摘要
为缓解固废处理压力及开发高效廉价Pb2+吸附产品,以平菇菌糠(PS)为原料,在250、450、650℃温度下,限氧热解制备生物炭(PSBC),并采用BET、SEM-EDS、XRD、FT-IR对样品的表面理化性质进行了探究。通过批量吸附、机制定性和定量分析实验,研究了PSBC对水体中Pb2+的吸附特性和吸附机理。结果表明:当热解温度由250℃升至650℃,含氧官能团数量减少,比表面积与芳构化程度急剧增加;PSBC对Pb2+的吸附依赖于溶液pH,当pH为6.0时吸附量最大。吸附过程符合准二级动力学与Freundlich模型,说明以多分子层上的化学吸附为主。相较PS250与PS450,PS650拥有较大比表面积与良好的介孔结构,可为Pb2+的吸附提供更多的结合位点。经Langmuir模型计算,PS650最大吸附量为215.30 mg·g-1,其吸附效果甚至高于一些改性生物炭。机理分析表明,PSBC吸附Pb2+的主要机制为碳酸盐的沉淀作用,同时还伴随着含氧官能团的络合以及π-Pb2+间相互作用的贡献。本研究结果可为菌糠固废管理以及污水中Pb2+的去除提供参考。
In order to alleviate the pressure of solid waste treatment and develop cheap and efficient Pb2+adsorbent products, spent Pleurotus ostreatus substrate(PS) was used as raw material to prepare biochar(PSBC)by limited oxygen pyrolysis at temperature of 250, 450 and 650 ℃, and the surface physical and chemical properties of the samples were studied by BET, SEM-EDS, XRD and FT-IR. The characteristics and mechanism of Pb2+ adsorption on PSBC were studied by the experiments of batch adsorption, mechanism qualitative and quantitative analysis. The results showed that the specific surface area and aromatization of PSBC increased sharply and oxygen-containing functional groups decreased when the pyrolysis temperature increased from 250 ℃to 650 ℃. The adsorption of Pb2+ on PSBC was pH-dependent, and the maximum adsorption amount occurred at pH 6.0. The pseudo second order kinetic model and the Freundlich model were suitable for fitting the adsorption process of Pb2+ onto PSBC, which proved that the process was chemical adsorption occurring on the multimolecular layer. Compared with PS250 and PS450, PS650 had larger specific surface area, better-developed mesoporous structure and more binding sites for Pb2+ adsorption. The maximum adsorption capacity calculated by Langmuir model was 215.30 mg·g-1, which was even higher than those of some modified biochars. The results of qualitative and quantitative analysis showed that the precipitation of carbonate always dominated the adsorption process of Pb2+ on PSBC, being accompanied by the complexation of oxygen-containing functional groups and the interaction between π-Pb2+.The results can provide reference for solid waste management of spent mushroom substrate and the removal of Pb2+ from sewage.
作者
张海波
闫洋洋
程红艳
常建宁
黄菲
张国胜
闫梦
ZHANG Haibo;YAN Yangyang;CHENG Hongyan;CHANG Jianning;HUANG Fei;ZHANG Guosheng;YAN Meng(College of Urban and Rural Construction,Shanxi Agricultural University,Taigu 030801,China;College of Resources and Environment,Shanxi Agricultural University,Taigu 030801,China)
出处
《环境工程学报》
CAS
CSCD
北大核心
2020年第11期3170-3181,共12页
Chinese Journal of Environmental Engineering
基金
山西省高校黄土高原食用菌提质增效协同创新中心平台项目
山西省自然科学基金资助项目(201901D111216)
山西省优秀博士来晋工作奖励基金(SXYBKY201803)
山西省优秀博士来晋工作奖励基金(SXYBKY201748
)山西农业大学科技创新基金项目(2018YJ39)。
关键词
平菇菌糠
生物炭
铅污染
热解温度
吸附特性与机理
spent Pleurotus ostreatus substrate
biochar
lead pollution
pyrolysis temperature
adsorption characteristics and mechanism
