Optimization of Temperature and Inoculum Size for Phycoremediation of Paddy-Soaked Rice Mill Wastewater
01 Jan 2020-Journal of Environmental Engineering (American Society of Civil Engineers (ASCE))-Vol. 146, Iss: 1, pp 04019091
TL;DR: In this article, microalgae is used as a sustainable treatment system by integrating the wastewater treatment with bioenergy recovery, transforming this technology to real-time, but it is difficult to implement in practice.
Abstract: Phycoremediation encompasses microalgae as a sustainable treatment system by integrating the wastewater treatment with bioenergy recovery. However, transforming this technology to real time...
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TL;DR: In this article, the selected microalgae (Chlorella pyrenoidosa) was cultured in paddy-soaked wastewater (PWW) using outdoor raceway ponds of 50 L capacity where biotransformation of nutrients (NH3−N removal: 75.89±−0.69); PO4−P removal: 73.71±− 0.75%; yield co-efficient YN: 6.56−±-0.
Abstract: Sustainable resources management, incorporating energy markets and resources such as electricity, fossil fuels, renewable and sustainable energy capital is essential for society to understand production and conversion of various forms of energy, their current as well as future supply. Waste-to-energy (WTE) or energy-from-waste (EFW) is a well-identified transitional technology which could prevent complete depletion of renewable resources. In our present study, the selected microalgae (Chlorella pyrenoidosa) was cultured in paddy-soaked wastewater (PWW) using outdoor raceway ponds of 50 L capacity where biotransformation of nutrients (NH3–N removal: 75.89 ± 0.69%; PO4–P removal: 73.71 ± 0.75%; yield co-efficient YN: 6.12 mg biomass/mg of N; YP: 7.77 mg biomass/mg P) has occurred with better growth and biochemical composition (dry biomass weight: 1.56 ± 0.11 g/L; chlorophyll: 15.57 ± 0.14 mg/L; specific growth rate (SGR): 0.42/d; lipids: 27.47 ± 1.41% biomass; carbohydrates: 23.77 ± 1.00% and protein: 46.12 ± 3.55%). Further, the obtained algal lipid was identified for a wide range of fatty acid methyl esters (FAME) and consequently brought forward to in-situ single-step transesterification by optimizing reaction conditions. Central composite design (CCD) of response surface methodology (RSM) has given optimized conditions of sample amount: 2 g (wet); methanol sulphuric acid volume: 3 mL; and hexane volume: 4 mL, under the reaction temperature of 90 °C for maximum biodiesel conversion (46.54% of algal lipids). The outcome of our current research may add value to the application and development of WTE technology for sustainable energy conservation.
14 citations
01 Feb 2021
TL;DR: The results demonstrate the potential of CO2 and HCO3 −1 in control the CCM pathways, thus, another step in the development of the photobioreactor design.
Abstract: A step to net-zero of carbon dioxide losses in the microalgae cultivation process was targeted in the current study. This research was carried out by using pre-dissolved inorganic carbon (DIC) as a source of carbon with two doses of twenty-five and fifty millilitres. C. sorokiniana MH923013, Coelastrella MH923011 and Coelastrella MH923012 strains were used in the present investigation. The experimental data emphasized the direct influence of carbonic solution on microalgal growth according to the fast adaption of algal cells and higher productivity compared to control and dilution cultures. It was observed that microalgae strains conduct a corresponding response associated with different dosing of the saturated carbonic solution. For instance, dosing of 50 ml carbon dioxide revealed fast performance to reach the stationary phase (23-25) day with clear growth improvement. In addition, 0.1633 day−1 as a maximum specific growth rate in the exponential phase was recorded with this dosing. While as there was another obvious growth enhancement with supplying 25 ml CO2 solution, but reached the stable phase after around (37-42) day from inoculation with a maximum specific growth rate 0.0987 day−1. These results demonstrate the potential of CO2 and HCO3 −1 in control the CCM pathways, thus, another step in the development of the photobioreactor design.
