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Odours emitted by biological wastewater treatment plants (WWTPs) may cause a nuisance and negatively impact people’s health. It is possible to tackle this issue using known deodorization technologies such as adsorption, absorption, combustion, catalytic oxidation, and biofiltration. However, applying some of these may lead to secondary pollution, high operating and investment costs, periodic replacing, utilising or regenerating reactor or filter bed, or using expensive catalysts. It is possible to avoid problems of this kind using the compact trickle-bed bioreactor (CTBB) technology to biodegrade odours emitted from WWTPs. A pilot-scale CTBB reactor, with a total volume of 1.07 m³, diameter of 0.8 m and height of 2.13 m, was installed on the premises of a municipal WWTP. At variable parameters of the biodegradation process, odour reduction was investigated using mobile measuring devices to detect hydrogen sulfide (H2 S) and volatile organic compounds (VOCs). The factor of H2 S conversion was 71%–97%, and that of VOC conversion was 82%–94% when the gaseous-phase flow rate ranged from 7–30 m³ h–1, at pH = 7 in the liquid-phase. The research results confirm the significant potential of CTBB technology for application in the municipal sector. [ABSTRACT FROM AUTHOR]

Following the 2015 Paris Agreement, the main challenge for world economies nowadays is to commit themselves to long-term reforms aimed at increasing and promoting sustainable, inclusive and balanced development. An adequate response to this challenge will certainly require using the best available scientific knowledge and constant re-evaluation of the development process in light of the scientific findings. To ensure that the sciences are responsive to the emerging needs and to address sustainable development issues. This Virtual Special Issue of the Journal of Cleaner Production is dedicated to both Sustainable Development of Energy, Water and Environment Systems 2016 Conferences – 2nd South East European Sustainable Development of Energy, Water and Environment Systems Conference and 11th Sustainable Development of Energy, Water and Environment Systems Conference. The Virtual Special Issue is focused on four main fields: Energy issues, Water issues, Environmental engineering and management, and Sustainable engineering solutions and large-scale sustainability approaches. The division of selected papers follows the previous Journal of Cleaner Production Special Sections and Volumes dedicated to the Sustainable Development of Energy, Water and Environment Systems Conference series. [ABSTRACT FROM AUTHOR]

Due to climate change concerns, various environmental stresses and social inequality among the people, the welfare of mankind is increasingly being viewed through the prism of sustainable development. Sustainable development is a highly multi-disciplinary field of research that has been extensively studied during last two decades. Therefore, from the beginning of the 21st century, a series of Sustainable Development of Energy, Water and Environment Systems (SDEWES) Conferences were founded to address sustainable development issues. This Journal of Cleaner Production Special Volume (SV) is dedicated to the 10th SDEWES Conference. The SV is focused on three main fields that are of strategic importance to sustainable development: energy issues, water issues, and environmental engineering and management. The division of selected papers according to the named research fields was established following the previous Journal of Cleaner Production Special Sections and Volumes dedicated to the SDEWES Conferences. Therefore, this Special Volume builds upon the previously generated SDEWES knowledge base. [ABSTRACT FROM AUTHOR]

The conventional approach to heat exchanger network (HEN) retrofit involving design techniques based on Pinch Technology (PT) is extended to include minimization of energy losses resulting from steam-condensate expansion. The authors proposed a new approach to minimize energy losses in utility system, thermally coupled with the combined heat and power (CHP) plant, using condensate subcooling phenomena. Moreover, applying condensate subcooling can counteract the drawbacks of commonly used multi-stage condensate expansion which increase operability and reduces investment and maintenance costs. A case study illustrates the suitability of improved condensate management as a HEN retrofit measure. The study object is a Methyl-Tert-Butyl Ether (MTBE) plant processing 18 t/h isobutylene and consuming 4386 kW of hot utility (steam) in the HEN. A study of the maximum possible heat recovery using PT indicates that the combined heat recovery from hot process streams and condensate can be increased by 510 kW compared to the existing state. At the same time, it is possible to generate additional power of 120 kW in the CHP plant that supplies energy to the MTBE plant. The locations of heat exchangers are accounted for in HEN reconfiguring. A new scheme of steam and condensate system is presented. • Heat exchanger network (HEN) is essential for the process plant's energy efficiency. • HEN retrofit may include introducing rational energy recovery from steam condensate. • Condensate subcooling in the retrofitted HEN may enhance the energy recovery. • Case study illustrates the effect of condensate subcooling as HEN retrofit measure. • Condensate subcooling enhance electricity production in combined heat and power plant. [ABSTRACT FROM AUTHOR]

