Conversion of biomass residual to acid-modified bio-chars for efficient adsorption of organic pollutants from industrial phosphoric acid: an experimental, kinetic and thermodynamic study

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

“…After equilibration, the sludge was removed from the phosphoric acid. The concentration of organic compounds in crude acid has been measured using a spectrophotometer at 418 nm (Taha et al 2019).…”

“…It is well known that phosphate rocks contain organic compounds as a result of the biological sedimentation of sea organisms (Taha et al 2019). In addition to organic compounds, phosphate rock is contains different hazardous elements such as U, Cd, and As (Fayiga and Nwoke 2016).…”

“…Organic compounds present in phosphoric acid have a negative impact on the quality and the quantity of the produced phosphoric acid whereas they give a dark color to the produced acid and affect the crystallization of the phosphogypsum (Singh et al 2016;Taha et al 2019). Furthermore, organic compounds result in serious operating problems during the application of liquid-liquid method for the recovery of uranium from phosphoric acid as well as the purification of phosphoric acid, whereas organic compounds accumulates and coagulates heavly at the interfacial area between the phosphoric acid and organic solvent which leads to the losses of the organic solvent and negatively impact on the process economy (Dissanayake and Chandrajith 2009;Awwad et al 2013;Singh et al 2016;El Naggar et al 2019).…”

“…Furthermore, organic compounds result in serious operating problems during the application of liquid-liquid method for the recovery of uranium from phosphoric acid as well as the purification of phosphoric acid, whereas organic compounds accumulates and coagulates heavly at the interfacial area between the phosphoric acid and organic solvent which leads to the losses of the organic solvent and negatively impact on the process economy (Dissanayake and Chandrajith 2009;Awwad et al 2013;Singh et al 2016;El Naggar et al 2019). Also, organic compounds forms stable toxic complexes with the harmful elements in the phosphoric acid, which accumulate in the environment as a result of the continuous application of phosphate fertilizers and also transfer to the human body through the food chain (Fayiga and Nwoke 2016;Taha et al 2019). Accordingly, the reduection of the organic compound from phosphoric acid is an important process in respect to improve the quality of phosphoric acid and produce eco-friendly fertilizers.…”

“…Various methods were applied for the reduction of organic compounds from crude phosphoric acid for example liquidliquid extraction or sorption (Awwad et al 2013;Hamza et al 2013;Singh et al 2016;Fawzy et al 2018;El Naggar et al 2019). Several materials were investigated for achieving this proposes such as clays (Hamza et al 2015;Singh et al 2016) and activated bio-chars (El Naggar et al 2019;Taha et al 2019).…”