In all inventories on the production of dioxins exists an incredible gap: no one has found dioxins in the ash produced by incinerators.
It 'a fact and documented that incinerators with energy recovery produce hazardous waste and toxic waste, or bottom ash remaining on the bottom of the oven and fly ash from flue gas purification.
For example, for every tonne of waste incinerator which was the incinerator of Brescia, this same system has produced 180 kg of bottom ash and 41 kg of fine dust and powders.
This is the most hazardous solid waste treatment of municipal waste, which must be safely disposed of.
not not a secondary issue, since the amount of ash in the game are far from negligible: in 2005 the incinerator of Brescia has produced a total of 167,389 tons of ash (136,268 tons of bottom ash and 31,121 tons of fly ash) a share of 882 pounds of waste per inhabitant of the town of Brescia who have not entered into any environmental report.
can not be ignored in the ashes that are present in quantities of toxic substances near far from negligible. In particular, according to studies on incinerators Italian and English, for every tonne of waste incinerated, thanks to this treatment, are produced from 2 to 7 micrograms of dioxins in the ash heavy and from 2 to 11 micrograms in the fly ash.
In particular, in English incinerator ash produced concentrations of dioxins were equal to 512 micrograms TEQ per tonne in the fly ash and 10 micrograms TEQ per tonne in the bottom ash.
As a tonne of waste incinerated in the same plant (estimated in the late 90's) are about 2 micrograms of the dioxins (mainly, in our food scraps contaminated) , the conclusion is that incineration is a system that, to recover some energy from municipal waste, producing more hazardous waste than incineration.
This statement is true because in the ashes, along with dioxins, there are several toxic metals and carcinogens such as polycyclic aromatic hydrocarbons and these pollutants in the ashes, are at concentration levels higher than those measured in the waste incinerated.
The idea of \u200b\u200bsolving the problem, as was done in the recent past in countries such as Denmark, using the bottom ash for road fill and asphalt using fly ash to make cement, there seems to be a choice prudent.
The prudent choice, if you insist in wanting to incinerate waste, is to mix the ashes with an adequate amount concrete and put everything in landfills that give assurance seals for centuries to come.
In Germany use to this end, the old salt mine, where they certainly fly ash and incinerator in Vienna for some time also go fly ash incinerator in Brescia.
Obviously the choice is even more prudent and wise, would be to give a clear commitment to incineration and patterns of production and consumption to zero waste, a choice far from utopian.
To quantify the problem of dioxins in the ashes, we recall that in 2006 we burned in Italy "only" 4 milioni di tonnellate di rifiuti; ipotizzando, con le ceneri, una produzione media di 5 microgrammi di diossine per ogni tonnellata incenerita, in quello stesso anno abbiamo prodotto, con le ceneri e grazie all’incenerimento, circa 20 grammi di diossine che, a nostro avviso, dovrebbero essere aggiunti ai 302 grammi di diossine della stima ufficiale di quell’anno, stima che ha valutato solo le diossine immesse nell’ atmosfera del nostro Paese.
Federico Valerio
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