摘要
使用无机絮凝剂聚合氯化铝和氯化铁对污泥进行预处理,研究无机絮凝剂对污泥屈服应力的影响机理,并阐明计算污泥屈服应力的最佳方法。结果表明,无机絮凝剂的添加提高了污泥絮体的强度,导致屈服应力显著增加。根据剪切速率由低到高扫描的稳态实验计算的动态屈服应力(τdi),比经过预剪切且剪切速率由高到低扫描计算出的动态屈服应力(τdd)高出50%~67%。利用动态应变扫描实验,将弹性模量降低为初始值10%时对应的应变值作为屈服应变点,更能揭示污泥固相特性的本质,根据其计算得到的静态屈服应力τs10更接近于真实值,且τs10与τdd接近。然而τs10的计算过程相对复杂,因此生产实践中可以考虑用τdd代替τs10。
Inorganic flocculant polyaluminium chloride and ferric chloride were employed to treat sludge for revealing their effect on the yield stress, and the optimum calculation method of yield stress was clarified. Results show that inorganic flocculant can improve the floc strength, lead to the higher yield stress. The dynamic yield stress(τdi) was calculated based on the steady test that the shear rate sweeps from low to high, and τddwas calculated by the shear rate sweeping from high to low. It was showed that τdiwas50%-67% higher than τdd. The static yield stress(τs10), obtained from strain sweep test where the yield strain point was determined as the elastic modulus reduced by 10%, could reveal the solid nature of sludge successfully and was close to the true value. Andτs10 was similar with τdd. While the calculation of τs10 was complicated relatively, so it may be considered that τs10 could be replaced by τddin practice.
作者
冯国红
胡智
白天添
FENG Guohong;HU Zhi;BAI Tiantian(School of Environment&.Safety,Taiyuan University of Science&.Technology,Taiyuan 030024,Shanxi,China)
出处
《武汉大学学报（理学版）》
CAS
CSCD
北大核心
2020年第4期354-360,共7页
Journal of Wuhan University:Natural Science Edition
基金
国家自然科学基金青年科学基金(21606157)
山西省青年科技研究基金(2015021034)
太原科技大学教学改革创新项目(201938)。
关键词
无机絮凝剂
聚合氯化铝
氯化铁
污泥
屈服应力
触变
inorganic flocculant
polyaluminium chloride
ferric chloride
sludge
yield stress
thixotropy
作者简介
冯国红,女,博士,副教授.现从事非均相固液分离、污泥减量化及综合利用研究。E-mail:jiin73063315@163.com.
