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1.
Amid a rapid expansion of global investments in biofuels there has been an equally rapid proliferation of concerns about the inadequacies of current governance schemes to mitigate the environmental impacts of growing agroenergy production. Managing the land use practices of small producers in a way that ensures their activities are financially and environmentally sustainable is a particularly pressing issue that has been overlooked in research on biofuel governance. I illuminate these challenges through an ethnographic study on the multiple breakdowns of environmental governance in the Southern Goiás region of Brazil, a major expansion region for sugarcane ethanol production. I focus on one of the most pressing compliance issues among small and medium size sugarcane farmers; their persistent use of federally mandated conservation areas for cattle production. I find that while these transgressions are often perceived by administrators and officials as being the result of a lack of “environmental awareness” among rural farmers, they are better understood as a safety net to protect landowners against perceived risks of sugarcane production. These violations are further enabled by continuing ambiguity in the enforcement structure for conservation legislation in the region. Recalibrating regulatory systems to better address these issues of accountability and risk is a critical step toward improving environmental governance of global biofuel commodity chains.  相似文献   

2.
The EU biofuels market is stimulating expansion of oil palm plantations in Indonesia. Little research has yet examined the impacts on water resources arising from this large-scale land use conversion to cultivation of biofuel feedstock or positioned contextual water resource governance in Indonesian locales in a wider political ecology of European climate politics. Through the concept of ‘hybrid accountability’, we examine primary evidence from an extensive action research process in Central Kalimantan Province, Indonesian Borneo, to assess whether the EU’s Renewable Energy Directive and existing certification schemes offer a way to improve the accountability of market actors and promote sustainable water resource management. We conclude that these initiatives have had no bearing on safeguarding local livelihoods and the water resources they depend on, with governance mechanisms largely failing to address people’s grievances. Rather, the EU’s policies on biofuels have supported a de-politicisation of what needs to be seen as ‘distributional water politics’. Furthermore, certification schemes such as the Roundtable for Sustainable Palm Oil offer, at present, only cosmetic tools and are insufficient to address deep structural governance issues. We argue that further hybridisation of market-based certification and governmental regulation should be designed with the purpose of providing new transnational recourse mechanisms and remedies for affected communities.  相似文献   

3.
An economic and environmentally friendly approach of overcoming the problem of fossil CO2 emissions would be to reuse it through fixation into biomass. Carbon dioxide (CO2), which is the basis for the formation of complex sugars by green plants and microalgae through photosynthesis, has been shown to significantly increase the growth rates of certain microalgal species. Microalgae possess a greater capacity to fix CO2 compared to C4 plants. Selection of appropriate microalgal strains is based on the CO2 fixation and tolerance capability together with lipid potential, both of which are a function of biomass productivity. Microalgae can be propagated in open raceway ponds or closed photobioreactors. Biological CO2 fixation also depends on the tolerance of selected strains to high temperatures and the amount of CO2 present in flue gas, together with SOx and NOx. Potential uses of microalgal biomass after sequestration could include biodiesel production, fodder for livestock, production of colorants and vitamins. This review summarizes commonly employed microalgal species as well as the physiological pathway involved in the biochemistry of CO2 fixation. It also presents an outlook on microalgal propagation systems for CO2 sequestration as well as a summary on the life cycle analysis of the process.  相似文献   

4.
In Ghana, the contested concepts of “land grabbing” and “land transaction” are strategically applied by proponents of critical and win–win discourses respectively to describe outcomes of land deals. Using case study methods and discourse analysis, this paper explores four cases of biofuels investments in Ghana and the implications of the choice of concepts used to represent them. Proponents of the critical discourse use the “land grabbing” concept to invoke imageries of “illegality”, “theft” and “food insecurity” when describing land deals. Consequently, some biofuels investments have been hampered in their potential to generate profit and local employment. The biofuel investors in this study, whose projects have been labeled “land grabbing”, therefore switched to food production to downplay public scepticism. Proponents of the win–win discourse portray biofuels investments as “pro-poor” projects and use the “land transaction” concept to pre-empt possible public criticisms in the media and elsewhere. Such representations of these biofuels investments are therefore mainly intended to pre-empt criticisms or attract public praise. Some projects with potentially promising outcomes have thus been terminated, while others with problematic outcomes have continued to be promoted. In contexts characterized by weak land regulations and ambivalence towards large-scale agriculture, the trajectory and outcomes of biofuels investments are often influenced by land deal representations drawn from global discourses and how they interact with pre-existing local discourses.  相似文献   

