الفهرس 
IntroductionOnly 14 pages are availabe for public view
Abstract
Over the past ten years, with the rapid upgrading of electronic products, large amounts of WEEE have been produced. It is the fastest growing waste stream in the world and also, it is a treasure of valuable materials when it is recovered. Hence, proper methods of disposal should be initiated to assure that it does not affect the environment or cause health hazards to the people. Physical and chemical methods have been the common methods used for recycling WPCBs. Physical recycling methods such as magnetic or density separation are rather simple, convenient, less environmentally polluting and require lower energy to operate. They are considered more economical for recycling and separating metallic portions than non-metallic ones. Chemical recycling methods convert brominated fire retardants to monomers. Lots of researches are progressing on the chemical recycling processes focusing more on the metallic fractions.
Almost all EEE contain printed circuit boards as an essential part. PCBs are the main necessary constituent of almost all electronic equipment. The typical ingredients in WPCBs are polymers, ceramics and metals. About 30% mass of WPCBs includes wide range of important metals, for example, copper, gold and silver and furthermore unsafe materials, for example, tin, lead and brominated fire retardants. Copper is the major metal in electronic products. It is the highest content in the WPCBs that ranges from 10 to 30 masses % among the metallic elements. Recycling of waste PCBs increased extraordinary considerations for the recovery of valuable materials.
Presently, many technologies have been suggested for recovering copper from WPCBs. The suggested technologies include primarily pyro metallurgy, hydrometallurgy, bio-technology, and mechanical methods. Among these technologies, hydrometallurgical processes with comparatively low costs, no gas or dust formation, selectivity and appropriateness for small scale applications are promising choices for the handling of WPCBs. various techniques in common use for recycling the most important metals from the metallic fractions of e - waste are illustrated. The recovery of metals from e-waste material after physical separation through pyro metallurgical, hydrometallurgical, or bio hydrometallurgical routes is also discussed, along with alternative uses of non-metallic fraction. The data are explained and compared with the current e-waste management efforts done in Egypt. Future perspectives and challenges facing Egypt for proper e-waste recycling are also discussed.
Egypt is an attainable market for e-waste recycling despite missing most of the desired elements to carry out e-waste system. Egypt suffers from many organizational restraints and technical issues. Absence of recycling strategies, lack of cost recovery of e-waste service, weak legislation constraint, limited civic awareness, and the shortage of acceptable dump sites are examples. In Egypt, the existing recycling actions are still in the early stages and are not compatible with the world environmental standards.
It has to be taken into consideration that, if the current generation rate of e-wastes in Egypt continued, there will be a huge hoard and the disposed waste will remarkably increase, as well as increasing the noxious influence on the people and the environment. To overcome this risk, combined efforts among the community and the government are a must. Each should take the liability, and the e-waste recycling system must be updated with the cooperation and support of all sectors.
This research based on extraction of copper as nanostructured powders by using two different types of leaching solution with different types of e-waste as follow:
- A hydrometallurgical procedure utilizing acid leaching to extract copper from the powdered fractions of WPCBs from old computer mother boards and the production of nanostructured copper particles from a solution is presented with minor percentage of calcium oxalate. Dissolution of copper was carried out by leaching in nitric acid and hydrochloric acid containing hydrogen peroxide as oxidant. The effect of temperature, liquid / solid ratio, dose of H2O2 and concentrations of HCl and HNO3 on the leaching of copper was investigated.
- Simple efficient and encouraging method for the preparation of copper nanoparticles from the leach liquor of WPCBs of old computers. Ammonia / ammonium salt leaching process is proposed to selectively extract copper from the WPCBs with high extraction yields over 90%. A green reducing agent called ascorbic acid was selected as a reductant and also as a stabilizing agent for copper nanoparticles. Extraction of copper was carried out by leaching in ammoniacal–ammonium carbonate, chloride and citrate solutions. The effect of different parameters as leaching time, temperature, liquid / solid ratio and concentrations of these alkaline solutions on the extraction of copper was investigated.
Copper was recovered from leaching solutions using a green reducing agent and CTAB as a cationic crystal modifier at room temperature. Produced copper nano powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR), UV–visible and transmission electron microscopy (TEM).
This green chemistry approach towards the synthesis of metal nanoparticles has many advantages such as feasibility in scale-up, economic viability. Applications of such eco-friendly nanoparticles in antimicrobials, wound healing and other medical and electronic applications make this method potentially exciting for the large-scale synthesis of other inorganic nanoparticles holding true to the phrase ‘Waste to Health’.
This research concluded by conducting a simple cost analysis study for the nano copper extraction from e-waste which get a high profit through using ammoniacal /ammonium salt for it is capability for giving a purest copper from powdered of PCBs.