: Environmental Management of E-Waste by Biological Process
Table of Contents:
APARNA GUNJAL,1 MEGHMALA WAGHMODE,2 NEHA PATH,3 and NEELU NAWANI4
'Department of Microbiology, Savitribai Phule Pune University, Pune-411007, Maharashtra, India
Pune-412301, Maharashtra, India
4Dr D.Y. Patil Vidyapeeth's, Dr. D. Y. Patil Biotechnology and Bioinformatics Institute, Tathawade, Pune-411033,
E-waste management can be defined as all the measures taken to protect humans and the environment from the toxic effects of constituents of electronic and other wastes. Active measures have to be taken to diminish its effects on health and the surroundings and capable of recovering valuable resources from them (Ogbuene et al., 2013). Electronic waste (e-waste) includes used electronic products that necessitate recycling or other proper forms of removal (Mohammed et al., 2013). Global production of e-waste has been reported to be 40 million tons per annum (Wath et al., 2010) and comprises 1-2% of the total solid waste. E-waste comprises remotes, compact discs, headphones, batteries, LCD, Plasma TVs, air conditioners, computer, and its accessories like monitors, printers, keyboards, central processing units; typewriters, mobile phones, chargers, refrigerators, and other household appliances. It contains more than 1000 different substances, which can be divided as ‘hazardous’ or ‘nonhazardous.’ Mostly, it consists of metals like copper (Cu), aluminum (Al) and expensive metals, viz., silver (Ag), gold (Au), platinum (Pt), and palladium (Pd). E-waste also found to contain miscellaneous substances (Bhat et al., 2012). E-waste contains approximately 20-50% heavy metals, which form a major part of the inorganic fraction. Every year, during the production of mobile phones and personal computers, 15% of cobalt, 13% of the palladium, and 3% of gold and silver are mined (Schhtep et al., 2009). E-wastes are considered hazardous due to toxic materials in certain components. Discarded electronic equipments, if improperly disposed-off, can leach lead and many other harmful substances into the soil and groundwater. Leached heavy metals generated due to the wrong disposal of e-waste hamper the human health and ecosystem (Mohan and Bhamawat, 2008).
CLASSIFICATION OF E-WASTE
Domestic appliances (ovens, refrigerators, toasters, vacuum cleaners) are referred to as “white goods” which also contain printed circuit boards (PCBs), electronic components, connectors (containing copper, gold, and other conductive elements), other plastics, and silicon (in integrated circuits). Communication systems (PCs, phones, faxes)-computer monitors contain Cathode Ray Tubes. Lead, which is toxic metal, is present in computer monitors and TVs. Entertainment electronics (TV, CD players)-even the mode of entertainments such as TVs, heavy metal like lead is present. Light system (fluorescent tubes)-fluorescent tubes contain mercury and become hazardous wastes when they no longer work. During disposal of mercury-containing lamps or tubes, mercury can escape to the environment, which through the lungs can enter into the bloodstream. People who are involved in the handling of this waste are especially at risk. Mercury has been reported to affect the health of pregnant women and small children. E-tools (chilling machines)-if not properly handled are dangerous. Leisure equipment (electronic toys)-according to the report of Perez-Belis et al. (2013), 1014.25 kg of waste toys components and automatic issuing systems (ticket issuing machines) contain 31.83% electric and electronic fraction.
GLOBAL SCENARIO OF E-WASTE
In developed countries, 1% of solid waste comprises e-waste, whereas in developing countries, it ranges from 0.01% to 1% (Anonymous, 2006). Developed countries, namely the United States of America, the United Kingdom, Germany, Japan, and New Zealand, have modem processing techniques for recycling of e-waste. The Union Miniere Company in Belgium (Hageluken, 2006) and Boliden Mineral in Sweden (Theo, 1999) have recycling plants to process e-waste; while China (Tong et al.,
2015), Taiwan (Lee et al., 2004) and South Korea (Lee et al., 2007) have implemented systems to recycle metals from e-waste; but in India no such measures are yet initiated. Each year, 20 to 50 million tons of electrical and electronic equipment wastes are discarded worldwide, while 12 million tons of electrical and electronic equipment wastes are discarded in Asian countries (Brigden, 2005). The share of the budding economies of China and India consumption of computers, in particular, is likely to increase, surpassing 178 and 80 million in the case of China and India, respectively (Anonymous, 2006).
E-waste generated in developed countries like the USA gets exported for recycling in developing countries. In 2003, approximately 23,000 metric tons of e-waste were exported from the UK to India, Africa, and China (Perkins et al., 2014). Significant quantities of e-waste like cell phone chargers, laptop computers, air-conditioners, printers, cameras, and other electronic refuse are in China. Developed countries like the USA, Europe, and Japan export e-waste to Hong Kong for dumping. Taiwan also needs adequate e-waste management facilities. Thailand generates a huge amount of e-waste from mobile phones and batteries, but relevant data on disposal of junk cell phones and batteries are not available.
