Sue Grimes

Review Article: Extended producer responsibility for packaging wastes and WEEE - a comparison of implementation and the role of local authorities across Europe

A comparison of the implementation of extended producer responsibility (EPR) to packaging waste and waste electrical and electronic equipment (WEEE) is presented for a representative sample of eleven European Union countries based on five indicators: stakeholders and responsibilities; compliance mechanisms; role of local authorities; financing mechanisms and merits and limitations, with four countries selected for more detailed case study analysis. Similarities, trends and differences in national systems are highlighted with particular focus on the role of local authorities and their relationship with obligated producers and the effect on the operation and success of each system. The national systems vary considerably in design, in terms of influence of pre-existing policy and systems, methods of achieving producer compliance (multiple or single collective schemes), fee structures, targets, waste stream prioritization and local authority involvement. Differing approaches are evident across all member states with respect to the role played by local authorities, responsibility apportioned to them, and the evolution of working relationships between obligated producers and municipalities. On the whole, EPR for packaging and WEEE has been successfully implemented throughout Europe in terms of Directive targets. It is, however, clear that the EPR systems currently in application across Europe differ primarily due to contrasting opinion on the legitimacy of local authorities as stakeholders and, in some cases, a fear on the part of industry of associated costs. Where local authorities have been engaged in the design and implementation of national systems, existing infrastructure used and defined roles established for producers and local authorities, results have been significantly more positive than in the cases where local authorities have had limited engagement.

Simultaneous recovery of metals and degradation of organic species: Copper and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T)

In mixed wastewater streams, the presence of metal ions can retard the destruction of organic contaminants and the efficiency of recovery of the metal is reduced by the presence of organic species. The reduction in the efficiency of these methods is due to the formation of complexes between the organic species and the metal ions in solution. Results are presented for copper-2,4,5-T system in which both effects occur. A photolytic cell alone can achieve the complete degradation of 2,4,5-T, in the presence of TiO(2) or H(2)O(2), at pH 3.5. The addition of Cu(II) ions, however, retard the degradation of 2,4,5-T and complete mineralisation of 2,4,5-T was not achieved and the system also leaves Cu(II) ions in solution. An electrolytic cell alone can be used to recover copper in pH range 1.5-4.5 but is not capable of achieving complete disappearance of 2,4,5-T by anodic oxidation. A combined photolytic-electrolytic system is capable of achieving simultaneous destruction of 2,4,5-T and recovery of copper from mixed wastewater streams at pH 3.5. The percentage destruction of 2,4,5-T and the recovery of copper can be increased further by using a combined photolytic and an activated carbon concentrator cell system. This system can achieve the simultaneous recovery of copper and the degradation of 2,4,5-T without the use of an additional oxidants or catalysts.

Production of pyroxene ceramics from the fine fraction of incinerator bottom ash

Incinerator bottom ash (IBA) is normally processed to extract metals and the coarse mineral fraction is used as secondary aggregate. This leaves significant quantities of fine material, typically less than 4mm, that is problematic as reuse options are limited. This work demonstrates that fine IBA can be mixed with glass and transformed by milling, calcining, pressing and sintering into high density ceramics. The addition of glass aids liquid phase sintering, milling increases sintering reactivity and calcining reduces volatile loss during firing. Calcining also changes the crystalline phases present from quartz (SiO2), calcite (CaCO3), gehlenite (Ca2Al2SiO7) and hematite (Fe2O3) to diopside (CaMgSi2O6), clinoenstatite (MgSiO3) and andradite (Ca3Fe2Si3O12). Calcined powders fired at 1080°C have high green density, low shrinkage (<7%) and produce dense (2.78 g/cm(3)) ceramics that have negligible water absorption. The transformation of the problematic fraction of IBA into a raw material suitable for the manufacture of ceramic tiles for use in urban paving and other applications is demonstrated.

