This study evaluated the characteristics and mechanism of phosphate adsorption by fly ash discharged from a biomass thermal power plant (BTP-FA) under various environmental conditions in order to increase the recyclability of BTP-FA. The phosphate adsorption properties of BTP-FA and fly ash derived from coal thermal power plant (CTP-FA) were better matched by those predicted by the Langmuir isothermal model and the pseudo-second-order model, and their maximum adsorption capacities were 62.1 and 4.1 mg/g, respectively. It was found that the adsorption of phosphate by BTP-FA was predominantly influenced by the outer boundary layer rather than the inner diffusion in the pores. The phosphate adsorption process by BTP-FA was greatly influenced by the initial pH and the BTP-FA dose. Therefore, to effectively treat phosphate using BTP-FA, the concentration and flow rate of phosphate in the incoming wastewater must be considered. The concentration of dissolved calcium from BTP-FA decreased sharply during the phosphate adsorption process compared to that in the phosphate-free solution. This was thought to be due to surface adsorption/reaction between calcium and phosphate. The SEM–EDS and FTIR results also supported the surface adsorption/precipitation reaction of Ca-P. Recycling fly ash discharged from biomass power plants as phosphate adsorbents is expected to contribute not only to waste reduction, but also to wastewater purification.

中文翻译：

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生物质热电厂排放的粉煤灰对磷酸盐的吸附行为

这项研究评估了生物质热电厂（BTP-FA）在各种环境条件下排放的粉煤灰对磷酸盐的吸附特性和机理，以提高BTP-FA的可回收性。燃煤电厂的BTP-FA和粉煤灰的磷酸盐吸附特性（CTP-FA）与Langmuir等温模型和拟二阶模型预测的磷酸盐具有更好的匹配性，它们的最大吸附容量为62.1和分别为4.1 mg / g。已经发现，BTP-FA对磷酸盐的吸附主要受外边界层的影响，而不是受孔中内部扩散的影响。BTP-FA对磷酸盐的吸附过程受初始pH和BTP-FA剂量的影响很大。因此，要使用BTP-FA有效处理磷酸盐，必须考虑进水废水中磷酸盐的浓度和流速。与无磷酸盐溶液相比，在磷酸盐吸附过程中，BTP-FA中溶解钙的浓度急剧下降。认为这是由于钙和磷酸盐之间的表面吸附/反应所致。SEM-EDS和FTIR结果也支持Ca-P的表面吸附/沉淀反应。将从生物质发电厂排放的粉煤灰作为磷酸盐吸附剂进行回收，不仅有助于减少废物，而且还有助于废水净化。认为这是由于钙和磷酸盐之间的表面吸附/反应所致。SEM-EDS和FTIR结果也支持Ca-P的表面吸附/沉淀反应。将从生物质发电厂排放的粉煤灰作为磷酸盐吸附剂进行回收，不仅有助于减少废物，而且还有助于废水净化。认为这是由于钙和磷酸盐之间的表面吸附/反应所致。SEM-EDS和FTIR结果也支持Ca-P的表面吸附/沉淀反应。将从生物质发电厂排放的粉煤灰作为磷酸盐吸附剂进行回收，不仅有助于减少废物，而且还有助于废水净化。