In simple terms incineration is the process of that treats waste though combustion of organic materials. This is an extremely high temperature treatment and is quite often referred to as the thermal treatment. The waste products are turned into ash, particulates, flue gases and heat that can also be used to generate electric power. Any harmful pollutants left behind from the flue gases are dispersed into the atmosphere.
Where the process is used to create energy, this is known as Waste-to-Energy (WtE) technology, this includes gasification, pyrolosis, anaerobic digestion and Plasma arc gasification. This can be incorporated without the need for energy and/or materials recovery. The impact of this kind of waste treatment has caused concern in some local communities with arguments that they may have a detrimental effect on the environment. These were sparked by incinerators in other countries, which were built twenty years ago and did not separate the harmful pollutants before releasing it into the atmosphere. The risks were high for the plant workers and branded a permanent mark on the incinerator treatment.
These days the incineration process does much more than just removes waste appropriately. When the process has completed, what's left behind is useful for generating electricity, reduces the mass of the waste, helps to reduce the volume in landfilling and is the only known treatment for effectively removing clinical and hazardous waste types.
Modern incinerators use a pollution mitigation equipment including flue gas cleaning. These come in different types and styles, can be done on and offsite and are much more environmentally friendly.