Waste Management is defined as its collection, transportation, processing and / or disposal with additional function of monitoring waste materials impact on environment, human health and aesthetics. Waste materials can be solid, liquid, gaseous or radioactive and waste management encompasses all of these. Out of these, Solid Waste Management ( SWM ) can be considered as an activity which can be participated by all sectors of society for affective implementation. This is true for developed as well as developing nations, for urban as well as rural areas and for residential as well as industrial producers. Although major responsibility of facilitating and monitoring SWM lies with local government authorities, the generators of this waste can significantly contribute to the success of such a program by implementing the required waste disposal practices.
Various methods are used for SWM as summarily described in following text.
INCINERATION (Waste-to-Energy) – Incineration is the process to generate green energy through Waste-to-Energy (WTE) technologies. There are various WTE technologies available like Gasification & Pyrolysis, Mass Burn and Refused-Derived Fuel (RDF). Gasification and Pyrolysis systems employ thermal processes to extract synthetic gas or vapor from waste by using heat in an atmosphere of deficient oxygen, such synthetic gas in turn is used as burning fuel. Mass Burn is a process whereby raw or post-recycled waste is fed into a furnace for supplementing normal fuel and thus creating extra energy for electricity generation. RDF systems convert recycled waste into solid fuel that is sold for commercial use or further processed through gasification & Pyrolysis or mass burn. The workings of these technologies differ but the underlying objective is the same – economically extracting renewable energy from left-over waste.
METAL RECYCLING (Resource Recovery) – Metal recycling is a major contributor to economy as well as environment. Through metal recycling, societies enable themselves to reuse metals that were otherwise difficult or uneconomical to obtain. Metal recycling involve Sorting, Shredding, Media Separation, Shearing, Melting and Baling (compacting steel products into large steel blocks to facilitate handling). Millions of Tons of ferrous as well as non-ferrous scrap is recycled every year to extract useful metals. The most commonly used non-ferrous metals are aluminium, copper, lead, zinc, nickel, titanium, cobalt, chromium and precious metals. Due to limited availability of some non-ferrous metals, recycling and flow of non-ferrous scrap from country to country according to industrial and consumer demand is crucial in today’s world.
ELECTRICAL & ELECTRONICS EQUIPMENT RECYCLING (Advanced Resource Recovery) – Electronics and electrical equipment waste is usually around 105 of the current solid waste stream, it is growing at the fastest rate as compared to any other solid waste. Such waste refers to electronic and electrical products that have finished their useful life for consumer. Such waste contains special metals including rare earth metals and precious metals which are recoverable through specialized recycling processes. These advanced metal extraction processes are very important in recovery of metals which are scarcely available in nature. Due to complex functionality, today’s electronic products contain complex compounds of metals, thus making it difficult to extract and reuse valuable metals from waste products due to laws of physics and related economics. To take an example, a mobile phone contain more than 40 elements, including base metals such as copper and tin and precious and platinum-group metals like silver, gold and palladium. Today the concentration of metal recyclers should be more on Product-Centric recycling wherein they should target specific metals recovery from End of Life (EoL) products.
BIOLOGICAL REPROCESSING (Composting) – Composting is very important to recycle food waste because food waste (and other organic materials). When such waste end up in garbage these do not decompose properly creating methane (a powerful greenhouse gas) and we lose the chance to recover resources by turning food scraps into energy or compost. Composting is a mixture of various decaying organic substances like food waste, dead leaves and manure that is used for fertilizing soil. Households and Offices can use backyard composting of worm bin composters to compost organic waste produced by them in most efficient manner. Most local governments are drafting laws to ban disposal of food waste and compostable organics in regular waste. Special incentives are also being arranged for onsite composting or to process such organic waste separate from other waste material.
HAZARDOUS WASTE MANAGEMENT (Small evil Big problem) – Hazardous waste like asbestos, lead acid batteries, automobile parts, fluorescent lights, gypsum, biomedical waste, pesticide products, containers of poisonous chemicals, thermostats, tires, waste containing polycyclic aromatic hydrocarbons and banned recycled plastic are some examples of hazardous waste that should not be mixed with regular waste material. Hazardous waste contains toxic chemicals and heavy metals which are harmful to environment as well as waste disposal staff, and should be managed through special waste treatment programs including recycling, treatment, abandonment, storage and disposal. Information regarding such waste disposal should be made available by local governments to the general public for ease of implementation.
WASTE MINIMIZATION (Sustainability) – Most of the problems related to solid waste management can be minimized through minimizing the waste produced by societies. We can reduce waste by considering the following:
- Intelligent selection of things that we use like selecting rechargeable batteries in place of simple batteries.
- Reconsider what we throw away – consider reuse.
- Inculcate food consumption habits that discourage food wastage.
- Reduce garbage at work.
- Local governments can encourage support for minimizing solid waste production through advocating reuse initiatives and starting a Zero Waste Community Challenge.
- Local governments should also create online databases allowing public awareness and interest in recycling of waste. Bureau of International Recycling provides information about benefits of recycling and currently provides following information for boosting interest in recycling:
- CO2 emissions are reduced by 58% through the use of ferrous scrap.
- An average stainless steel object is composed of about 60% recycled material.
- Almost 40% of world’s requirements of copper are met by recycling.
- Of all collected textile, 50% are reused and 50% are recycled.
- Recycling paper saves 65% of the energy used to produce new paper.
- Recycling a single plastic bottle can conserve energy to light 60-watt bulb for six hours
- Scrap tyres used as fuel can produce same amount of energy as oil and 25% more than coal.