改性玉米芯生物炭对废水中磷酸根态磷的吸附

Performance Study of Modified Biochar for Phosphorus Adsorption in Water Bodies

以玉米芯为原料,经NH_(3)·H_(2)O预处理、MgCl_(2)·6H_(2)O溶液浸渍后制备改性玉米芯生物炭(MCC),对改性前后生物炭的形貌进行了表征,并探究了MCC对废水中磷酸根态磷的吸附性能.结果表明,与原始生物炭相比,MCC更加疏松多孔,其BET比表面积为原始生物炭的2.04倍.此外,MCC还具有更多的羰基官能团,这使得MCC对磷的吸附能力更强,废水中磷的初始质量浓度为40 mg/L时,MCC的吸附量达到16.59 mg/g.模拟吸附体系中,当pH值为6、吸附温度为25℃时,MCC对磷的吸附性能最佳.初始磷质量浓度在0~60 mg/L范围内时,MCC的吸附能力随着磷质量浓度的升高而增强.MCC对磷的吸附过程符合Langmuir、Freundlich模型和准二级动力学模型,吸附既存在单分子层化学吸附,又存在多分子层物理吸附.MCC的理论饱和吸附量为32.60 mg/g,在废水除磷方面具有较好的应用潜力.

Modified charcoal(MCC)was made from corn cobs pretreated by NH_(3)·H_(2)O and impregnated with MgCl_(2)·6H_(2)O.The morphology and functional groups of MCC was characterized,and its impact on phosphate phosphorus adsorption was investigated.The results showed that MCC had a more porous structure,with a BET surface area of 2.04 times that of pristine biochar.Additionally,MCC had more carbonyl functional groups,and a higher capacity for phosphorus adsorption.When the initial phosphorus concentration was 40 mg/L,the phosphorous adsorption by MCC reached 16.59 mg/g.In simulated adsorption,the ideal adsorption conditions were found to be at pH 6 and 25℃.When the initial phosphorus concentration is between 0 and 60 mg/L,the adsorption capacity of MCC increases with the increase in phosphorus content.The adsorption process followed the pseudo-secondary kinetic model and the Langmuir and Freundlich models,with both single molecular layer chemical adsorption and multi molecular layer physical adsorption.The theoretical saturation adsorption capacity of 32.60 mg/g demonstrated the potential for phosphorus removal from wastewater.