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Mixed Wastewater Coupled with CO2 for Microalgae Culturing and Nutrient Removal.

Yao L, Shi J, Miao X - PLoS ONE (2015)

Bottom Line: Lipid content reached 17.04% for C. sorokiniana and 20.37% for D. communis after 10 days culture.CO2 aeration increased intracellular particle numbers of both microalgae and made D. communis tend to be solitary.The research suggested the aeration of CO2 improve the tolerance of microalgae to high concentration of NH4-N, and nutrient excess stress could induce lipid accumulation of microalgae.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Microbial Metabolism and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China; Biomass Energy Research Center, Shanghai Jiao Tong University, Shanghai 200240, China.

ABSTRACT
Biomass, nutrient removal capacity, lipid productivity and morphological changes of Chlorella sorokiniana and Desmodesmus communis were investigated in mixed wastewaters with different CO2 concentrations. Under optimal condition, which was 1:3 ratio of swine wastewater to second treated municipal wastewater with 5% CO2, the maximum biomass concentrations were 1.22 g L-1 and 0.84 g L-1 for C. sorokiniana and D. communis, respectively. Almost all of the ammonia and phosphorus were removed, the removal rates of total nitrogen were 88.05% for C. sorokiniana and 83.18% for D. communis. Lipid content reached 17.04% for C. sorokiniana and 20.37% for D. communis after 10 days culture. CO2 aeration increased intracellular particle numbers of both microalgae and made D. communis tend to be solitary. The research suggested the aeration of CO2 improve the tolerance of microalgae to high concentration of NH4-N, and nutrient excess stress could induce lipid accumulation of microalgae.

No MeSH data available.


Related in: MedlinePlus

Time course of pH evolution for Chlorella sorokiniana, Desmodesmus communis and control (Blank) cultivated in different media under 0.03% (a, b and c), 5% (d, e and f) and 10% (g, h and i) CO2 concentrations, respectively.Error bars represent ± SD of three replicates.
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pone.0139117.g003: Time course of pH evolution for Chlorella sorokiniana, Desmodesmus communis and control (Blank) cultivated in different media under 0.03% (a, b and c), 5% (d, e and f) and 10% (g, h and i) CO2 concentrations, respectively.Error bars represent ± SD of three replicates.

Mentions: Microalgae-based nutrient removal in wastewater is a much accepted concept worldwide. Nutrient-rich wastewater has been considered to be more appropriate for microalgal growth because it enables an increment in biomass concentration along with nutrient removal [24]. As shown in Table 1, medium 4:0 (SW:STMW) contained the highest levels of TN, NH4+-N and TP, while medium 0:4 (SW:STMW) had the lowest content of these nutrients. The analysis of NH4+-N showed that nearly all ammonia in the different media was removed by C. sorokiniana and D. communis under 0.03% CO2 (Fig 2a, 2b and Table 3). A similar phenomenon was also found by other scientists [22–23, 25–26]. The removal of ammonia was not only due to its up-take by C. sorokiniana and D. communis but also due to stripping and loss to the atmosphere. It has been noted that ammonia stripping and loss to the atmosphere may be the most important mechanisms of ammonia removal when microalgae or cyanobacteria are used for nutrient removal from wastewater [27]. Previous researchers have found that when media contained a high initial concentration of ammonia, the intensified growth inhibition would cause a decrease in ammonia uptake; consequently, ammonia was more susceptible to be stripped and lost, particularly in alkaline medium [26]. In the present study, a net increase in pH values without extra CO2 aeration was observed (Fig 3a and 3b), increasing the removal rate of ammonia.


Mixed Wastewater Coupled with CO2 for Microalgae Culturing and Nutrient Removal.

Yao L, Shi J, Miao X - PLoS ONE (2015)

Time course of pH evolution for Chlorella sorokiniana, Desmodesmus communis and control (Blank) cultivated in different media under 0.03% (a, b and c), 5% (d, e and f) and 10% (g, h and i) CO2 concentrations, respectively.Error bars represent ± SD of three replicates.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4587883&req=5

pone.0139117.g003: Time course of pH evolution for Chlorella sorokiniana, Desmodesmus communis and control (Blank) cultivated in different media under 0.03% (a, b and c), 5% (d, e and f) and 10% (g, h and i) CO2 concentrations, respectively.Error bars represent ± SD of three replicates.
Mentions: Microalgae-based nutrient removal in wastewater is a much accepted concept worldwide. Nutrient-rich wastewater has been considered to be more appropriate for microalgal growth because it enables an increment in biomass concentration along with nutrient removal [24]. As shown in Table 1, medium 4:0 (SW:STMW) contained the highest levels of TN, NH4+-N and TP, while medium 0:4 (SW:STMW) had the lowest content of these nutrients. The analysis of NH4+-N showed that nearly all ammonia in the different media was removed by C. sorokiniana and D. communis under 0.03% CO2 (Fig 2a, 2b and Table 3). A similar phenomenon was also found by other scientists [22–23, 25–26]. The removal of ammonia was not only due to its up-take by C. sorokiniana and D. communis but also due to stripping and loss to the atmosphere. It has been noted that ammonia stripping and loss to the atmosphere may be the most important mechanisms of ammonia removal when microalgae or cyanobacteria are used for nutrient removal from wastewater [27]. Previous researchers have found that when media contained a high initial concentration of ammonia, the intensified growth inhibition would cause a decrease in ammonia uptake; consequently, ammonia was more susceptible to be stripped and lost, particularly in alkaline medium [26]. In the present study, a net increase in pH values without extra CO2 aeration was observed (Fig 3a and 3b), increasing the removal rate of ammonia.

Bottom Line: Lipid content reached 17.04% for C. sorokiniana and 20.37% for D. communis after 10 days culture.CO2 aeration increased intracellular particle numbers of both microalgae and made D. communis tend to be solitary.The research suggested the aeration of CO2 improve the tolerance of microalgae to high concentration of NH4-N, and nutrient excess stress could induce lipid accumulation of microalgae.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Microbial Metabolism and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China; Biomass Energy Research Center, Shanghai Jiao Tong University, Shanghai 200240, China.

ABSTRACT
Biomass, nutrient removal capacity, lipid productivity and morphological changes of Chlorella sorokiniana and Desmodesmus communis were investigated in mixed wastewaters with different CO2 concentrations. Under optimal condition, which was 1:3 ratio of swine wastewater to second treated municipal wastewater with 5% CO2, the maximum biomass concentrations were 1.22 g L-1 and 0.84 g L-1 for C. sorokiniana and D. communis, respectively. Almost all of the ammonia and phosphorus were removed, the removal rates of total nitrogen were 88.05% for C. sorokiniana and 83.18% for D. communis. Lipid content reached 17.04% for C. sorokiniana and 20.37% for D. communis after 10 days culture. CO2 aeration increased intracellular particle numbers of both microalgae and made D. communis tend to be solitary. The research suggested the aeration of CO2 improve the tolerance of microalgae to high concentration of NH4-N, and nutrient excess stress could induce lipid accumulation of microalgae.

No MeSH data available.


Related in: MedlinePlus