Performance comparison between TEMO and a typical FMS in presence of CTA and wind uncertainties

© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Best session (Aiport Management & Arrival/Departure operations) paper award - 35th DASC. 2016Continuous Descent Operations (CDO) with Con- trolled Times of Arrival (CTA) at one or several metering fixes could enable environmentally friendly procedures without com- promising airspace capacity. Extending the current capabilities of state-of-the-art Flight Management Systems (FMS), the Time and Energy Managed Operations (TEMO) concept is able to generate optimal descent trajectories with an improved planning and guidance strategy to meet CTA. The primary aim of this paper is to compare the performances of TEMO (in terms of fuel consumption and time error) with respect to a typical FMS, that is an FMS without re-planning mechanism during descent based on time or altitude errors. The comparison is performed through simulation, using an A320-alike simulation model and considering several scenarios in presence of CTA and wind uncertainties. Results show that TEMO is capable of guiding the aircraft along a minimum fuel trajectory still complying with a CTA, even if significant wind prediction errors are present. For a same scenario, a typical FMS without re-planning capabilities or tactical time-error nulling mechanism during the descent, would miss the CTA in most cases.Peer ReviewedAward-winningPostprint (published version

Biotechnological exploration of nitrate-accumulating microalgae for nutrient recovery from saline wastewaters

Within sustainable resource management, the recovery of nitrogen and phosphorus nutrients from waste streams is becoming increasingly important. Although the use of microalgae has been described extensively in environmental biotechnology, the potential of nitrate-accumulating microalgae for nutrient recovery has not been investigated yet. The ability of these marine microorganisms to concentrate environmental nitrate within their biomass is remarkable. The aim of this study was to investigate the application potential of nitrate-accumulating diatoms for nutrient recovery from marine wastewaters. The intracellular nitrate storage capacity was quantified for six marine diatom strains in synthetic wastewater. Amphora coffeaeformis and Phaeodactylum tricornutum stored the highest amount of nitrate with respectively 3.15 and 2.10 g N L−1 of cell volume, which accounted for 17.3 and 4.6 %, respectively, of the total nitrogen content. The growth and nitrate and phosphate uptake of both diatoms were further analyzed and based on these features P. tricornutum showed the highest potential for nutrient recovery. A mathematicalmodel was developed which included intracellular nitrate storage and the kinetic parameters were derived for P. tricornutum. Furthermore, a simulation study was performed to compare the performance of a proposed microalgal nutrient recovery unit with a conventional denitrification system for marine wastewater treatment. Overall, this study demonstrates the potential application of P. tricornutum for saline wastewater treatment with concurrent nitrogen and phosphorus recycling

Inoculation with a mixed degrading culture improves the pesticide removal of an on-farm biopurification system

To investigate whether the pesticide removal in on-farm biopurification systems (BPS) filled with two different types of substrata (biomix and plastic carriers) is affected by inoculation with a pesticide-degrading strain or mixed culture, lab-scale BPS used to treat chloropropham point source contaminations were bioaugmented with either a specialized chloropropham-degrading strain or a chloropropham-degrading enrichment culture. Application of both inoculum types leads to an accelerated degradation activity in the columns filled with plastic carriers. For both substratum types, inoculation with the mixed culture resulted in a lower breakthrough of the toxic intermediate 3-chloroaniline at high hydraulic loads, compared to inoculation with the pure isolate and no inoculation. This study suggests that the use of plastic carrier materials could be a proficient alternative to the use of a conventional biomix as a substratum in on-farm BPS and that inoculation with a mixed degrading culture can reduce the leaching of more mobile toxic intermediates

Biofilm based bioremediation strategies for the treatment of pesticide wastestreams

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Spatial heterogeneity in degradation characteristics and microbial community composition of pesticide biopurification systems

Aims: To investigate spatial and temporal differences in degradation characteristics and microbial community composition of pesticide biopurification systems. Methods and Results: Pilot-scale biofilters were supplemented with the potato-sprouting suppressant chloropropham. Two biofilters were inoculated with a chloropropham-degrading mixed culture, while the other two were not inoculated. Biodegradation rate, size and composition of the microbial community were monitored during 72days at different biofilter depths. First of all, results showed that inoculation was not necessary to obtain efficient degradation although it shortens the biofilter's start-up period. Secondly, a higher biodegradation rate and chloropropham- and 3-chloroaniline-degrading microbial community size could be seen in the top part of the inoculated as well as the noninoculated biofilters. Finally, analysis of the microbial community composition shows that no clear spatial stratification of the microbial community could be found in any biofilter. However, the microbial diversity increases over time in all biofilters and on all biofilter depths, suggesting that during the time of the experiment, the biofilters develop a broad carrying capacity in which a genetically very diverse range of chloropropham- and 3-chloroaniline-degrading species can thrive. Conclusions: In this study, a vertical gradient of the chloropropham- and 3-chloroaniline-degrading community composition, in terms of density and temporal and spatial diversity, was clearly established and was directly connected to a vertical gradient of chloropropham biodegradation activity. Significance and Impact of the Study: The major part of degradation activity takes place in the top part of the biofilter, suggesting that it could be possible to use shorter biofilter reactors or higher loading rates to treat chloropropham waste streams, making this type of bioremediation technique economically more feasible

Real-time aircraft continuous descent trajectory optimization with ATC time constraints using direct collocation methods.

1 Abstract In this paper an initial implementation of a real - time aircraft trajectory optimization algorithm is presented . The aircraft trajectory for descent and approach is computed for minimum use of thrust and speed brake in support of a “green” continuous descent and approach flight operation, while complying with ATC time constraints for maintaining runway throughput and considering realistic wind conditions. The trajectory opti mizer forms an important part of a new integrated, planning and guidance concept name d TEMO (Time and Energy Managed Operations) developed in the Systems for Green Operat ions (SGO) Clean Sky EU - program . It is compared with a typical A320 Flight Mana gement System ( FMS ) showing improvement s regarding time adherence performance and environmental impact.Peer ReviewedPostprint (published version