Engineering analyses based on the results of numerical simulation enable shortening the duration and reducing the costs of the development and tests of equipment models or prototypes. As numerical modeling methods have uncertainties, experimental verification is required. In the literature, there are many examples of application of numerical modelling to the thermal processes occurring in electric motors but the experimental methods of model validation are not so well described. In this work, numerical and experimental investigations of heat conduction in the finned housing of an electric motor, and the comparison between their results are presented. 3D geometrical model of the motor rated 7.5 kW was imported to COMSOL Multiphysics software package. After defining thermophysical properties of the housing material and heat flows generated in the motor, and setting boundary conditions, a numerical model of heat conduction in the motor housing was obtained. The model allowed to calculate steady-state temperature distribution in the housing cross section. In order to validate the model, investigations of the temperature distribution were carried out using FLIR SC7600 thermovision camera. Steady-state temperature distribution on the surface of housing of the motor run in idling conditions was recorded by thermography. The obtained thermograms were found to be in satisfactory quantitative agreement with the simulated temperature distribution as the real values of temperature differences measured across the housing cross section deviated not more than 10% from the calculated ones. The research confirmed that a thermovision camera is an efficient experimental tool for the validation of numerical models of the heat transfer phenomena in the finned housing of an electric motor. [ABSTRACT FROM AUTHOR]

One of the main issues of the coming decades is to improve resource efficiencies by integrating various life supporting systems, using waste from one, as resource in other, and in exact moment when it is beneficial to all. The challenge is on the electricity, heating, cooling, transport, water, buildings, industry, forestry and agriculture systems to integrate and become more sustainable. Since the sustainable development depends more and more on the holistic approach on the integration of energy, water and environment systems, from the beginning of the 21st century, a series of Sustainable Development of Energy, Water and Environment Systems (SDEWES) Conferences has been founded to cover these issues. The background of this Special Section of the Journal of Cleaner Production is therefore the Sustainable Development of Energy, Water and Environment Systems dedicated to both SDEWES 2014 Conferences – 1st South East European SDEWES Conference and 9th SDEWES Conference. The Special Section focuses on scientists, researchers, policy makers, educators, general public and practitioners in various branches of industry including the energy and water & wastewater sectors and environmental services. The purpose of this Special Section is to increase public awareness of key issues of sustainable development and to stimulate exchange of research results, practical experience and novel ideas among actors involved in investigating, planning and implementing sustainable development. The Special Section is focused upon four main fields that are of strategic importance to the sustainable development: Energy issues; Water issues; Environmental engineering and management; Sustainability approaches and promotion of sustainability concepts. The division of selected papers according to the named research fields has been established by the previous Journal of Cleaner Production Special Sections and Volumes dedicated to the SDEWES 2013 Conference. Hence, this Special Section is an extension of the previously generated SDEWES knowledge base in these four main research areas. As sustainable development is improving piecewise, so although it is necessary to see the big picture, actual technological improvement is one aspect of the technology systems. It has been shown that the sustainability can be improved by improving certain systems taking care of holistic sustainability criteria or integrating various systems in a way to improve the efficiency or resource efficiency of the combined system. [ABSTRACT FROM AUTHOR]

It is now widely recognized that considerable amounts of hydrogen can be produced from renewable resources without using energy from fossil fuels. Biological processes and mainly bacterial hydrogen fermentation are considered as the most environmentally friendly alternatives for satisfying future hydrogen demand. In particular, biohydrogen production from agricultural and agro-industrial solid waste and wastewater is considered as highly advantageous as materials of this kind are abundant, cheap and biodegradable. Apart from economic considerations, the conversion of such materials into hydrogen is in many cases stimulated by the need to solve environmental problems. However, the suitability of various kinds of biomass-derived feedstock for industrial-scale hydrogen production is widely differentiated. In this paper, on the basis of numerous research contributions published mainly in the period 2008–2013, recent findings on the use of biomass residues and waste for biohydrogen production by bacterial fermentation are reviewed. The focus is on second generation (lignocellulosic) biomass substrates that are most widely available but can be fermented only after appropriate pretreatment which is rather costly at present and therefore requires further development. Research results pertaining to the use of selected sugar-containing and starchy residues are also mentioned as the conversion of these materials into biohydrogen is not in competition with food production, and their pretreatment is cheaper than that of lignocellulosic biomass. In addition to an extensive literature review, the state of the art in the area of pretreatment of biomass residues for hydrogen fermentation is evaluated, and the authors' view of challenges for future research is presented. [ABSTRACT FROM AUTHOR]

