New organic compounds detection and potential removal in crude phosphoric acid using waste sludge

Abstract

Some organic compounds in phosphoric acid are a potential mediator of adverse environmental impacts on soil. This work aims to detect and reduce the content of organic compounds in crude phosphoric acid using waste sludge, from water treatment plants, as a low-cost sorbent. Gas chromatography/Mass spectrometry (GC/MS) was used to detect the organic species in crude phosphoric acid, while X-ray fluorescence (XRF), X-ray Diffraction (XRD), and Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy were used to characterize waste sludges. Practically, three sludge samples were utilized and different factors including shaking time, sorbent dose, and phosphoric acid concentration were studied.The results of GC/MS revealed that crude phosphoric acid contains bis [tert-butyl(dimethyl)silyl] azelaate, dibutyl phthalate, and 2,6-di-tert-butyl-4-methylphenol as the main organic species. Moreover, the clay content and the surface charge of sludge strongly affect the removal efficiency of organic species. Kinetic analysis using Lagregran pseudo-first-order, pseudo-second-order, Morris-Weber, and Elvoich models display that the sorption process using waste sludges is a chemisorption process. Finally, the three sludge samples exhibit potential sorbents for the clarification of phosphoric acid and sequentially to produce green phosphate fertilizers.

Recycling waste polymer packaging materials as an effective active carbon porous materials for uranium removal from commercial phosphoric acid

“…Nevertheless, with the excessive world annual rate production rate of phosphate rocks, around 150 million tons/year, the slight amount of uranium pollution signifies economic amounts of this element (Adel A. El-Zahhar et al 2015;Kouzbour et al 2019;Ibrahim et al 2021b). Uranium is responsible for several health troubles and considered to be the most hazardous contaminant due to its chemical poisonousness and radioactivity (Beltrami et al 2014a;Morshedy et al 2021;Gandhi et al 2022).…”