Search results for "algae"
showing 10 items of 403 documents
Maximising resource recovery from wastewater grown microalgae and primary sludge in an anaerobic membrane co-digestion pilot plant coupled to a compo…
2021
[EN] A pilot-scale microalgae (Chlorella spp.) and primary sludge anaerobic co-digestion (ACoD) plant was run for one year in an anaerobic membrane bioreactor (AnMBR) at 35 °C, 70 d solids retention time and 30 d hydraulic retention time, showing high stability in terms of pH and VFA concentration. The plant achieved a high degree of microalgae and primary sludge substrate degradation, resulting in a methane yield of 370 mLCH4·gVSinf¿1. Nutrient-rich effluent streams (685 mgN·L¿1 and 145 mgP·L¿1 in digestate and 395 mgNH4-N·L¿1 and 37 mgPO4-P·L¿1 in permeate) were obtained, allowing posterior nutrient recovery. Ammonium was recovered from the permeate as ammonia sulphate through a hydrophob…
Effect of intracellular P content on phosphate removal in Scenedesmus sp. Experimental study and kinetic expression
2014
The present work determines the effect of phosphorus content on phosphate uptake rate in a mixed culture of Chlorophyceae in which the genus Scenedesmus dominates. Phosphate uptake rate was determined in eighteen laboratory batch experiments, with samples taken from a progressively more P-starved culture in which a minimum P content of 0.11% (w/w) was achieved. The results obtained showed that the higher the internal biomass P content, the lower the phosphate removal rate. The highest specific phosphate removal rate was 6.5 mgPO4 P gTSS -1 h -1 . Microalgae with a P content around 1% (w/w) attained 10% of this highest removal rate, whereas those with a P content of 0.6% (w/w) presented 50% …
Modeling light and temperature influence on ammonium removal by Scenedesmus sp. under outdoor conditions.
2016
[EN] The ammonium removal rate of the microalga Scenedesmus sp. was studied under outdoor conditions. Microalgae were grown in a 500 L flat-plate photobioreactor and fed with the effluent of a submerged anaerobic membrane bioreactor. Temperature ranged between 9.5 WC and 32.5 WC and maximum light intensity was 1,860 μmol·m2·s1. A maximum specific ammonium removal rate of 3.71 mg NH4 þ-N·g TSS1·h1 was measured (at 22.6 WC and with a light intensity of 1,734 μmol·m2·s1). A mathematical model considering the influence of ammonium concentration, light and temperature was validated. The model successfully reproduced the observed values of ammonium removal rate obtained and it is thus p…
Microalgae-bacteria consortia in high-rate ponds for treating urban wastewater: Elucidating the key state indicators under dynamic conditions
2020
[EN] On-line performance indicators of a microalgae-bacteria consortium were screened out from different variables based on pH and dissolved oxygen on-line measurements via multivariate projection analysis, aiming at finding on-line key state indicators to easily monitor the process. To fulfil this objective, a pilot-scale high-rate pond for urban wastewater treatment was evaluated under highly variable conditions, i.e. during the start-up period. The system was started-up without seed of either bacterial or microalgal biomass. It took around 19 days to fully develop a microalgal community assimilating nutrients significantly. Slight increases in the biomass productivities in days 26-30 sug…
Global sensitivity and uncertainty analysis of a microalgae model for wastewater treatment.
2022
The results of a global sensitivity and uncertainty analysis of a microalgae model applied to a Membrane Photobioreactor (MPBR) pilot plant were assessed. The main goals of this study were: (I) to identify the sensitivity factors of the model through the Morris screening method, i.e. the most influential factors; (II) to calibrate the influential factors online or offline; and (III) to assess the model's uncertainty. Four experimental periods were evaluated, which encompassed a wide range of environmental and operational conditions. Eleven influential factors (e.g. maximum specific growth rate, light intensity and maximum temperature) were identified in the model from a set of 34 kinetic pa…
The impact of various cations on the sorption of manganese in the thallus of freshwater algae spirogyra sp. and sea algae palmaria palmata
2014
Abstract Due to their occurrence in very different conditions and high resistance to physical and chemical factors, algae are pioneers colonising new environments and their sorption properties are used in biomonitoring and water remediation. The efficiency of the process of heavy metal sorption in algae used for in situ tests depends on abiotic factors, such as the chemical composition of water. Freshwater algae Spirogyra sp. were used in tests. Algae were exposed in the laboratory in manganese chloride solutions with various contents of other cations, including heavy metals and macronutrients. It has been shown that some heavy metals may desorb manganese bound to the surface of algae as a …
PESI - a taxonomic backbone for Europe
2015
Reliable taxonomy underpins communication in all of biology, not least nature conservation and sustainable use of ecosystem resources. The flexibility of taxonomic interpretations, however, presents a serious challenge for end-users of taxonomic concepts. Users need standardised and continuously harmonised taxonomic reference systems, as well as highquality and complete taxonomic data sets, but these are generally lacking for nonspecialists. The solution is in dynamic, expertly curated web-based taxonomic tools. The Pan-European Species-directories Infrastructure (PESI) worked to solve this key issue by providing a taxonomic e-infrastructure for Europe. It strengthened the relevant social (…
Use of Algae in Active Biomonitoring of Surface Waters
2015
Abstract Biomonitoring studies have been carried out in three retention reservoirs located in the Opole Province (southern Poland): Turawa reservoir, Nysa reservoir and Otmuchow reservoir. The increases of concentrations of Mn, Fe, Cu, Zn, Cd and Pb in fresh water algae Spirogyra sp. and sea water Palmaria palmata (Linnaeus) Weber & Mohr, exposed in the analysed waters, were determined by the atomic absorption spectrometry method (AAS). Also the waters pH, conductivity and Mn and Fe concentrations were determined. The concentrations of Cu, Zn, Cd and Pb in the analysed waters were lower than the method limit of determination. The analyses were carried out during the period from June to …
Molluscan assemblages associated with photophilic algae in the Marine Reserve of Ustica Island (Lower Tyrrhenian Sea, Italy)
2000
Abstract Very few studies have addressed the effect of protection on macrozoobenthos in marine protected areas, and particularly for sites in the Mediterranean Sea. In the present study, the molluscan assemblages associated with photophilic algal communities of the Marine Reserve of Ustica Island, were investigated. A survey was carried out along transects from 1 to 15 m in depth, during the spring of 1996 at three different sites, subjected to different levels of reserve protection. Species richness and number of individuals reflected the level of protection, and both variables were significantly higher in the integral (most heavily protected) part of the reserve compared with the less wel…
Bioflocculation of Euglena gracilis via direct application of fungal filaments: a rapid harvesting method
2021
Funding Information: Special thanks to the US Agricultural Research Service for the provision of fungal strains. Thanks also to Dr Marilyn Wiebe (Technical Research Centre of Finland) for her expert advice on fungi and Johanna Oja for her technical help. This research was enabled by funding from The Land and Water Technology Foundation, The Finnish Cultural Foundation, and The Finnish Foundation for Technology Promotion. Publisher Copyright: © 2021, The Author(s). The high cost and environmental impact of traditional microalgal harvesting methods limit commercialization of microalgal biomass. Fungal bioflocculation of microalgae is a promising low-cost, eco-friendly method but the range of …