Cultivation of Chlorella sp. IM-01 in municipal wastewater for simultaneous nutrient removal and energy feedstock production

doi:10.1016/j.ecoleng.2014.09.094

Ecological Engineering

Volume 73, December 2014, Pages 326-330

https://doi.org/10.1016/j.ecoleng.2014.09.094 Get rights and content

Highlights

•
Microalgae- a plausible solution for wastewater treatment with nitrogen and phosphorus removal.
•
Carbohydrates and lipids from microalgae can be converted into biofuels.
•
This study suggests the possible cultivation of Chlorella sp. in sewage wastewater with harvesting period of 4–5 days for biofuels production.

Abstract

Current study assesses the potential of indigenously isolated microalgae Chlorella sp. IM-01 for nutrients removal from sewage wastewater and also usability of this wastewater for mass cultivation of microalgae for biofuels production. Growth of Chlorella sp. IM-01 is studied in BG-11 nutrient media and wastewater samples (inlet and outlet from primary treatment point designated as S1 and S2, respectively) at the retention period of 4th and 10th day. In wastewater samples, better growth rate is found in S2 as compared to S1. Biochemical analysis in terms of carbohydrates, proteins and lipids is also done at 4th and 10th day. Biochemical analysis revealed that S2 has better prospect for biofuel production and retention period of 4–5 days is sufficient. These finding suggest that use of such potential species not only prove to deplete the water pollution levels but also act as energy feedstock for biofuels production.

Introduction

Depletion in conventional sources of energy has caused major focus on socio-economic challenges (Barbara, 2007). With an inadequate availability of fossil fuels, there is an urgent need to search for new cheaper sources of renewable energy. Even though terrestrial oilseed crops have good prospects as replacement of conventional sources but other associated reasons such as food security and lower oil yield per hectare are responsible for lowering interest in terrestrial plants for biofuel production. Currently microalgae are projected as sustainable source for biofuel generation (Georgianna and Mayfield, 2012, Kiran et al., 2014). Water pollution is another important issue. Alarming increase in water pollution level in recent time has proved to be one of the foremost threats to the living organisms. Improper disposal of organic and inorganic wastes from households and industries is the basic cause for deterioration of potable natural water bodies. There are several physical and chemical methods available for wastewater treatment. Most commonly nitrogen is removed through the process of denitrification in which nitrate get reduced to nitrogen gas and finally released into the atmosphere. Whereas, phosphorus is removed by chemical precipitation using ferrous chloride. However, these methods have their own disadvantages such as production of toxic sludge, cost intensive etc. Microalgal cultivation generally requires inorganic nutrients and carbon dioxide in the presence of sunlight through photosynthesis. As microalgae require both organic and inorganic nutritional inputs for their survival, wastewater can be a potential source of these nutritional requirements and hence forth microalgae can help in bioremedy of wastewater. Oswald and Gotaas, (1957) first time demonstrated use of algae for nutrient removal. Microalgae had been shown to efficiently utilize nitrogen and phosphorus from municipal wastewater as nutrient source (Oswald et al., 1953, Boonchai et al., 2012). High potential of cyanobacterial species for heavy metal tolerance and removal have been shown in ealier studies (Kiran and Kaushik, 2008, Kiran et al., 2008, Kiran and Thanasekaran, 2011). Thus, microalgae can be a plausible solution for the treatment of wastewater in a cost effective and environmentally safe manner apart of their potential to be used as feed stock for biofuel generation.

In recent years, research has initiated on integration of microalgae biofuel production with wastewater treatment in batch culture, semi-continuous and continuous culture systems. Dickinson et al. (2013) revealed that municipal wastewater as growth medium with unbalanced N/P ratio has negligible effect on nutrient assimilation efficiency of microalgae. Chlorella sp., a unicellular green alga, has been found to be effective for nutrient removal from wastewater (Lim et al., 2010, Cho et al., 2011 Wang et al., 2013). This species has appreciable generation time resulting in high lipid content. Conversion of microalgal biomass into energy product is a promising outlook but feasibility of this further depends upon the quality and quantity of lipids obtainable from microalgae grown in wastewater. Several companies are growing microalgae and producing biodiesel but successful commercialization has not yet been achieved. Hence, lots of research is needed on this concept in order to overcome current economic unsustainability of this system.

