scholarly journals Optimisation of microalgal cultivation via nutrient-enhanced strategies: the biorefinery paradigm

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Gonzalo M. Figueroa-Torres ◽  
Jon K. Pittman ◽  
Constantinos Theodoropoulos
Keyword(s):  
Kinetic Model ◽  
Growth Dynamics ◽  
Value Added ◽  
Cost Effective ◽  
Predictive Modelling ◽  
Nitrogen And Phosphorus ◽  
Predictive Capacity ◽  
Microalgal Biomass ◽  
Microalgal Cultivation ◽  
Lipid Formation

Abstract Background The production of microalgal biofuels, despite their sustainable and renowned potential, is not yet cost-effective compared to current conventional fuel technologies. However, the biorefinery concept increases the prospects of microalgal biomass as an economically viable feedstock suitable for the co-production of multiple biofuels along with value-added chemicals. To integrate biofuels production within the framework of a microalgae biorefinery, it is not only necessary to exploit multi-product platforms, but also to identify optimal microalgal cultivation strategies maximising the microalgal metabolites from which biofuels are obtained: starch and lipids. Whilst nutrient limitation is widely known for increasing starch and lipid formation, this cultivation strategy can greatly reduce microalgal growth. This work presents an optimisation framework combining predictive modelling and experimental methodologies to effectively simulate and predict microalgal growth dynamics and identify optimal cultivation strategies. Results Microalgal cultivation strategies for maximised starch and lipid formation were successfully established by developing a multi-parametric kinetic model suitable for the prediction of mixotrophic microalgal growth dynamics co-limited by nitrogen and phosphorus. The model’s high predictive capacity was experimentally validated against various datasets obtained from laboratory-scale cultures of Chlamydomonas reinhardtii CCAP 11/32C subject to different initial nutrient regimes. The identified model-based optimal cultivation strategies were further validated experimentally and yielded significant increases in starch (+ 270%) and lipid (+ 74%) production against a non-optimised strategy. Conclusions The optimised microalgal cultivation scenarios for maximised starch and lipids, as identified by the kinetic model presented here, highlight the benefits of exploiting modelling frameworks as optimisation tools that facilitate the development and commercialisation of microalgae-to-fuel technologies.

scholarly journals Optimisation of Microalgal Cultivation via Nutrient-Enhanced Strategies: the Biorefinery Paradigm

2021 ◽  
Author(s):  
Gonzalo M. Figueroa-Torres ◽  
Jon Pittman ◽  
Constantinos Theodoropoulos
Keyword(s):  
Kinetic Model ◽  
Growth Dynamics ◽  
Value Added ◽  
Cost Effective ◽  
Predictive Modelling ◽  
Nitrogen And Phosphorus ◽  
Predictive Capacity ◽  
Microalgal Biomass ◽  
Microalgal Cultivation ◽  
Lipid Formation

Abstract Background: The production of microalgal biofuels, despite their sustainable and renowned potential, is not yet cost-effective compared to current conventional fuel technologies. However, the biorefinery concept increases the prospects of microalgal biomass as an economically viable feedstock suitable for the co-production of multiple biofuels along with value-added chemicals. To integrate biofuels production within the framework of a microalgae biorefinery, it is not only necessary to exploit multi-product platforms, but also to identify optimal microalgal cultivation strategies maximising the microalgal metabolites from which biofuels are obtained: starch and lipids. Whilst nutrient limitation is widely known for increasing starch and lipid formation, this cultivation strategy can greatly reduce microalgal growth. This work presents an optimisation framework combining predictive modelling and experimental methodologies to effectively simulate and predict microalgal growth dynamics and identify optimal cultivation strategies. Results: Microalgal cultivation strategies for maximised starch and lipid formation were successfully established by developing a multi-parametric kinetic model suitable for the prediction of mixotrophic microalgal growth dynamics co-limited by nitrogen and phosphorus. The model’s high predictive capacity was experimentally validated against various datasets obtained from laboratory-scale cultures of Chlamydomonas reinhardtti CCAP 11/32C subject to different initial nutrient regimes. The identified model-based optimal cultivation strategies were further validated experimentally and yielded significant increases in starch (+270 %) and lipid (+74 %) production against a non-optimised strategy. Conclusions: The optimised microalgal cultivation scenarios for maximised starch and lipids, as identified by the kinetic model presented here, highlight the benefits of exploiting modelling frameworks as optimisation tools that facilitate the development and commercialisation of microalgae-to-fuel technologies.

