School of Water Conservancy and Civil Engineering, Northeast Agricultural University, Harbin 150030, China.
School of Water Conservancy and Civil Engineering, Northeast Agricultural University, Harbin 150030, China.
J Hazard Mater. 2019 Mar 5;365:665-673. doi: 10.1016/j.jhazmat.2018.11.047. Epub 2018 Nov 17.
Highly efficient and cost-effective adsorbents for phosphate (P) recovery are the key to control eutrophication and recover phosphorus from waste streams to enhance food production. This study assembled corn stalk-derived biochar (BC) with various forms of layered double hydroxides (LDHs) (B-M-LDH) through simultaneous pyrolysis of waste biomass and metal (i.e., Zn/Al, Mg/Al, and Ni/Fe) hydroxide precipitates. Batch sorption experiments evaluated the kinetics and isotherms of phosphate adsorption as well as the influence of pH value and co-existing anions. Morphological characterization showed that crystalline LDH flakes were impregnated within the framework of fabricated B-M-LDH composites. Superior P adsorption capacity (152.1 mg (P) g) and fast Elovich kinetics (5925 mg g h) could be achieved by the B-Zn/Al-LDH composite at pH 5. The P adsorption onto BC-LDHs was pH dependent and subjected to adverse influence of co-existing anions. Interlayer anion exchange and surface complexation were probably the predominant adsorption mechanisms at the studied phosphate concentration. Therefore, BC can be functionalized as mineral composites for enhancing P recovery and wastewater treatment.
高效且经济实用的磷（P）吸附剂是控制富营养化和从废水中回收磷以提高粮食产量的关键。本研究通过废生物质与金属（即 Zn/Al、Mg/Al 和 Ni/Fe）氢氧化物沉淀的同步热解，将玉米秸秆衍生的生物炭（BC）与各种形式的层状双氢氧化物（LDHs）（B-M-LDH）组装在一起。批处理吸附实验评估了磷酸盐吸附的动力学和等温线以及 pH 值和共存阴离子的影响。形态特征表明，结晶 LDH 薄片浸渍在制备的 B-M-LDH 复合材料的骨架中。在 pH 5 下，B-Zn/Al-LDH 复合材料可实现优异的磷吸附容量（152.1 mg（P）g）和快速的 Elovich 动力学（5925 mg g h）。BC-LDHs 上的磷吸附受 pH 值影响，并受到共存阴离子的不利影响。层间阴离子交换和表面络合可能是在研究的磷酸盐浓度下的主要吸附机制。因此，BC 可以官能化为矿物复合材料，以增强磷的回收和废水处理。