In view of above, the present study has been carried out to observe the nutrients uptake capability of an indigenously isolated microalgal strain Chlorella sp. IM-01 from wastewater. Growth is measured through pigment concentration and biomass production. Subsequently, biochemical changes in terms of proteins, carbohydrate and lipid content have also been recorded at retention time interval of 4th and 10th day in order to investigate the effect of wastewater as growth media on biofuel production efficiency.

Section snippets

Isolation and growth conditions of microalgal strain

Chlorella sp. IM-01 has been isolated from wastewater sample collected from sewage treatment plant at Kabirkhedi, Indore (Madhya Pradesh). Strain was isolated and purified by repeated streaking on basal agar medium at pH 8.5 using standard isolation and culturing techniques on nitrogen supplemented BG-11 medium (Kaushik, 1987). Composition of the medium (per liter) is: NaNO₃ 1.5 g, K₂HPO₄ 0.04 g, MgSO₄ 0.075 g, CaCl₂ 0.036 g, citric acid 0.006 g, ferric ammonium citrate 0.006 g, EDTA 0.001 g, Na₂CO₃

Results and discussion

Chlorella sp. IM-01 is cultured in BG-11 media with initial OD 0.01 at 2000 lux light intensity and 27 ± 3°C temperature for 25 days to observe the growth pattern and optical density is read at 680 nm (Fig. 1). This figure shows that initially cells are stabilizing themselves in the medium upto 2nd day after that the growth rate increases upto 6th day. From 6th to 17th day growth rate is maximum. Hence, microalgae utilize nutrients as a very fast rate in this period. Afterwards, growth of

Conclusion

Wastewater contains many organic and inorganic nutrients, which are dumped into water streams causing environmental pollution and health hazards. Utilization of these nutrients for the growth of microalgal species will not only control eutrophication but will also help in sustainable energy development. Focusing on the nutrient uptake capacity of Chlorella sp. IM-01, cultivation of this species for biofuels production can be integrated with wastewater treatment. Current study shows that C

Conflict of Interest statement

The authors declare that there are no conflicts of interest.

Acknowledgement

The authors acknowledge financial assistance provided by Department of Science and Technology, Govt. of India under the INSPIRE Faculty Scheme (IFA12–EAS-01). The funding organization has not played any role in study design, decision to publish or preparation of the manuscript.

References (28)

A.J. Albalasmeh et al.
A new method for rapid determination of carbohydrate and total carbon concentrations using UV spectrophotometry
Carbohydr. Polym.
(2013)
Y. Chen et al.
A simple, reproducible and sensitive spectrophotometric method to estimate microalgal lipids
Anal. Chim. Acta
(2012)
S. Cho et al.
Reuse of effluent water from a municipal wastewater treatment plant in microalgae cultivation for biofuel production
Bioresour. Technol.
(2011)
K.E. Dickinson et al.
Nutrient remediation rates in municipal wastewater and their effect on biochemical composition of the microalga Scenedesmus sp. AMDD
Algal Res.
(2013)
M.K. Garrett et al.
Photosynthetic purification of the liquid phase of animal slurry
Environ. Pollut.
(1976)
B. Kiran et al.
Cyanobacterial biosorption of Cr(VI): application of two parameter and Bohart Adams models for batch and column studies
Chem. Eng. J.
(2008)
B. Kiran et al.
Metal–salt cotolerance and metal removal by indigenous cyanobacterial strains
Process Biochem.
(2008)
B. Kiran et al.
Metal tolernace of an indigenous cyanobacterial strain: lyngbya putealis
Int. Biodeterior. Biodegrad.
(2011)
S. Lim et al.
Use of Chlorella vulgaris for bioremediation of textile wastwater
Bioresour. Technol.
(2010)
O.H. Lowry et al.
Protein measurement with Folin–Phenol reagent
J. Biol. Chem.
(1951)

G. Mackinney

Absorption of light by chlorophyll solutions

J. Biol. Chem.

(1941)

N.F.Y. Tam et al.

The comparison of growth and nutrient removal efficiency of Chlorella pyrenoidosa in settled and activated sewage

Environ. Pollut.

