Question

Discuss the Fundamental mechanisms for biodegradation of organic waste in a landfill.

Answer 1

Biodegradation

A process by which microbial organisms transform or alter the structure of chemicals introduced into

the environment”.

Mechanisms-

The process of biodegradation can be divided into three stages: biodeterioration, biofragmentation, and assimilation.

Biodeterioration is sometimes described as a surface-level degradation that modifies the mechanical, physical and chemical properties of the material. This stage occurs when the material is exposed to abiotic factors in the outdoor environment and allows for further degradation by weakening the material's structure. Examples of abiotic factors are compression (mechanical), light, temperature and chemicals in the environment.

Biofragmentation aresteps taken to fragment these materials also differ based on the presence of oxygen in the system. The breakdown of materials by microorganisms when oxygen is present, it's aerobic digestion. And the breakdown of materials when oxygen is not present, is anaerobic digestion.The main difference between these processes is that anaerobic reactions produce methane, while aerobic reactions do not. In addition, aerobic digestion typically occurs more rapidly than anaerobic digestion, while anaerobic digestion does a better job reducing the volume and mass of the material.

The resulting products from biofragmentation are then integrated into microbial cells, this is the assimilation stage. Some of the products from fragmentation are easily transported within the cell by membrane carriers. However, others still have to undergo biotransformation reactions to yield products that can then be transported inside the cell. Once inside the cell, the products enter catabolic pathways that either lead to the production of adenosine triphosphate (ATP) or elements of the cells structure.