5.
Recently, microalgae are considered as lipid sources for biodiesel production. A photobioreactor was designed and fabricated for Scenedesmus sp. microalgae cultivation. The effect of several nitrogen sources, light intensity, iron ions, silicon, magnesium sulfate and ethanol concentrations on Scenedesmus sp. microalgae growth were investigated. For incubation period of 8 days, sodium nitrate and ammonium carbonate were the best nitrogen sources with biomass concentrations of 2.373 and 2.254 g L?1, respectively. Microalgae growth was reduced using nitrogen concentrations above 0.7 g L?1. In the first 10 days of incubation, maximum cell dry weight (0.7 g L?1) was obtained with light intensity of 10,000 lx, whiles after that, the results were desired (1 g L?1) using interior lighting at 7500 lx. Magnesium sulfate had a positive effect on cell growth. The biomass concentration of 1.65 g L?1 was obtained using 0.06 g L?1 magnesium sulfate. Maximum obtained biomass with silicon (0.7 Mm), ethanol (1.8 mL L?1) and ferric ammonium citrate (0.02 g L?1) was 1.7 and 1.3 and 2.16 g L?1, respectively. Logistic model was found to be a suitable model for cell growth forecast. Fatty acid analysis showed that composition of the most dominant synthesized fatty acids, palmitic and oleic acids, was 21.16 and 33.58%, respectively. Oil produced by Scenedesmus sp. microalgae composed of 49.08% saturated and 43.53% unsaturated fatty acids has a suitable composition for a desired biodiesel.  相似文献   

6.
Production of microbial oil has attracted a great attention in recent years. The potential of lipid production by the yeast strains is the reason for using microorganisms for biodiesel production. Microbial lipid has high similarity to the oil obtained from plants and animals in type and composition. Production of oil from yeasts must be economical, so optimization of the cultivation condition to reach higher production must be done. Native oleaginous yeast, Cryptococcus albidus, was isolated from soil by the nitrogen-limited medium and screened by Nile red staining. Yarrowia lipolytica DSM 8218 was used for lipid production as a standard strain. C. albidus was an excellent oleaginous yeast, and the lipid quantity, dry biomass and lipid productivity of this strain were 11.81 g/l, 19.65 g/l and 60.1 %, respectively, in shaking flask cultivation at 150 rpm and 25 °C in nitrogen-limited medium containing per liter 75 g glucose, 1 g (NH4)2SO4, 1 g yeast extract, 3 g KH2PO4, 1.5 g MgSO4.7H2O, 0.15 g CaCl2, 0.06 g MnSO4.H2O, 0.02 g ZnSO4.7H2O and 0.15 g FeCl3.6H2O with pH adjusted to 6.5. Fourier transform infrared spectroscopy was used for analyzing and confirming the production of microbial oil in this study.  相似文献   

7.
The microphytobenthos consists of unicellular eukaryotic algae and cyanobacteria that grow within the upper several millimeters of illuminated sediments, typically appearing only as a subtle brownish or greenish shading. The surficial layer of the sediment is a zone of intense microbial and geochemical activity and of considerable physical reworking. In many shallow ecosystems, the biomass of benthic microalgae often exceeds that of the phytoplankton in the overlying waters. Direct comparison of the abundance of benthic and suspended microalgae is complicated by the means used to measure biomass and by the vertical and horizontal distribution of the microphytobenthos in the sediment. Where biomass has been estimated as chlorophyll a, there may be negligible to large (40%) error due to interference by degradation products, except where chlorophyll is measured by high-performance liquid chromatography. The vertical distribution of microphytobenthos, aside from mat-forming species, is determined by the opposing effects of their vertical migration, which tends to concentrate them near the surface, and physical mixing by overlying currents, which tends to cause an even vertical distribution through the mixed layer of sediment. Uncertainties in vertical distribution are compounded by frequently patchy horizontal distribution. Under-sampling on small (<1 m) scales can lead to errors in the estimate that are comparable to the ranges of seasonal and geographic variation. These uncertainties are compounded by biases in the techniques used to estimate production by the microphytobenthos. In most environments studied, biomass (as chlorophyll a) and light availability appear to be the principal determinants of benthic primary production. The effect of variable light intensities on integral production can be described by a functional response curve. When normalized to the chlorophyll content of the surficial sediment, the residual variation in the data described by the functional response curve is due to changes in the chlorophyll-specific response to irradiance. Production by the benthos is often a significant fraction of production in the water column and microphytobenthos may contribute directly to water column production when they are resuspended. Thus on both the basis of biomass and biogeochemical reactivity, benthic microalgae play significant roles in system productivity and trophic dynamics, as well as such habitat characteristics as sediment stability. *** DIRECT SUPPORT *** A01BY074 00003  相似文献   

