改性毛竹生物炭复合材料对水中磷的动态吸附试验

Dynamic adsorption of phosphorus in water by modified Moso bamboo biochar composite

以铁改性毛竹生物炭复合材料(PMC-Fe/C-B)为吸附剂,使用固定床吸附装置模拟动态吸附过程,探究P(Ⅴ)溶液初始浓度、流速、pH、吸附剂投加量、吸附剂粒径以及吸附温度等因素对PMC-Fe/C-B吸附P(Ⅴ)的影响。通过SEM-EDS、XRD、FT-IR和XPS等现代表征手段分别对吸附P(Ⅴ)前后的PMC-Fe/C-B进行表征,结果显示PMC-Fe/C-B表面的含氧官能团与P(Ⅴ)发生了氧化还原反应,同时伴随有物理吸附和离子交换。动态吸附模型结果显示,在初始浓度为10 mg·L^(-1),进水流速为5.136 mL·min^(-1),pH为3,吸附剂粒径>100目(<0.149 mm)、吸附温度为35℃以及投加量为0.5 g的条件下,PMC-Fe/C-B对P(Ⅴ)的最大吸附容量q_(e,exp)为14.26 mg·g^(-1),去除率为77.65%。Thomas模型能较好地拟合PMC-Fe/C-B对P(Ⅴ)的动态吸附数据,C_(t)/C_(0)、t之间的相关性显著(R^(2)=0.9368~0.9912)。改性材料PMC-Fe/C-B在废水除P(Ⅴ)的实际应用中具有较好的可行性。

Iron modified bamboo biochar composite(PMC-Fe/C-B)was synthesized as adsorbent and the influence of initial concentration of P solution,flow rate,pH,particle size,temperature and dosage on the adsorption of P(Ⅴ)by PMC-Fe/C-B were investigated.The PMC-Fe/C-B before and after adsorption of P(Ⅴ)was characterized by SEM-EDS,XRD,FT-IR and XPS.The results showed that the redox reaction of oxygen-containing functional groups on PMC-Fe/C-B surface with P(Ⅴ)was the main adsorption mechanism,followed by physical adsorption and ion exchange.The results of the dynamic adsorption model showed that the adsorption capacity q_(e,exp)of PMC-Fe/C-B to P(Ⅴ)was 14.26 mg/g and the removal rate of 77.65%when the initial concentration of 10 mg/L,the influent flow rate of 5.136 mL/min,the pH of 3,the adsorbent particle size of<0.149 mm,the adsorption temperature of 35℃and the dosage of 0.5 g.Thomas model can well fit the dynamic adsorption data of PMC-Fe/C-B on P(Ⅴ),and the correlation between C_(t)/C_(0)and t is significant(R^(2)=0.9368~0.9912).Therefore,PMC-Fe/C-B modified material has certain feasibility in the practical application of phosphorus removal from wastewater.