Nangui Abrogoua University, Department of Sciences and Environmental Management, Laboratory of Environmental Sciences, 02 BP 801 Abidjan 02, Cote d’Ivoire
Smoking is a processing operation that has been practiced for generations in many parts of the world, for the preservation of products such as meat and fish. However, when smoking fish, the smoke carries polycyclic aromatic hydrocarbons (PAHs) which have an impact on health. The objective of this study was to assess the performance of the Thiaroye oven in reducing the PAH levels of two species of smoked fish in Côte d'Ivoire. The smoking of the fish was carried out at the Guéssabo smoking site and the samples were sent to the laboratory for analysis. The fish samples were divided into two lots. One batch was smoked with the traditional oven and the second batch was smoked with the Thiaroye oven. The fuel used was redwood (Cassine Orientalis). The PAH contents were evaluated by high performance liquid chromatography - fluorescence detection. The PAH contents, in particular Benzo (a) Pyrene, Chrysene, Benzo (a) Anthracene, and Benzo (b) Fluoranthene are different depending on the species of fish and the smoking technology applied. According to the analysis results of the two species of fish, and by referring to the European standards which is 2 µg / kg for B (a) P and 12 µg / kg for the sum of the PAHs, it emerged that the catfish was more contaminated than tuna regardless of the technology applied. However, the results showed a reduction of 61.70% for B (a) P and 86.73% for the sum of PAHs with tuna and 73.93% for B (a) P and 98.44 % for the sum of the PAHs in the case of the catfish. The smoking of fish in the Thiaroye oven leads to a considerable decrease in the PAHs content.
Coconut shells have been used as a precursor for the preparation of activated carbon by the chemical activation method. The full factorial design was applied to determine the optimum conditions for preparing the activated carbon. The factors studied were the carbonization temperature, the carbonization time and the concentration of the activating agent. Phosphoric acid was the activating agent, used for chemical activation. Planning of the experiments using the three-level full factorial design method resulted in eight trials with the iodine number as the answer to each trial. The various results obtained were analyzed using Nemrow software in order to highlight the influence of factors and their interaction. The results reveal that carbonization temperature, the carbonization time and the concentration exert a significant influence on the iodine number, when they are at their high level, respectively 600 ° C, 4h, 30% for the value of the iodine index of 445.44mg/g.