Liu Yanfang, Gao Wei, Liu Rui, Zhang Wenjing, Niu Jianrui, Lou Xiaoyue, Li Gong, Liu Haoyun, Li Zaixing
School of Environmental Science and Engineering, Hebei University of Science and Technology, Shijiazhuang, China.
Pollution Prevention Biotechnology Laboratory of Hebei Province, Shijiazhuang, China.
Water Environ Res. 2022 Jul;94(7):e10763. doi: 10.1002/wer.10763.
A phosphorus removal biochar adsorbent was prepared from Fenton sludge. The adsorption process was optimized, and its phosphorus adsorption mechanism was discussed. It was found that the phosphorus adsorption performance of biochar prepared from single Fenton sludge (FBC-400) was better than that of co-pyrolysis of Fenton sludge and bamboo powder. The optimum condition was that Fenton sludge pyrolyzed at 400°C (FBC-400). FBC-400 had a larger specific surface area than that prepared by co-pyrolysis with bamboo powder. And the high content of iron element could provide a higher surface charge of the biochar, thereby increasing the electrostatic adsorption of phosphorus onto FBC-400. The phosphorus adsorption was highly pH dependent by FBC-400, which can enhance electrostatic adsorption and increase adsorption capacity in acidic conditions. The effect of coexisting anion on adsorption performance was mainly affected by CO , reducing the adsorption capacity by at least 49%, whereas other anions had no obvious interference. The adsorption process of FBC-400 accorded with the pseudo-second-order kinetic model and the Langmuir model, which indicated that the adsorption process was monolayer adsorption and mainly chemical adsorption, and the maximum saturated phosphorus adsorption capacity was 8.77 mg g . The mechanisms for phosphorus adsorption were electrostatic adsorption and inner-sphere complexing. 1 M NaOH was used for desorption, and the adsorption capacity remained at 81% in the fifth cycle. PRACTITIONER POINTS: The Fenton sludge biochar usage as an adsorbent could be a win-win strategy to convert waste biomass to valuable - product. The adsorption process accorded with the Langmuir model, the maximum phosphorus adsorption capacity was 8.77 mg/g at 25°C. The adsorption mechanisms were electrostatic adsorption and inner-sphere complexing. 1M NaOH was used for desorption, and the adsorption capacity remained at 81% in the fifth cycle.
以芬顿污泥为原料制备了一种除磷生物炭吸附剂。对吸附过程进行了优化，并探讨了其磷吸附机理。结果发现，单一芬顿污泥制备的生物炭（FBC - 400）的磷吸附性能优于芬顿污泥与竹粉共热解制备的生物炭。最佳条件是芬顿污泥在400℃下热解（FBC - 400）。FBC - 400比与竹粉共热解制备的生物炭具有更大的比表面积。并且铁元素的高含量能够为生物炭提供更高的表面电荷，从而增加磷在FBC - 400上的静电吸附。FBC - 400对磷的吸附高度依赖于pH值，在酸性条件下可增强静电吸附并提高吸附容量。共存阴离子对吸附性能的影响主要受碳酸根影响，使吸附容量至少降低49%，而其他阴离子无明显干扰。FBC - 400的吸附过程符合准二级动力学模型和朗缪尔模型，表明吸附过程为单层吸附且主要是化学吸附，最大饱和磷吸附容量为8.77 mg/g。磷吸附的机制为静电吸附和内层络合。采用1 M NaOH进行解吸，在第五个循环中吸附容量仍保持在81%。从业者要点：将芬顿污泥生物炭用作吸附剂可能是一种将废弃生物质转化为有价值产品的双赢策略。吸附过程符合朗缪尔模型，在25℃下最大磷吸附容量为8.77 mg/g。吸附机制为静电吸附和内层络合。采用1 M NaOH进行解吸，在第五个循环中吸附容量仍保持在81%。
