Eva Pongrácz

Micellar-enhanced ultrafiltration for the removal of cadmium and zinc: use of response surface methodology to improve understanding of process performance and optimisation.

In this study, removal of cadmium and zinc from their respective water samples was conducted by micellar-enhanced ultrafiltration (MEUF), using sodium dodecyl sulfate (SDS) as the surfactant. Response surface methodology (RSM) was used for modelling and optimising the process, and to gain a better understanding of the process performance. Face Centred Composite (CCF) Design was used as the experimental design. The factors studied were pressure (P), nominal molecular weight limit (NMWL), heavy metal feed concentration (C(Zn), C(Cd)) and SDS feed concentration (C(SDS)). Using RSM the retention of heavy metals was maximized while optimising the surfactant to metal ratio (S/M). Response surface plots improved the understanding the effect of the factors on permeate flux. Concentration polarisation was negligible and therefore, high NMWL membranes with high pressure provided high flux with negligible effect on the retention of heavy metals. The optimal conditions of zinc removal were C(SDS)=13.9 mM, C(Zn)=0.5 mM, NMWL=10 kDa and P=3.0 bar, and for cadmium removal C(SDS)=14.2 mM, C(Cd)=0.5 mM, NMWL=10 kDa and P=3.0 bar. The retentions achieved were 98.0+/-0.4% for zinc and 99.0+/-0.4% for cadmium. To improve resource efficiency, the surfactant was reclaimed after use; 84% of the initial SDS was recovered by precipitation.

Re-defining waste, the concept of ownership and the role of waste management

In an attempt to construct a new agenda for waste management, this paper explores the complex relationship between definitions of waste and their subsequent impact on its ownership and management. A range of internationally accepted definitions for waste are analysed and it is concluded that they are inadequate in scope in an attempt to describe waste. The philosophical ramifications inherent in such definitions mean that they are not capable of constructing a system that by its very nature results in a sustainable waste management system. This paper explores the concept of waste and a new waste taxonomy is proposed, based on the reason for waste creation, this has profound implications for ownership which in itself often dictates which waste management options are preferentially adopted by a given community. The role of legislation in producing monitoring systems for the transfer of ownership as well as abandonment of ownership is analysed. The new agenda for waste management focuses upon the development of more appropriate, sustainable definitions so that what is now commonly perceived as being waste will in fact be increasingly seen as resource-rich, ‘non-waste’. To avoid obstacles to resource conservation due to materials being considered waste, a definition for non-waste is introduced. Finally, a new definition for waste management is proposed, one that has profound implications for the introduction of a more sustainable waste practice.

Alkaline modified oil shale fly ash: optimal synthesis conditions and preliminary tests on CO2 adsorption.

Environmentally friendly product, calcium-silica-aluminum hydrate, was synthesized from oil shale fly ash, which is rendered so far partly as an industrial waste. Reaction conditions were: temperature 130 and 160°C, NaOH concentrations 1, 3, 5 and 8M and synthesis time 24h. Optimal conditions were found to be 5M at 130°C at given parameter range. Original and activated ash samples were characterized by XRD, XRF, SEM, EFTEM, (29)Si MAS-NMR, BET and TGA. Semi-quantitative XRD and MAS-NMR showed that mainly tobermorites and katoite are formed during alkaline hydrothermal treatment. Physical adsorption of CO(2) on the surface of the original and activated ash samples was measured with thermo-gravimetric analysis. TGA showed that the physical adsorption of CO(2) on the oil shale fly ash sample increases from 0.06 to 3-4 mass% after alkaline hydrothermal activation with NaOH. The activated product has a potential to be used in industrial processes for physical adsorption of CO(2) emissions.

Industrial ecology and waste management: from theories to applications

The paper describes the conceptual framework of the Waste Management Theory (WMT). WMT is a unified body of knowledge about waste and waste management, founded on the expectation that waste management is to prevent waste to cause harm to human health and the environment. The intersection of WMT with Industrial Ecology (IE) is presented and the mutual benefits of developing WMT alongside IE are described. A common interest of WMT and IE is to find a proper definition of waste. A radically new approach, based on an object-oriented modelling language is presented, to define the key concepts of the waste management domain. It is described how the goals and values of Industrial Ecology have been crucial to WMT development, by providing insights that are otherwise not considered in waste management. In turn, the Waste Management Theory acts as a filter to translate these goals and values to industrial systems, and helps selecting the tools by which they can be achieved.

