To fully understand the economic viability and implementation strategy of the emerging algae-based de- salination technology, this study investigates the economic aspects of algae-based desalination system by comparing the life-cycle costs of three different scenarios: (1) a multi-stage microalgae based desalina- tion system; (2) a hybrid desalination system based on the combination of microalgae and low pressure reverse osmosis (LPRO) system; and (3) a seawater reverse osmosis (SWRO) desalination system. It is identified that the capital expenditure (CAPEX) and operational expenditure (OPEX) of scenario 1 are significantly higher than those of scenarios 2 and 3, when algal biomass reuse is not taken into consider- ation. If the revenues obtained from the algal biomass reuse are taken into account, the OPEX of scenario 1 will decrease significantly, and scenarios 2 and 3 will have the highest and lowest OPEX, respectively. However, due to the high CAPEX of scenario 1, the total expenditure (TOTEX) of scenario 1 is still 27% and 33% higher than those of scenarios 2 and 3, respectively. A sensitivity study is undertaken to understand the effects of six key parameters on water total cost for different scenarios. It is suggested that the elec- tricity unit price plays the most important role in determining the water total cost for different scenarios. An uncertainty analysis is also conducted to investigate the effects and limitations of the key assumptions made in this study. It is suggested that the assumption of total dissolved solids (TDS) removal efficiency of microalgae results in a high uncertainty of life-cycle cost analysis (LCCA). Additionally, it is estimated that 1.58 megaton and 0.30 megaton CO2 can be captured by the algae-based desalination process for scenarios 1 and 2, respectively, over 20 years service period, which could result in approximately AU $18 million and AU $3 million indirect financial benefits for scenarios 1 and 2, respectively. When algal biomass reuse, CO2 bio-fixation and land availability are all taken into account, scenario 2 with hybrid desalination system is considered as the most economical and environmentally friendly option.
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“When I was growing up, if you went to a lūʻau, you would know who prepared the food and what area it came from by just knowing the taste of the limu and the kinds of limu that were utilized. Basically, you could tell where the families came from by the raw stuf they made,” says Malia Akutagawa, who was raised on the east end of Molokaʻi. Now 48 years old and an assistant professor of law and Hawaiian Studies with both the University of Hawaiʻi at Mānoa’s William S. Richardson School of Law and the Kamakakūokalani Center for Hawaiian Studies in the Hawai‘inuiākea School of Hawaiian Knowledge, Malia Akutagawa was taught by her grandmother from a young age how to pick limu. She says her grandmother, Katharine Kalua Hagemann Akutagawa, or Grandma Kitty, was known as one of the best limu pickers on the island. Grandma Kitty learned from Tūtū Hapa Kalua, who was cousin to Malia’s great grandmother, Haʻaheo.
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The nutritional value and chemical changes in the lipid content of the green macroalgae, Ulva sp., were assayed in the present study. Ulva samples were collected from two stations, Ras Al-Tin (station A) and El-Muntazah (Station B) along Alexandria shore on the Mediterranean Sea, in twelve sampling periods (from January to December 2012). Each three samples of each station were plotted to represent one season. The chemical characterization of the lipid fractions was performed by gas liquid chromatography. The result showed that Ulva lipid content is relatively high (9.4±1.5 and 12.2±2.7%DW, at station A and B respectively) that can be explained by the higher pollution level at the station A. The fatty acids (FAs) of Ulva sp. lipidic extract mainly composed of palmitic, oleic and linoleic FAs. Saturated fatty acids (SFAs) represented about 50% of the total FAs (TFAs). Monounsaturated fatty acids (MUFAs) accounted for a high percent, 17.6-33.4% of TFAs. Polyunsaturated fatty acids (PUFAs) existed in a high percent in Ulva extraction reaching a maximum in winter and spring at both stations, about 38.4 and 30.5% of TFAs at station A and B, respectively. The high percent of PUFA can be attributed to the correlation between the low temperature and the degree of unsaturation. Also, the long chain fatty acids (C16 and C18) constitute more than 82% of the TFAs, which are the main components for biofuel. The results indicate that Ulva has a good potential for its use in human and animal food and health maintenance as a rich source of MUFAs and PUFA as well as in biodiesel production. Also, the wide ranges of the fatty acids indicate the possibility of manipulating the fatty acids profile through the cultivation conditions.