8.
Algae are regarded as the form of biomass most likely to provide sufficient quantities of fuels without impacting our food supplies. Studies investigating the potential of hydrothermal treatment of algae to produce biofuels show that, in many instances, the produced oils do not resemble crude oils and have a high heteroatom content. In this study, Scenedesmus spp. algae and isolated algaenan, a type of biopolymeric cell wall in certain algae and an important precursor to some kerogens, are subjected to hydrous pyrolysis in efforts to mimic the thermal maturation occurring in sediments as a proxy for biofuels production. Our study shows that algaenan can be subjected to hydrous pyrolysis to yield a hydrocarbon rich mixture that resembles many fossil fuel crude oils. More importantly, separation of the algaenan prior to the hydrothermal treatment can yield a paraffin rich crude requiring little additional processing to attempt to reproduce the geological process that gave us crude oils from ancient Type I kerogen. Although it requires algaenan isolation as a prerequisite, this could be a first step in the direction of producing oils without need for further upgrading. Whole algae, however, yield additional oxygenated products derived from oxygenated biopolymers even though the paraffins derived from algaenan dominate.  相似文献   

9.
This study examined the cell growth rate, lipid contents, lipid productivity, chlorophyll a concentration, and carbon dioxide tolerance of Chlorella vulgaris under various cultivation conditions. The pH, concentration of carbon dioxide in media, and light intensity variables were manipulated to obtain high lipid productivity. The optimum conditions were at pH 7.0, 2,930 lux, and 30 % carbon dioxide. Biomass concentration reached 1,288, 1,130, and 1,083 mg L?1 at 15, 30, and 50 % CO2 after 6 days, respectively, implying that this strain has appreciable tolerance to carbon dioxide. The highest concentration of chlorophyll a occurred at 2,930 lux and decreased with increasing light intensity gradually. The maximum specific growth rate was 3.25 day?1 based on the dry weight and 4.63 day?1 based on the cell number. The lipid content (45.68 %) and lipid productivity (86.03 mg day?1 L?1) obtained in this study are higher than reported values in literatures. Hence, C. vulgaris is a good candidate for subsequent research in biodiesel production under elevated carbon dioxide concentration by microalgae.  相似文献   

10.
Microalgal lipids can be enhanced through varying nitrogen (N) content, and limited supply of nitrogen source seems to be valuable approach for increased lipid accumulation in microalgae. In this study, Chlorella sp. IM-02 was observed under fluorescence microscope for increased number of lipid bodies under nitrogen scarcity. Fourier transform infrared spectroscopy was used to determine spectral changes due to varying lipid content under nitrogen-starved (N0, without sodium nitrate), nitrogen-limited (N0.1, N0.25, N0.5 and N1.0 representing 0.1, 0.25, 0.5 and 1.0 g/L of sodium nitrate, respectively) and nitrogen-sufficient (N1.5, i.e., 1.5 g/L sodium nitrate) setting. Chlorophyll content was also monitored under these conditions as growth indicator. Various biochemical components viz. total carbohydrates, total proteins and total lipids were also estimated under varying nitrogen levels spectrophotometrically. On fourth day itself, maximum lipid productivity was observed in case of N0.5, which is having one-third of nitrogen concentration present in original growth media, BG-11. This concludes N0.5 as suitable nitrogen provision for better production of lipids in Chlorella sp. IM-02 without much compromising the biomass production as both growth and lipid quantity are key parameters affecting the lipid productivity of any microalgal strain.  相似文献   

