scholarly journals Lab-scale assessment and adaptation of wastewater for cultivation of microalgal biomass for biodiesel production

2015 ◽  
Author(s):  
◽  
Luveshan Ramanna
Keyword(s):  
Large Scale ◽  
Physiological Stress ◽  
Lipid Production ◽  
Domestic Wastewater ◽  
Potassium Nitrate ◽  
Wastewater Effluent ◽  
Biodiesel Production ◽  
Available Nitrogen ◽  
Microalgal Biomass ◽  
Microalgal Culture

In light of the world’s declining fossil fuel reserves, the use of microalgal biodiesel has come to the forefront as a potentially viable alternative liquid fuel. The depleting freshwater reserves make the feasibility of this concept questionable. The use of wastewater reduces the requirement for depleting freshwater supplies. This project aimed to determine the viability of municipal domestic wastewater effluent as a substrate for microalgal growth, in order to generate an economical and environmentally friendly source of biofuel. Wastewater effluents from three domestic wastewater treatment plants were characterized in terms of known microalgal nutrients viz., ammonia, phosphate and nitrates. Phosphate concentrations varied throughout the year and were found to be low (< 3 mgL-1) whilst ammonia and nitrate concentrations ranged from 0 to 10 mgL-1 throughout the experimental period. These wastewaters were found to be suitable for cultivating microalgae. The study explored the cultivation of Chlorella sorokiniana on pre- and post-chlorinated domestic wastewater effluent to assess their potential as a medium for high microalgal culture density and lipid production. Post-chlorinated wastewater effluent was found to be superior to pre-chlorinated wastewater effluent, as evident by the higher biomass concentration. This wastewater stream did not contain high concentrations of bacteria when compared to pre-chlorinated wastewater effluent. Nitrogen is an essential nutrient required for regulating the growth and lipid accumulation in microalgae. Cultures growing in post-chlorinated effluent had a lifespan of 18 d. Residual nitrogen in wastewater effluent supported microalgal growth for limited periods. Supplementation using cheap, readily available nitrogen sources was required for optimal biomass and lipid production. Urea, potassium nitrate, sodium nitrate and ammonium nitrate were evaluated in terms of biomass and lipid production of C. sorokiniana. Urea showed the highest biomass yield of 0.216 gL-1 and was selected for further experimentation. Urea concentrations (0–10 gL-1) were assessed for their effect on growth and microalgal physiology using pulse amplitude modulated fluorometry. A concentration of 1.5 gL-1 urea produced 0.218 gL-1 biomass and 61.52 % lipid by relative fluorescence. Physiological stress was evident by the decrease in relative Electron Transport Rate from 10.45 to 6.77 and quantum efficiency of photosystem II charge separation from 0.665 to 0.131. Gas chromatography analysis revealed that C16:0, C18:0, C18:1, C18:2 and C18:3 were the major fatty acids produced by C. sorokiniana. Wastewater effluent has been considered an important resource for economical and sustainable microalgal biomass/lipid production. The study showed that C. sorokiniana was sufficiently robust to be cultivated on wastewater effluent supplemented with urea. The results indicate that supplemented wastewater effluent was an acceptable alternative to conventional media. Using a relatively cheap nitrogen source like urea can certainly improve the techno-economics of large scale biodiesel production.

Optimisation of biomass and lipid production of a tropical thraustochytrid Aurantiochytrium sp. UMACC-T023 in submerged-liquid fermentation for large-scale biodiesel production

2020 ◽  
Vol 23 ◽  
pp. 101496 ◽  
Author(s):  
Mohamad Nor Azzimi Sohedein ◽  
Wan Abd Al Qadr Imad Wan-Mohtar ◽  
Yeong Hui-Yin ◽  
Zul Ilham ◽  
Jo-Shu Chang ◽  
...  
Keyword(s):  
Large Scale ◽  
Lipid Production ◽  
Biodiesel Production ◽  
Liquid Fermentation

Biodiesel production potential of mixed microalgal culture grown in domestic wastewater

2015 ◽  
Vol 39 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Gulfem Soydemir ◽  
Ulker Diler Keris-Sen ◽  
Unal Sen ◽  
Mirat D. Gurol
Keyword(s):  
Domestic Wastewater ◽  
Biodiesel Production ◽  
Production Potential ◽  
Microalgal Culture

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 Highly Valuable Polyunsaturated Fatty Acids from Microalgae: Strategies to Improve Their Yields and Their Potential Exploitation in Aquaculture

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7697
Author(s):  
Anna Santin ◽  
Monia Teresa Russo ◽  
Maria Immacolata Ferrante ◽  
Sergio Balzano ◽  
Ida Orefice ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Polyunsaturated Fatty Acids ◽  
Large Scale ◽  
Abiotic Factors ◽  
Lipid Production ◽  
Alternative Source ◽  
Microalgal Biomass ◽  
Food Ingredients ◽  
Extraction And Purification ◽  
Food And Feed

Microalgae have a great potential for the production of healthy food and feed supplements. Their ability to convert carbon into high-value compounds and to be cultured in large scale without interfering with crop cultivation makes these photosynthetic microorganisms promising for the sustainable production of lipids. In particular, microalgae represent an alternative source of polyunsaturated fatty acids (PUFAs), whose consumption is related to various health benefits for humans and animals. In recent years, several strategies to improve PUFAs’ production in microalgae have been investigated. Such strategies include selecting the best performing species and strains and the optimization of culturing conditions, with special emphasis on the different cultivation systems and the effect of different abiotic factors on PUFAs’ accumulation in microalgae. Moreover, developments and results obtained through the most modern genetic and metabolic engineering techniques are described, focusing on the strategies that lead to an increased lipid production or an altered PUFAs’ profile. Additionally, we provide an overview of biotechnological applications of PUFAs derived from microalgae as safe and sustainable organisms, such as aquafeed and food ingredients, and of the main techniques (and their related issues) for PUFAs’ extraction and purification from microalgal biomass.

