29 March 2013

Management and recycling of electronic wastes

Abstract

Among the major problems, that humanity has to face, are: the rational solid waste management, 
the minimization of environmental harmful effects, the effective management of raw materials and the component's recovery of the waste-circuit, so that quality of the environment and life  will be improved. The electronic wastes, also called e-wastes, are among the most important  solid wastes and their quantities are significantly increased. These are wastes which contain toxic and hazardous substances, as well as, recyclable materials. 

According to the framework of the European Union's environmental policy for the problem of 
electric - electronic wastes, the directive WEEE (Waste of Electrical and Electronic Equipment) 
was instituted. WEEE proposes the right way of management and treatment of electronic wastes (e-wastes). The directive was published taking into consideration the decisions about Sustainable Development.

Based on this directive, and applies the following method of recycling of electronic wastes, 
aiming at the rational management of these wastes and at recovery of metals of them. 
In the first stage, the dismantling of the electrical and electronic equipment is applied after the 
collection, in order that parts that contain toxic and hazardous substances ares removed. 
These parts, as toxic and hazardous wastes, require special treatment. Next, the parts, which 
can be reused are separated, as spare parts for the same or other use.

Finally, the parts, which can be recycled, are separated from all the other materials, and they 
are led to the beginning of the life cycle, as secondary raw materials. Parts, which are not 
cost-effective to be recycled for material recovery, are led to the energy recycling. The landfill 
disposal is the last ring of the chain and it should be avoided when it is possible. 

One material category, which is possible to be recovered, so that the materials can be led 
to the beginning of their life cycle, is the group of metals, which their recycling value is very
important. After the dismantling, the parts with high content in metals are separated and led to further treatment. Fragmentation of these parts that contain metals take place and then the fragments are 
treated with acids, in order to turn these metals from solid to solvent form. 

The electrochemical recovery method that is applied, makes possible the separation of metals. 
Specifically, the metals are reduced by their ionic form and are separated by the electric field 
effect. In this process, insoluble anode is used, in contrary to other methods of electrolysis
This method aims at the recovery of metals from electronic wastes, which contains high purity 
metals. It is sought that the process should have high recovery rate. 

During the application of this particular method is also attempted the minimization of 
flow-circuit-wastes, which may appear, so that the process can be considered as an environmental 
friendly method of metals recovery.



 2nd European Bioremediation Conference,
 Chania - Greece, June 30 - July 4 2003.




Keywords:  Materials Recycling, Sustainability