The degree and source of plastic recyclates contamination with polycyclic aromatic hydrocarbons.

In this research, the degree and source of recyclates contamination with polycyclic aromatic hydrocarbons (PAH) was studied in eight different polyolefin recyclate samples; four originating from post-consumer packaging waste and four originating from a mixed source (post-industrial, post-commercial, and post-consumer). The aim was to assess the applicability of these recyclates in the different products' categories. Furthermore, the impact of previous contamination with PAH was excluded by analysing pure plastics before and after undergoing simulated recycling processes.

Reduction of fuel side costs due to biomass co-combustion.

The feasibility and influence of co-combustion of woody biomass on the fuel side costs is discussed for three hard coal power plants located in Berlin, Germany. Fuel side costs are defined as the costs resulting from flue gas cleaning and by-products. To have reliable data, co-firing tests were conducted in two power plants (i.

Iron-oxidation processes in an electroflocculation (electrocoagulation) cell.

The processes of iron oxidation in an electroflocculation cell were investigated for a pH range of 5-9 and electric currents of 0.05-0.4A (equivalent current densities of 8.

Wet extraction of heavy metals and chloride from MSWI and straw combustion fly ashes.

Fly ash residues from combustion often do not meet the criteria neither for reuse as construction materials nor landfilling as non-hazardous waste, mainly because of the high concentration of heavy metals and chlorides. This work aimed to technically evaluate an innovative wet treatment process for the extraction of chloride (Cl(-)), cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) from fly ashes from a municipal solid waste incineration (MSWI) plant and from a straw combustion (SC) facility. Factors investigated were liquid/solid (L/S) ratio, full carbonation (CO(2) treatment), influence of pH and leaching time, using a two-level full factorial design.

Removal of Zn(II), Cu(II), Ni(II), Ag(I) and Cr(VI) present in aqueous solutions by aluminium electrocoagulation.

The performance of an electrocoagulation system with aluminium electrodes for removing heavy metal ions (Zn2+, Cu2+, Ni2+, Ag+, Cr2O7(2-)) on laboratory scale was studied systematically. Several parameters - such as initial metal concentration, numbers of metals present, charge loading and current density - and their influence on the electrocoagulation process were investigated. Initial concentrations from 50 to 5000 mg L(-1) Zn, Cu, Ni and Ag did not influence the removal rates, whereas higher initial concentrations caused higher removal rates of Cr.

Studies on electrochemical treatment of wastewater contaminated with organotin compounds.

Different anode materials were tested to evaluate their suitability to eliminate organotin compounds electrochemically from shipyard process waters. The capacity of two types of anode materials was investigated: niobium coated with boron-doped diamond (BDD) and titanium coated with iridium dioxide, (Ti/IrO(2)). The aim of this work was to characterize the performance of the process using both anode materials at different current densities, and also to evaluate the generation of by-products.

Topics of water sciences and technology.

In the preceding series of contributions to ESPR typical examples from actual fields of water chemistry were presented on various topics: integrated water quality management, diagnosis of water bodies, therapy of aquatic systems, and fitness for aquatic systems. These contributions clearly showed the need and importance of more intensive research. In the principle committee III 'Basic Research' of the Water Chemical Society, various expert groups work on scientific backgrounds in these fields.

Evaluation of a leaching process coupled with regeneration/recycling of the extractant for treatment of heavy metal contaminated solids.

A hydrometallurgical circuit process combining the leaching of metals with the electrolytic regeneration of the mass separating agent is an option to effectively treat heavy metal contaminated solids. This process aims towards a dosed loop utilisation of the extractant by its regeneration and recycling, enabling the use of high cost extractants and the recovery of the heavy metals as well. The circuit process, in which each cycle consists of an extraction step followed by the electrolytic regeneration of the mass separating agent and a second extraction to finally recycle the separating agent and start a new cycle, was applied on a lead contaminated soil from an accumulator manufacturing facility and for the removal of copper from a municipal solid waste incinerator bottom ash.

An XAFS investigation of the artefacts caused by sequential extraction analyses of Pb-contaminated soils.

The chemical processes that occur during sequential extraction of a highly Pb-contaminated soil sample were investigated using XAFS spectroscopy for the identification of the Pb species in the solid residues after each step. The sequential extraction was performed following the procedure described by Salomons and Förstner. It was found that during the sequential extraction serious alteration of the chemical binding forms of the Pb occurs.

Detoxification of tributyltin contaminated sediments by an electrochemical process.

Preliminary experiments have shown that dibutyl and tributyltin can be decomposed by the electrochemical treatment of sediment. Two different process pathways have been described and compared. A slurry electrolysis of the suspended sediment seemed to be more efficient than column leaching followed by electrolysis.

Contaminants in sediments: remobilisation and demobilisation.

In this study, the contaminated anoxic sediment of the Mulde reservoir (Saxony, Germany) was investigated. Several sediment cores were analysed for heavy metals and organic chemicals such as chlorobenzenes and DDTs. The comparison between anoxic and oxidised sediment cores showed the potential danger for heavy metal (Zn and Cd) remobilisation from sediment due to bioturbation or resuspension by flooding.