Optimising microalgal cultivation for biofuels production: the biorefinery paradigm

2020 ◽  
Author(s):  
Gonzalo M. Figueroa-Torres ◽  
Jon Pittman ◽  
Constantinos Theodoropoulos
Keyword(s):  
Kinetic Model ◽  
Growth Dynamics ◽  
Value Added ◽  
Cost Effective ◽  
Predictive Modelling ◽  
Nitrogen And Phosphorus ◽  
Predictive Capacity ◽  
Microalgal Cultivation ◽  
Product Platforms ◽  
Lipid Formation

Abstract Background: Microalgae are regarded as a viable biorefinery platform for the sustainable and cost-effective production of biofuels and other value-added chemicals. However, to allow this promising biomass to compete with existing biofuel feedstock technologies, it is necessary to exploit multi-product platforms and to identify optimal microalgal cultivation strategies maximising the microalgal metabolites from which biofuels are obtained: starch and lipids. Whilst nutrient limitation is widely known for increasing starch and lipid formation, this cultivation strategy can greatly reduce microalgal growth. This work presents an optimisation framework combining predictive modelling and experimental methodologies to simulate microalgal growth dynamics and identify optimal cultivation strategies.Results: Microalgal cultivation strategies for maximised starch and lipid formation were successfully established by developing a multi-parametric kinetic model suitable for the prediction of mixotrophic microalgal growth dynamics co-limited by nitrogen and phosphorus. The model’s high predictive capacity was experimentally validated against various datasets obtained from laboratory-scale cultures of Chlamydomonas reinhardtti CCAP 11/32C subject to different initial nutrient regimes. The identified model-based optimal cultivation strategies were further validated experimentally and yielded significant increases in starch (+270 %) and lipid (+74 %) production against a non-optimised strategy.Conclusions: The optimised microalgal cultivation scenarios for maximised starch and lipids, as identified by the kinetic model presented here, highlight the benefits of exploiting modelling frameworks as optimisation tools that facilitate the development and commercialisation of microalgae-to-fuel technologies.

scholarly journals Valorization of Wastewater Resources Into Biofuel and Value-Added Products Using Microalgal System

2021 ◽  
Vol 9 ◽  
Author(s):  
Kanika Arora ◽  
Parneet Kaur ◽  
Pradeep Kumar ◽  
Archana Singh ◽  
Sanjay Kumar Singh Patel ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Industrial Wastewater ◽  
Microbial Growth ◽  
Oxygen Demand ◽  
Value Added ◽  
Aquatic Organisms ◽  
Pilot Scale ◽  
Microalgal Biomass ◽  
Microalgal Cultivation ◽  
Value Added Products

Wastewater is not a liability, instead considered as a resource for microbial fermentation and value-added products. Most of the wastewater contains various nutrients like nitrates and phosphates apart from the organic constituents that favor microbial growth. Microalgae are unicellular aquatic organisms and are widely used for wastewater treatment. Various cultivation methods such as open, closed, and integrated have been reported for microalgal cultivation to treat wastewater and resource recovery simultaneously. Microalgal growth is affected by various factors such as sunlight, temperature, pH, and nutrients that affect the growth rate of microalgae. Microalgae can consume urea, phosphates, and metals such as magnesium, zinc, lead, cadmium, arsenic, etc. for their growth and reduces the biochemical oxygen demand (BOD). The microalgal biomass produced during the wastewater treatment can be further used to produce carbon-neutral products such as biofuel, feed, bio-fertilizer, bioplastic, and exopolysaccharides. Integration of wastewater treatment with microalgal bio-refinery not only solves the wastewater treatment problem but also generates revenue and supports a sustainable and circular bio-economy. The present review will highlight the current and advanced methods used to integrate microalgae for the complete reclamation of nutrients from industrial wastewater sources and their utilization for value-added compound production. Furthermore, pertaining challenges are briefly discussed along with the techno-economic analysis of current pilot-scale projects worldwide.

