Separation of Fumaric and Maleic Acid Crystals from the Industrial Wastewater of Maleic Anhydride Production

Abstract

In this research, a physicochemical analysis of the industrial wastewater from a factory that produces maleic anhydride was performed. Based on the conducted analysis (pH, electrical conductivity, density of the liquid phase, boiling point of the waste suspension, chemical as well as biological oxygen demand, and dry matter), it can be concluded that the waste stream obtained at the outlet pipe from the plant resulting from the production of maleic anhydride requires appropriate treatments. Some of the parameters measured, e.g. pH (0.97±0.06), boiling point (106.8±1.3°C) and acidity, indicate the presence of organic acids such as fumaric and maleic acids, which are formed during the production of maleic anhydride. The possibility of extracting crystals by adding urea and thiourea followed by forced cooling in a heat exchanger was investigated. The most effective method was the addition of thiourea when the most significant amount of crystals was obtained, namely 17.29 wt%. The addition of thiourea in combination with forced cooling greatly facilitates the process of separating the solid and liquid phases of the waste suspension, which could later be adequately treated by physical, chemical or biological methods.

Extraction of the Food Additive Tartaric Acid Using Octanol, Methyl Isobutyl Ketone, Kerosene, Mustard Oil, And Groundnut Oil

“…The wine industry generates a substantial amount of environmentally damaging waste streams during production where tartaric acid is readily available. Before being released, their environmental impact must be reduced [6]. TA is separated by precipitation in the form of calcium or potassium tartrate, which can be recovered through filtration and sulfuric acid treatment.…”