Waste generated bio-char supported co-nanoparticles of nickel and cobalt oxides for efficient adsorption of uranium and organic pollutants from industrial phosphoric acid

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

“…It is obvious that the organic compounds adsorption percent increases by increasing the three waste sludge sorbents' amount of addition. This performance may be attributed to the existence of more active reaction sites as the sorbent dose increases (Zou et al 2017;El Naggar et al 2019). Numerically, The organic compounds sorption changed from 16.2 to 71.5% for S1, from 11.0 to 61.7% for S2, and from 13.5 to 59.1% for S3 sorbent as the waste sludge dose increased from 0.5 to 20.0g L -1 .…”

“…Specifically, the sorption capacity, qe value, decreased from145.6 to 16.1 mg/ g for S1, from 99.0 to 13.9 mg g -1 for S2, and from 121.5 to 13.3 mg g -1 for S3 as the sorbent dose increased from 0.5 to 20.0 g L -1 . This performance could be attributed to the sorbent active sits were not freely available for binding with organic compounds molecules, and the low concentration of organic compounds species could not meet the adsorption capacities of adsorbents, and thereby decreased the qe (Zou et al 2017;El Naggar et al 2019). This result is consistent with studies applying alum sludge and sewage sludge for wastewater treatment (Nawar et al 2015;Abo-El-Enein et al 2017).…”

“…Organic compounds as well as other harmful elements are introduced to phosphoric acid and phosphate fertilizers during the acidulation of phosphate rock (Zhang and Zhang 2010;Fayiga and Nwoke 2016). Most of previous studies reported that the organic compounds in the phosphoric acid mainly consists of humic compounds, aromatics, and other saturated and unsaturated fatty acids (Awwad et al 2013;Hamza et al 2013;Fawzy et al 2018;El Naggar et al 2019), however, , the main organic compounds in wet crude phosphoric acid have not been detected.…”

“…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). 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).…”