The filtration characteristics of anaerobic digester effluents employing cross flow ceramic membrane microfiltration for nutrient recovery

<p>In the present study, a monolithic alumina coated microfiltration ceramic membrane was used for solid particulate removal and nutrient recovery from anaerobic digester complex effluent streams. The aim was to test the effect of the cake layer developed by the solids, on the surface of the membrane channels, to the filterability of these materials. The solid content ranged between 2.6 g/L to 15.1 g/L. During practical application, two processing techniques targeting the enhanced recovery of the materials of interest including ammonia, phosphate, calcium bicarbonate and volatile fatty acids, namely dewatering and diafiltration, were used. These had an immediate effect on the solid content (PDS 13 μm to 3.97 μm) enhancing the filterability of the effluents. Their processability was evaluated in terms of flux, cross flow velocity, membrane resistance and cake resistance. An important finding of this study is the nonalignment of the flux rates to the cake resistance, explained by the formation of a compressible, permeable cake layer that allowed the continuous operation of the system, under constant low pressure conditions (TMP 15 psi). Permeate flux remained constant to 120 L/m² h when applying diafiltration, while when dewatering process is used the permeate flux remained constant at 115.4 L/m² h.</p> <p>This is an Audioslide presentation supportive to the full paper titled " The filtration characteristics of anaerobic digester effluents employing cross flow ceramic membrane microfiltration for nutrient recovery" published by Desalination journal , May 2014, Vol:341, pp:27-37</p

Report on VECTO Technology Simulation Capabilities and Future Outlook

The European Commission is developing the Vehicle Energy Consumption Calculation Tool (VECTO) for Heavy Duty Vehicle CO2 certification purposes. VECTO is a vehicle simulation tool tailored to estimate CO2 emissions from heavy-duty vehicles of different categories, sizes and technologies. Further development and optimization of VECTO and the CO2 certification methodology requires assessing their capacity to properly simulate specific vehicle technologies and gathering additional feedback on the possibility to capture future technologies which are expected to be deployed on heavy-duty vehicles in the years to come. In order to investigate the VECTO capabilities and performance a dedicated questionnaire was formulated and distributed to various stakeholders. The technologies under investigation were previously identified through a literature review. The feedback received clearly pointed out the technologies that can be properly simulated by VECTO, which constituted an important part of the initial technology list, pointing out that VECTO and the accompanying certification methodology have reached a good level of maturity. The responses provided also some initial feedback on the implementation approach for the technologies which are not properly captured at the moment. The latter were separated into three groups based on the type of work that is required for including them in the certification methodology which could relate either to the development of the VECTO software or further expansion-specialization of CO2 certification methodology or a combination of the two. The current report presents the findings of the survey and outlines possible future steps for the further development of VECTO software and the accompanying certification methodologyJRC.C.4 - Sustainable Transpor

Review of in use factors affecting the fuel consumption and CO2 emissions of passenger cars

This report primarily investigates the factors that affect fuel consumption and CO2 emissions which are not accounted for in the current type approval test and result in a shortfall between type approval and real-world fuel consumption or the corresponding CO2 emission values. A comprehensive literature review is carried out, in which we examine the available information and aim to provide qualitative and quantitative data. Where information is e insufficient, we point out the gap in knowledge. In addition, we have examined by means of simulation the significance of several factors that may change during every-day operation and may depend either on the driver or on external conditions. Several factors were identified affecting the in-use fuel consumption and CO2 emissions resulting in a shortfall between the type approval and real-world values. These include the increased electrical power load (e.g. A/C, steering assist), aerodynamic alterations (roof box, aerofoils), ambient conditions (temperature, wind, rain and altitude), driving behavior (aggressive driving, driver training), vehicle condition (lubrication, tyre condition), increased vehicle mass (passengers, additional equipment), road conditions (road surface, traffic conditions). They are complemented by so-called "flexibilities" associated with the existing NEDC-based type approval procedure. The combined effect of the different factors affecting CO2 emissions,, although not fully cumulative, can result in shortfall values ranging between 25% and 35%, based on information collected, the calculations run and the assumptions adopted in this study. These figures are in line with other literature sources where shortfall ranges from 20% up to 50% compared to the official certification value are reported. The per-passenger CO2 performance significantly improves when the occupancy rate is considered, hence a separate analysis was performed to this end. It can be concluded that due to the increase complexity of modern vehicles, the increasing number of passenger comfort systems and the great variety of possible operating conditions, it is difficult to capture the real-world fuel consumption with an exhaustive accuracy. It is expected that the introduction of the new test protocol (WLTP) will be a step forward in closing this shortfall. A separate analysis on the expected WLTP impact on CO2 is presented. It cannot be overlooked that driver behavior is an important element and therefore additional measures, in particular proper driver training and information, can help to reduce the discrepancy observed by drivers between their own in-use CO2 emissions from passenger cars compared to the test results.JRC.C.4-Sustainable Transpor