An approach to the formal theory of waste management

A solid foundation for a formal theory of waste management is offered in terms of consistent building blocks: language, conceptual schemes, models, and sentence systems. The language used to formulate the theory is the PSSP language, which is a formal modeling language having certain unique features stemming from the ontology behind the language. Via conceptual schemes, which are explications of domain concepts translated to the PSSP language, the language is enriched to cover domain terms and to become the theory-language of waste management. The models have functionality, which makes it possible to simulate waste management. The functionality is implemented as mutual communication of objects representing reality, i.e. activities and things acted on. The models are transparent dynamic object hierarchies capable of providing a holistic view of waste management, providing consistent explanation of all waste related concepts and offering a formal methodology of waste management. The plausibility test requires more sentence systems, i.e. propositions with empirical reference to waste management, to be included.

Sustainability Assessment of Chemical Processes: Evaluation of Three Synthesis Routes of DMC

This paper suggested multicriteria based evaluation tool to assess the sustainability of three different reaction routes to dimethyl carbonate: direct synthesis from carbon dioxide and methanol, transesterification of methanol and propylene carbonate, and oxidative carbonylation of methanol. The first two routes are CO2-based and in a research and development phase, whereas the last one is a commercial process. The set of environmental, social, and economic indicators selected were renewability of feedstock, energy intensity, waste generation, CO2 balance, yield, feedstock price, process costs, health and safety issues of feedstock, process conditions, and innovation potential. The performance in these indicators was evaluated with the normalized scores from 0 to

Overview of the WEEE Directive and Its Implementation in the Nordic Countries: National Realisations and Best Practices

Electronic devices and mobile applications have become a part of everyday life. Fast technological progress and rapid product obsolescence have led to the rapid growth of waste electrical and electronic equipment (WEEE). Due to hazardous substances and also substantial amounts of valuable materials contained in electrical and electronic equipment, the European Union has implemented Directives related to WEEE, in order to reduce negative environmental and health impacts and to improve material recovery of valuable substances from WEEE. This paper provides an overview of the WEEE Directive and its implementation to national legislations in Finland, Sweden, and Norway and, further, describes how the nationwide WEEE recovery infrastructures in the Nordic countries have been built. The Nordic WEEE management systems are evaluated from the point of resource efficiency and best practices. Evidently, the WEEE management systems as established in the Nordic countries have advantages because the WEEE collection rates in 2012 were 12 kg/inhab./year, in Finland, 16 kg/inhab./year, in Sweden, and 27 kg/ inhab./year, in Norway, despite their sparsely populated nature. The Swedish and Norwegian experiences, especially, with long history of WEEE recovery indicate that increasing consumer awareness leads to more environmentally sound behaviour and improves recovery efficiency.

The trade-off between technology deployment and enviro-economic benefits in smart buildings

Smart grids are meant to reach multiple goals such as leveling the electricity demand profile, reducing electricity consumption and increasing the energy efficiency of the electrical grid. Smart buildings play an important role in achieving these goals. With an increased number of measuring and controlling tools, new problems also arise, such as their economic and environmental impacts, juxtaposed to the levels of savings achieved by them. This research investigated the impact of home automation on electricity consumption, related CO2 emissions and costs. A smart building model with its appliances and different number of inhabitants was used along with eight electricity contracts and four different technology systems deployed. The results showed that a fully deployed automation system may be counterproductive, as the electricity need of the system may exceed the savings achieved by it. Therefore, a careful selection of the appliances to be used should be performed.

Waste-based biofuel technologies in Finland — Current research and industrial activities*

Further to Directive 2009/28/EC on the promotion of the use of energy from renewable sources, the share of biofuels in transport should rise to a minimum of 10% in Member States by 2020. In Finland, the goal is set at 20%, and it is estimated that this can be produced entirely in domestic factories, as long as the projects already underway will be successful and additional industrial-scale biofuel plants would be built. The paper reviews the state of projects underway in Finland, and outlines current research activity in promoting waste and by-product — based biofuels.

Drivers of solid waste minimisation in Finnish metal engineering SMEs: the role of Environmental Management Systems

The paper reports on a survey in Finnish small- and medium-sized metal engineering enterprises (SMEs) with certified Environmental Management System (EMS). Waste awareness has increased after certifying EMS and the treatment of solid waste has improved; source separation of solid waste facilitated the recovery of recyclables and their diversion from landfill. EMS has raised knowledge levels, in particular on recycling of solid waste, and the attitudes toward environmental improvements have improved. However, it is concluded that, while certified EMS brought positive changes in waste treatment, it did not promote waste minimisation and prevention.