The focus of this Special Volume (SV) of the Journal of Cleaner Production is “Sustainable Development of Energy, Water and Environmental Systems”. It is of interest to practitioners in various branches of industry including the energy and water & wastewater sectors and environmental services, governmental policy makers, researchers, educators and the general public. The purpose of this SV is to increase public awareness of key issues of sustainable development and to stimulate exchange of research results, practical experience and new ideas among actors involved in investigating, planning and implementing sustainable development, regarding energy, transport, water, environment and production systems. The SV is focused upon four main fields that are of strategic importance to the sustainable development: energy resources and energy management, water management and wastewater treatment, environmental engineering and management, and promotion of sustainability concepts. The systems under consideration are differentiated in scale, ranging from countries or groups of countries, through regions or branches of industry, municipalities or industrial plants, down to single processes or equipment pieces. Examples of on-going research including case studies are presented along with examples of innovative practical solutions. In the energy field, examples are presented of the development and applications of energy systems analysis, planning and design methods and tools, which can be used to analyse the coherency of the whole systems and to augment the creation of sustainable energy policies and action plans on a large scale, as well as small-scale systems for efficient energy management. Regarding water issues, water management in water stressed regions is discussed indicating the usefulness of advanced mathematical models that take system dynamics and the stochastic nature of rainwater availability as planning tools, and LCA-based methods for assessing the diverse water supply alternatives within a dry region. In the field of environmental engineering and management, large-scale systems for solid waste collection, management and recovery are analysed, and the formation of air pollutants in industrial sources and diesel engines is studied by simulation. Finally, sustainable use of biomass resources and the role of sustainability thinking in the investment planning and management are addressed. In each of the four fields, strategically important challenges for future research are identified including the use of advanced mathematical models and multi-criteria analysis for the optimisation, from the sustainability point of view, of the systems for energy and water supply and management, solid waste management and the utilisation of biomass resources. [ABSTRACT FROM AUTHOR]

Abstract: A conceptual factory to produce hydrogen from starchy biomass is considered. The production plant comprises a pretreatment unit for starchy raw material, a bioreactor for dark fermentation, a photobioreactor for photofermentation and gas upgrading & compression units, and is supplied with the necessary heat and power from the power plant. In the power plant, a part of the stream of raw gas produced in bioreactors is burned in a steam boiler and in addition some product gas from the upgrading unit is directed to fuel cells from which waste gas flows to a catalytic oxidizer. The demand for process heat is covered by steam generation in the boiler and oxidizer, and the power demand is covered by electricity generation in the fuel cells. The energy demand is studied as a function of selected process parameters; among them, CO2 content in the product gas is of key importance. Conclusions are presented regarding the practicability of using own-produced hydrogen for the energy supply. [Copyright &y& Elsevier]

Abstract: Two-stage fermentative hydrogen production process comprising dark fermentation and photofermentation followed by gas upgrading is studied from the technical and economic points of view. It is assumed that a conceptual hydrogen plant is connected to a sugar factory so that technical sucrose solutions produced there (raw juice, thick juice and molasses) can be used as fermentation feedstocks. Process data needed for the study are based on the results of a recently completed research project and in the techno-economic assessment of hydrogen production, data acquired in the sugar industry are taken into account. A parametric study of the cost of hydrogen production from molasses shows that the total cost is highly sensitive to the capital and operating costs of the photofermentation stage. Prospects of cost reduction through further development of the two-stage fermentative process are discussed. [Copyright &y& Elsevier]

Abstract: The basics of hydrogen production by thermophilic fermentation and photofermentation are outlined. Various types of biomass, which can be used as raw materials for hydrogen fermentation are named and the methods of biomass pretreatment are highlighted. The approach to technical assessment of biomass suitability is reviewed and several promising raw materials are compared with respect to the attainable hydrogen yield. [Copyright &y& Elsevier]

