Sequence crystallization during isotherm evaporation of southern Algeria chott Baghdad natural brine

Southern Algerian's natural brine sampled from chott Baghdad may be a source of mineral salts with a high economic value. These salts are recoverable by simple solar evaporation. Indeed, during isothermal solar evaporation, it is possible to recover mineral salts and to determine the precipitation sequences of different salts as a function of the chemical composition and the density of the brine. In this study, the variation of ionic composition of concentrated brine during isothermal evaporation was measured; then the experimental pathway of the point representing its composition on the oceanic fivefold diagram Na+, K+, Mg2+, Cl-, SO4 2-//H2O was plotted. In order to follow the precipitation sequences of mineral salts, during solar evaporation at 35°C, X-Ray diffraction was performed on the precipitated and removed salts from the brine during evaporation.Keywords: seawater quinary diagram, Jänecke projection, isothermal evaporation, mineral salts, chott Baghdad brin

Modeling and Optimization of Phosphate Recovery from Industrial Wastewater and Precipitation of Solid Fertilizer using Experimental Design Methodology

In this work, the experimental design methodology is applied to optimize phosphate salts precipitation as struvite and others applied in soil fertilization from treated industrial wastewater stream. This is a process to maximize phosphate recovery percentage from inlet wastewater stream containing interfering foreign ions. Therefore, these optimized conditions could be used as input data for engineering design-software for successive equipment required in wastewater treatment plant. A four factors Box–Behnken experimental design was used to model and optimize the operating parameters. The optimum operating conditions were quite efficient in trapping 86.10 % recovered phosphates in industrial stream, and 92.6 % in synthetic solution at pH of 10.89, time of reaction of 34.76 min, temperature of 25.23 °C and R of 2.25 with an insignificance effect for molar ratio (R) between Mg and PO4 ions. If these optimal parameters were shifted, the reached recovery percentage would decrease with the precipitated struvite. The precipitated salts were subjected to characterization through different chemical techniques confirming the presence of struvite with schertelite as a mixed slow release fertilizer

Chemin de cristallisation informatisé : analyse critique des données

In former works we described the DPAO method "Diagram of Phases Computer-assisted" and we applied it to the study of the isothermal and isobar evaporation of a point mixture representing the natural brine resulting from Sebkha El Melah de Zarzis (Tunisia). The quality of the data, as well in precision as in number, is discussed in this presentation, whatever the method of adopted advance: computerized or manual