CRISPIM, A. C.; http://lattes.cnpq.br/5027826794239264; CRISPIM, Alana Carolyne.
Abstract:
The oily sludge of petroleum is one of residues produced for the exploitation and
production of petroleum that requires a proper disposal, because it has a variety of
contaminants, as heavy metals and oils and grease. In this context, the following work
aimed to evaluate the disposal of oily sludge of petroleum, which has heavy metals and
oils and greases, inside of a cell of industrial landfill in experimental scale after the
stabilization using bentonite clay. The classification and chemical characterization of
oily sludge of petroleum were made in the first stage of the work, in order to identifying
elements that give it dangerousness. The oily sludge of petroleum kept a concentration
of 8,27 mg.L"1 of chrome, above of Maximum Allowable Limit value which is 5 mg.L"1,
therefore, the oily sludge is characterized as toxic and it can be classified as Grade I
residue (dangerous). The content of oils and greases was of 46 mg.L"1, exceeding the
limit of 20 mg.L"1 established by CONAMA Resolution n° 430/2011 for effluents from
any pollution source. Preliminary tests were made in the second stage of work to justify
the choice of configuration of experimental cell of industrial landfill, which were
supported in the monitoring of four cells, varying the cover layers and the shape of
disposal of residue. Precipitations were simulated during the monitoring of cells, and
the produced leachate was analysed periodically. All test cells reduced, significantly,
concentrations of metals and oils and greases to available level, especially those which
had clay layer. In the last stage of work, before the mounting of cell of industrial
landfill, the residue was subjected to the stabilization process using bentonite clay and
placed into landfill cell with layer of sand and gravel. The cell was monitored during 75
days and the leachate was analysed periodically. At the final of monitoring, the
concentration of oils and greases declined for 7,10 mg.L"1 and the chromium metal,
which was in greater concentration, reduced for 0,12 mg.L"1. Results of analyse of
leachates indicate that the oily sludge of petroleum is in decomposition stage of organic
matter. The balance of mass was made to evaluate the stabilization of oily sludge of
petroleum with bentonite clay and it showed that, O&G contaminants, total chromium
and total lead, were reduced in 44,2%, 44,4% e 25,0%, respectively. The efficiency of
retention of contaminants was significant, especially for DQO, chromium and O&G,
whose values were 49,12%, 44,40% e 44,20%, respectively. The greater speeds of
biostabilization were for DQO, chromium and O&G, in other words, 0,00867, 0,00754
e 0,00745 d"1, respectively. At the final of research, it is possible to conclude that with
the stabilization of oily sludge of petroleum into clay mass and the disposition of this
material into experimental cell of industrial landfill, it obtained a non-hazardous
material (Grade II) and contaminants that there were into oily sludge of petroleum were
attenuated.