(1990)

C. Wang et al.

Nitrogen and phosphorus remvoal from municipal wastewater by the green alga Chlorella sp

J. Env. Biol.

(2013)

American Public Health Association

Standard Methods for the Examination of Water and Wastewater

(2005)

Cited by (47)

Effect of different microalgae-bacterium-fungus symbiont technologies on nutrient removal from aquaculture wastewater and biogas upgrading under a variety of mixed light wavelengths
2024, Algal Research
To develop and characterize novel microalgae-based technology under different mixed light-emitting diode (LED) light wavelengths for simultaneous treatment of actual aquaculture tailwater and biogas upgrading, the performance of four microalgal cultivations in bamboo shrimp aquaculture tailwater treatment and biogas upgrading were systematically examined and analyzed. The results demonstrated that Chlorella vulgaris (C. vulgaris)-endophytic bacterium (S395-2)-Clonostachys rosea (C. rosea) symbiont had the highest growth rate, daily production rate and carbonic anhydrase activity at the 7th d treatment time-point under Red(5): Blue(5) LED mixed light source. After 10d treatment, the nutrient removal efficiency of C. vulgaris-S395-2-C. rosea symbiont under Red(5): Blue(5) LED mixed wavelengths reached up to 93.7% for total inorganic nitrogen, 97.4% for ammonium nitrogen, 96.9% for nitrate nitrogen and 98.8% for phosphate; carbon dioxide (CO₂) removal rate maintained at 53.1% without significantly affecting methane (CH₄) level. In summary, the present study demonstrates that Red (5): Blue(5) LED mixed wavelengths optimally increase the performance of C. vulgaris-S395-2-C. rosea symbiont in nutrient and CO₂ removal without loss of CH₄, providing a framework for future simultaneous performing actual aquaculture tailwater treatment and biogas upgrading using microalgae-endophytic bacteria-fungus symbiont.
In-situ pretreatment of aquaculture tail water by molasses addition and the responses of bacterioplankton communities
2023, Journal of Water Process Engineering
To reduce the pollutant concentrations in aquaculture tail water before discharging is important. Microcosmic experiment on pond culture of tilapia was conducted, in-situ molasses addition before 58 days of harvest was performed, and its effects on quality of aquaculture tail water and the responses of bacterioplankton communities were detected. Our findings showed that the molasses addition effectively reduced the concentration of total phosphorus, total nitrogen, and three kinds of inorganic nitrogen in aquaculture tail water. And its linear effect on nitrate and nitrite nitrogen was through the impact on the bacterioplankton communities.
The dominant bacteria observed were Proteobacteria and Bacteroidetes, indicating that water quality physicochemical parameters have a significant correlation with different bacterial communities. FAPROTAX software provided bacterial function predictions and identified chemoheterotrophic bacteria as dominant in the tail water. In addition, abundance of functional microorganisms associated with nitrogen and phosphorus cycling was high. Interestingly, the growth-promoting effect of molasses on cultured organisms may not be due to the ingestion of biofloc by animals but could be a direct effect of molasses.
Our study demonstrates that the addition of molasses can improve the quality of cultured tail water, reduce the environmental purification pressure, significantly alter microbial community structure in the water, enhance the nitrogen cycling capacity of the aquatic environment, and promote the growth of cultured animals. These results can provide a theoretical basis for the application of molasses in in-situ pretreatment of aquaculture tail water.
Scaling up of native species for a sustainable microalgal biorefinery targeting different microalgal products
2023, Algal Research
The present study aims to establish a sustainable bio refinery production in a semi-outdoor environment using two different types of media; fertilizer-based medium (FBM) and wastewater based medium (WWBM). A comparative study was performed under laboratory conditions to evaluate the effects of these media on a smaller scale. Cultivation was further scaled up to 500 L volume using WWBM resulting in four folds more biomass accumulation, 1.3 folds more carbohydrate accumulation, and 1.2 folds more lipids compared to cultivation under laboratory conditions. In this study, the species Ettlia texensis was used. It was isolated from the nearby regions of Indore. Being indigenous, Ettlia texensis easily adapted to Indore's climatic conditions and produced important precursors without compromising biomass. With the supplementation of WWBM at 500 L cultivation volume, E. texensis was able to produce 493.4 ± 34.4 μg of lipid per mg of biomass, which was 1.5 folds higher than at the laboratory scale. This study facilitates successful up-scaling of the process by providing insight into the utilization of low-cost media for microalgal production. The semi-outdoor cultivation of E. texensis to produce precursors of various compounds is used in this study for the first time.