The automotive painting industry is a source of environmental pollution caused by Volatile Organic Compounds (VOCs) present in the discharged ventilation air. To contribute to the mitigation of this type of air pollution, Ekoinwentyka Ltd. developed – from pilot scale to full scale – and adapted the technology of Compact Trickle Bed Bioreactor (CTBB) whose operating principle builds upon co-current downflow of the gas phase (polluted air) and liquid phase (solution of mineral salts) through a packed bed where active microorganisms are immobilized in the biofilm on the surfaces of packing elements. Pilot-scale bioreactor 0.32 m in diameter and 1.50 m total height had its packed bed inoculated with a consortium of microorganisms dominated by Pseudomonas fluorescens bacteria. During the experimental programme that lasted several months, the flow rate of air drawn from the ventilation system of the painting shop was changing between 1.0 and 10.0 m3/h and the inlet concentration of VOCs ranged from 10 to 200 ppm. By measuring VOC concentration in the purified air, the factor of VOC biodegradation was found to range between 85 and 99%. Based on pilot-scale experiments, full-scale CTBB has been developed 2.8 m in diameter and 10 m total height and installed as an add-on component of the ventilation system of the painting shop. Test operation at gas flow rates up to 6000 m3/h, confirmed VOC biodegradation factor at the level of 85–99% thus proving a positive result of CTBB technology adaptation to the conditions of the automotive painting industry. [ABSTRACT FROM AUTHOR]

Abstract: The International Conference on Advances in Biological Hydrogen Production and Applications was held on December 14–15, 2012 at Jawaharlal Nehru Technological University Hyderabad, India. It was dedicated mainly to the improvement and dissemination of knowledge on methods and technologies for hydrogen production from bioresources. Other topics including hydrogen storage and use of hydrogen in fuel cells were also discussed. [Copyright &y& Elsevier]

Abstract: Report is given on the 19th World Hydrogen Energy Conference held on 3–7 June 2012 in Toronto, Canada. Basic facts about conference organization, and its goal, scientific programme and conclusions are reviewed. [Copyright &y& Elsevier]

A real-life benchmark system comprising a Heat Exchanger Network operated as part of Crude Distillation Unit is considered. In such systems, the crude oil stream is typically split into parallel branches and the oil mass flows through the branches are kept in constant proportion, i.e., at constant split ratio, by the process control system. In this paper, linear control systems (proportional-integral-derivative controllers) are considered and the proposed control strategy is to adjust the parallel flows so that identical temperature values are maintained at the outlets from two parallel branches and consequently, the heat recovery in the network is maximized. The aim is to enhance the energy efficiency of the system and minimise greenhouse gas emissions. A mathematical model of the heat exchanger network was built and validated on the basis of real-life data recorded during operation of the crude distillation unit. Using MATLAB/Simulink, closed-loop control was simulated to enable comparative evaluation of the studied strategy of proportional-integral-derivative control and its potential to achieve energy savings in the operation of the distillation unit under fouling conditions. Compared to the strategy of constant split ratio, the proposed strategy of equal outlet temperatures from the network branches was found to increase the total heat recovery by about 1.5%. In the studied operation period, the heat-recovery increase fluctuated in the range 150–1100 kW and the average daily energy saving was estimated at 18 MWh. • Heat exchanger networks are needed for efficient energy use in industry. • Fouling in heat exchangers can negatively affect network performance. • Dynamic model of a network comprising shell and tube heat exchangers is developed. • The model implemented in MATLAB/Simulink simulates the effects of exchanger fouling. • Energy saving potential of a novel control strategy for network operation is simulated. [ABSTRACT FROM AUTHOR]

Abstract: The 6th Dubrovnik Conference was held on September 25–29, 2011 at the University of Dubrovnik, Croatia. It was dedicated to the improvement and dissemination of knowledge on methods, policies and technologies for increasing the sustainability of development of energy, transport, water and environment systems. [Copyright &y& Elsevier]

Abstract: Report is given on the 18th Word Hydrogen Energy Conference held on 16--20 May 2010 in Essen, Germany. Basic facts about conference organization, and its goal, scientific programme and conclusions are reviewed. [ABSTRACT FROM AUTHOR]

Abstract: The paper is concerned with estimation of heat and power consumption in a conceptual plant to produce hydrogen from sucrose-containing or starchy biomass by fermentation. A hydrogen plant connected with a sugar factory is regarded as the basic option; the sugar factory serves as a source of sucrose-containing thick juice for the hydrogen plant, where this feedstock is processed to hydrogen. As another option, a stand-alone hydrogen plant in which starch must initially be converted to fermentable glucose solution is considered. The values of key process parameters are assumed on the basis of preliminary experimental data. For both options of the hydrogen plant, heat consumption is estimated taking heat recovery in a heat exchanger network into account. Power consumption is estimated by calculating power needed for pumping of liquid and gaseous process media. [ABSTRACT FROM AUTHOR]