In countries like Africa, there are about 62 million TVs, 200 million radios and about 7 million PCs. About 400,000 used PCs are imported through Lagos in Nigeria each month, and 1.2 to 1.5 million computers are made available in the market of South Africa each year. Universal Recycling Company, Desco Electronic Recyclers, and African Sky are three main recycling companies for e-waste in South Africa. Desco company is handling about 400 tons of PC boards and 2000 tons of e-waste, while Universal Recycling processes about 1800 tons e-waste in a year. Recycled e-waste is then exported to Asia and Europe by South Africa (Mohan and Bhamawat, 2008).
In the United Kingdom, the framework for legislation on the disposal of e-waste is the EU Waste Electrical and Electronic Equipment (WEEE) Directive. After the collection of WEEE, sorting depot separates its component parts and raw materials without incineration. Monitors are repaired or resale by an organization in Germany. From irreparable monitors, glass, plastics, PCBs, and other components are recycled (Mohan and Bhamawat, 2008).
INDIAN SCENARIO OF E-WASTE
In India, 146180 tons of electronic waste is generated per year. The e-waste problem in India seems to be compounding due to rapid changes taking place not only in computers and cell phones but also in domestic appliances. Environmental and health problems are the main issues due to uncontrolled burning, disassembly, and disposal, counting occupational safety and health hazards among those directly involved, due to unscientific methods for the processing of the waste. About 25,000 workers are working at a scrapyard in Delhi alone. Other e-waste scrap-yards exist in Meerut, Ferozabad, Bangalore, Chennai, and Mumbai. Most of the Municipal Corporation’s destroy e-waste by burning in the open ah' along with garbage (Rao et al., 2014). The amount of e-waste generated in the top 9 states of India is shown hi Table 5.1.
TABLE 5.1 E-Waste in Top 10 States in India
Source: Jayapradha, 2015.
In India, each year, 10-20 thousand tons of e-waste is handled in Delhi alone, with 25% of this being the computers. Total WEEE waste generation in Maharashtra is 20270 tons, 646.48 tons, and 11017.06 tons from Navi Mumbai and Mumbai counterparts, 2584.21 tons, and 1032.37 tons from Pune and Pimpri-Chinchwad respectively. Mumbai and Pune fall under the top ten cities that are generating the highest quantities of e-waste, and Mumbai is the first in e-waste generation among all the cities of India (Borthakur and Sinlia, 2013). Many developed nations, viz., USA, UK, and Germany, use India as a dumping ground for e-waste.
DISPOSAL METHODS OF E-WASTE
The disposal of e-waste is a major problem suffered in many regions across the globe and is of primary concern due to the toxicity and carcinogenicity of incompletely processed substances. The sources of e-waste are comparatively high-priced, and basically, long-lasting products applied for data processing, telecommunications, or entertainment in private households and businesses, hi India, handling of computer scrap is done using diverse approaches in management alternatives such as product reuse, usual disposal in landfills, and incineration or open-air burning. The recycling of computer waste can be done using efficient and advanced processing technology, which are capital intensive, entails high-end effective skills and training of the processing personnel. Incineration of e-waste in open-air affects the environment.
5.5.1 PRODUCT REUSE
Refurbishing used computers and other electronic goods for reuse, apart from the customary trend of passing on the same to relatives and friends, is a general societal practice. Educational institutes or charitable institutions can accept old computers for their use. Such deemed damaging practice adopted for product reuse contributes significantly to the rapidly increasing burden of computer waste.
5.5.2 CONVENTIONAL DISPOSAL IN LANDFILLS
Dumping of the waste is at landfill sites where it may remain for an uncertain period. According to the report of the Environmental Protection
Agency (EPA), more than 3.2 million tons of e-waste was dumped in US landfills in 1997 (Anonymous, 2004). The tremendously low biodegradable properties of plastic components in computers get further compounded in diy conditions, which complements landfills, and in strictly regulated landfill sites, the degradation rate is found to be slower. The highly toxic constituents found in computers contribute to metal leaching, which causes large-scale soil and groundwater pollution. In landfills, the multi-layered configuration of computer waste becomes a congregation of plastic and steel casings, circuit boards, glass tubes, wires, and other assorted parts and materials. Electronic discards contribute about 70% of heavy metals (including mercury and cadmium) found in landfills (Tachi et al., 2001).
5.5.3 INCINERA TION OR OPEN-AIR BURNING
After manual separation of components, motherboards are applied to open-pit burning for the extraction of the thin layer of copper foils laminated on the circuit board. After charring, the material is distilled through a simple froth floating process. Ash is removed, and the copper with some carbon impurity are processed in the recycling stage. Worthless, defective integrated circuit chips and condensers are burned in small enclosures with chimneys for the extraction of metals (Anonymous, 2003).