LEACHING OF HEAVY METALS FROM SELECTED ELECTRONIC WASTE COMPONENTS USING DIFFERENT SOLVENT MIXTURE
1.1 Background to Study
In recent years, a dramatic increase in the production and consumption of electrical and electronic equipment with a sharp decrease in their lifespan has led to the generation of large quantities of waste. E-waste as this waste is popularly known, is the waste near or at the end of their useful life period and are of no further use (Ropafadzo et al, 2014). The growing quantity of e-waste from electronic industry is beginning to reach disastrous proportions. It is estimated that the world generates 20-50 million tonnes annually (Herat 2013).
Despite the growing awareness and deterring legislation, most e-wasteare disposed improperly, mostly landfilled (Cucchiella et al., 2015).Management of e-waste is of environmental and social concern with global implications due to its hazardous nature. The nature of the production, distribution and disposal of electronic devices include global chains (Breivik et al., 2014). The source of the global problem has its roots in lack of technologically mature solutions, poor enforcement and high costs of legal operations, and waste being a global commodity in contrast with the regulations (Baird et al., 2014).Internationally, various legal frameworks have been enacted and enforced to regulate E-waste. E-waste is extremely important in diverting solid waste and supporting zero landfill initiatives. It helps prevent and eliminate toxic scrap. By implementing the ‘3 Rs’ Reduce, Recycle, Reuse and the green technology, the problem of e-waste can be reduced, thus e-waste can be utilised as raw materials for secondary source of precious and base metals.
Microbial leaching (bioleaching) of metals from waste materials is an attractive field of research with vast potential. Moreover, conventional chemical technologies, despite their several bottlenecks and disadvantages, are effective in the leaching of metals from primary ores. However, their effectiveness in disposing and conserving E-waste is largely unexplored. As a result, this study intends to investigate the leaching of heavy metals from selected electronic waste components using different solvent mixture
1.2 Statement of the Research Problem
Electronic waste deposition and incineration, without recycling the non-renewable resources present in it, is an energy inefficient and environmentally unfriendly process of e-waste disposal. There is therefore need for a recycling (metal recovery) process that is both economically active and environmentally friendly. The feasibility study for such a process is to be carried out.
E-waste recycling enables recovering of renewable resources which serve as a secondary source of metals. Also, recycling of e-waste is a social benefit as it creates employment for the recycling industry. This project intends to recovermetals in an environmental friendly way and also reduces the land degradation as compared to the present practice.
This research will attempt to evaluate the leaching process conditions using data obtained from leach sample analysis. To the best of my knowledge no work has been carried out in the present area of study and hence prompted me to carry out this research.
1.4 Aim and Objectives
The aim of this work is to study the leaching of heavy metals from selected electronic waste components using different solvent mixture through the following objectives:
- To recover metals through a profitable and highly efficient process
- To conserve the limited non-renewable resources through recycling and reducing overall land digging as the only source to get the metals.
- To reduce burning of e-waste in open environment or uncontrolled burning
1.5 Scope and Limitation of the Study
The aim of this work is to study the leaching of heavy metals from selected electronic waste components using different solvent mixture. This research work is limited to the qualitative and quantitative analysis of zinc-carbon battery using hydrometallurgical process of samples, collected from Samaru Area of Sabon-Gari Local Government Area of Kaduna State. Also, it does not involve purification of the metals in solution form and life cycle analysis (LCA).