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The present study evaluated the efficiency of seaweeds collected from Abu Qir Bay, Alexandria, Egypt, as a feedstock for biodiesel. A total of 15 macroalgal species were collected overall in the four seasons. The highest seasonal biomass production of 652.1 and 626.3 g m⁻² was recorded with Chaetomorpha linum and Ulva compressa in autumn and spring, respectively. While the highest annual biomass production was detected in Ulva fasciata (1056.8 g m⁻²). Lipid content varied among species, with the highest value of 14.66 % and 9.94 % dw in U. fasciata and U. compressa during spring, which resulted in the highest annual lipid productivity of 67.4 and 63.3 g m⁻², respectively. Palmitic acid (C16:0) showed the highest value among all fatty acids (1.12-19.62 mg g−¹ dw) in all studied species. The biodiesel characteristics of all algae species tested are in agreement with the values of international standards. Overall, the present study recommended U. compressa and U. fasciata as a promising biodiesel feedstock due to the relatively higher lipid productivity and FAMEs characteristics that comply with the international standards and high net energy output that reached 1.24 and 1.30 GJ ton⁻¹, respectively.
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Biological lipids derived from oleaginous microorganisms are promising precursors for renewable biofuel productions. Direct lipid extraction from wet cell-biomass is favored because it eliminates the need for costly dehydration. However, the development of a practical and scalable process for extracting lipids from wet cell-biomass is far from ready to be commercialized, instead, requiring intensive research and development to understand the lipid accessibility, mechanisms in mass transfer and establish robust lipid extraction approaches that are practical for industrial applications. This paper aims to present a critical review on lipid recovery in the context of biofuel productions with special attention to cell disruption and lipid mass transfer to support extraction from wet biomass.
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The repertoire of novel biobased materials is continually expanding as they represent green alternatives to carbon-intensive fossil materials. Lipid-extracted algae (LEA) biomass is a promising feedstock for the production of a spectrum of biobased materials, such as hydrochar and biochar, electrodes in microbial fuel cells (MFCs), supercapacitors, biocomposites, biopolymers, activated carbon including N-doping, and biosorbents. By selecting appropriate process conditions, these renewable products can be designed to possess desirable properties and, at the same time, be more sustainable. Most importantly, we view LEA as a potentially significant additional source of revenue for algae biorefineries that can accelerate the commercial development of algae. The present study assesses the utilization of LEA for the production of biobased materials, their applications and sustainability profile, and future trends.
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Today, mariculture is one of the fastest growing food production sectors, with an annual growth rate of 4-11%. This rapid growth is likely due in part to the large area of “usable land” in the ocean and the high protein food that can be produced and harvested, one of which is seaweed. (Troell, 1999; CBD, 2013). In addition, seaweed is not only a source of food, but has properties that make it an option for utilization in pharmaceuticals, biofuels, and other applications. A unique advantage of this type of systems is that growing seaweed consumes excess nutrients and CO2, two compounds believed to have ecologically dangerous impacts (Troell, 1999). With these benefits to the marine agronomy, it is not hard to see why scientists and engineers are interested farther developing this unique industry.
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Forage fish play a crucial role in marine food webs in many ecosystems (Box 1.1). These small and medium-sized pelagic species are the primary food source for many marine mammals, seabirds, and larger fish, transferring energy from plankton to larger predators. Forage fish are also important predators in marine ecosystems, feeding upon phytoplankton, zooplankton, and, in some cases, the early life stages of their predators.
Forage fish play an intermediary role in many marine ecosystems, including estuaries, shelf seas, upwelling, and open ocean systems occurring from the tropics to the Earth’s poles. They constitute the majority of prey upon which some predators depend. Such highly dependent predators may be iconic or ecologically important, while others may be commercially or recreationally valuable fish species. In some cases, highly dependent predators may include threatened or endangered species. A reduction in available prey—because of fishing, environmental conditions, or a combination of both—can have direct and lasting impacts and can fundamentally change the structure and functioning of an ecosystem.
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The animal feeding industry is looking for new local sources of high quality protein in order to reduce import and ensure sustainable and environmental friendly animal production systems. Local legumes and seaweeds may be alternative sources of protein. We present in this paper the background for the ongoing Norwegian Research Council project Legumes and seaweeds as alternative protein sources for sheep (AltPro), which aims to investigate the suitability and potential of legumes and seaweeds as new and underutilized protein sources in sheep diets. The project addresses several critical aspects for the future development of the agriculture industry in Norway applicable to other European countries from an integrated social and natural scientific approach: 1. use of protein sources alternative to soya, 2. environmental, climatic, societal and economical sustainability, 3. animal health and welfare.
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It's Rich In Vitamins And Antioxidants, But It's Not What You Think It Is. The latest cash crop in the farm-to-table food craze doesn’t come from the land; it comes from the Long Island Sound. In spite of what you might think, this new cash crop isn’t shell-fish; it’s kelp. The superfood is loaded with vitamins, minerals, and antioxidants, and is being served up at local restaurants.
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