scholarly journals Evaluation of Pre-Chlorinated Wastewater Effluent for Microalgal Cultivation and Biodiesel Production

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 977 ◽  
Author(s):  
Ejovwokoghene Odjadjare ◽  
Taurai Mutanda ◽  
Yi-Feng Chen ◽  
Ademola Olaniran
Keyword(s):  
Total Nitrogen ◽  
Water Footprint ◽  
Oxidation Stability ◽  
Value Added ◽  
Wastewater Effluent ◽  
Biodiesel Production ◽  
Growth Media ◽  
Total Carbohydrate ◽  
Microalgal Biomass ◽  
Microalgal Cultivation

Microalgae are promising feedstock to produce biodiesel and other value added products. However, the water footprint for producing microalgal biodiesel is enormous and would put a strain on the water resources of water stressed countries like South Africa if freshwater is used without recycling. This study evaluates the utilization of pre-chlorinated wastewater as a cheap growth media for microalgal biomass propagation with the aim of producing biodiesel whilst simultaneously remediating the wastewater. Wastewater was collected from two wastewater treatment plants (WWTPs) in Durban, inoculated with Neochloris aquatica and Asterarcys quadricellulare and the growth kinetics monitored for a period of 8 days. The physicochemical parameters; including chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) were determined before microalgal cultivation and after harvesting. Total lipids were quantified gravimetrically after extraction by hexane/isopropanol (3:2 v/v). Biodiesel was produced by transesterification and characterised by gas chromatography. The total carbohydrate was extracted by acid hydrolysis and quantified by spectrophotometric method based on aldehyde functional group derivatization. Asterarcys quadricellulare utilized the wastewater for growth and reduced the COD of the wastewater effluent from the Umbilo WWTP by 12.4%. Total nitrogen (TN) and phosphorus (TP) were reduced by 48% and 50% respectively by Asterarcys quadricellulare cultivated in sterile wastewater while, Neochloris reduced the TP by 37% and TN by 29%. Although the highest biomass yield (460 mg dry weight) was obtained for Asterarcys, the highest amount of lipid (14.85 ± 1.63 mg L−1) and carbohydrate (14.84 ± 0.1 mg L−1) content were recorded in Neochloris aquatica. The dominant fatty acids in the microalgae were palmitic acid (C16:0), stearic acid (C18:0) and oleic acid (C18:1). The biodiesel produced was determined to be of good quality with high oxidation stability and low viscosity, and conformed to the American society for testing and materials (ASTM) guidelines.

scholarly journals Multi-Country Scale Assessment of Available Energy Recovery Potential Using Micro-Hydropower in Drinking, Pressurised Irrigation and Wastewater Networks, Covering Part of the EU

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 899
Author(s):  
Djordje Mitrovic ◽  
Miguel Crespo Chacón ◽  
Aida Mérida García ◽  
Jorge García Morillo ◽  
Juan Antonio Rodríguez Diaz ◽  
...  
Keyword(s):  
Drinking Water ◽  
Northern Ireland ◽  
Energy Recovery ◽  
Large Scale ◽  
Significant Proportion ◽  
Value Added ◽  
Cost Effective ◽  
Net Energy ◽  
Water Networks ◽  
Scale Assessment

