磷酸活化核桃壳炭制备及吸附罗丹明B的研究

以核桃壳为原料，采用H₃PO₄活化法制备了核桃壳炭（WSBC）用于去除水溶液中的罗丹明B（RhB），应用FTIR、XRD、SEM和BET等技术对WSBC进行物相表征，利用UV–vis跟踪吸附过程，分析了H₃PO₄浓度、焙烧温度、吸附温度、投加量、溶液pH、RhB初始浓度对WSBC吸附性能的影响。结果表明：物相表征方面，制备的WSBC具有良好的孔隙结构，其表面具有丰富的官能团，吸附RhB前后，晶相无明显改变。吸附活性方面，采用0.5 mol/L的H₃PO₄溶液活化，600 ℃焙烧2 h制备的WSBC，在20 ℃，初始RhB浓度10 mg/L，投加量0.2 g，吸附时间60 min，RhB的吸附率为90%。WSBC吸附RhB过程符合准二级动力学方程，RhB在WSBC上的吸附遵循Langmuir吸附模型，最大理论吸附量为12.61 mg/g。

Phosphoric Acid Activation for Preparation of Walnut Shell Biochar and Adsorption of Rhodamine B

Using walnut shell as raw material, walnut shell biochar (WSBC) was synthesized via H3PO4 activation for Rhodamine B(RhB) removal. The obtained WSBC was characterized by FTIR, XRD, SEM, BET and the adsorption process was investigated by UV–vis. The effects of concentration of H3PO4, roasting temperature, adsorption temperature, adsorbent dosage, initial concentration, pH value were investigated on RhB adsorption over WSBC. Results suggested that WSBC had available porosity and rich functional groups on the surface of WSBC. There was no obvious change in crystal phase before and after adsorption. When the concentration of H3PO4 was 0.5 mol/L, roasting temperature was 600 ℃, roasting time was 2 h, reaction temperature was 20 ℃, the initial concentration of RhB was 10 mg/L, the amount of WSBC was 2 g/L and adsorption time was 60 min, the removal rate of RhB could reach 90%. The adsorption of RhB on WSBC could well-fitted by pseudo-second-order kinetic model and Langmuir isotherms model, the maximum theoretical adsorption capacity of WSBC for RhB is 12.61 mg/g.