Waste Management And Recycling Environmental Sciences Essay

Waste management means collecting, transporting, processing, recycling and monitoring of the waste materials. The term waste management generally relates to those materials which are produced by human activity and is usually undertaken to reduce the effect of these activities on their health and environment. Waste management is also useful to recover useful resources from the waste. Waste management involves all solid, liquid and gaseous or radioactive substances which are managed with different methods and expertise is required for each of them. Waste management practices are different for different countries of the world be it developed or developing nations. The management is different for urban and rural areas, for residential and industrial waste producers. Management of residential and institutional waste in cities and metros is done by the local government authorities or what we call as Municipal Corporation, while management of non-hazardous commercial and industrial waste is done by the generator of such waste.

Solid waste Management

Techniques of solid waste management are:

1. Plasma gasification- Plasma is a highly electrically charged or ionized gas. An example of this in nature is lightning which is capable of producing temperatures more than 12,600 °F or 6,980 °C. A gasifier vessel is one which utilizes proprietary plasma torches operating at more than 10,000 °F or 5,540 °C which is the surface temperature of the Sun, so as to order to create a gasification zone of up to 3,000 °F or 1,650 °C which will convert solid or liquid wastes into a sun gas. When the municipal solid waste is subjected to this intense heat within the vessel, the molecular bonds of the wastes break down into elemental components. The process results in elemental destruction of waste and hazardous materials which were originally present. Plasma gasification offers states new opportunities for waste disposal, and more importantly for renewable power generation in an environmentally sustainable manner.

2. Landfill- Disposing of waste in a landfill involves burying the waste under the ground which is a common practice in most countries of the world. Landfills are often established in abandoned or unused quarries, borrow pits or mining voids. If a landfill is properly designed and well-managed it can become a hygienic and relatively inexpensive method of disposing of waste materials. Landfills which are older, poorly designed or poorly managed create a number of adverse environmental impacts like attraction of vermin, wind-blown litter, and generation of liquid leach ate. A byproduct of landfills is gas which mostly comprises of carbon dioxide and methane, which is produced as and when organic waste breaks down. This gas might kill surface vegetation, create odour problems, and is a greenhouse gas. Waste which is deposited is normally compacted to increase its stability and density, and is always covered to prevent attracting mice or rats. To extract the landfill gas many landfills have gas extraction systems installed. Gas is pumped out of the landfill using pipes which have holes and are flared off or burnt in a gas engine to generate electricity.

Water Treatment

Water treatment means all those processes which are used to make water acceptable for a desired end-use. These include use of water for drinking, medical, industrial processes and many other uses. The goal of all such water treatment is to remove the contaminants present in the water or reduce the concentration of contaminants so that the water becomes fit for consumption. One meaning to it is returning water to its natural environment without adversely impacting the ecology. The processes for treating water for drinking purpose can be solids separation by using physical processes such as settling and filtration, and chemical processes such as disinfection and coagulation and Biological processes if required. In general the process includes:

Pre-chlorination – which is used for algae control and arresting any biological growth

Aeration – used along with pre-chlorination for removal of dissolved manganese and iron

Coagulation – for flocculation

Coagulant aids – used to improve clotting and for thicker flock formation

Sedimentation -done to separate solids i.e. removing suspended solids trapped in the flock

Filtration – it involves removing particles from water

Desalination – it is the Process of removing salt from the water

Disinfection – for killing bacteria in the water.

There is no fixed formula for water treatment. It all depends on the quality and level of impurity. Sewage treatment is the process of removing the majority of the contamination from sewage or wastewater and producing a liquid effluent which is suitable for disposal to the environment. Sewage must be conveyed and transferred to a treatment plant by appropriate pipes and infrastructure and the process must be properly regulated and controlled.

