Controlling noxious emissions: Segregating combustible and non-combustible wastes
Incinerators as effective waste management devices are gaining currency. Recycled waste is subjected to complete combustion in incinerator wherein it is converted into inert bottom ash. The smoke, noxious gases and fly ash generated in the process are minimal. Effective operation of incinerator is contingent on calorific value, moisture level and chemical formation of the waste along with the incinerator burn chamber’s operating temperature, turbulence and holding time. Operator skill is equally important.
Waste categorization for optimum incineration
The design of the incinerator and provision of adequate air pollution control are pivotal for incinerating some waste types for achieving particular air emission standards. Wastes which have presence of chlorinated solvents, PVC pipes, plastics, PCB modified paints, pentachlorophenol treated wood and marine driftwood need to be alienated from waste heap. This is because incinerating such wastes will cause creation of de novo and result in dioxin and furan compounds emission.
Mercurial waste such as fluorescent light bulbs, thermostats and batteries and waste with high content of heavy metals such as lead paint treated wood, and lead acid batteries must not be incinerated. This is because heavy metals and mercury are immune to burning. This is true for other kind of wastes such as hydrocarbon polluted soil, sewage sludge, lubricants, biomedical waste and waste types forbidden by federal environmental department. Such wastes require special modifications in the incinerator to control toxic emissions. These wastes should not be burnt in open also as this will result in incomplete combustion. Within an Kerala incinerator, a deft operator can strategically control the combustion process.
Glass and metal are completely non-combustible. They will interfere with the burning of other kind of materials in the waste and consequently will reduce the effective heat value intended to be generated from burning of wastes. It is imperative that combustible and non-combustible constituents of the waste should be segregated prior to loading the same into burn chamber.