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TL;DR: Version 4 of MEGA software expands on the existing facilities for editing DNA sequence data from autosequencers, mining Web-databases, performing automatic and manual sequence alignment, analyzing sequence alignments to estimate evolutionary distances, inferring phylogenetic trees, and testing evolutionary hypotheses.
Abstract: We announce the release of the fourth version of MEGA software, which expands on the existing facilities for editing DNA sequence data from autosequencers, mining Web-databases, performing automatic and manual sequence alignment, analyzing sequence alignments to estimate evolutionary distances, inferring phylogenetic trees, and testing evolutionary hypotheses. Version 4 includes a unique facility to generate captions, written in figure legend format, in order to provide natural language descriptions of the models and methods used in the analyses. This facility aims to promote a better understanding of the underlying assumptions used in analyses, and of the results generated. Another new feature is the Maximum Composite Likelihood (MCL) method for estimating evolutionary distances between all pairs of sequences simultaneously, with and without incorporating rate variation among sites and substitution pattern heterogeneities among lineages. This MCL method also can be used to estimate transition/transversion bias and nucleotide substitution pattern without knowledge of the phylogenetic tree. This new version is a native 32-bit Windows application with multi-threading and multi-user supports, and it is also available to run in a Linux desktop environment (via the Wine compatibility layer) and on Intel-based Macintosh computers under the Parallels program. The current version of MEGA is available free of charge at (http://www.megasoftware.net).
29,021 citations
TL;DR: In this paper, the effects of temperature and nitrogen concentration on the lipid content of Nannochloropsis oculata and Chlorella vulgaris in view of their possible utilization as novel raw materials for biodiesel production were investigated.
Abstract: A possible source of biological material for the production of biodiesel is represented by microalgae, in particular by their lipid content. The aim of the present work was to study of the effects of temperature and nitrogen concentration on the lipid content of Nannochloropsis oculata and Chlorella vulgaris in view of their possible utilization as novel raw materials for biodiesel production. In addition, various lipid extraction methods were investigated. The extracted lipids were quantitatively and qualitatively analyzed by gravimetric and gas chromatographic methods, respectively, in order to check their suitability according to the European standards for biodiesel. The lipid content of microalgae was strongly influenced by the variation of tested parameters; indeed, an increase in temperature from 20 to 25 °C practically doubled the lipid content of N. oculata (from 7.90 to 14.92%), while an increase from 25 to 30 °C brought about a decrease of the lipid content of C. vulgaris from 14.71 to 5.90%. On the other hand, a 75% decrease of the nitrogen concentration in the medium, with respect to the optimal values for growth, increased the lipid fractions of N. oculata from 7.90 to 15.31% and of C. vulgaris from 5.90 to 16.41%, respectively.
1,292 citations
TL;DR: In this paper, the major nutrient components of different wastewater streams, the mechanisms of algal nutrient uptake, nutrient removal performance of various species of microalgae when cultured in wastewater, and current micro-algae production systems are discussed.
Abstract: Disposal of wastewater often results in high nutrient loading into aquatic environments, which may lead to favorable conditions for undesirable phytoplankton blooms. Microalgae are efficient in removing nitrogen, phosphorus, and toxic metals from wastewater under controlled environments. If key nutrients in the wastewater stream can be used to grow microalgae for biofuel production, the nutrients can be removed, thus significantly reducing the risk of harmful phytoplankton overgrowth. This review paper summarizes the major nutrient components of different wastewater streams, the mechanisms of algal nutrient uptake, nutrient removal performance of various species of microalgae when cultured in wastewater, and current microalgae production systems. Finally, new algae cultivation technologies applicable for biofuel production and nutrient recovery in polluted water bodies are discussed.
1,249 citations
TL;DR: The critical parameters that limit algal cultivation, production and harvest are reviewed and practical options that may enhance the net harvestable algal production from wastewater treatment HRAPs including CO(2) addition, species control, control of grazers and parasites and bioflocculation are discussed.
989 citations
TL;DR: Preliminary growth studies indicated both fresh water and marine algae showed good growth in wastewaters, and further studies on anaerobic digestion and thermochemical liquefaction are required to make this consortium approach economically viable for producing algae biofuels.
756 citations