An exploration of the sub-register of chemical engineering research papers published in english

The combination of increased pressures for high-volume, high-impact publications in English language with the high rejection rates of submitted manuscripts for publications presents an often unsurpassable obstacle for (early career) researchers. At the same, the register requirements of peer-reviewed journals -that can contribute to whether a paper is accepted for publication- has received little attention. This paper redresses this gap, by investigating the linguistic choices in 60 published manuscripts in four journals, with impact factor (IF) above 2; all 4 journals, publish original research papers in the field of chemical engineering science and specifically focus on wastewater treatment. Our survey shows that chemical engineering research publications tend to comply to a set of unwritten requirements: multidisciplinarity, brevity, co-authorship, focus on the description of practical results (rather than methods), and awareness of non-specialised audiences. It is found that less discipline-specific vocabulary was used in higher IF journals and this is interpreted within the current context of manuscript publication and consumption. Also, a complex relationship between the advertised scope of each journal and the actual published papers exists, indicating that guide for authors and aims and objective published by the journal's editorial office should be critically evaluated

An exploration of the sub-register of chemical engineering research papers published in English

The increased pressures for high-volume, high-impact publications in English language and the high rejection rates of submitted manuscripts for publications present an often unsurpassable obstacle for (early career) researchers. At the same time, register variation of peer-reviewed journals—that can contribute to whether a paper is accepted for publication—has received little attention. This paper redresses this gap, by investigating the register (especially discourse moves and lexical choices) in 60 published, original-research articles on wastewater treatment published in four Chemical Engineering journals, with impact factor (IF) above 2. Our survey shows that chemical engineering research publications tend to comply with a set of requirements: multidisciplinarity, brevity, co-authorship, focus on the description of practical results (rather than methods), and awareness of non-specialised audiences. Lexical choices were analysed through frequency tables, phrase nets and word trees produced by data visualisation software (ManyEyes). It was found that less discipline-specific vocabulary is used in higher IF journals and this is interpreted within the current context of manuscript publication and consumption. This study concludes that data visualisation can provide an efficient and effective tool for prospective authors that wish to gauge telling details of the sub-register of a specific journal

Nutrient recovery and fractionation of anaerobic digester effluents employing pilot scale membrane technology

Anaerobic Digester (AD) waste, known as digestate (spent anaerobically digested effluents) of agricultural origin, was collected for a feasibility study on the use of membrane filtration to fractionate phosphate and ammonia from digestate into nutrient streams. The digestate was pre-treated to remove bulk solids and then filtered using diafiltration (DF) with ultrafiltration (UF) (5.65 psi TMP) and then nanofiltration (NF) (operating pressure 253.82 psi). Having set the pre-treated effluents at pH 4.0, retention of phosphate reached 6.78 mmols L−1 during UF with lower values being achieved with repeated DF steps. In contrast, nitrogen retention was lower at 8.21 mmols L-1 and was continuously dropping at each DF step. During NF phosphorus was shown to be strongly retained by the membrane at 31.8 mmols L−1, while retention of ammonium was low at 13.4 mmols L-1 demonstrating the potential for this combination of membrane types for fractionating high value components from AD waste