Studies have shown micro-hydropower (MHP) opportunities for energy recovery and CO2 reductions in the water sector. This paper conducts a large-scale assessment of this potential using a dataset amassed across six EU countries (Ireland, Northern Ireland, Scotland, Wales, Spain, and Portugal) for the drinking water, irrigation, and wastewater sectors. Extrapolating the collected data, the total annual MHP potential was estimated between 482.3 and 821.6 GWh, depending on the assumptions, divided among Ireland (15.5–32.2 GWh), Scotland (17.8–139.7 GWh), Northern Ireland (5.9–8.2 GWh), Wales (10.2–8.1 GWh), Spain (375.3–539.9 GWh), and Portugal (57.6–93.5 GWh) and distributed across the drinking water (43–67%), irrigation (51–30%), and wastewater (6–3%) sectors. The findings demonstrated reductions in energy consumption in water networks between 1.7 and 13.0%. Forty-five percent of the energy estimated from the analysed sites was associated with just 3% of their number, having a power output capacity >15 kW. This demonstrated that a significant proportion of energy could be exploited at a small number of sites, with a valuable contribution to net energy efficiency gains and CO2 emission reductions. This also demonstrates cost-effective, value-added, multi-country benefits to policy makers, establishing the case to incentivise MHP in water networks to help achieve the desired CO2 emissions reductions targets.

scholarly journals Advances in Circular Bioeconomy Technologies: From Agricultural Wastewater to Value-Added Resources

Environments ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 20
Author(s):  
Nidhi Mehta ◽  
Kinjal J Shah ◽  
Yu-I Lin ◽  
Yongjun Sun ◽  
Shu-Yuan Pan
Keyword(s):  
Membrane Separation ◽  
Value Added ◽  
Fulvic Acids ◽  
Chemical Precipitation ◽  
Environmental Benefits ◽  
Nitrogen And Phosphorus ◽  
Piggery Wastewater ◽  
Agricultural Wastewater ◽  
Treatment Processes ◽  
Electrokinetic Separation

This review systematically outlines the recent advances in the application of circular bioeconomy technologies for converting agricultural wastewater to value-added resources. The properties and applications of the value-added products from agricultural wastewater are first summarized. Various types of agricultural wastewater, such as piggery wastewater and digestate from anaerobic digestion, are focused on. Next, different types of circular technologies for recovery of humic substances (e.g., humin, humic acids and fulvic acids) and nutrients (e.g., nitrogen and phosphorus) from agricultural wastewater are reviewed and discussed. Advanced technologies, such as chemical precipitation, membrane separation and electrokinetic separation, are evaluated. The environmental benefits of the circular technologies compared to conventional wastewater treatment processes are also addressed. Lastly, the perspectives and prospects of the circular technologies for agricultural wastewater are provided.

scholarly journals Exploiting the Potential in Water Cleanup from Metals and Nutrients of Desmodesmus sp. and Ampelodesmos mauritanicus

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1461
Author(s):  
Roberto Braglia ◽  
Lorenza Rugnini ◽  
Sara Malizia ◽  
Francesco Scuderi ◽  
Enrico Luigi Redi ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Metal Removal ◽  
Anthropogenic Activities ◽  
Cost Effective ◽  
Single Species ◽  
Nitrogen And Phosphorus ◽  
Removal Rates ◽  
Sequential Approach ◽  
Removal Capacity ◽  
Green Microalga

Increasing levels of freshwater contaminants, mainly due to anthropogenic activities, have resulted in a great deal of interest in finding new eco-friendly, cost-effective and efficient methods for remediating polluted waters. The aim of this work was to assess the feasibility of using a green microalga Desmodesmus sp., a cyanobacterium Nostoc sp. and a hemicryptophyte Ampelodesmos mauritanicus to bioremediate a water polluted with an excess of nutrients (nitrogen and phosphorus) and heavy metals (copper and nickel). We immediately determined that Nostoc sp. was sensitive to metal toxicity, and thus Desmodesmus sp. was chosen for sequential tests with A. mauritanicus. First, A. mauritanicus plants were grown in the ‘polluted’ culture medium for seven days and were, then, substituted by Desmodesmus sp. for a further seven days (14 days in total). Heavy metals were shown to negatively affect both the growth rates and nutrient removal capacity. The sequential approach resulted in high metal removal rates in the single metal solutions up to 74% for Cu and 85% for Ni, while, in the bi-metal solutions, the removal rates were lower and showed a bias for Cu uptake. Single species controls showed better outcomes; however, further studies are necessary to investigate the behavior of new species.