Abstract: The topic of this special issue of the Journal of Cleaner Production is “Sustainable Hydrogen from Biomass.” It is of interest to practitioners in the energy sector, governmental policy makers, researchers, educators, as well as to the general public. The purpose of this special issue is to increase public awareness and to stimulate exchange of information among actors expected to play important roles in making hydrogen available for the sustainable energy system of the future. Hydrogen as a biofuel, that is, hydrogen produced from biomass in a sustainable way is recognised as an important component of the fuel market for the future low or non-carbon based energy systems. In this special issue, the main focus is on hydrogen produced from vegetable biomass by fermentation. The development of a two-stage bioprocess for the cost-effective and environmentally friendly production of pure hydrogen from multiple biomass feedstocks is elucidated by a collection of papers presenting preliminary results of Integrated Research Project HYVOLUTION supported by the 6th Framework Programme of the European Union. The attention is turned to: - the over-all concept and characteristics of the two-stage hydrogen fermentation process, - key technological issues of fermentative hydrogen production, - the availability of vegetable feedstocks including agricultural byproducts that suitable for fermentative processing, - prospects of societal integration and sustainability of the fermentative hydrogen production technology. Other papers included in this special issue are devoted to: - simultaneous production of hydrogen and methane by fermentation of lactose-containing feedstocks derived from byproducts of milk processing, - hydrogen gas generation from organic material by electrohydrogenesis, that is, a bioelectrochemical process performed in reactors known as a microbial electrolysis cells, - the ideas for Europe-wide effort on education of hydrogen users and training of skilled staff needed for facilitating the transition to the future hydrogen economy. [Copyright &y& Elsevier]

Heat exchanger fouling may impair energy recovery in Heat Exchanger Networks (HENs), thereby increasing the energy intensity of production processes. Fouling growth on the heat-transfer surfaces of the exchangers can be monitored to mitigate its adverse effects, using measurement data that also enable scheduling exchanger cleaning when economically justified. The research builds on the authors' previous work devoted to different measurement-aided monitoring methods of fouling thermal resistance, where the method based on the least-square approach to measurement data is the preferred one. The aim is to apply the preferred approach to and perform a case study on the optimization of scheduling of cleaning actions on heat exchangers operated in a HEN. The avoided HEN operating cost is employed as an objective function to be maximized by the optimal cleaning schedule that also has to satisfy a set of constraints related to the timing of cleaning actions. The mathematical formulation of the schedule optimization problem is simplified to make solution finding easier. The case study uses historical operation records covering three years of the real-life HEN composed of 26 shell-and-tube heat exchangers working continuously in connection with a Crude Distillation Unit. Having identified historical time characteristics of the thermal resistance of fouling in all the heat exchangers, one can retroactively determine optimal HEN cleaning schedules. The optimization results are discussed, considering their economic aspects and potential for energy saving and pollution reduction. • Heat exchanger fouling impairs heat recovery in industrial exchanger networks. • Measurement-aided fouling monitoring provides data for planning cleaning actions. • Effect of exchanger cleaning is evaluated using avoided network operation cost. • Optimal schedule of cleaning actions is postulated to maximize the avoided cost. • Case study on optimal cleaning of real-life 26-exchanger network in an oil refinery. [ABSTRACT FROM AUTHOR]

Highlights: [•] Heat recovery in a heat exchanger network (HEN). [•] A novel method for on-line determination of the thermal resistance of fouling is presented. [•] Details are developed for shell and tube heat exchangers. [•] The method was validated and sensibility analysis was carried out. [•] Developed approach allows long-term monitoring of changes in the HEN efficiency. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this work is to elaborate a method of identification of the influence of fouling on the heat recovery in a heat exchanger network (HEN). The method is based on mathematical models enabling the interpretation of industrial measurements of operating parameters of the HEN. Details of the models are developed for shell and tube heat exchangers. The crucial assumption is that measurements of the mass flowrate and inlet and outlet temperature, and chemical composition are available for each process stream, this making it possible to evaluate fouling-induced reduction in the recovered energy flow. Using the proposed identification method and an industrial data base acquired in a typical crude distillation unit, the mathematical models are thoroughly tested. The developed approach allows long-term monitoring of changes in the condition of the HEN and assisting plant operator decisions aimed at maximizing heat recovery over the period of plant operation. A case study and an example of optimal scheduling of cleaning interventions on the individual exchangers are presented. [Copyright &y& Elsevier]

