Solid waste:Types, source and composition

SOLID WASTE

Definition

• Solid waste is defined as all solid and semi-solid materials that are discarded by a community.

Types

• Solid waste generated through domestic and commercial activities is classified as municipal solid waste (MSW). MSW is also called refuse. 
• Solid waste generated by industries is known as industrial solid waste
• Agricultural activities generate waste that may become part of municipal solid waste
• Biomedical waste from hospitals and nursing homes finds entry into municipal solid waste. Biomedical waste is supposed to be disposed off separately as hazardous biomedical waste
• Animal waste and human excreta is not included in municipal solid waste.

Source & Composition

•  Residences are the major sources of solid waste. Garbage from these places include food wastes, plastics, glass, leather, cardboard, metals, garden waste, ashes and special wastes like electronics, tires, batteries and used oil.
• Industries are the biggest contributors of solid waste.
• One of the negative effects of industrialization is the creation of solid waste
• Commercial facilities and buildings are another source of solid waste
• Institutional centers like schools, colleges, prisons, and other government centers also produce solid waste.
• Construction sites and demolition sites also contribute to the problem of solid waste
• Municipal services also contribute to the problem of solid waste in the form of street cleanings, wastes from parks and beaches, wastewater treatment plants, landscaping wastes and wastes from recreational areas
• Industrial units like refineries, power plants, processing plants, mineral extracting plants, plastics, metal part manufacturing industries etc
• Farms are the main source of agricultural waste in the form of spoiled food, pesticide containers and other hazardous material.
• Solid waste from hospitals include syringes, bandages, used gloves, drugs, paper, plastic and chemicals. Biomedical waste is considered to be hazardous and is disposed separately

Solid waste management refers to the process of collecting and treating solid wastes

• Solid waste management refers to the collection, treatment and disposal of solid material that is discarded because it has served its purpose and is no longer useful

Effects of poor solid waste management

• Dumping solid wastes affects the environment and community negatively
• Improper dumping of solid wastes forces biodegradable materials to rot and decompose leading to unhygenic conditions
• Decomposition leads to development of foul odour and becomes a breeding ground for disease causing insects and infectious organisms
• Aesthetic value of the area is affected
• Solid wastes from industries contain toxic metals, hazardous wastes and chemicals. When they are released in the environment, they cause biological and physicochemical problems in the form of affecting the productivity of soils
• Toxic chemicals may seep into the ground and contaminate the ground water

STEPS INVOLVED IN SOLID WASTE MANAGEMENT:
Two important steps involved in solid waste management are:
Reduce, Reuse and Recycle of Raw Materials
Discarding wastes

Reduce - If usage of raw materials is reduced, the generation of waste also gets reduced
Reuse  - Refillable containers that are discarded after use can be reused
               Rubber rings can be made from discarded cycle tubes and this reduces waste generation during      manufacture of rubber bands.
Recycle- Recycling is the reprocessing of discarded materials into new useful products
Ex:     Old aluminum cans and glass bottles are melted and recast into new cans and bottles
          Preparation of cellulose insulation from paper
          Preparation of automobile body and construction material from steel cans
This method (Reduce, Reuse & Recycle), i.e, 3R's help save money, energy, raw materials and reduces pollution.