I am agricultural engineer and I work in a composting Company in Brazil.
One of the raw materials used in the process is the textile sludge. I am
aware that it can contain some contamination of dangerous substances as, for
example, the aromatic amines of the dyes usedto make colored clothes.
The fact is checked because some of those sludge present positive reaction
in the Ames's Test.
For to compost that sludge is necessary to increase matters rich in
carbon as, for example peels of trees, cane of sugars trash and others, that give
structuring to the sludge, so the air can circulate appropriately inside of the piles.
The used volumes of each component are calculated so that the final mixture
has relationship C/N 30/1 and humidity of 60%.
The aeration flows are calculated so that the conditions are strictly aerobics
and the responsible microorganisms of the organic matter degradation can be
developed in the best way and the temperatures rise quickly up to 65ºC
and stay like this for 10 to 14 days, until beginning to drop about more or
The piles stay under aeration forced for approximately one month, later they
are unmade and taken for the cure patio where they are for at least more two months.
In the cured organic compost are made analyses of heavy metals (As, Cd, Pb, Hg, Cr, Cu, Ni, Mo, and Zn), fecal Coliformes and Salmonellas, and Ames's Test.
The metals As, Cd, Hg and Se are below 0,2ppm; Pb below 45ppm; Cu below 70 ppm; Ni and Mo below 25ppm and Zn below 150 ppm.
The fecal Coliformes at the most of 10 unidades/g and there is not Salmonellas.
In 5 samples analyzed just one had positive reaction to Ames's Test (it lowers).
That organic compost possesses excellent agronomic characteristics, and it
doesn't present effects phitoxicity in any indicative plant as for example
the water cress, cucumber or tomato.
My doubts are:
- Is there some law that prohibits the use of textle sludge as raw materials in the composting processes?
- the mixture of the sludge with peels of trees and is trash of cane of sugar can be considered a dilution?
- the textiles sludges can be consired a dangerous residue? Which characteristics are considered in that classification?
- the composting can be consider an inefficient process of transformation of a residue like the textiles sludges? Why?
- what is safer for the environment? To discard the textile sludge in landfill where it stays for years without suffering any significant alteration, therefore maintaining its dangerous characteristics and creating a passive environmental what can very be harmful ?
Or through a composting process to transform that dangerous residue in a safe product for the environment, that brings agricultural benefits for the cultures, mainly in Brazil that possesses very poor soils in organic matter (due to our climatic conditions) and the traditional sources of organic matter are expensive and scarce.
- Does some study group for the subject in another countries?
Can you supply me the name or e-mail?
I apologize for my terrible English and I wait anxious for an answer.
Kátia Goldschmidt Beltrame
Piracicaba, São Paulo State, Brazil