11.
Biofuels are environment friendly and economical. First-generation biofuels are made from sugar, starch and vegetable oils, and have an impact on food security, while second generation biofuels are generated from plant or algal material and are greener and sustainable. The present work focused on lab-scale application of hydrothermal carbonization to convert aquatic weed Ceratophyllum demersum into a second-generation biofuel—hydrochar. Hydrothermal carbonization has been carried out with and without catalysts in a high-pressure reactor under subcritical temperatures 240–320 °C, residence times 10–40 min and biomass to water dilution ratios varying from 1:4 to 1:12. Under noncatalytic conditions higher heating value and energy density were highest, 24.11 MJ/kg and 1.64 respectively at temperature of 300 °C and residence time of 30 min. The calorific value of noncatalytic hydrochar was enhanced further, respectively, to 29.0, 27.5 and 26.48 MJ/kg by catalysts KOH, Na2CO3 and acetic acid. Catalytic hydrochar had H/C and O/C atomic ratios of same order as that of high-rank bituminous coal. Van Krevelen diagram indicated KOH to be better catalyst followed by Na2CO3 and acetic acid. Hydrochar yield of 38% obtained in noncatalytic hydrothermal carbonization decreased with catalysts in following order; acetic acid > Na2CO3 > KOH, however, energy density was enhanced in order KOH > Na2CO3 > acetic acid. The research can prove a way forward in the direction of meeting part of global energy demand. At the same time, the problem of secondary pollution caused by piling up and decay of aquatic weeds will also be addressed to.  相似文献   

12.
While transesterification is well established, there remain considerable inefficiencies in existing transesterification processes. In this study an alternative energy stimulant, “microwave irradiation” was used for the production of the alternative energy source, biodiesel. The optimum parametric conditions obtained from the conventional technique were applied using microwave irradiation in order to compare both systems. The results showed that application of radio frequency microwave energy offers a fast, easy route to this valuable biofuel with advantages of enhancing the reaction rate and improving the separation process. The methodology allows for the use of high free fatty acid content feedstock, including used cooking oil; hence it helps to reduce the cost of production which constitutes a major hurdle towards widespread commercialization of biodiesel. The study also showed that the optimum reaction time for microwave-enhanced biodiesel production should be highly respected. Exceeding the optimum reaction time will lead to deterioration of both biodiesel yield and purity. This paper also reported the performance and exhaust emissions from a diesel engine when fuelled with a petroleum diesel fuel and two different biodiesel fuels; one obtained by the conventional technique and the other by microwave irradiation. It was concluded that microwave-enhanced biodiesel is not, at least, inferior to that produced by the conventional technique.  相似文献   

13.
The potential of the autoclaved Tunisian landfill leachate treatment using microalgae (Chlorella sp.) cultivation was investigated in this study. Landfill leachate was collected from Borj Chakir landfill, Tunisia. A full factorial experimental design 22 was proposed to study the effects of the incubation time and leachate ratio factors on the organic matter removal expressed in chemical oxygen demand (COD) and ammoniacal nitrogen (NH4─N) and on the biological response of Chlorella sp. expressed by the cell density and chlorophyll content. All experiments were batch runs at ambient temperature (25 ± 2 °C). The Chlorella sp. biomass and chlorophyll a concentrations of 1.2 and 5.32 mg L?1, respectively, were obtained with 10% leachate spike ratio. The obtained results showed that up to 90% of the ammoniacal nitrogen in landfill leachate was removed in 10% leachate ratio spiked medium with a residual concentration of 40 mg L?1. The maximum COD removal rate reached 60% within 13 days of incubation time indicating that microalgae consortium was quite effective for treating landfill leachate organic contaminants. Furthermore, with the 10% leachate ratio spiked medium, the maximum lipid productivity was 4.74 mg L?1 d?1. The present study provides valuable information for potential adaptation of microalgae culture and its contribution for the treatment of Tunisian landfill leachate.  相似文献   

14.
Benthic microalgae (BMA) inhabit the upper few centimeters of shelf sediments. This review summarizes the current information on BMA communities in the South Atlantic Bight (SAB) region of the Southeastern US continental shelf to provide insights into the potential role of these communities in the trophodynamics and biogeochemical cycling in shelf waters. Benthic irradiance is generally 2–6% of surface irradiance in the SAB region, providing sufficient light to support BMA primary production over 80–90% of the shelf width. BMA biomass greatly exceeds that of integrated phytoplankton biomass in the overlying water column on an areal basis. The SAB appears to have lower BMA biomass, but higher production than most temperate continental shelves. Annual production estimates average 101 and 89 g C m?2 year?1 for 5–20 and >?20 depth intervals, respectively. However, high variation in rates and biomass in time and space make comparisons between studies difficult. Submarine groundwater discharge (SGD) rather than the water column or in situ N regeneration from organic matter maybe the major “new” N source for BMA. The estimated supply of N (1.2 mmol N m?2 day?1) by SGD closely approximates the rates needed to support BMA primary production (3.1 to 1.6 mmol N m?2 day?1) in the sediments of the SAB. Identifying the source(s) of fixed N supporting the BMA community is essential for understanding the carbon dynamics and net ecosystem metabolism within the large area (76,000 km2) of the continental shelf in the SAB as well other temperate shelves worldwide.  相似文献   