A combined photolytic-electrolytic system for the simultaneous recovery of copper and degradation of phenol or 4-chlorophenol in mixed solutions

The effects of the presence of copper on the photooxidation of phenol and 4-chlorophenol and of the presence of the phenols on the recovery of copper by electrodeposition are studied in three systems: a photolytic cell in the presence and absence of TiO2 as a catalyst or H2O2 as an oxidant; an electrolytic cell and a combined photolytic-electrolytic system. The optimum system for the simultaneous removal of copper and destruction of the phenols which overcomes the effects of copper-phenol reactions is a combined system with concentrator electrode technology incorporated into the electrolytic cell. This combined system achieves >99% removal of copper and destruction of phenol or 4-chlorophenol in an 8 h period.

Properties of ceramics prepared using dry discharged waste to energy bottom ash dust

The fine dust of incinerator bottom ash generated from dry discharge systems can be transformed into an inert material suitable for the production of hard, dense ceramics. Processing involves the addition of glass, ball milling and calcining to remove volatile components from the incinerator bottom ash. This transforms the major crystalline phases present in fine incinerator bottom ash dust from quartz (SiO2), calcite (CaCO3), gehlenite (Ca2Al2SiO7) and hematite (Fe2O3), to the pyroxene group minerals diopside (CaMgSi2O6), clinoenstatite (MgSi2O6), wollastonite (CaSiO3) together with some albite (NaAlSi3O8) and andradite (Ca3Fe2Si3O12). Processed powders show minimal leaching and can be pressed and sintered to form dense (>2.5 g cm-3), hard ceramics that exhibit low firing shrinkage (<7%) and zero water absorption. The research demonstrates the potential to beneficially up-cycle the fine incinerator bottom ash dust from dry discharge technology into a raw material suitable for the production of ceramic tiles that have potential for use in a range of industrial applications.

Experimental Study of Microwave-Induced Discharge and Mechanism Analysis Based on Spectrum Acquisition

When conductor or semiconductor materials are exposed to microwave radiation in different atmospheres (Ar, He, N2, and O2+N2) intense discharge phenomena are observed. The discharge phenomena, generated when strips of the metals Fe, Al, and Zn or particles of the semiconductor SiC are irradiated with microwaves, are characterized experimentally using spectrum acquisition and analysis. Filamentary discharge is observed in an Ar atmosphere while spark discharge is observed in He, N2, and O2+N2 atmospheres. The spectral lines of the discharges are concentrated mainly in the visible region, but there are also peaks in the ultraviolet region. The nature of the discharge and the specific details of the spectra are influenced by: 1) the target metal or semiconductor used; 2) the atmosphere; and 3) the microwave field characteristics. The spectra always consist of two parts: one corresponding to the target metal or semiconductor irradiated by the microwaves and the other due to the formation of the high-energy excitation states of atoms, molecules, and ions induced in the gaseous atmosphere. The microwave-induced discharge and the corresponding luminous and plasma effects have potential uses as energy sources in many applications including chemical or photocatalytic enhancement of reactions and the destruction of volatile organic compounds for which preliminary results are encouraging.

Report: Potential environmental impact of exempt site materials - a case study of bituminous road planings and waste soils.

The use of waste materials for ecological benefit, agricultural improvement or as part of construction works are often exempt from waste management control in order to maximize the reuse of material that would otherwise be disposed of to landfill. It is important, however, to determine whether there is potential for such waste to cause environmental harm in the context of the basis for granting exemptions under the relevant framework objective to ensure that waste is recovered or disposed of without risk to water, air, soil, plants or animals. The potential for environmental harm was investigated by leaching studies on two wastes commonly found at exempt sites: bituminous road planings and waste soils. For bituminous road planings, the organic components of the waste were identified by their solubility in organic solvents but these components would have low environmental impact in terms of bioavailability. Leaching studies of the heavy metals copper, lead and zinc, into the environment, under specific conditions and particularly those modelling acid rain and landfill leachate conditions showed that, except for copper, the amounts leached fell within Waste Acceptance Criteria compliance limits for defining waste as inert waste. The fact that the amount of copper leached was greater than the Waste Acceptance Criteria level suggests that either additional testing of wastes regarded as exempt should be carried out to ensure that they are in analytical compliance or that legislation should allow for the potential benefits of reuse to supersede deviations from analytical compliance.