Investigation of Microwave-Induced Thin-Layer Drying for Municipal Sludge

Abstract:

Since the adverse factors such as deficient penetration and long reaction time have restricted the complete microwave-used drying of municipal sludge, the microwave-induced drying was considered which has advantages in such aspects. The investigation of the microwave-induced drying to uncover the mechanism has great meaning for its development and usage. The experiments indicated that temperature was the decisive factor affecting the drying rate. The microwave-induced sludge reached the highest drying rate at the moisture rate of 40%, with a 20% grade promotion compared with that of the original one. The molecular fracture caused by microwave radiation had obviously accelerated the drying process and the drying rate was rising in proportion to the microwave radiation dose. The diffusion coefficient of microwave-induced sludge was obviously enlarged more than 2 times grade. In this research, model Weibull proved to fit the experiment of thin-layer drying for municipal sludge best compared with the other ones.

• Periodical: Advanced Materials Research (Volumes 518-523)
• Pages: 3227-3230
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.518-523.3227
• Online since: May 2012
• Authors: He Xun Huang, Han Ping Chen, Zhi Feng Hu, Xiao Qian Ma
• Keywords: Drying Model, Effective Diffusion Coefficient, Municipal Sludge, Thin-Layer Drying

References

[1] Kaijun Wang, Insist on correctly technology direction steady promoting sludge treatment and disposal work, Water & Wastewater Engineering, 2010. 36(10):1-3, 18.

[2] Shaozhen Xie, Xiaobin Zheng, Chunxiu Xu, Analysis on the Ingredients of the Sludge and its Recycle in Sewage Treatment Plant , Guangzhou Chemical Industry, 2006. 34(2):54-57.

[3] Xiangjuan Kong, Qiang He, Hong-xiang Cai, Technological status and development for Sludge Treatment and Disposal in Municipal Wastewater Treatment Plant, Construction Science And Technology, 2009(19):57-59.

[4] W.A.M McMinn, Thin-layer modelling of the convective, microwave, microwave-convective and microwave-vacuum drying of lactose powder, Journal Of Food Engineering, 2006, 72(2):113-123.

DOI: 10.1016/j.jfoodeng.2004.11.025

[5] D.G. Prabhanjan, H.S. Ramaswamy and G.S.V. Raghavan, Microwave-assisted convective air drying of thin layer carrots, Journal Of Food Engineering, 1995. 25(2):283-293.

DOI: 10.1016/0260-8774(94)00031-4

[6] Z W Cui, S Y Xu and D W Sun, Microwave-vacuum drying kinetics of carrot slices, Journal Of Food Engineering, 2004. 65(2):157-164.

DOI: 10.1016/j.jfoodeng.2004.01.008

[7] B.Özbek, and G. Dadali, Thin-layer drying characteristics and modelling of mint leaves undergoing microwave treatment, Journal Of Food Engineering, 2007. 83(4): 541-549.

DOI: 10.1016/j.jfoodeng.2007.04.004

[8] I.A. Ozkan, B. Akbudak, and N. Akbudak, Microwave drying characteristics of spinach, Journal Of Food Engineering, 2007. 78(2):577-583.

DOI: 10.1016/j.jfoodeng.2005.10.026

[9] Chaolun Xiao, Jiali Tang, Feng PAN, et.al., Effect of microwave irradiation on the penetrability and dewaterability of dewatered municipal sewage sludge, The Chinese Journal Of Process Engineering, 2011, 11(2):215-220.