15.
以岩溶湖泊——红枫湖的微藻为研究对象,通过添加两种标记稳定碳同位素组成的无机碳进行室内模拟岩溶环境条件;并通过添加不同浓度的乙酰唑胺（AZ）,来模拟岩溶湖泊中碳酸酐酶胞外酶活性差异的各类微藻。重点监测微藻蛋白质含量及其稳定碳同位素组成变化等指标,计算其对不同来源无机碳的吸收利用份额,并结合微藻的生物量生长指标,最终计算出碳酸酐酶胞外酶活性差异的各种微藻的碳汇能力。结果显示:在岩溶湖泊的自然水体中,碳酸酐酶胞外酶活性强的微藻碳汇能力是缺乏碳酸酐酶胞外酶的微藻碳汇能力的5倍。碳酸酐酶胞外酶对微藻光合碳汇能力的影响显著。   相似文献   

16.
Anthropogenic activities, such as construction work, dredging, and different kinds of recreation activities, can alter sediment loading in shallow coastal areas. The effect of increased load of fine sediment on the microbenthos (benthic microalgae, bacteria, and meiofauna) was studied in two experiments using undisturbed cores of a sandy sediment from a microtidal bay on the Swedish west coast. In each experiment, a total of 24 cores were incubated in an outdoor flow-through set-up. Twelve cores were treated with a 2.5-mm thick layer of autoclaved fine-grained, (silt) carbon-rich surface sediment. In the first experiment, estimates of the impact were based on measurements of chlorophylla, biomass of microalgae, bacteria, and meiofauna, and bacterial production. The main purpose of the second experiment was to study the effect on sediment oxygen profiles using microsensors. Within a week, after being covered by fine sediment, benthic microalgae (particularly diatoms) had migrated upward and the oxygen profiles were restored at the sediment surface by photosynthesis. However, the oxygen-producing layer became thinner and the algal composition changed. Bacterial biomass was restored to the same level as in the sandy sediment. Meiofauna also appeared to move upward and the meiofaunal composition was re-established. The results suggest that the microbenthic community of sandy sediment has an inherent capacity to recover after a moderate deposition of fine-particle sediment. Active upward migration of benthic diatoms appears to be a key mechanism for restoring the oxygenation of the sediment surface. The altered sediment type also implies changed species composition, and hence altered benthic trophic interactions, which may affect, for example, flatfish recruitment.  相似文献   

17.
The world is presently faced to the many calamities, mainly the increased and rapidly developing environmental changes, soil degradation as an example of such environmental problems which is correlated with the destructive effects of the sandstorms. Biological soil crust (BSC), a main component of soil, has various environmental functions including reduction in the erosion by increasing soil stability and providing a sanctuary for the growth of the taxa and vascular plants communities. Destruction of BSC, which naturally can be recovered slowly in a long time processes, contributes to the desertification and other environmental catastrophes. Therefore, accelerating the BSC recovery both the quality and the quantity of the crust development, especially in the desert areas, is of the prime interest. Recent advances in the BSC restoration have provided an immense potential for emulating the natural restoration methods mainly through providing soils with inoculant. This paper reviews the present restoration-based procedures for the biological soil crust restoration practice. The main landmarks are presented and highlighted including strain(s) selection and development, mass biomass production, inoculum preparation, soil inoculation, soil augmentation, nurseries, and crust succession monitoring and control. The review also introduces several successful case studies in the USA and the Republic of China. Thereafter, the paper briefly documents the future directions of the research and technologies. Development of a restoration system through the application of the microalgae inoculant is an encouraging aspect for accelerating the BSC recovery of the arid and semi-arid areas. However, further researches will help to establish and consolidate the potential of the microalgae cells and their application in desertification programs in large scales and in accordance with principles and requirements mandated by economic standards.  相似文献   