Abstract Joint efforts and interdisciplinary approach are proper means to face the issue of global warming. An adequate response should be to employ state of the art scientific knowledge for the technology advancement, as well as for fostering new scientific insights. Together with resource efficiency, circular economy is getting in focus of researchers and consequently policymakers. Sustainable development is a multidisciplinary topic and interaction of energy, water and environment systems plays one of the central roles. Within the paradigm of circular economy, there is growing need for system integration where a by-product of one system can represent resource for the other. This review is dedicated to the 12th Conference on Sustainable Development of Energy, Water and Environment Sysmems, and discusses some latest developments in three main areas of sustainability themes: (i) Energy, (ii) Water and (iii) Environmental Systems. Examples of circular economy approach have been emphasized which improve economic efficiency of the whole chain and further decrease environmental burden, enabling cleaner production. Although integrative concept of energy, water and environmental systems is coming in the research focus, more effort is necessary for further integration of those systems, whereby increased complexity is going to be handled only by multidisciplinary, intersectoral scientific cooperation. [ABSTRACT FROM AUTHOR]

Abstract: The 7th International Conference on Environmental Engineering and Management (ICEEM07) was held on September 19–20, 2013 at Vienna University of Technology, Austria. Organized in close cooperation with the Environmental Biotechnology section of the European Biotechnology Federation, it was dedicated to integrating cutting-edge environmental technologies with efficient management practices, contributing thus to a sustainable future. [Copyright &y& Elsevier]

Odors are emitted from agricultural and industrial activities, such as animal farms, rendering plants, wastewater treatment plants, waste treatment or disposal facilities, paint shops, oil refineries, pulp and paper mills, and various chemical industries. Effects of this kind of air pollution may include: impairment of the quality of the environment; interference with business activities; discomfort, harm or impairment of the safety of any person; rendering any property, plant or animal unsuitable for human use. Odor treatment technologies can be classified into three categories, namely ones employing chemical (thermal oxidation, catalytic oxidation, ozonation), physical (condensation, adsorption, absorption) and biological (using biofilters, biotrickling filters, bioscrubbers and other bioreactor types) treatment methods. An important advantage of biological treatment methods over physical and chemical technologies is that the biological processes can be conducted at moderate temperatures (10–40 °C) and atmospheric pressure. Moreover, microbial degradation processes are generally oxidative in nature and produce compounds such as carbon dioxide, water, sulfate and nitrate that are ecologically safe. Applications of biological odor treatment date back to 1950ties. Initially, simple biofilters with soil beds have been employed and later, the use of other bed materials in more advanced filter structures has been reported and more sophisticated types of filtration equipment such as biotrickling filters and bioscrubbers have been developed. On the basis of accumulated experience, some more process options and equipment types for the application of biological methods emerged in recent years. During more than 30 years covered by the present review, biological methods of odor treatment have matured to become a well-developed field of process technology. In order to provide an overview of the state of the art, process principles and characteristics including the use of various microorganisms and nutrients, variations in equipment design and application ranges of the different odor treatment technologies are outlined and compared. [ABSTRACT FROM AUTHOR]

[Display omitted] • H 2 S, NH 3 and VOCs are odorous gases emitted from municipal WWTP. • Compact trickle bed bioreactor (CTBB) is highly effective at removing VOCs and odors. • A pilot-scale, continuously operated CTBB was tested in a municipal WWTP, Poland. • Removal efficiencies: 87.5–98.9 % for H 2 S, >99.0 % for NH 3 , 81.5–99.5 % for VOCs. The main aim of this study was to optimize and maximize the impacts of odor and volatile organic compounds (VOCs) biodegradation in a wastewater treatment plant utilizing a pilot-scale compact trickle bed bioreactor (CTBB). A CTBB was built and tested for its long-term performance during which gases were supplied from the tank containing semi-liquid fats, oils, and fat waste. The concentrations of pollutants ranged from 0 to 140.75 mg/m3 H 2 S, 0 to 2500 mg/m3 VOCs, and 0 to 21.5 mg/m3 NH 3. The CTBB was tested at different gas flow rates and at two pH values for the liquid phase: pH = 7.0 and 5.0. In the liquid phase, the pollutant removal efficiency was higher at pH = 7.0 than at pH = 5.0. Overall, the removal efficiency was between 81.5 % and 99.5 % for the VOCs and 87.5 % and 98.9 % for H 2 S, while NH 3 removals were >99 %. [ABSTRACT FROM AUTHOR]