Multiple objective optimal control of integrated urban wastewater systems

Copyright © 2008 Elsevier. NOTICE: this is the author’s version of a work that was accepted for publication in Environmental Modelling and Software. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Environmental Modelling and Software, Vol. 23 Issue 2 (2008). DOI: 10.1016/j.envsoft.2007.06.003Integrated modelling of the urban wastewater system has received increasing attention in recent years and it has been clearly demonstrated, at least at a theoretical level, that system performance can be enhanced through optimized, integrated control. However, most research to date has focused on simple, single objective control. This paper proposes consideration of multiple objectives to more readily tackle complex real world situations. The water quality indicators of the receiving water are considered as control objectives directly, rather than by reference to surrogate criteria in the sewer system or treatment plant. A powerful multi-objective optimization genetic algorithm, NSGA II, is used to derive the Pareto optimal solutions, which can illustrate the whole trade-off relationships between objectives. A case study is used to demonstrate the benefits of multiple objective control and a significant improvement in each of the objectives can be observed in comparison with a conventional base case scenario. The simulation results also show the effectiveness of NSGA 11 for the integrated urban wastewater system despite its complexity

Future CO2 reducing technologies in VECTO

The software tool VECTO is used to determine the energy demand, fuel consumption and CO2 emissions of new heavy-duty vehicles. The tool takes into account the relevant vehicle component technologies that affect fuel consumption and CO2 emissions and should be updated when new relevant technologies are brought to the market. This work presents the results of a survey investigating the capability of VECTO to simulate new vehicle technologies, along with CO2 reduction potential and the expected penetration rate in the market of these technologies. An in-depth analysis of these new technologies is presented in this work. Many of the technologies demonstrating high potential in reducing CO2 and market uptake in the near future (e.g. aero devices for trailers and bodies and hybrid electric powertrains) are currently being implemented in VECTO. The next steps can include zero-emission vehicles, such as fuel cell vehicles, and technologies that could be easily implemented.JRC.C.4 - Sustainable Transpor

Intensive propagation of the lactic acid bacterium Lactococcus lactis.

L.lactis is an important lactic acid bacterium, widely used in the dairy industry nowadays. The coccus is used as a natural acidifier for the inoculation of bulk quantities of milk in order to produce a variety of fermented products. As such, large quantities of its biomass are necessary. The possibility of producing the cellular biomass of the coccus in mass quantities was investigated through several techniques. Firstly, the bacterium was grown into simple batch cultures without pH control where the physicochemical needs of the coccus were determined. Through the determination of the optimum nutritional conditions for the propagation of the coccus, an optimised medium for growth occurred. The growth efficiency on the medium was tested on a 2L STR reactor operated batchwise with continuous pH control. The optimum pH conditions for the growth of the coccus were determined as well as parameters such as cellular yield coefficient, substrate and starter inoculum concentration. The metabolism o the coccus was determined as homofermentative, mainly producing lactic acid through measurements of the organic acids produced at the end of the fermentation process in the STR. In addition carbohydrate consumption rate in the optimum pH values selected was measure and the constant coefficients for substrate consumption end product inhibition effect and a maintenance coefficient term was determined. A simple mathematical model was constructed to describe the growth of the coccus batchwise and a correlation was made between the experimental data obtained from the STR fermentations and the theoretical predictions. An inhibition term was incorporated in the model in order to describe the inhibitory effect of lactic acid over the growth. With the use of the inhibition term a good fit between the experimental data and the model was obtained. The growth kinetics of L.lactis were further investigated by modelling its growth in a continuous system and in a Membrane Bioreactor system. The feasibility and the efficiency in all 3 systems was evaluated in terms of the volumetric cell productivity, (g/l/h). The models were also tested against different substrate concentrations, different starter inoculums, different dilution and flux rates. The MBR system has found to be highly productive especially when operated in the continuous mode of substrate feed, the volumetric cell productivity (g/l/h) (45.94 g/l/h) was over 10 times higher when compared with the volumetric cell productivity (g/l/h) given by the continuous system (1.4 g/l/h)and over 30 times when compared with the batch system(0.45 g/l/h). MBR was proven to be a possibly useful system for the development of high concentrations of cellular biomass but its practical application has to be further investigated