Yi Man, Chen Yucheng
Chongqing Engineering Research Center of Rural Cleaning, Chongqing 400716, China and College of Resources & Environment, Southwest University, Chongqing 400715, China E-mail:
Water Sci Technol. 2018 Dec;78(11):2427-2436. doi: 10.2166/wst.2019.001.
Tobacco stems were used as precursors to prepare biochars (YGs) and develop Ca-Mg-loaded biochars (CMYGs) to enhance phosphate adsorption from aqueous solutions. Some influencing factors, such as pH, adsorption time, temperature, and structure characterization, were investigated. Fourier transform infrared (FTIR) spectra and X-ray diffraction (XRD) patterns showed several new peaks, indicating that Mg(OH) and MgO have been present on the surface of the CMYGs. The adsorption could reach equilibrium in 100 min reaction. The equilibrium data were well described by the Langmuir and Freundlich model. After five recycles, the phosphate removal capacity of CMYGs biochar retained over 50%. Moreover, the XRD and FTIR analyses showed that the phosphate sorption mechanisms involved surface electrostatic attraction, inner-sphere complexation and precipitation reactions. Overall, the soaking method could be used to effectively load Mg onto the surface of YGs. The CMYGs synthesized at 750 °C is a promising adsorbent for phosphate removal with a high adsorption capacity for phosphate-polluted wastewater.
烟草茎杆被用作前驱体来制备生物炭（YGs），并开发负载钙镁的生物炭（CMYGs）以增强对水溶液中磷酸盐的吸附。研究了一些影响因素，如pH值、吸附时间、温度和结构表征。傅里叶变换红外（FTIR）光谱和X射线衍射（XRD）图谱显示出几个新峰，表明CMYGs表面存在Mg(OH)和MgO。吸附在100分钟反应内可达到平衡。平衡数据用Langmuir和Freundlich模型能很好地描述。经过五次循环后，CMYGs生物炭的磷酸盐去除能力保持在50%以上。此外，XRD和FTIR分析表明，磷酸盐吸附机制涉及表面静电吸引、内球络合和沉淀反应。总体而言，浸泡法可有效将镁负载到YGs表面。在750°C合成的CMYGs是一种有前景的吸附剂，对含磷酸盐废水具有高吸附容量，可用于去除磷酸盐。
