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Some volatile organic compounds (VOCs), generated and accumulated in exhibition cases, are capable of inducing degradation in historical artifacts. In this context, it is of special importance to distinguish between VOCs emitted by the construction materials and/or the historical objects, with the ultimate goal of proposing an appropriate mitigation strategy. To pursue this goal, a comprehensive analysis based on solid phase microextraction (SPME) coupled to gas chromatography-mass spectrometry (GC-MS) has been optimized. The sampling setup used in this study does not require any modification of the exhibition design, and the testing remained nearly invisible and unobtrusive to museum visitors. This methodology has been applied to an issue encountered at the National Museum of the American Indian (Smithsonian Institution), where an unpleasant smell was detected in airtight exhibition cases already on display containing sensitive historical objects. The analysis of the volatiles emitted by construction materials allowed for identification of characteristic markers emitted by each material, and the ability to identify their overall contribution in the exhibition case. Via this method, SPME-GC-MS confirmed via the detection of some specific markers that the unpleasant smell was released by one of the construction materials and had accumulated in the exhibition case. In addition, due to the measurements taken in different positions around the exhibition cases, results were useful to point out the range of efficiency of the sorbent material placed in some of the exhibition cases as a first attempt of mitigation technique.

Copper is commonly produced by hydrometallurgical processes. The production of this metal results in the formation of emissions (unwanted solids, liquids and gases). In this paper, an effluent from a Cu producer company is valorized by means of Fe and Cu recovery. In the current process, an effluent from the secondary solvent extraction (secondary raffinate) was sent to neutralization plant to be discharged. In this paper a modification of the process is proposed. The secondary raffinate was contacted with TP207 resin for Fe3 + and Cu recovery. Metals were eluted from the resins using another real effluent (primary raffinate, effluent from the primary solvent extraction) from the same plant. Experiments for the uptake and elution were carried out in batch and in columns. The effect of pH, resin dosing, and temperature onto metals retention are analyzed. Retention efficiencies (loading capacities) were 50.1% (8.1 mg·g− 1) for Cu and 54.8% (23.2 mg·g− 1) for Fe3 + under the optimal operational conditions (pH = 0.45 and T = 65 °C). These values were confirmed in column tests. It is possible to recover Fe3 + and Cu from the secondary raffinate, leaving most of Fe2 + and other elements in solution. The experimental affinities that TP207 showed are: Cu > Fe3 + > Fe2 + > Zn. The elution of Fe and Cu was quantitatively achieved with concentrated H2SO4 solution. When acidified primary raffinate was used as eluting solution, an enriched solution containing 14.3 g Cu·L− 1, 20.3 g Fe2 +·L− 1, and 18.6 de g Fe3 +·L− 1 was obtained. This enriched primary raffinate can be reintroduced in the process as leaching solution. So, after the modification of the process, using secondary raffinate as loading solution and acidified primary raffinate as eluting solution, the ion-exchange stage could substitute the external FeSO4 addition. In addition, 30–80 kg Cu·h− 1 are reintroduced in the process.

The identification of volatile organic compounds (VOCs) emitted by a complex museum object, composed of materials of different nature, has been optimized by solid-phase microextraction coupled to gas chromatography-mass spectrometry (SPME-GC–MS). The performance of two fiber coatings and four sampling times were tested and compared in order to define the best sampling conditions. The method allowed a fair extraction of volatile and semivolatile compounds emitted naturally by the object, without any type of accelerating aging. In addition, on-fiber derivatization was applied to improve the extraction efficiency and reduce the sampling time of harmful carboxylic acids emitted by the object. The results obtained are of prime importance to show the off-gassing activity of a valuable museum object in order to take further decisions related with its storage and display conditions.