The effects of combined ultrasound and low temperature thermal pretreatments on disintegration and anaerobic digestion of waste activated sludge
XU Hui-min1, HE Guo-fu1, DAI Xiao-hu2,3, XIANG Wei-ning1,4
1. College of Ecological and Environmental Science, East China Normal University, Shanghai 200241, China;
2. National Engineering Research Center for Urban Pollution Control, Shanghai 200092, China;
3. College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China;
4. Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, Shanghai 200241, China
To explore the effects of ultrasound and low temperature thermal pretreatments on anaerobic digestion of waste activated sludge (WAS), ultrasound, thermal, and combined (ultrasound+thermal) pretreatments were conducted. Taking temperature and specific energy as control parameters, disintegration degree of SCOD(DD) and organic disintegration before and after pretreatments were measured. Prior to anaerobic digestion, combined pretreatment significantly improved DD and soluble organic matter concentrations which were better than the sum of ultrasound and thermal pretreatments. The combination of ultrasound and thermal pretreatment under specific energy of 12000kJ/kg TS and temperature of 80℃, DD and soluble organic concentration were 4.04%、36.62mg/L higher than the sum of pretreatment alone. Besides, there was a highly linear relationship between DD and actual energies imparted to sludge (R2=0.977). Combined pretreatments improved the methane production of WAS during anaerobic digestion by 30.2%~55.4% than untreated sludge. It was also found that DD and anaerobic biodegradability had a conical relationship (R2=0.821). The optimum anaerobic biodegradability, 877.76LCH4/kg VSSremoved, was achieved with combined pretreatment at temperature of 80℃ and specific energy of 12000kJ/kg TS.
徐慧敏, 何国富, 戴晓虎, 象伟宁. 超声联合低温热水解促进剩余污泥破解和厌氧消化的研究[J]. 中国环境科学, 2016, 36(9): 2703-2708.
XU Hui-min, HE Guo-fu, DAI Xiao-hu, XIANG Wei-ning. The effects of combined ultrasound and low temperature thermal pretreatments on disintegration and anaerobic digestion of waste activated sludge. CHINA ENVIRONMENTAL SCIENCECE, 2016, 36(9): 2703-2708.
Tiehm A, Nickel K, Neis U. The use of ultrasound to accelerate the anaerobic digestion of sewage sludge[J]. Water Science and Technology, 1997,36(11):121-128.
[2]
中华人民共和国环境保护部.全国环境统计公报(2014年)[R]. 2015.
[3]
Tiehm A, Nickel K, Zellhorn M, et al. Ultrasonic waste activated sludge disintegration for improving anaerobic stabilization[J]. Water Research, 2001,35(8):2003-2009.
[4]
Carrère H, Dumas C, Battimelli A, et al. Pretreatment methods to improve sludge anaerobic degradability: A review[J]. Journal of Hazardous Materials, 2010,183(1-3):1-15.
[5]
Nickel K, Neis U. Ultrasonic disintegration of biosolids for improved biodegradation[J]. Ultrasonics Sonochemistry, 2007,14(4):450-455.
[6]
Jin Y, Li H, Mahar R B, et al. Combined alkaline and ultrasonic pretreatment of sludge before aerobic digestion[J]. Journal of Environmental Sciences, 2009,21(3):279-284.
Saha M, Eskicioglu C, Marin J. Microwave, ultrasonic and chemo-mechanical pretreatments for enhancing methane potential of pulp mill wastewater treatment sludge[J]. Bioresource Technology, 2011,102(17):7815-7826.
[9]
Bougrier C, Albasi C, Delgenès J P, et al. Effect of ultrasonic, thermal and ozone pre-treatments on waste activated sludge solubilisation and anaerobic biodegradability[J]. Chemical Engineering and Processing: Process Intensification, 2006,45(8):711-718.
Carlsson M, Lagerkvist A, Morgan-Sagastume F. The effects of substrate pre-treatment on anaerobic digestion systems: A review[J]. Waste Management, 2012,32(9):1634-1650.
[12]
Appels L, Degrève J, Van der Bruggen B, et al. Influence of low temperature thermal pre-treatment on sludge solubilisation, heavy metal release and anaerobic digestion[J]. Bioresource Technology, 2010,101(15):5743-5748.
[13]
Dhar B R, Nakhla G, Ray M B. Techno-economic evaluation of ultrasound and thermal pretreatments for enhanced anaerobic digestion of municipal waste activated sludge[J]. Waste Management, 2012,32(3):542-549.
[14]
Śahinkaya S, Sevimli M F. Sono-thermal pre-treatment of waste activated sludge before anaerobic digestion[J]. Ultrasonics Sonochemistry, 2013,20(1):587-594.
[15]
Trzcinski A P, Tian X, Wang C, et al. Combined ultrasonication and thermal pre-treatment of sewage sludge for increasing methane production[J]. Journal of Environmental Science and Health, Part A, 2015,50(2):213-223.
[16]
Kim D, Cho S, Lee M, et al. Increased solubilization of excess sludge does not always result in enhanced anaerobic digestion efficiency[J]. Bioresource Technology, 2013,143(0):660-664.
[17]
Wilson C A, Novak J T. Hydrolysis of macromolecular components of primary and secondary wastewater sludge by thermal hydrolytic pretreatment[J]. Water Research, 2009,43(18): 4489-4498.
[18]
Feng X, Lei H, Deng J, et al. Physical and chemical characteristics of waste activated sludge treated ultrasonically[J]. Chemical Engineering and Processing: Process Intensification, 2009,48(1):187-194.
[19]
Vlyssides A G, Karlis P K. Thermal-alkaline solubilization of waste activated sludge as a pre-treatment stage for anaerobic digestion[J]. Bioresource Technology, 2004,91(2):201-206.
[20]
Kim D, Youn Y. Characteristics of sludge hydrolysis by ultrasound and thermal pretreatment at low temperature[J]. Korean Journal of Chemical Engineering, 2011,28(9):1876-1881.