Presently every city in India faces the hazardous effects of old dump yard material which not only creates aesthetic nuisance but is a big health hazard to city.
Old dump yard has material accumulated over period of decades and it continuously pollutes all aspects of environment. It pollutes water , air , spreads pathogens , promotes breeding of stray animals , spreads foul smell etc.
Bio mining is an scientific solution of all these problems where remediation is done followed by material separation to recover valuable resources and it is preferable to closure because it recovers valuable land for various uses.
Bio-mining is a form of recycling. Like other recycling systems, the bio mining of dump yard can help decrease the amount of solid waste that must be sent to a landfill thereby reducing disposal costs. The organic material present in the waste can be converted into a stable mass known as HUMUS which is weak in nutrients but is a good fiberous material . Other inerts and recyclables can be sorted and used for recycling.
Design of a bio mining setup is influenced by many factors such asquantity to be handled , space availability , average rainfall period per annum , various contours of the land available , automation of various processes , future requirement , end products market etc. Design is said to be complete only when all the factors affecting the construction , operation , maintenance and longevity of the project is taken into consideration .
Composting is a biological process involving specific microorganisms ,which convert all biodegradable fraction present in MSW into rich compost .
Micro organisms oxidize organic compounds to carbon dioxide and oxides of nitrogen and carbon from organic compounds is used as a source of energy, while nitrogen is recycled. Due to exothermic process the temperature of compost rises to 75 degrees which makes the material hygienic and safe to use. Further RDF is recovered from the material which is not suitable for composting and after proper conditioning , as size reduction , drying etc. , of input material the RDF briquette or bails are prepared.
Proper compost & RDF recovery process is mainly divided into six stages under the headings of :
- 1. Pre-sorting
- 2. Composting
- 3. Preparatory
- 4. Refinement.
- 5. RDF Processing Section
- 6. Inert stabilizing & processing section