Conclusions
The results revealed that magnetic nanoparticle impregnated onto tea biochar, can be a very promising alternative for wastewater treatment especially considering removal of heavy metals and nutrients and slow-release fertilizer to improve the composition of soil elements.
Methods
Standard carbonization process and ultrafast microwave have been used for fabrication of TBCs. The removal of nickel, cobalt as the representatives of heavy metals, and over-enriched nutrients (NH4+ and PO43-) from water were tested and the removal kinetics, mechanism, and the effect of pH, dissolved organic matter and ionic strength were studied. Simultaneously, possible fertilizing effect of TBC for controlled release of nutrients (NH4+ and PO43-) in soil was investigated.
Results
Up to 147.84 mg g-1 of Ni2+ and 160.00 mg g-1 of Co2+ were adsorbed onto tested biochars. The process of co-adsorption was also efficient (at least 131.68 mg g-1 of Co2+ and 160.00 mg g-1 of Ni2+). The highest adsorbed amount of NH4+ was 49.43 mg g-1, and the highest amount of PO43- was 112.61 mg g-1. The increase of the solution ionic strength and the presence of natural organic matter affected both the amount of adsorbed Ni2++Co2+ and the reaction mechanism. Conclusions: The results revealed that magnetic nanoparticle impregnated onto tea biochar, can be a very promising alternative for wastewater treatment especially considering removal of heavy metals and nutrients and slow-release fertilizer to improve the composition of soil elements.