铁硫改性生物炭去除水中的磷

Application of Iron and Sulfate-Modified Biochar in Phosphorus Removal from Water

磷元素向天然水体中的过度排放引发了严重环境问题.以吸附剂为技术核心的吸附法作为一种有效的除磷方法而受到研究人员的关注.本研究中,以壳聚糖、硫酸亚铁和硫化钠为改性剂研发的污泥生物炭对水中磷的去除效果良好.批次实验表明在最佳原料配比下,298 K时材料可吸附49.32 mg·g^(-1)的磷.此外,实验模拟表明材料对磷的吸附符合伪二级动力学和Langmuir模型;吸附速率主要受到孔隙内部三维扩散影响;吸附方式认定为物理化学吸附;吸附机制可概括为静电吸引、孔隙填充、表面化学沉淀、氢键结合和配位体效应.本研究证明了合成的材料是一种新型的高效除磷吸附剂,为吸附剂设计以及吸附机制的探讨提供借鉴.

The excessive discharge of phosphate into natural water has caused serious environmental problems. Adsorption is an efficient technology for phosphorus removal from water. In this study,a novel biochar modified by chitosan,ferrous sulfate,and sodium sulfide was synthesized and performed well in phosphorus adsorption. The results of batch experiments showed that the optimum synthesized composite could adsorb 49. 32 mg·g^(-1) of phosphate at 298 K. Meanwhile,the simulation results showed better fitting with the pseudo-second-order model and Langmuir model. The adsorption rate was dominated by three-dimensional diffusion within the inner pores. The adsorption process was defined as physic/chemisorption,while the adsorption mechanism was concluded to be electrostatic adsorption,porous filling,surface chemical precipitation,hydrogen binding,and the ligand effect. This study showed that the composite is effective in phosphorus removal from water,and we anticipate that our research will offer guidelines for adsorbent design and reveal the adsorption mechanism.