摘要
以花生壳为原料,利用H_(3)PO_(4)为活化剂,低温热解制备了改性生物炭,并对其去除水中Cr(Ⅵ)的效果及机理进行了探究。研究了溶液p H、生物炭投加量、反应时间及初始质量浓度对去除效果的影响,借助SEM、BET、 XPS、 FTIR表征了其结构和组成,并探讨了去除机理。结果表明,低温热解与高温热解制备的改性生物炭对Cr(Ⅵ)的去除效果无显著性差异,且低温热解节能环保。低温热解磷酸改性生物炭(PBC350)去除Cr(Ⅵ)的最适条件为Cr(Ⅵ)的初始质量浓度为100 mg/L, 50 mL溶液中投加量为0.10 g, pH=2,反应时间8 h,在最适条件下,Cr(Ⅵ)的去除率达到99.0%,约为未改性生物炭(BC350)的1.5倍。表征结果表明,PBC350表面形成了致密的、蜂窝状的孔隙结构,比表面积为17.75 m^(2)/g,比BC350的比表面积提升了近20倍,同时,XPS和FTIR结果显示,PBC350成功掺杂了磷元素,引入大量含磷(P-O)官能团,能提供电子参与Cr(Ⅵ)还原,提高了Cr(Ⅵ)的去除率。本研究为低温热解磷酸改性生物炭在废水重金属治理中的应用提供了理论基础。
Modified biochar was prepared using peanut shell as raw material and H_(3)PO_(4) as activator at low pyrolysis temperatures,and its effect and mechanism of Cr(Ⅵ)removal from water were studied.The effects of solution pH,biochar dosage,reaction time and initial mass concentration on the performance of Cr(Ⅵ)removal were investigated,the structure and composition of the modified biochar were characterized by SEM,BET,XPS and FTIR.,and analyzed the removal mechanism.The results show that there is no significant difference in the removal effect of Cr(Ⅵ)from modified biochar prepared by low temperature pyrolysis and higher temperature pyrolysis,the low pyrolysis temperature of modified biochar (PBC350) have energy saving and environmental protection advantage. The optimum conditions for theremoval of C(r Ⅵ) by low pyrolysis temperature of modified biochar( PBC350) are initial concentration ofCr(Ⅵ) 100 mg/L, dosage of 0. 10 g in 50 mL solution, pH=2, and reaction time of 8 h. Under theoptimized conditions, the C(r Ⅵ) removal rate reach 99. 0%, which is about 1. 5 times that of unmodifiedbiochar( BC350). The characterization results show that the surface of PBC350 forms densely honeycombpore structures, its specific surface area is 17. 75 m2/g, which is nearly 20 times higher than that ofBC350. Moreover, XPS and FTIR results show that PBC350 is successfully doped with P, and introduceda large number of phosphorus containing( P−O) functional groups, which can provide electrons toparticipate in C(r Ⅵ) reduction reaction and increase the removal of C(r Ⅵ). This study provides a theoreticalbasis for the application of low temperature pyrolytic phosphoric acid modified biochar in the treatmentof heavy metals in wastewater.
作者
赵啟超
白红娟
韩群英
孙竹梅
刘鹏霄
王子豪
叶宇晗
王瑶
ZHAO Qichao;BAI Hongjuan;HAN Qunying;SUN Zhumei;LIU Pengxiao;WANG Zihao;YE Yuhan;WANG Yao(School of Environment and Safety Engineering,North University of China,Taiyuan 030051,China)
出处
《中北大学学报（自然科学版）》
CAS
2024年第4期503-512,共10页
Journal of North University of China(Natural Science Edition)
基金
山西省研究生教育创新项目(2022Y651)
大学生创新创业训练项目(202310110009)。
关键词
花生壳生物炭
六价铬Cr(Ⅵ)
磷酸改性
低温热解
peanut shell biochar
C(rⅥ)
phosphoric acid modification
low temperature pyrolysis
