Waste Management

                                                   - Divyanshu Singh                              

The process of managing unwanted waste items that have served their purpose but are no longer useful is referred to as Waste Management. Collecting solid waste materials, processing them, and disposing of them are all part of the solid waste management process. Human interaction with the environment has always resulted in the creation of waste.

Wastes include dead and decaying plant and animal remains, metabolic by-products (faecal remains, excreta, etc.), discarded materials from homes, workplaces, businesses, restaurants, factories, hospitals, pesticides, herbicides sprayed on fields, and many more. This article will teach students about solid waste management, including the many trash management methods and their benefits.

Waste Management: What is Waste?

The unwanted or unusable materials that are thrown away after the primary use are called waste. 

Sources of Waste

Wastes are generated from several sources such as domestic, industries, agriculture, and commercial activities.

(i) Domestic Wastes

The waste materials produced from our households in our daily activities are called domestic waste. These include:

• Kitchen waste like vegetables, fruits, and other food waste.
• Sewage-human excreta and waste from bathrooms and kitchens.
• Garbage-newspapers, rags, hair, house dust.
• Others-plastic bags, bottles, tins, etc.

In general, domestic waste is referred to as refuse. About 90%$90\mathrm{\%}$ of domestic waste is directly dumped on land thereby increasing land or soil pollution.

(ii) Industrial Wastes

All Industries generate waste materials. The wastes typically include ashes, rubbish, building material wastes, toxic wastes, metal containers, plastic containers, paints, oils, and other complex synthetic materials.

• Mining operations leave tailings (rocks of little or no value) as waste.
• Metallurgical industries release waste like slag and scrap metal.
• Paper and pulp mills release effluents containing wood chips, bits of bark, cellulose fibres, and a number of chemicals.
• Oil refineries and petrochemical units release a mixture of wastes containing hydrocarbons, organic acids, and sulphur compounds.
• Food processing units such as dairy, breweries, and meatpacking units release organic wastes.

(iii) Agricultural Wastes

Modern techniques employed in agriculture and the use of a variety of chemicals have contributed to the production of large quantities of agricultural waste.

1. Agricultural wastes include crop residues like husk and straws, farm animal waste, and chemicals like pesticides, rodenticides, fungicides, herbicides, and fertilizers.
2. These wastes can enter the water table as runoff from agricultural fields.
3. Chemicals used in agriculture are toxic in nature.

(iv) Commercial Wastes

A lot of waste is generated from commercial establishments such as restaurants, hotels, markets, offices, printing shops, auto repair shops, medical institutions, and hospitals.

Types of Waste

There are mainly two types of waste:

1. Biodegradable Waste: The waste which can be decomposed by the action of microorganisms is called biodegradable waste. For example, domestic sewage, newspapers, and vegetable matter are biodegradable and undergo rotting.
2. Non-biodegradable Waste: The wastes which cannot be decomposed easily are called non-biodegradable wastes. These wastes do not undergo rotting. For example, polythene bags, plastics, glass, aluminium cans, iron nails, and DDT. Plastic waste management is the need of the hour.

What is Waste Management?

Waste management can be simply defined as the collection, transport, recovery, and disposal of waste, together with monitoring and regulation of the waste management process. However, the newer concept of waste management talks about the 7 R’s – Rethink, Refuse, Reduce, Reuse, Recycle, Regulate, and Research.

7 R’s of Waste Management

Rethink

Refuse

Reduce

Reuse

Recycle

Regulate

Research

Types of Waste Management

There are various types of waste management, few of them are listed below:

1. Solid Waste Management
2. Liquid Waste Management
3. Biomedical Waste Management

Solid Waste Management

The term solid waste refers to all discarded and thrown away solid and semi-solid wastes arising from human and animal activities. These may be classified as municipal wastes, industrial waste, and hazardous waste. The use and throw culture of advanced societies has led to a tremendous increase in the generation of solid waste. To overcome the major causes of solid waste, we have to practice the rules of no littering zone, separate the dry waste and wet waste and dump it into the municipal vans, avoid usage of plastic, etc.

Six Main Functional Elements of a Solid Waste Management System:

• Waste Generation
• On-site Handling (sorting, storage and processing)
• Collection
• Transfer and Transport
• Processing and Recovery
• Disposal

Waste Handling and Separation, Storage and Processing at the Source:

1. The best place or source to collect waste materials for reuse and recycling is from the homeowners.
2. The separation of newspaper, cardboard, bottles, yard wastes, aluminum cans, ferrous materials, and especially hazardous wastes.
3. Waste processing can reduce the volume of waste, recycle the usable materials and change the shape of solid wastes.
4. The most common on-site processing operations used are:
• Food Waste: grinding and releasing it into the sewer system
• Component separation
• Compaction: decrease the volume up to 70%.$70\mathrm{\%}.$
• Incineration, yard waste composting, etc.

Liquid Waste Management

Practice is followed to remove or prevent the discharge of pollutants to the drain system or to watercourses as a result of the creation, collection, and disposal of non-hazardous liquid materials. To overcome the problem of liquid waste, we should stop dumping the oil containers on the ships, which disturb marine life, stop washing animals across the rivers, etc.

Process of treating Liquid Waste by the Management:

1. Primary treatment: Screening, grit removal, and sedimentation (settling).
2. Secondary or biological treatment: Biological processes and additional settling.
3. Tertiary or advanced treatment: Not all sewage treatment plant requires tertiary (advanced) treatment.

Biomedical Waste Management

Biological wastes are generated during the diagnosis, testing, treatment, research, or production of biological products for humans or animals. Major sources of biomedical waste are hospitals, blood banks, labs, etc.

Process of treating Biomedical Waste Management:

1. Incineration
2. Autoclaves
3. Mechanical/Chemical Disinfection
4. Microwave
5. Irradiation
6. Vitrification

Recycling or Reuse of Waste

he non-biodegradable wastes can, however, be recycled or reused.

Recycling means the conservation of resources in used items by converting them into new products. For example, old newspapers can be recycled to make tissue paper and cardboard. Aluminum cans can be recycled to produce new cans.

Reuse means conservation of the resources in used items by using them over and over again. For example, glass bottles can be collected, washed, and refilled again.

Hazardous Waste

Nuclear reactors produce toxic, radioactive substances, such as heavy water or spent nuclear fuel. Radioactive waste is hazardous to all life forms as well as to the environment. These are substances that have characteristics of ignitability or corrosivity or reactivity or toxicity.

Advantages of Waste Management

Find below some of the advantages of waste management:

1. Decrease bad odour
2. Reduces pollution
3. Reduces the production of waste
4. It generates employment
5. Produces Energy

Summary About Waste Management

Waste management involves a process whereby wastes are collected, transported, and disposed of in the best possible way of limiting or eliminating the harmful effect of wastes. This aspect of environmental management is as important as other public amenities or infrastructures without which the life of a contemporary man would be extremely difficult.

This is because studies have shown a direct link between air, water, and land pollution and diseases such as lung cancer, heart disease, cholera, and hepatitis. In addition, climate change and eutrophication are a direct result of water and air pollution. Little wonder why there is a huge disparity in the life expectancy of people in developed and developing countries.