Papers by Keyword: Carboxylic Acids

Abstract: Separation of carboxylic acids by liquid-liquid extraction method using 1-heptanol solvent and the addition of EPPS biological buffer was studied in this research. Liquid-liquid equilibrium (LLE) data on carboxylic acid systems (butyric acid/propionic acid), water, 1- heptanol, biological buffer EPPS at 303.15 K and atmospheric pressure were obtained. Experimental data were correlated well using the NRTL model with the RMSD below 1%. Based on experimental data, the effect of adding EPPS biological buffer can increase extraction performance as indicated by the value of separation factor (S) of butyric acid increasing two times higher, while separation factor values of propionic acid can be increased 4 times higher than the system without EPPS biological buffer. These results can be used as a reference for the design of the extraction column in the carboxylic acid extraction process so that the extraction process can run more efficiently and optimally.

Abstract: Among the new oxidation methods in advanced oxidation processes, heterogeneous photocatalysis based on UV/ titanium dioxide is one of the emerging technologies for degrading and totally mineralizing toxic and highly stable carboxylic acids from waste water has attracted great attention in last decade. The aliphatic and aromatic carboxylic acids are widely used as reactants or produced as main products or byproducts in various chemical process industries. These chemical process industries generates waste water containing significant amount of carboxylic acids, which need to be removed from waste water before disposal to natural water bodies due to the environmental restrictions and their hazardous effects on flora and fauna. This paper reviews photocatalytic degradation (PCD) process for various carboxylic acids in detail, including basic mechanism of titanium dioxide, effect of carboxylic acid structure and various reaction parameters like effect of initial concentration and kinetic study, catalyst loading, pH, adsorption and deactivation of the photocatalyst. A critical analysis of the available literature has been made and some general conclusions have been drawn related to the above mentioned parameters. The photocatalytic degradation pathways for carboxylic acids are also discussed to understand this process thoroughly.