摘要
以中晚期生长的加拿大一枝黄花茎秆为材料,在热解温度400-650℃下制备生物炭,探究了生物炭对吡啶的去除效果.采用红外光谱、扫描电镜、比表面积测定仪和X射线衍射仪表征生物炭的微观结构,考察吡啶的初始浓度、反应时间、生物炭用量等对其吸附性能的影响,探讨了其吸附动力学和吸附等温曲线.结果表明,随着炭化温度升高,生物炭的含氧官能团、芳香化程度和比表面积增大;烧结温度为600℃制备的生物炭结构规则,稳定性最佳.当吡啶浓度为100 mg·L^(−1)时,生物炭的用量为2 g·L^(−1)时,600℃所制生物炭的吸附性能最佳,反应2 h后达到吸附平衡,吸附容量为32.9 mg·g^(−1).吡啶的吸附符合伪一级动力学模型,对吸附等温线进行分析可得,Langmuir模型能更好地拟合生物炭对吡啶的吸附过程,生物炭吸附吡啶以单分子层吸附为主.600℃下制备的生物炭对吡啶的最大吸附量高达144.44 mg·g^(−1).以600℃所制生物炭为吸附剂的响应面优化结果表明,生物炭投加量4 g·L^(−1)、吡啶初始浓度102.10 mg·L^(−1)、吸附时间2.89 h的最优条件下,吡啶的去除率最大,达到97.92%,表明加拿大一枝黄花是潜在的制备优异吸附性能生物炭的原料.
Biochar was prepared with Solidago canadensis L.of middle and late phase at the temperature of 400-650℃ and its pyridine adsorption capability was investigated.The microstructures of the biochar were characterized by infrared spectroscopy,scanning electron microscopy,specific surface area analyzer and X-ray diffraction.The effects of the initial pyridine concentration,reaction time and the dosage on the adsorption properties of biochar were discussed.The adsorption kinetics and isothermal curves were also investigated.Results showed that the oxygen-containing functional groups,aromatization degree,and specific surface area of the biochar increased with the increase of carbonization temperature.The biochar prepared with a sintering temperature of 600℃ had a regular structure and the best stability.When the concentration of pyridine was 100 mg·L^(−1) and the amount of biochar was 2 g·L^(−1),the adsorption performance of biochar produced at 600℃ was the best and after 2 h of reaction,the adsorption equilibrium was reached and the adsorption capacity was 32.9 mg·g^(−1).The adsorption of pyridine conformed to a pseudo-first-order kinetic model.The analysis of the adsorption isotherm showed that the Langmuir model can better fit the adsorption process of pyridine by biochar.Biochar adsorption of pyridine was mainly monolayer adsorption.The maximum adsorption capacity of pyridine by biochar prepared at 600℃ was as high as 144.44 mg·g^(−1).The response surface optimization results using biochar prepared at 600℃ as the adsorbent showed that under the optimal conditions of 4 g·L^(−1) of biochar,an initial concentration of pyridine of 102.10 mg·L^(−1),and an adsorption time of 2.89 h,the pyridine removal rate was the highest,reaching 97.92%.It was indicated that Solidago canadensis L.was a potential raw material for preparing biochar with excellent adsorption performance.
作者
杨海君
邓蓉蓉
易勇
谭菊
YANG Haijun;DENG Rongrong;YI Yong;TAN Ju(College of Plant Protection,Hunan Agricultural University,Changsha,410128,China;College of Science,Hunan Agricultural University,Changsha,410128,China;Changsha Environmental Monitoring Center Station,Changsha,410001,China)
出处
《环境化学》
CAS
CSCD
北大核心
2021年第6期1922-1932,共11页
Environmental Chemistry
基金
湖南省自然科学基金(2018JJ5015)
长沙市科学技术局(kq1801021)资助。
关键词
加拿大一枝黄花
生物炭
吡啶
吸附
响应面优化
Solidago canadensis L.
biochar
pyridine
adsorption
response surface optimization
