make a hand written project on waste management on non biodegradable waste
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Biodegradation is the disintegration of materials by bacteria, fungi, or other biological means. Although often conflated, biodegradable is distinct in meaning from compostable. While biodegradable simply means to be consumed by microorganisms, "compostable" makes the specific demand that the object break down under composting conditions. The term is often used in relation to ecology, waste management, biomedicine, and the natural environment (bioremediation) and is now commonly associated with environmentally friendly products that are capable of decomposing back into natural elements. Organic material can be degraded aerobically with oxygen, or anaerobically, without oxygen. Bio surfactant, an extracellular surfactant secreted by microorganisms, enhances the biodegradation process.
Biodegradable matter is generally organic material that serves as a nutrient for microorganisms. Microorganisms are so numerous and diverse that, a huge range of compounds are biodegraded, including hydrocarbons (e.g. oil), polychlorinated biphenyls (PCBs), and polyromantic hydrocarbons (PAHs), pharmaceutical substances. Decomposition of biodegradable substances may include both biological and abiotic steps.
FACTORS AFFECTING RATE OF BIODEGRADABILITY
In practice, almost all chemical compounds and materials are subject to biodegradation, the key is the relative rates of such processes - minutes, days, years, centuries... A number of factors determine the degradation rate of organic compounds. Salient factors include light, water and oxygen. Temperature is also important because chemical reactions proceed more quickly at higher temperatures. The degradation rate of many organic compounds is limited by their bioavailability. Compounds must be released into solution before organisms can degrade them.
Biodegradability can be measured in a number of ways. Respirometry tests can be used for aerobic microbes. First one places a solid waste sample in a container with microorganisms and soil, and then aerate the mixture. Over the course of several days, microorganisms digest the sample bit by bit and produce carbon dioxide – the resulting amount of CO2 serves as an indicator of degradation. Biodegradability can also be measured by anaerobic microbes
and the amount of methane or alloy that they are able to produce. In formal scientific literature, the process is termed bio-remediation.
Approximated time for compounds to biodegrade in a marine environment
Product
Time to Biodegrade
Paper towel
2–4 weeks
Newspaper
6 weeks
Apple core
2 months
Cardboard box
2 months
Wax coated milk carton
3 months
Cotton gloves
1–5 months
Wool gloves
1 year
Plywood
1–3 years
Painted wooden sticks
13 years
Plastic bags
10–20 years
BIODEGRADABILITY OF PLASTICS
Plastics biodegrade at highly variable rates. PVC-based plumbing is specifically selected for handing sewage because PVC biodegrades very slowly. Some packaging materials on the other hand are being developed that would degrade readily upon exposure to the environment. Illustrative synthetic polymers that are biodegrade quickly include polycaprolactone, others are polyesters and aromatic-aliphatic esters, due to their ester bonds being susceptible to attack by water. A prominent example is poly-3-hydroxybutyrate, the renewably derived polylactic acid, and the synthetic polycaprolactone. .