18.
Despite a recent review concluding that there is little or no reason to expect that the production of fish and other animals will increase with nutrient enrichment or eutrophication, there is a variety of evidence that anthropogenic nutrients can stimulate secondary production in marine ecosystems. Unique multiple-year fertilization experiments were carried out over fifty years ago in Scottish sea lochs that showed dramatic increases in the abundance of benthic infauna and greatly enhanced growth of fish as a result of inorganic nitrogen (N) and phosphorus (P) additions. These experiments appear to have provided a good qualitative model for the responses of the Baltic Sea to nutrient enrichment and resulting eutrophication. Historical comparisons by others have shown that the weight of benthic animals per unit area above the halocline in the Baltic is now up to 10 or 20 times greater than it was in the early 1920s and that the total fish biomass in the system may have increased 8 fold between the early part of the 1900s and the 1970s. While there are no similar data for the highly enriched central and southern North Sea, there is convincing evidence that the growth rates of plaice, sole, and other species have increased there since the 1960s or 1970s. Cross-system comparisons have also shown that there are strong correlations between primary production and the production and yield of fish and the standing crop and production of benthic macrofauma in phytoplankton-dominated marine ecosystems. Concerns over the growing nutrient (especially N) enrichment of coastal marine waters are clearly valid and deserve the attention of scientists and managers, but the recent demonizing of N ignores the fact that nutrients are a fundamental requirement for producing biomass. Decisions regarding the amount of N or P that will be allowed to enter marine ecosystems should be made with the full knowledge that there may be tradeoffs between increases in water clarity and dissolved oxygen and the abundance of oysters, clams, fish, and other animals we desire.  相似文献   

19.
Field experiments were conducted to examine spatial and temporal variation in chironomid (predominantlyTanypus clavatus) abundance, and their trophic relationship with benthic microalgae. High performance liquid chromatography (HPLC) analysis of chironomid gut pigments indicated that diatoms comprised the bulk of the microalgae ingested by chironomids.14C-feeding studies were used to obtain quantitative estimates of chironomid, copepod, ostracod, and nematode grazing on benthic microalgae. Daily consumption of standing microalgal biomass by chironomids ranged from 0.12% (January) to 125% (May), but was highly variable. There were no significant diel, temporal (over the scale of months), or spatial patterns in individual chironomid grazing rates. There was significant temporal variation in the proportion of microalgal biomass consumed by the total meiofaunal assemblage, and highest grazing impacts occurred in May, coincident with high abundances of chironomids, harpacticoid copepods, and ostracods. The grazing impact of chironomids was comparable to or greater than that of other known grazers of microalgae (copepods, ostracods). Functional-response experiments performed in the laboratory revealed that chironomid ingestion rates increased with increasing food availability over short (1 to 2 h) time scales. Field data did not indicate a functional response to food availability over longer (mo) time scales, possibly because of other environmental incluences. Gut residence time (determined using fluorescently labeled beads) changed with variable feeding rates, which were in turn a function of variable food availability. Chironomid larvae have the ability to consume significant fraction of the microphytobenthos in absolute terms, and relative to other meiofauna, indicating that they are an important component of the salt marsh food web.  相似文献   

20.
After decades of ‘living dangerously’, the human kind has paused to think of Mother Nature. Alternate energy sources are being developed as a part of this realization. The use of indigenous sources of nutrients would considerably bring down the cost of production. A mixed consortium of Chlorella vulgaris, Arthrospira platensis, and tap water-originated Scenedesmus dimorphus was cultured using natural seawater, anaerobic digester sludge, and its growth was compared with synthetic commercial media like Zarrouk’s media, NaNO3 media, and NH4Cl media. A spectrophotometric method was standardized for regular biomass estimation. The dry biomass of a 15-day pure, batch culture of Arthrospira was found to yield around 600 mg/L in anaerobic digester sludge, whereas the pure batch culture of chlorella’s growth was hindered mainly due to the presence of bacteria and grazers. Regular microscopic observation and biomass monitoring revealed a drastic reduction in grazing activity, with the use of autoclaved AD sludge, resulting in a strong and stable microalgal mixed consortia. The consortia growth in AD sludge was found to be better than with the synthetic media with no cost of nutrient. The mixed consortia yielded a biomass up to 600 mg/L and lipid of 21.18%. The lipid generated from AD sludge had around 95% unsaturates and contained around 5% omega-3 fatty acids. The use of anaerobic digester sludge in a non-sterile condition reduces the total cost of the biodiesel production process as a whole and introduces a decentralized system for waste water treatment as well.  相似文献   

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