环境工程学报2017，Vol.11Issue(7)：4331-4336,6.DOI:10.12030/j.cjee.201605202
高钙矾石改性剂对污泥孔隙结构的影响
Influence of pore structure change on high content of ettrigite modified sludge effect
摘要
Abstract
Sludge resources can be effectively utilized by controlling the sludge structure,a process that is usually realized using silicates as modifying agents.Much effort has been devoted to studying the mechanical effect and toxicity leaching of sludge solidified by silicates,whereas little attention has been paid to analyzing the sludge pore structure.In this study,the sludge was modified by four types of agents including High anorthite modifier S1 (Silicate Base,sulfur rich type),Modified S1 agent (S2,Silicate Base,low sulfur type),Portland cement,and Lime.The effects of the hydration products of these agents on the water content,porosity,and pore structure of the sludge were studied.Moreover,it was found that huge differences exists among hydration products once modifiers are added to the sludge.At the early stage of hydration,S1 produced complete needle-shaped ettringite or iron ettringite ～ 3 μm long.The hydration products of S2 were hexahedron-shaped calcium aluminate or calcium ferrite with diameter of ～ 3 μm.Ettringite,as the hydration product of cement,exhibited limited growth reflected by its incomplete,short shape (length ～3 μm).Lime had the hydration product Portlandite,with a sheet-like form and diameter around 10 μm.The needle-shaped ettringite promotes the uniform distribution of pores and structural damage in the sludge.When 20％ S1 (in relation to total content of sludge) was added to modify the sludge,the porosity of the sludge increased from 32.64％ to 49.14％,while its water content dropped to ＜ 30％ after curing for seven days under aerobic conditions.According to the experimental results,S1 effectively changed the pore structure of the sludge to facilitate evaporation of water from the sludge pores,thus improving the efficiency of sludge drying under ambient conditions.关键词
污泥/钙矾石/改性/孔隙结构Key words
sludge/ettrigite/modified/pore structure分类
资源环境引用本文复制引用
朱熙,李飞,宋永伟..高钙矾石改性剂对污泥孔隙结构的影响[J].环境工程学报,2017,11(7):4331-4336,6.基金项目
国家自然科学基金资助项目(51308076,51178172,51509087) （51308076,51178172,51509087）
中南财经政法大学青年教师创新项目(31541311313) （31541311313）
