GUIMARÃES, D. L.; http://lattes.cnpq.br/1664859548221991; GUIMARÃES, Diane Leal.
Résumé:
The primary sludge resulting from sewage treatment station of tannery is categorized
according to the standard 10.004 of the Brazilian Association of Technical Standards,
as Class I, or dangerous, posing a problem for companies, as to their management.
Currently, the sludge has been launched in rivers or buried in soil and deposited in
the courtyards of industries, consisting in an environmental liability. The purpose of
this work was to realize the processing of the sludge and assess the material
resulting from the stabilization/solidification by applying the specific protocol for
evaluation this process. This work was done in the laboratory for environmental
management and waste treatment, belonging to the Academic Unit of Chemical
Engineering, of the Federal University of Campina Grande. The research comprised
the following steps: First, was the planning of the experiment, which was used
factorial 22 with three central points. The factors used in the study were the time and
percentage of mud. The levels of the factor time were 7, 14 and 28 days and for the
factor of sludge percentage were adopted levels 5, 25 and 45%. In this step was
proposed the optimization process of expanding and reproducing the best results. In
The second stage was performed the statistical analysis of data through the analysis
of variance, to decide with some level of confidence, if the effects are significantly
different, through their interaction and curvature. The third phase involved the
characterization of materials (sludge and mortar of cement), through the tests of
moisture content, total solids, fixed and volatile, lixiviation and solubilization of heavy
metals and preparation of bodies-of-proof. The fourth stage was held to assess the
stability of the materials submitted by solidification. With this work we can conclude
that the time factor and percentage of sludge primary influence on the integrity
/durability and detention of contaminants. The result was better for low quantity of
sludge and greater time to cure the resultant material, that is, 2,5 and 5% of sludge
and 28 days, representing, respectively, 97,79% and 86,58% efficiency of reduction
of chromium. With the implementation of the Protocol was possible to classify and
identify the routes for disposal and use of the material end. In this case, treatment
with 2,5% of sludge was not known as dangerous and stabilized by solidifying with
restraint, while the treatment with 5% was called solidified with restriction being able
to be prepared in a special cell landfill industry.
