摘要
通过不同掺入量和养护龄期下矿渣基改性剂对城市污泥含水率的影响,采用X射线衍射、扫描电镜和热重分析方法表征矿渣基改性材料和干化污泥的水化产物和微观结构,探讨矿渣基改性材料对污泥干化的效果及机理。结果表明:随着矿渣基改性剂掺量的增加和养护龄期的延长,污泥含水率大幅减少;在相同条件下,矿渣基改性剂对污泥的干化效果明显好于生石灰。微观试验表明:改性剂遇水后,矿渣基改性材料中的SiO_(2)和Al_(2)O_(3)会在碱性条件下与污泥中的水发生水化反应,生成水化硅酸钙凝胶和钙矾石晶体,将大量自由水转化为结晶水,降低污泥中的含水率,同时也会填补污泥内部的孔隙,改变原污泥松散团聚的结构体系,使污泥牢固地联结成一个整体,有助于污泥的进一步资源化利用。
The effect and mechanism of municipal sludge drying with slag-based modified material were revealed by the study of moisture content at different contents of modified material and curing times.The hydration products and microstructure of slag-based modified material and the dried sludge were characterized by using X-ray diffraction analysis,scanning electron microscopy and thermogravimetric analysis.The results showed that the moisture content of dried sludge reduced gradually with the contents of modified material and curing age.The drying effect of slag-based modified material on sludge was better than that of quick lime at the same conditions.Microscopic experimental results indicated that insoluble calcium silicate hydrate gels and ettringite crystal were formed during the hydration process of slag-based modified materials at alkaline conation,transforming a lot of free water into crystalline water in order to reduce moisture content of sludge.Meanwhile,these hydration products filled the pores of sludge,inducing to a thorough from loose agglomerate structure system of original sludge to a firmly bonded structure with different phases.It is helpful to the further resource utilization of sludge.
作者
张发文
何禹龙
董明坤
赵长民
张雪娇
ZHANG Fawen;HE Yulong;DONG Mingkun;ZHAO Changmin;ZHANG Xuejiao(College of Forestry,Henan Agricultural University,Zhengzhou 450002,P.R.China;Zhengzhou Ecological Environment Monitoring Center of Henan Province,Zhengzhou 450007,P.R.China)
出处
《土木与环境工程学报(中英文)》
CSCD
北大核心
2022年第3期177-185,共9页
Journal of Civil and Environmental Engineering
基金
国家自然科学基金(51008118)
河南省高等学校重点科研项目(18B610001)
河南农业大学科技创新基金(KJCX2017A06)。
关键词
矿渣
城市污泥
干化
微观试验
改性材料
slag
municipal sludge
drying
microscopic experiment
modified material