Roles of microalgae-based biofertilizer in sustainability of green agriculture and food-water-energy security nexus
2023, Science of the Total Environment
For years, agrochemical fertilizers have been used in agriculture for crop production. However, intensive utilization of chemical fertilizers is not an ecological and environmental choice since they are destroying soil health and causing an emerging threat to agricultural production on a global scale. Under the circumstances of the increasing utilization of chemical fertilizers, cultivating microalgae to produce biofertilizers would be a wise solution since desired environmental targets will be obtained including (1) replacing chemical fertilizer while improving crop yields and soil health; (2) reducing the harvest of non-renewable elements from limited natural resources for chemical fertilizers production, and (3) mitigating negative influences of climate change through CO₂ capture through microalgae cultivation. Recent improvements in microalgae-derived-biofertilizer-applied agriculture will be summarized in this review article. At last, the recent challenges of applying biofertilizers will be discussed as well as the perspective regarding the concept of circular bio-economy and sustainable development goals (SDGs).
A review on the sustainable procurement of microalgal biomass from wastewaters for the production of biofuels
2023, Chemosphere
The feasibility of microalgal biomass as one of the most promising and renewable sources for the production of biofuels is being studied extensively. Microalgal biomass can be cultivated under photoautotrophic, heterotrophic, photoheterotrophic, and mixotrophic cultivation conditions. Photoautotrophic cultivation is the most common way of microalgal biomass production. Under mixotrophic cultivation, microalgae can utilize both organic carbon and CO₂ simultaneously. Mixotrophic cultivation depicts higher biomass productivity as compared to photoautotrophic cultivation. It is evident from the literature that mixotrophic cultivation yields higher quantities of polyunsaturated fatty acids as compared to that photoautotrophic cultivation. In this context, for economical biomass production, the organic carbon of industrial wastewaters can be valorized for the mixotrophic cultivation of microalgae. Following the way, contaminants’ load of wastewaters can be reduced while concomitantly producing highly productive microalgal biomass. This review focuses on different aspects covering the sustainable cultivation of different microalgal species in different types of wastewaters.
A review on algal-bacterial symbiosis system for aquaculture tail water treatment
2022, Science of the Total Environment
Citation Excerpt :
Typical chemical treatment techniques include advanced oxidation and electrochemical treatment. They are either expensive or can easily produce recalcitrant by-products that are not environmentally friendly (Guldhe et al., 2017; Kiran et al., 2014). Traditional biotechnologies, such as activated sludge, biofiltration and biofilm-based method, can effectively remove organic matter.
Aquaculture is one of the fastest growing fields of global food production industry in recent years. To maintain the ecological health of aquaculture water body and the sustainable development of aquaculture industry, the treatment of aquaculture tail water (ATW) is becoming an indispensable task. This paper discussed the demand of environmentally friendly and cost-effective technologies for ATW treatment and the potential of algal-bacterial symbiosis system (ABSS) in ATW treatment. The characteristics of ABSS based technology for ATW treatment were analyzed, such as energy consumption, greenhouse gas emission, environmental adaptability and the possibility of removal or recovery of carbon, nitrogen and phosphorus as resource simultaneously. Based on the principle of ABSS, this paper introduced the key environmental factors that should be paid attention to in the establishment of ABSS, and then summarized the species of algae, bacteria and the proportion of algae and bacteria commonly used in the establishment of ABSS. Finally, the reactor technologies and the relevant research gaps in the establishment of ABSS were reviewed and discussed.

View all citing articles on Scopus

View full text

Cultivation of Chlorella sp. IM-01 in municipal wastewater for simultaneous nutrient removal and energy feedstock production

Highlights

Abstract

Introduction

Section snippets

Isolation and growth conditions of microalgal strain

Results and discussion

Conclusion

Conflict of Interest statement

Acknowledgement

Carbohydr. Polym.

Anal. Chim. Acta

Bioresour. Technol.

Algal Res.

Environ. Pollut.

Chem. Eng. J.

Process Biochem.

Int. Biodeterior. Biodegrad.

Bioresour. Technol.

J. Biol. Chem.

J. Biol. Chem.

Environ. Pollut.

J. Env. Biol.

Standard Methods for the Examination of Water and Wastewater