One of the main issues in the fluorescent lamp recycling sector is the mercury contamination of output fractions and occupational exposure associated with recycling operations. The aim of this study is to carry out effective mercury mass balance determinations and improve mercury recovery by finding the optimal levels for the recycling process parameters. These optimizations will allow upstream mercury emissions to be reduced, which will help to avoid mercury exposure among WEEE recycling workers. Firstly, the distribution of mercury was assessed in new and spent lamps. For new fluorescent tubes, the mean percentage of mercury in the solid phase is lower in new fluorescent tubes (19.5% with 5.5% in glass, 9.7% in end caps and 4.3% in luminescent powder) than in spent tubes (33.3% with 8.3% in glass, 12.9% in end caps and 12.1% in luminescent powder). The parametric study also shows that the finer the grains of glass, the higher the concentration of mercury (1.2 mu g Hg/g for glass size particle >1000 mu m and 152.0 mu g Hg/g for glass size particle <100 mu m); the crushing time required for the optimal removal of mercury from spent tubes is 24 h; on average 71% of the mercury is desorbed at a temperature of 400 degrees C. The effects of air flow rate, rotation speed and number of balls could not be determined due to wide variations in the results. It is recommended that recycling companies employ processes combining as heating and mixing techniques for the recovery of mercury from lamps in order to both (i) remove as much of the mercury as possible in vapor form and (ii) avoid adsorption of the mercury at new sites created during the crushing process. (C) 2018 Elsevier Ltd. All rights reserved.

A rising concern is addressed to occupational safety and health administrations for evaluation of the risk of respiratory cartridge reuse exposed to organic vapour. Immediate breakthrough upon reuse has been experimentally demonstrated by several studies, but mathematical model is still lacking. An experimental reuse procedure also reported significant immediate breakthrough for acetone, acetonitrile and dichloromethane in PICA activated carbon bed column. This phenomenon is caused by so called static diffusion which is the transport of adsorbed molecules in the adsorbent bed during the period of storage. In this work, a static diffusion model is proposed. Intraparticle mass transfer is described by a pore diffusion model involving surface diffusion following Higashi model, and measured by the perturbation chromatography method. The model sheds the light on a kinetics parameter DS0 from the Higashi model for surface diffusion, which can be a relevant indicator of the risk of immediate breakthrough upon reuse and permits to distinguish fast diffusing species and slower diffusing species for a given activated carbon adsorbent.

•Chemical risks were assessed in the nine cathode ray tube screens recycling facilities.•The main hazardous agents are dust containing lead, cadmium, barium and yttrium.•Exposure and pollutant levels are described for different operations and processes.•All the operations and processes are concerned by significant levels of pollutants.•We suggest recommendations to reduce chemical risk.

The fluorescent lamp recycling sector is growing considerably in Europe due to increasingly strict regulations aimed at inciting the consumption of low energy light bulbs and their end-of-life management. Chemical risks were assessed in fluorescent lamp recycling facilities by field measurement surveys in France, highlighting that occupational exposure and pollutant levels in the working environment were correlated with the main recycling steps and processes. The mean levels of worker exposure are 4.4 mg/m(3), 15.4 μg/m(3), 14.0 μg/m(3), 247.6 μg/m(3), respectively, for total inhalable dust, mercury, lead and yttrium. The mean levels of airborne pollutants are 3.1mg/m(3), 9.0 μg/m(3), 9.0 μg/m(3), 219.2 μg/m(3), respectively, for total inhalable dust, mercury, lead and yttrium. The ranges are very wide. Surface samples from employees' skin and granulometric analysis were also carried out. The overview shows that all the stages and processes involved in lamp recycling are concerned by the risk of hazardous substances penetrating into the bodies of employees, although exposure of the latter varies depending on the processes and tasks they perform. The conclusion of this study strongly recommends the development of a new generation of processes in parallel with more information sharing and regulatory measures.

Consequence des cycles de vie des consommables de plus en plus courts et d’un contexte reglementaire de plus en plus contraignant, le secteur du recyclage des dechets a largement evolue depuis une quinzaine d’annees. Dans les filieres de traitement des dechets d’equipements electriques et electroniques (DEEE), de nombreux risques sont presents et notamment le risque chimique qui est particulierement preoccupant. Le manque d’eco-conception, l’augmentation des flux ainsi que l’organisation des postes de travail et des procedes de traitement de ces equipements en fin de vie sont, en grande partie, responsables des expositions professionnelles – plomb, cadmium, baryum, yttrium et mercure – dans les principales filieres de traitement primaires – ecrans a tubes cathodiques et lampes usagees – et secondaires – cartes electroniques, câbles electriques et plastique. L’evaluation du risque chimique par filiere et par procede de traitement presentee dans cet article a permis de realiser un etat des lieux du secteur d’activite, d’identifier les operations les plus polluantes et de hierarchiser les actions de prevention a mettre en œuvre pour reduire le risque chimique a la source. Les propositions d’ingenierie de prevention relatives a l’amelioration des installations existantes testees en laboratoire et sur site contribueront a la reduction du risque chimique dans ces filieres de traitement des DEEE et favoriseront la conception et le developpement de procedes « propres et surs » dans les filieres emergentes.

According to the directive n°2000/53/CE 85 % by weight of an end-of-life vehicle (EVL) must be recycled. The current state of practice comprises four steps. Liquids from battery, gearboxes casing, brake fluid, coolant and air conditioning circuit are first collected. Tyres, catalysts, windscreens and windows are then manually removed, prior to the shredding of the car. A magnetic separation is processed on the shredded materials, to recover valuable ferrous components. The remaining part (Automotive Shredder Residue - ASR) undergoes successive separation steps, leading among others to two potentially valuable fractions, one mostly composed of plastics (P1) and the other of iron oxides (P2). Currently, P2 and P1 are respectively landfilled or used as a fuel source in various processes. In the blast furnace (BF) and the electric arc furnace (EAF) routes, P1 could be used as substitute for coal or coke, and P2 could replace part of the ore, provided some elements (Cl, Cu, Zn) are removed. Chlorinated compounds (PVC) can release toxics (dioxin) or corrosive metal chlorides, detrimental to the installations and the environment. Copper can spoil the cast-iron produced, and zinc favors the development of scabs that modify the flow configuration inside the BF. The whole objective of REFORBA is to assess the possibility of using "purified" fractions P1 and P2 in the BF and the EAF, as reducing agents or "iron ore". This would provide steelmakers with raw materials cheaper than coke. As additional potential benefits the amount of CO2 generated in the processes and the volume of landfilled shredded residues would be lowered. Representative fractions of P1 and P2 are obtained by sampling an industrial line of treatment. Comprehensive chemical characterization (ICP-AES, SEM, FTIR, thermal analyses) is performed to know the global content and localization of materials containing chemicals to remove. Sorting operations (grinding, screening, magnetic, eddy current, and sink float separations) are then performed on P1 and P2, until the modeled BF global heat and flow profiles match the classical configuration. The possibility of using P1 in place of C and CO is evaluated by a lab-scale thermochemical characterization of the iron oxides reduction, and of the quality of the cast-iron processed with some percent of P2 in the ore feed. This will give estimations of P1 and P2 nominal contents to use in the BF, and assess the feasibility of a pilot-scale demonstration.