秸秆粉煤灰基颗粒填料激发水化与除磷耦合机理研究
Coupling mechanism of induced hydration and phosphorus removal with straw fly ash-based granular fillers
马海涛 1代鸿刚 1吴军 1郭小境 1吕宜廉 1陈轶凡 1潘周志 1余书瑶 1高林燕 1寿文琪 1苏子龙 1宋立杰2
作者信息
- 1. 南京大学环境学院污染控制与资源化研究国家重点实验室,南京,210023
- 2. 上海环境卫生工程设计院有限公司,上海,200232
- 折叠
摘要
粉煤灰添加水泥、生石灰和秸秆等辅料利用团粒、喷水养护并结合煅烧成孔的方式制备弱碱激发颗粒填料.颗粒填料在间歇循环流态化完全混合反应器中进行除磷实验,通过比较除磷组和对照组(超纯水)中颗粒填料的抗压强度、结合水含量以及粉煤灰反应程度研究除磷过程对粉煤灰水化进程的影响,反应产物(凝胶态)Al含量、未反应粉煤灰(残余态)Al含量以及磷形态及含量研究粉煤灰玻璃体中Al的激发规律以及激发水化与除磷过程耦合机理.研究结果表明,粉煤灰激发水化和除磷反应同步进行,难溶磷酸钙的形成有利于Ca(OH)2溶解释放OH-,促进粉煤灰玻璃体解构释放活性Al2O3和SiO2等除磷和水化活性物质,所释放的活性物质可以在Ca(OH)2存在的情况下发生火山灰反应,生成水化硅酸钙和水化铝酸钙等水化产物,进而实现长期有效除磷.同时活性Al2O3可以发挥较大的除磷作用,Al-P含量占填料内总磷含量的比例可达40％左右.
Abstract
The fly ash is added with auxiliary materials such as cement,quicklime and straw,and the weak alkali excited particle filler is prepared by agglomeration,water spray curing and combined with calcination to form pores.The granular packing is subjected to phosphorus removal experiments in a batch cyclic fluidized complete mixing reactor.The effect of phosphorus removal process on fly ash hydration process was studied by comparing the compressive strength,bound water content and fly ash reaction degree of granular fillers in phosphorus removal group and control group(ultrapure water).The activated law of Al in fly ash vitreous and the coupling mechanism of activated hydration and phosphorus removal processes were studied by comparing the Al content of reaction products(gel state),unreacted fly ash(residual state)Al content,and phosphorus speciation and content.The results show that the activated hydration and phosphorus removal of fly ash are synchronized.In this process,the formation of insoluble calcium phosphate is conducive to the electrolytic release of OH-from Ca(OH)2,then promote the release of active phosphorus removal and hydration active substances such as Al2O3 and SiO2 from fly ash glass phase,the released active material can undergo volcanic ash reaction in the presence of Ca(OH)2 to generate hydrated products such as calcium silicate hydrate and calcium aluminate hydrate,thereby achieving long-term effective phosphorus removal.The active Al2O3 can play a large phosphorus removal effect,and the proportion of Al-P content in the total phosphorus content in the filler can reach about 40％.
关键词
粉煤灰/水化反应/除磷/耦合机理Key words
fly ash/hydration reaction/phosphorus removal/coupling mechanism引用本文复制引用
基金项目
国家重点研发计划"固废资源化"重点专项(2018YFC1901404)
出版年
2024
NETL
NSTL
万方数据