Adsorption characteristics of tetracycline on biochar from agricultural wastes

The use of biochar prepared from waste crop straw for the removal of tetracycline (TC) in water has a profound influence on the protection of agricultural water environment. In this study, biochar (BC) was prepared from waste corn straw and wheat straw. The adsorption experiments were carried out on few factors: adsorption time, BC dosages, pH and ionic strength. The results showed that the adsorption of TC by BC derived from corn (C-BC) and BC derived from wheat (W-BC) fitted to the Langmuir model. The equilibrium time for adsorption of C-BC and W-BC was 60 min, the optimal amount of BCs dose was 10 g.L-1. The maximum saturated adsorption of TC by C-BC and W-BC were 49.56 and 42.12 mg.g(-1), respectively. The presence of Mg2+ hindered the adsorption of TC by BCs. The adsorption mechanism was analyzed from the perspective of adsorption kinetics, and both BCs were chemical adsorption. Research showed that biochar in the northeast is cheap and easy to obtain, and the adsorption efficiency was high. Therefore, the use of BC which prepared from corn straw and wheat straw to removal TC has broad prospect.