摘要
为拓展城市剩余污泥资源化利用途径,本文以剩余污泥球粒为原料在高温限氧条件下制备污泥生物炭粒(SBC),同时以氢氧化铝溶胶为前体浸渍污泥球粒后在500℃下热解获得氧化铝改性污泥生物炭粒(SBC-Al)。使用BET、XRD、FTIR和SEM对生物炭粒进行了表征,并研究了生物炭粒改性前后对Pb(Ⅱ)的吸附特征及效果。结果表明:SBC-Al比表面积和总孔容分别达到83.266m2/g和0.158cm3/g,相比于SBC分别增大了142.42%和167.80%;XRD显示氢氧化铝溶胶浸渍使SBC-Al表面负载了γ-Al2O3粒子,FTIR红外谱图说明氧化铝改性可能会增加炭粒表面官能团数量,同时SEM显示出SBC-Al表面相较于SBC具有更多的层片状结构,从而增加生物炭粒的吸附性能。Pb(Ⅱ)的吸附动力学符合二级动力学方程和Elovich方程,同时用二阶段颗粒内扩散模型可以较好地拟合。吸附等温线以Freundlich模型为主,且SBC和SBC-Al对低浓度(<50mg/L) Pb(Ⅱ)的去除率均较高,分别在95%和99%以上,实测最大吸附量可分别达626.73mg/g和663.97mg/g,但SBC-Al提高了对更高浓度(50~100mg/L) Pb(Ⅱ)的去除率。热力学计算数据表明吸附过程为吸热反应;脱附解吸试验说明,生物炭粒具有良好的循环再生利用性能。
In order to expand the utilization of municipal excess sludge, activated sludge biochar particles(SBC) were prepared by using excess sludge pellets as raw materials under high temperature and oxygen limitation. At the same time, activated sludge biochar particles modified by alumina(SBC-Al)were obtained by impregnating sludge pellets with alumina hydroxide sol as precursor at 500°C. Biochar particles were characterized by BET, XRD, FTIR and SEM. The adsorption characteristics and effects of Pb(Ⅱ) on biochar particles before and after modification were studied. The results showed that the specific surface area and total pore volume of SBC-Al were 83.266 m2/g and 0.158 cm3/g, respectively, which increased by 142.42% and 167.80% compared with SBC. XRD showed that alumina sol impregnation loaded the SBC-Al surface with γ-Al2 O3 particles. FTIR spectra showed that alumina modification might increase the number of functional groups on the surface of carbon particles. Meanwhile, SEM showed that SBC-Al surface had more lamellar structure than SBC, thus increasing the adsorption performance of biochar particles. The adsorption kinetics of Pb(Ⅱ) conforms to the second-order kinetics equation and Elovich equation. At the same time, the two-stage intraparticle diffusion model can be used to fit the adsorption kinetics of Pb(Ⅱ). The adsorption isotherm is based on Freundlich model, and the removal rates of low concentration(<50 mg/L) Pb(Ⅱ) by SBC and SBC-Al are higher than 95% and 99%,respectively. The maximum adsorption amounts can reach 626.73 mg/g and 663.97 mg/g, respectively.However, SBC-Al improves the removal rates of higher concentration(50-100 mg/L) Pb(Ⅱ).Thermodynamic calculation data showed that the adsorption process is endothermic reaction. Desorption and desorption experiments showed that biochar particles have good recycling performance.
作者
徐大勇
张苗
杨伟伟
刘婷婷
姚巧凤
洪亚军
XU Dayong;ZHANG Miao;YANG Weiwei;LIU Tingting;YAO Qiaofeng;HONG Yajun(College of Biotechnology and Chemical Engineering,Anhui Engineering University,Wuhu 241000,Anhui,China)
出处
《化工进展》
EI
CAS
CSCD
北大核心
2020年第3期1153-1166,共14页
Chemical Industry and Engineering Progress
基金
安徽高校自然科学研究重点项目(KJ2018A0103)
安徽工程大学“中青年拔尖人才”培养计划。
