Facile fabrication of dolomite-doped biochar/bentonite for effective removal of phosphate from complex wastewaters  

作　　者：Huan Xi Fanlu Min Zhanhu Yao Jianfeng Zhang 

机构地区：[1]College of Mechanics and Materials,Hohai University,Nanjing 211100,China [2]Key Laboratory of Geomechanics and Embankment Engineering(Ministry of Education),Hohai University,Nanjing 210098,China [3]CCCC First Highway Engineering Group Co.,Ltd.,Beijing 100102,China

出　　处：《Frontiers of Environmental Science & Engineering》2023年第6期85-98,共14页环境科学与工程前沿（英文）

基　　金：The authors would like to acknowledge the National Natural Science Foundation of China(No.52078189);the Key R&D Program of Jiangsu Province(China)(No.BE2020024)for supporting this research.

摘　　要：The removal of phosphate from wastewater using traditional biological or precipitation methods is a huge challenge.The use of high-performance adsorbents has been shown to address this problem.In this study,a novel composite adsorbent,composed of dolomite-doped biochar and bentonite(DO/BB),was first synthesized via co-pyrolysis.The combination of initial phosphate concentration of 100 mg/L and 1.6 g/L of DO/BB exhibited a high phosphate-adsorption capacity of 62 mg/g with a removal efficiency of 99.8%.It was also stable in complex water environments with various levels of solution pH,coexisting anions,high salinity,and humic acid.With this new composite,the phosphate concentration of the actual domestic sewage decreased from 9 mg/L to less than 1 mg/L,and the total nitrogen and chemical oxygen demand also decreased effectively.Further,the cross-flow treatment using a PVC membrane loaded with DO/BB(PVC-DO/BB),decreased the phosphate concentration from 1 to 0.08 mg/L,suggesting outstanding separation of phosphate pollutants via a combination of adsorption and separation.In addition,the removal of phosphate by the PVC-DO/BB membrane using NaOH solution as an eluent was almost 90%after 5 cycles.The kinetic,isotherm and XPS analysis before and after adsorption suggested that adsorption via a combination of electrostatic interaction,complexation and precipitation contributed to the excellent separation by the as-obtained membranes.

关 键 词：Biochar-bentonitecomposite Dolomite doping Phosphate adsorption Polymericmatrixmembrane Adsorption-filtration dual functions Low-concentration phosphate 

分 类 号：O64[理学—物理化学]