The cement production industry worldwide is one of the largest CO 2 emitting industrial sectors. It accounts for a considerable amount of total global greenhouse gas (GHG) emissions. Due to the increasing awareness of global warming, more energy efficient cement production is increasingly being emphasized. One of the priorities is to reduce the energy demand and innovate the production process to move towards the cleaner production as: Energy efficiency improvements; Waste heat recovery; Reduction of clinker/cement ratio and use of alternative raw materials; Substitution of fossil fuels with alternative energy sources. When the GHG emissions at source opportunities are close to being exhausted, the other mitigations options should be considered such as: CO 2 capture and storage. This is however in most cases not the final solution from the point of Life cycle assessment (LCA). In recent years various mitigation measures are gaining on the importance and the cement industry is more and more shifting to cleaner production. Among the others, there are two measures, which can reduce the GHG emissions considerably: the use of alternative raw materials and alternative fuels. The challenge for the cement industry is to use alternative raw materials especially those originating from other industries where they are considered as by-products or even waste. Some of these by-products include: Bottom ash from municipal solid waste incinerators; Fly ash from coal power plants; Gypsum from the desulfurization plants used in power plants. Another important measure is the energy efficiency improvement in existing cement plants. There are various approaches for controlling and improving the energy efficiency within existing cement manufacturing units, however, mathematical modelling, simulation, optimisation and Process Integration are increasingly gaining in importance. The mathematical modelling approach uses the numerical simulations for the investigation of the thermo-chemical processes occurring inside of the manufacturing unit. The results gained are being used to enhance the efficiency of cement production. They improve the understanding of the flow characteristics and transport phenomena taking place inside the cement combustion unit. The objective of this paper is to review the current status of the cleaner cement manufacturing, the cement industry's shifting to alternative raw materials and alternative energy sources, and the modelling of the thermo-chemical processes inside the cement combustion units. Additionally, some critical issues, which up to now have not been adequately resolved, are outlined. [ABSTRACT FROM AUTHOR]

Abstract: In the past years we evaluated different strategies with the aim of eliminating completely from the beet sugar factory, the traditional calco-carbonic purification process taking into account the well-known problems related to the utilization of lime and the production of carbonation sludge. To complete the picture of the possible solutions to be adopted for the elimination of the traditional purification process, we tested and evaluated in laboratory and in pilot plants a new eco-friendly proposal. The results obtained, as well as the proposed flow-sheet and some economic evaluations, are presented and discussed. [Copyright &y& Elsevier]

Abstract: Fermentation of biomass residues and second generation biomasses is potentially a way to enable a sustainable production of hydrogen. Simulation models which calculate mass and energy balances, developed with Aspen Plus®, are used to integrate the process steps necessary to produce pure hydrogen from biomass in a 2-stage fermentation process. Process and heat integration are introduced to reduce the high water and heat demand of the process, connected to the low substrate concentrations in the involved process streams. The results show that the recirculation of process effluents, together with the use of properly designed heat exchangers, can reduce the water and heat demand up to 90% from a non-integrated process, but is also subject to restrictions due to an increase in osmolality in the system. [ABSTRACT FROM AUTHOR]

Abstract: Hydrogen can be produced through dark anaerobic fermentation using carbohydrate-rich biomass, and through photofermentation using the organic acids produced from dark fermentation. Sugar beet is an ideal energy crop for fermentative production of hydrogen in the EU due to its environmental profile and its potential availability in the area. In this work, various aspects of cultivating sugar beet in the EU for biohydrogen were highlighted, with special focus on The Netherlands and Greece. Moreover, fermentation of sugar beet juice with Caldicellulosiruptor saccharolyticus at sucrose concentration 10 g/l was performed, and was found comparable to the fermentation on pure sucrose except that the hydrogen production was 10% higher on sugar beet juice. A conservative estimate of the annual hydrogen potential in the EU was made (300 × 106 kg hydrogen), considering the utilization of sugar beet pulp in hydrogen production. [ABSTRACT FROM AUTHOR]