Solidification/stabilization of Dewatered Sludge with Multi-Component Solidifying Agents

Jun-Qiu Jiang¹, Kun Wang¹, Zi-Ye Li², Yang Li¹, Qing-Liang Zhao¹, Guang-Yi Liu¹

(1.Department of Municipal and Environmental ＆ Engineering, Harbin Institute of Technology, Harbin 150090, China; 2.Southwest Municipal Engineering Design ＆ Research Institute of China, Chengdu 610081, China)



Abstract:

This work experimentally examined the optimal proportioning of sludge curing agent for dewatered sludge curing on solidified sludge, two components sludge curing agent consisted of cement and slag, and three components consisted of cement, slag and inorganic salt. The results showed that, increasing of curing ages could increase unconfined compressive strength and reduce moisture content for solidified sludge. For the test of two components, the biggest unconfined compressive strength of the solidified sludge achieved to 543.72 kPa and the minimum moisture content achieved to 3.56％ of 21 d. The optimum proportion of the sludge curing agent of two components is sludge: cement: slag=1∶0.05∶0.2 which selected by Design-expert. It could rapidly increasing the unconfined compressive strength of solidified sludge when added three components sludge curing agent (sludge: cement: slag: MgSO₄=1∶0.05∶0.2∶0.03) on sludge curing. The results showed that, curing ages of 7 d, the unconfined compressive strength could achieve to 126.74 kPa, which was more than 11 times comparison with the solidified sludge curing by two components curing agent. Two or three components sludge curing agent all could stabilize the heavy metals on solidified sludge and the leaching of heavy metals was below the government standard, while the stability of the heavy metals was superior for three components sludge curing agent.

Key words:  dewatered sludge  solidification  curing agent  stabilization

DOI：10.11916/j.issn.1005-9113.2013.06.007

Clc Number:X705

Fund: