文献类型： 外文期刊

作者： Ramola, Sudipta ¹ ; Belwal, Tarun ² ; Li, Cun Jun ¹ ; Wang, Yu Ying ³ ; Lu, Hao Hao ³ ; Yang, Sheng Mao ³ ; Zhou, Chun ¹ ;

作者机构： 1.Zhejiang Univ Technol, Coll Chem Engn, State Key Lab Breeding Base Green Chem Synth Tech, Res Grp Adv Mat & Sustainable Catalysis AMSC, Hangzhou 310014, Peoples R China

2.Zhejiang Univ, Coll Biosyst Engn & Food Sci, Zhejiang Key Lab Agrifood Proc, Key Lab Agroprod Postharvest Handling,Minist Agr, Hangzhou 310058, Peoples R China

3.Zhejiang Acad Agr Sci, Inst Environm Resource Soil & Fertilizer, Hangzhou 310021, Peoples R China

4.Engn Res Ctr Biochar Zhejiang Prov, Hangzhou 310021, Peoples R China

5.Qing Yang Inst Ind Minerals, Qing Yang 242804, Anhui, Peoples R China

关键词： Biochar-mineral composite; Bentonite; Calcite; Optimization; Lead removal; Adsorption capacity

期刊名称：SCIENCE OF THE TOTAL ENVIRONMENT （ 影响因子：7.963； 五年影响因子：7.842 ）

ISSN： 0048-9697

年卷期： 2020 年 709 卷

页码：

收录情况： SCI

摘要： Biochar-mineral (bentonite/calcite) composite (BC-CM) prepared at different temperatures were tested under varied conditions for effective removal of lead (Pb) from aqueous solution. With increasing pyrolysis temperature, increased surface area, pore volume, bentonite decomposition and less or no decomposition of calcite occurred. Bentonite-biochar (BCS) and calcite-biochar (CCS) prepared at 700 degrees C were found most suitable for efficient removal of Pb (99.9%). Bentonite and calcite acted as catalyst and contributed to changes in yield, pH, texture, functional groups, minerals and carbonization that facilitated efficient Pb removal by BCS 700 and CCS 700. Pb concentration, pH, dose of BCS and CCS, and contact time were further optimized using response surface methodology (RSM) for maximizing removal percentage (R%) of Pb and adsorption capacity (qt). Both BCS 700 and CCS 700 showed similar effects (positive/negative) of factors on R% and qt. Under optimized conditions, 0.21 g of BCS 700 effectively removed 99.2% of 431 mg/L in 3.6 h at solution pH of 4.2, while 0.07 g CCS 700 removed 97.06% of 232 mg/L in 3.5 h at 5.5 pH. Removal of Pb onto both BCS and CCS was by monolayer adsorption with maximum adsorption capacity of 500 mg/g. Rapid Pb removal was observed within 2 h of contact time (CCS 700 > BCS 700) and equilibrium was achieved within 10 h. BCS 700 followed first order and CCS 700 followed second order kinetic model. Electrostatic attraction between Pb ions and mineral groups present in BCS 700 and CCS 700 also played important role in Pb removal. This study clearly demonstrated that composite of biochar with bentonite or calcite under optimized conditions significantly improved Pb removal and adsorption capacity that can be further utilized for larger scale applications. (C) 2019 Elsevier B.V. All rights reserved.