrent generation of biomass containing lipids for biofuel production. The effect of nitrogen to phosphorous (N:P) ratios (1:1 to 8:1) in culture media without carbon dioxide (CO2) supplementation (air supply alone, Case 1) and with CO2 supplementation (2% CO2 in air, Case 2) was investigated through a series of systematic parametric batch experiments. Case 2 produces greater biomass at all N:P ratios than Case 1. In Case 1, the highest biomass output for a N:P ratio of 8:1 is 567 mg/L at pH 8.4. In Case 2, however, the maximum biomass yield is 733 mg/L when the N:P ratio is 2:1 and the pH is 7.23. Scenedesmus dimorphus is capable of absorbing nitrogen and phosphorous from wastewater in a CO2 environment and at the optimal N:P ratio. In Case 1, total nitrogen removal ranges from 28% to 100% and in Case 2, total nitrogen removal ranges from 60% to 100%, depending on the N:P ratio. For an initial concentration of 13 mg/L, the total phosphorous removal ranges from 37% to 57%, depending on the N:P ratio in both cases. Case 2 yields a maximum lipid content of 29% of the biomass dry weight when the N:P ratio is 1:1. These results suggest the viability of removing nutrients from secondary treated wastewater utilizing microalgae Scenedesmus dimorphus and lipid biosynthesis in the generated biomass.