Biology - Waste Generation and Management (Sources of Waste, Methods of Safe Disposal)

Waste is defined as any unwanted or discarded material that is no longer useful to the owner. It can be classified into Biodegradable and Non-biodegradable waste.

Biodegradable waste consists of organic matter (e.g., food scraps, paper) that can be broken down by microorganisms into simpler substances like $CO_2$, $H_2O$, and minerals.

Non-biodegradable waste includes materials like plastics, glass, and metals ($Al$, $Fe$) that do not decompose naturally and persist in the environment for long periods.

Sources of waste include Domestic (household), Industrial (fly ash, chemical residues), Agricultural (pesticides, animal dung), and Municipal (sewage, street sweepings).

Segregation is the process of separating waste at the source into dry and wet categories to facilitate recycling and safe disposal.

Sanitary Landfills involve burying waste in low-lying areas in layers, compacted and covered with soil to prevent odor and pest breeding.

Incineration is the process of burning waste at high temperatures (typically $900^{\circ}C$ to $1200^{\circ}C$) to reduce volume and destroy pathogens, commonly used for medical waste.

Composting is the aerobic biological decomposition of organic waste to produce nutrient-rich manure.

The 3 R's principle: Reduce (minimize consumption), Reuse (use items multiple times), and Recycle (process waste into new products).