Question

Write down the methods in a sustainable solid waste management hierarchy. List the methods from the most to the least preferred option. Describe briefly each method indicating clearly the differences between them.

Answer 1

Nature or environment is the gift of god.All our duty is to protect it.But now a days we are polluting this presious nature by dumping waste.The waste include both decomposable and nondecomposable.Decomposable waste is some sort better Though it may cause foul smells and become the breeding place of bees and mosquitoes in the initial stages as the time goes it will get fully decomposed into the soil and make the soil more fertile for the growth of vegetation.But the situation is very different in the case of nondecomposable waste such as plastics. it will remain in the soil as such and there by reducing the penetration of rain water into the ground apart from that it reduces the fertility of the soil and make it unsuitable for cultivation.If we burn these plastics instead of dumping iton the ground it will harmful to the nature .The harmful gases released while burning the plastics make air pollution which may lead to serious respiratory problems to the people living in.All we need is propal waste management.Sustainable waste management is the better option.Sustainable waste management aims at disposing the waste in a much better way such that the consumption of natural resources is reduced to minimum and it confirm the reuse and recycling of different materials taken from the nature as many times as possible there by reducing the amount of waste created to a minimum.

Sustainable waste management heirarchy includes mainly four methods .The four methods in the order of preference is

• Source reduction and reuse
• Recycling and Composting
• Energy recovery
• Treatment and Composting

Source reduction and reuse

Source reduction is also known as waste prevention.Reducing the chances of waste production at its source itself.The purpose of source reduction is that it will decrease the amount and toxicityof any material that requires management through prevention at the source.This is the most preffered and it is different from other wastemangement methods because it eliminates the need of waste mangement.Source redution can be done by

• Reducing the amount of toxic materials used at manufacturing and packaging sectors.
• Redesigning a product so that it can be used in multiple ways there by increasing its lifespan ,reusability and its repairability.
• By changing the pattern of consumption in such a way that it will reduce the amount of waste generated.This method encourages the consumtion of only the essential things.
• This method encourages the use of reusable and non toxic packaging materials like paper bags,cloth bags etc instead of using use an throw plastic carriage bags which is harmful to the environment.

Source reduction and reuse have both economic and environmental benefits.It reduce the amount of waste generated there by reducing the pollution load and it reduces the cost of waste disposal and waste mangement.Apart from all that it encourages a good culture of reusing the possible things instead of throwing it into the environment amoung people.

Recycling and composting

Recycling means converting used,unused or damaged items that are kept aside as wastes into a usable thing.In this method the items which are fully used,or unused due to various reasons or damaged due to the improper usage is collected and processed to form rawmaterials .This raw materials are further useto manufacture new products.The making of compost from organic waste including food waste are also considered as a recycling method.This recyclyingmethod also has both environmental and economic benefits.At most it reduces the waste generated but the most important thing is that it will reduce the amount of harmful gases emitted during the manufacture of new products every time.Recycled products have less cost as compared to the fresh products so this has economic benefits also.Apart from all these this recycling method protect our resources which get depleted during the continous manufacturing of several products.And there by the resources can be conserved fir our future generation.

Energy recovery

With population growth and economic development both waste generation and energy demand is increasing gradually around the world.Thus the energy recovery from waste is very important in the present scenario.If this situation continues the increased waste generation will lead to the destruction of our environment and the increased energy demand will lead to the depletionof our natural energy sources.There lies the importance of waste to energy conversion.Different types of solid waste such as muncipal solid waste ,agricultural waste.and industrial waste as well as waste water can be used for producing energy through thermal, biological and chemical methods.Non recyclable wastes can be converted into usable heat energy,electrical energy or fuel through different processes such as combustion,pyrolization,anaerobic digestion etc.

Treatment and disposal

There are different methods for the effective treatment and disposal of solid waste.Some of them are open dumps,land fills,sanitary landfills,incineration ,pyrolysis, composting ,vermiculture etc.Amoung these landfills is the most commonly adoptedand it is a systematic burial of solid waste.The land fully is perfectly desined structure built intoor on top of the ground in which it is isolated from the environment such that groundwater ,air or water doesnot enter into it.There is clay layer at the bottom and the waste is daily covere woth soil on tlop of it such that thewaste will get decompose quickly.The ground with a land fill has more stability so sometime once the landfill is capped that ground may used as recreation area as parks.golf courses etc.The methane gas that is produced from the landfill is collected and used as afuel.