scholarly journals Screening of Industrial Wastewaters as Feedstock for the Microbial Production of Oils for Biodiesel Production and High-Quality Pigments

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Teresa Schneider ◽  
Simone Graeff-Hönninger ◽  
William Todd French ◽  
Rafael Hernandez ◽  
Wilhelm Claupein ◽  
...  
Keyword(s):  
Fruit Juice ◽  
Low Cost ◽  
Lipid Production ◽  
Rhodotorula Glutinis ◽  
Biodiesel Production ◽  
Carotenoid Content ◽  
Plant Oil ◽  
Available Nitrogen ◽  
Carotenoid Production ◽  
Economic Constraints

The production of biodiesel has notably increased over the past decade. Currently, plant oil is the main feedstock for biodiesel production, but, due to concerns related to the competition with food production, alternative oil feedstocks have to be found. Oleaginous yeasts are known to produce high amounts of lipids, but no integrated process from microbial fermentation to final biodiesel production has reached commercial realization yet due to economic constraints. Therefore, growth and lipid production of red yeastRhodotorula glutiniswas tested on low-cost substrates, namely, wastewaters from potato, fruit juice, and lettuce processing. Additionally, the production of carotenoids as high-value by-products was examined. All evaluated wastewaters met the general criteria for microbial lipid production. However, no significant increase in lipid content was observed, probably due to lack of available carbon in wastewaters from fruit juice and lettuce processing, and excess of available nitrogen in potato processing wastewater, respectively. During growth on wastewaters from fruit juice and lettuce processing the carotenoid content increased significantly in the first 48 hours. The relations between carbon content, nitrogen content, and carotenoid production need to be further assessed. For economic viability, lipid and carotenoid production needs to be increased significantly. The screening of feedstocks should be extended to other wastewaters.

Bottlenecks in the Implementation of On-Site Wastewater Treatment Plants on a Large Scale in The Netherlands

1990 ◽  
Vol 22 (3-4) ◽  
pp. 291-298
Author(s):  
Frits A. Fastenau ◽  
Jaap H. J. M. van der Graaf ◽  
Gerard Martijnse
Keyword(s):  
Wastewater Treatment ◽  
The Netherlands ◽  
Large Scale ◽  
Wastewater Treatment Plants ◽  
Housing Stock ◽  
Research Work ◽  
Field Research ◽  
Domestic Wastewater ◽  
Research Programme ◽  
Definition Of

More than 95 % of the total housing stock in the Netherlands is connected to central sewerage systems and in most cases the wastewater is treated biologically. As connection to central sewerage systems has reached its economic limits, interest in on-site treatment of the domestic wastewater of the remaining premises is increasing. A large scale research programme into on-site wastewater treatment up to population equivalents of 200 persons has therefore been initiated by the Dutch Ministry of Housing, Physical Planning and Environment. Intensive field-research work did establish that the technological features of most on-site biological treatment systems were satisfactory. A large scale implementation of these systems is however obstructed in different extents by problems of an organisational, financial and/or juridical nature and management difficulties. At present research is carried out to identify these bottlenecks and to analyse possible solutions. Some preliminary results are given which involve the following ‘bottlenecks':-legislation: absence of co-ordination and absence of a definition of ‘surface water';-absence of subsidies;-ownership: divisions in task-setting of Municipalities and Waterboards; divisions involved with cost-sharing;-inspection; operational control and maintenance; organisation of management;-discharge permits;-pollution levy;-sludge disposal. Final decisions and practical elaboration of policies towards on-site treatment will have to be formulated in a broad discussion with all the authorities and interest groups involved.

scholarly journals Physical Methods of Microalgal Biomass Pretreatment

2014 ◽  
Vol 28 (3) ◽  
pp. 341-348 ◽  
Author(s):  
Agata Piasecka ◽  
Izabela Krzemińska ◽  
Jerzy Tys
Keyword(s):  
Alternative Energy ◽  
Lipid Extraction ◽  
Physical Method ◽  
Extraction Methods ◽  
Biodiesel Production ◽  
Biomass Pretreatment ◽  
Microalgal Biomass ◽  
Alternative Energy Sources ◽  
Wet Biomass ◽  
Microwave Techniques

Abstract The prospect of depletion of natural energy resources on the Earth forces researchers to seek and explore new and alternative energy sources. Biomass is a composite resource that can be used in many ways leading to diversity of products. Therefore, microalgal biomass offers great potential. The main aim of this study is to find the best physical method of microalgal biomass pretreatment that guarantees efficient lipid extraction. These studies identifies biochemical composition of microalgal biomass as source for biodisel production. The influence of drying at different temperatures and lyophilization was investigated. In addition, wet and untreated biomass was examined. Cell disruption (sonication and microwave) techniques were used to improve lipid extraction from wet biomass. Additionally, two different extraction methods were carried out to select the best method of crude oil extraction. The results of this study show that wet biomass after sonication is the most suitable for extraction. The fatty acid composition of microalgal biomass includes linoleic acid (C18:2), palmitic acid (C16:0), oleic acid (C18:1), linolenic acid (C18:3), and stearic acid (C18:0), which play a key role in biodiesel production.

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