*2.3.1 Principle*

*Electrochemical Impedance Spectroscopy*

chemical impedance spectroscopy (EIS).

**2. Materials and methods**

**2.2 Culinary media preparation**

water (WS) titrated at 3 g·L<sup>−</sup><sup>1</sup>

**2.1 Sample preparation**

density (2.7 g·cm<sup>−</sup><sup>3</sup>

This can lead to a release of a localized aggression [1]. Aluminum alloys have a low

point, easy to shape, a relatively low price, which is advantageous for local people [2]. Moreover, they are of high mechanical characteristics which make them to be utilized as structural materials. In Africa and particularly in Burkina Faso, craft industry turns to profit these properties in the recycling of aluminum alloys for kitchen utensils manufacturing; the raw material used in this field is made of combined or non-aluminum waste, from old car spare parts, beverage cans and tins [3]. Manufacture techniques remain empirical and recycled aluminum alloys are not homogeneous. Corrosion phenomena is favored when utensils are used for food cooking at high temperature or for long cooking time and when acidic or alkaline food are stocked in these same containers for long time [4, 5]. The humidity, the high temperature, and the cooking times are factors which favor the metallic materials corrosion, from which some of the component elements of the corroded material get through the surrounding aqueous media. Despite the numerous studies related to aluminum and their alloys corrosion, few scientific, strict and comprehensive studies on the behavior to corrosion, recycled allows in the craft industry have been conducted. The objective of this work was to study the corrosion behavior of a recycled aluminum alloy collected in the city of Ouagadougou (Burkina Faso) in various culinary media and to evaluate the anti-corrosion effect in these media. This study was carried out by the use of an electrochemical technique: electro-

The chemical composition of the recycled aluminum alloy is shown in **Table 1** [6]. Before each measurement, the aluminum allow surface preparation of these discs for electrochemical tests was the following: the discs were first ground with 400 through 4000 grit SiC papers and then polished with diamond down to 6 μm and followed by 1 μm alumina – 30% chrome oxide suspension, and finishing with 5% oxalic acid solution. Later, each polished sample was rinsed with acetone and put in an ultrasonic cleaner for 10 min. Subsequently, it was rinsed with milliQ water (with a conductivity of 0.7 μs/cm) and ethyl alcohol and finally dried under a

To simulate similar Burkina Faso operation, the testing media was local culinary

and broken rice (WR) in tap water (5 g of broken

**Al Si Fe Cu Zn Mg Cl Mn P Pb Remainder**

media whose composition is given below. The media used in this study are: salt

rice in 250 ml water) reserve for local consumption. The selection is made based on the fact that rice is the most consumed cereal in Burkina Faso. In this country,

Wt. % 82.8 12.76 0.76 1.21 1.27 0.48 0.19 0.27 0.22 0.01 0.03

*Chemical composition of the recycled aluminum alloy determined by X-ray fluorescent technique.*

.

hot air flow. The contact area with the culinary media is 3.46 cm<sup>2</sup>

), a good thermal and electrical conductivity, a low melting

**38**

**Table 1.**

**Chemical elements**

Eriochrome Black T is a (3-hydroxy-4-[(1-hydroxy-2-naphthalenyl)azo]-7-nitro-1-naphthalenesulphonic) acid sodium salt, Mordant Black 11. In the presence of colored indicator [9], diluted aluminum in the buffer solution forms a complex which changes at wine-colored. The formed complex is more stable. Acidity of the obtained solution depended on aluminum content. The various measures of aluminum content in culinary media will be done by colorimetric with a spectrophotometer 7315 of JEWAY mark at 560 nm wavelength [10, 11].