Aligning the flow cytometric evaluation with the diagnostic need: an evidence-based approach

2017 ◽  
Vol 70 (9) ◽  
pp. 740-744 ◽  
Author(s):  
Dawn Williams-Voorbeijtel ◽  
Francisco Sanchez ◽  
Christine G Roth
Keyword(s):  
Clinical Care ◽  
Cost Savings ◽  
Value Added ◽  
Cost Effective ◽  
Just In Time ◽  
Evidence Based ◽  
Flow Cytometric ◽  
A Value ◽  
Screening Approach ◽  
Minimum Requirements

AimsElimination of non-value added testing without compromising high-quality clinical care is an important mandate for laboratories in a value-based reimbursement system. The goal of this study was to determine the optimal combination of flow cytometric markers for a screening approach that balances efficiency and accuracy.MethodsAn audit over 9 months of flow cytometric testing was performed, including rereview of all dot plots from positive cases.ResultsOf the 807 cases in which leukaemia/lymphoma testing was performed, 23 were non-diagnostic and 189 represented bronchoalveolar lavage specimens. Of the remaining 595 cases, 137 (23%) were positive for an abnormal haematolymphoid population. Review of the positive cases identified minimum requirements for a screening tube as well as analysis strategies to overcome the diagnostic pitfalls noted. It is estimated that 38% fewer antibodies would be used in a screening approach, representing an opportunity for significant cost savings.ConclusionsWe provide a framework for developing an evidence-based screening combination for cost-effective characterisation of haematolymphoid malignancies, promoting adoption of ‘just-in-time’ testing systems that tailor the evaluation to the diagnostic need.

Processing and Value Addition of Bamboo Shoots for Utilization as Food Products

2020 ◽  
Vol 27 (1) ◽  
pp. 27-32
Author(s):  
Ashok Kumar Pandey ◽  
Keyword(s):  
Shelf Life ◽  
Value Added ◽  
Cost Effective ◽  
Nutrient Content ◽  
Food Products ◽  
Value Addition ◽  
Mineral Contents ◽  
Bamboo Shoots ◽  
Processed Products ◽  
Edible Products

Bamboo shoots being low in fat, high in dietary fiber and rich in mineral contents have been consumed traditionally by the people world over. Besides nutrients it also contains some anti-nutrients e.g. cyanogens. Due to seasonal availability of bamboo shoots, processing for reducing anti-nutrients in raw shoots while keeping nutrients intact and enhancement of shelf life of the value added products assume great significance for its utilization. This paper focuses on post harvest processing and value addition of bamboo shoots for its utilization as food products. Juvenile bamboo shoots of Bambusa bambos, B. tulda, Dendrocalamus asper and D. strictus were collected and processed, by boiling in brine solution, to remove the anti-nutrients (cyanogen). A simple, efficient and cost effective processing method for bamboo shoots was developed. This method significantly reduces the amount of cyanogens and retains considerable amount of nutrients and thus may be utilized for processing of bamboo shoots. Different value added edible products viz. chunks or bari (by adding pulses), pickle, sauce and papad (by adding potato) were prepared. All products were good in taste and texture. Nutritional analysis was done to determine the shelf life of the products. The nutrient content of processed products (chunks, sauce, pickle and papad) showed a gradual decrease and need to be consumed within 6 months from the date of making. However, in case of papad the carbohydrate content did not decrease much but the taste was not acceptable after 8 months. Whereas, in case of pickles, even nutrient content decreased but the product was acceptable even after two years after preparation as it was good in taste and texture. Thus, processing and value addition practices can be considered as key to the future of sustainable management of bamboo resources because they not only provide quality edible products but also enable harvesters/collectors to get better income opportunities.

Biorefinery aspects for cost-effective production of nanocellulose and high value-added biocomposites

Fuel ◽  
2021 ◽  
pp. 122575
Author(s):  
R. Reshmy ◽  
Eapen Philip ◽  
Aravind Madhavan ◽  
Ayon Tarfdar ◽  
Raveendran Sindhu ◽  
...  
Keyword(s):  
Value Added ◽  
Cost Effective
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