Conversion of sheep manure to biochar and its U(VI) removal application: green and sustainable method to overcome manure contamination

The conversion of sheep manure into biochar was considered as a waste treatment plan as a result of the effective adsorption of U(VI) by using biochar as an economical adsorbent. In this work, two kinds of modified sheep manure–derived biochars (SMB) were obtained by using TiCl 3 and TBT (the modified SMB were called SMB-Ti and SMB-Te, respectively) as titanium source precursors to adsorb U(VI) from wastewater. The introduction of TiO 2 could improve the affinity of biochar for U(VI), enhancing the adsorption performance. The experimental data indicated that SMB-Ti possessed large removal capacity (674.81 mg/g) and high adsorption efficiency (95%). The adsorption behavior was in accord with pseudo-second-order and Langmuir model, indicating the monolayer chemisorption on SMB-Ti. The practical application ability of SMB-Ti was proved by the dynamic adsorption experiments with excellent removal efficiency (> 94%). The effective U(VI) removal was assigned to the chemical complexation and electrostatic attraction. This paper not only offers a proper way for animal manure treatment, but also poses an effective adsorbent for U(VI) adsorption in aqueous solution. Graphical abstract