Incidence de la présence simultanée de la minéralisation et de la matière organique azotée sur la combinaison chloration adsorption des substances humiques sur charbon actif. Application à des eaux de surface.

Abstract

Abstract The objective of our study is to contribute to the knowledge of the impact of the presence of two individually amino acids (tyrosine, histidine), and two nitrogenous bases (caffeine, cytosine), on the chlorination of humic substances, and record the performance of activated carbon in retention and removal the humic substances by adsorption in the presence individually of these aforementioned organic nitrogenous compounds in the variables media of mineralization. Various reaction parameters were controlled. A hybrid process tested, coupling adsorption and chlorination in order to reduce trihalomethane precursor compounds. In the end, an application of the process of chlorination and adsorption on activated carbon powder and types grains of five Algerian surface water conducted. The experimental results the chlorine reactivity of humic substances in the presence of caffeine, cytosine, tyrosine and histidine testing is very important both in distilled or mineralized water and regardless the variation of the different parameters. This consumption correlated to the physicochemical characteristics of the water and especially the nature of organic and inorganic constituents of water content. Similarly, in our results the appearance of the break point did not successfully register. By against, in surface waters tested, the results showed a known curve in the water treatment field under the name of the break-point or point-critical curve. The adsorption of humic substances in the presence of two individually nitrogen bases and two amino acids aforementioned on activated carbon powder and grains presented very good yields regardless of the nature of the tested water (distilled, groundwater and surface). The variation of the initial content of humic substance on the one hand, and activated carbon either in powder or in grainss other hand, in the separately presence of caffeine, cytosine, histidine and tyrosine in the tested waters induced antagonistic phenomena both in distilled water in mineralized waters. While, the effect of the change in mass of the aforementioned organic nitrogenous compounds recorded an inhibitory effect on the adsorption of humic substances. Similar results were also obtained with the surface water, in particular for the variation of the initial content of humic substance and activated carbon. The chlorination of synthetic solutions in the presence of humic substances separately of histidine, tyrosine, cytosine and caffeine, or the chlorination of surface water after adsorption induced a reduction of the chlorine consumption potentials. Therefore, reducing the formation of organohalogens compounds in particular trihalomethanes, which have toxic effects to human health (mutagenic and carcinogenic).