Page 12 - PR 2014 2016 08 Environmental Science and Technology

228 Environmental Science and Technology | Progress Report

lem, researchers of CQMA have performed a Besides the development of characterization
study that aimed to develop and validate a methods, IPEN has also developed advanced
method to identify and quantify persistent processes for safe decomposition of POPs. The
organic pollutants, known as POPs in soil of technology developed at IPEN is applicable to
industrial regions Caieiras and Franco da Rocha intrinsically safe disposal of hazardous organ-
municipalities in São Paulo by gas chromatog- ic wastes, particularly the organochlorides,
raphy coupled with Mass Spectrometry (GC/ whose degradation has presented problems
MS) and Electron Capture Detector (GC/ECD), when using the most common methods, such
as it can be observed in the figures 1 and 2. as incineration. The molten salt oxidation is
To ensure reliability of the analysis carried a process which promotes a more complete
out, tests were carried out validation method. and safer decomposition of wastes consid-
The extraction technique used was QuEChERS, ered critical, such as POPs, as can be observed
achieving recovery in the range 70 to 120% schematically in the figure 7.
for most of the compounds, acceptable for
complex matrices. The limits of detection and Organochloride compounds can be de-
quantification of the method comprises the composed in a safe way in the molten salt
range of 0.0002 and 0.01 µg.g-1, respectively. equipment because the chlorine present in
The samples analyzed were contaminated by the wastes reacts with elements present in
compounds hexachlorobenzene α, β, γ and δ, the bath salt, such as sodium, for example,
many of which are above the maximum allow- forming the sodium chloride which is retained
able in accordance with national legislation in the salt. It is important to mention that the
and international law (FIG. 5; FIG 6). retention of chlorine has greater importance

Exhaustion
CO 2, H 2O v
Compressed air

Liquid waste Compressed air
and/or oxigen

Wastes
Pressurized
reservoir

Air/oxigen and waste lance

Reactor vessel Heating system

Molten salt

FIGURE 7- Schematically
description of the
molten salt oxidation.

Instituto de Pesquisas Energéticas e Nucleares