Solid Waste Management

Solid waste is the general term for discarded solid material from households, commerce,

agriculture and industry that is no longer wanted by its original owner. Managing it responsibly

begins with a simple but important first step: segregation at source, meaning that waste is

sorted into different streams -- typically biodegradable (food scraps, garden waste, paper) and

non-biodegradable (plastics, glass, metal) -- at the point where it is generated, such as in a

household kitchen or a shop, rather than being mixed together in a single bin.

Segregation matters because the two streams need to be handled very differently afterward.

Biodegradable waste can be composted -- broken down by micro-organisms into a nutrient-rich soil

conditioner -- or, on a larger scale, processed anaerobically to recover biogas as a fuel.

Non-biodegradable waste, by contrast, cannot be composted at all; a useful fraction of it (many

plastics, glass, metal, paper) can instead be recovered and recycled into new material, while

what remains genuinely unusable typically ends up in a sanitary landfill or is burnt in a

controlled incinerator, generally as a last resort since both landfilling and incineration carry

their own environmental costs (land use and leachate for landfill; air emissions for

incineration). Mixing biodegradable and non-biodegradable waste together makes both composting and

recycling far less efficient, since contaminated organic matter is harder to compost cleanly and

recyclable material fouled with food waste is harder to process.

The wider strategy for reducing the total burden of solid waste is captured in the 3R principle:

• Reduce -- cutting down the amount of waste generated in the first place, for example by buying products with less packaging, or choosing durable goods over disposable ones.
• Reuse -- using an item again for its original purpose or a new one instead of discarding it after a single use, for example refilling a glass bottle or repurposing a container for storage.
• Recycle -- processing discarded material (paper, glass, metal, many plastics) back into raw …