E-waste management

“Electronic waste” is defined as all the secondary computers, entertainment devices, mobile phones, all other items like television, refrigerators, whether they are sold or donated or discarded by their original owners or users. In simple terms all those items mentioned above which are either dumped or disposed or discarded by their buyers rather than recycling and reusing them is called E-Waste. A major portion of this waste is generated through products like personal computers, laptops etc. According to recent estimates about 50 million tons of E-waste is produced each year around the globe. The USA alone discards 30 million computers each year and nearly 100 million phones are discarded in Europe each year. The reasons for these huge figures are that there are the rapid changes in technology, low cost of the product initially which encourages people to buy new instead of repairing and reusing and also the cost of modifying the features is much more than the original cost. Moreover the electronic goods today are made in such a way that they follow something called as planned obsolescence which means they get obsolete with the passage of time. Electronic waste processing first involves dismantling the equipment or the electronic item into various parts i.e. metal frames, circuit boards, power supplies, plastics etc. and this is often done manually. The advantage of this process is that human’s have the ability to recognize and save those parts which are working and are repairable which includes chips, RAM, transistors etc. The disadvantage of this process is that the labour might often be expensive in those countries which have high health and safety standards. An alternative to this is called bulk system; wherein a hopper conveys material meant for shredding into a very sophisticated mechanical separator which has screening and grinding machines to separate the constituents of metal and plastic fractions. These plastic fractions are then sold to plastics recyclers or smelters. Emissions are caught by the scrubbers and screens. To separate glass, plastic, harmful and unharmful metals; magnets and eddy currents are used. Copper, gold silver, tin etc. valuable metals are sold to smelters for recycling purpose. Hazardous smoke and gases are captured, and then treated to remove the environmental threat. An ideal electronic waste recycling plant is one which combines dismantling for recovery of its components with increased cost-effectiveness of processing of bulk electronic waste. Reuse is an alternative option to recycling because it extends the life of the device.

Recycling

“Reduce, Reuse, Recycle” are known as the 3R of the waste hierarchy. Recycling involves processing used materials to make a new product which prevents waste of potentially useful materials that will reduce the consumption of fresh raw materials and reduce the energy usage, water pollution and reduce air pollution by reducing the need for “conventional” waste disposal, and lower the greenhouse gas emissions as compared to original and fresh production. Recycling is a key component of modern waste reduction and is the third component of Recyclable materials include many kinds of glass, paper, metal, plastic, textiles, and electronics. Although similar in effect, the composting or other reuse of biodegradable waste – such as food or garden waste – is not typically considered recycling. Materials to be recycled are either brought to a collection center or picked up from the curbside, then sorted, cleaned, and reprocessed into new materials bound for manufacturing. Recycling Saves money, energy, trees the planet Earth. Recycling of a material will produce a fresh supply of the same material like for instance used office paper can be converted into new office paper. This is often difficult and expensive so “recycling” of many products involves their reuse in producing different materials. Another form of recycling is the salvage of certain materials from complex products due to their intrinsic value like lead from car batteries or gold from computer components, or due to their hazardous nature. The costs and energy used in collection and transportation outweigh the costs and energy saved in the production process which is a disadvantage of recycling and also that the jobs produced by the recycling industry can be of poor trade. Also materials like paper pulp are such which can only be recycled a few times before degradation prevents further recycling.

Recent developments: As reported in the Financial Express on 20th July 2010, Jamshedpur Utilities & Services Company (Jusco), which is a fully owned subsidiary of Tata Steel, recently bagged the Municipal Solid Waste management contract for Mysore city from the Mysore City Corporation and Municipal Solid Waste (MSW) management contract under the Kolkata metropolitan area for six municipalities. Under the project Jusco will construct 5’transfer stations’ and 6 ‘compost plants’ in the municipalities of Champdani, Baidyabati, Serampore, Rishra, Konnagar and Uttarapara-Kotrung which fall under Kolkata Metropolitan Development Authority (KMDA). The Rs 39 crore projects will be funded by Japan International Cooperation Agency (JICA). Jusco offers integrated solutions to municipal waste management which comprises of waste transfer, transfer station management, composting, engineered structured landfills, integrated waste recycling and reclamation, recycling of municipal and specialized wastes, etc. The utilities major also bagged the ‘TPM Excellence Award -2008’ instituted by the Japan Institute of Plant Maintenance (JIPM) and has several other national and international awards like National Urban Water Awards (NUWA) in the “citizen services & governance category” for 2009.