Chemicalthermal pretreatment and subsequent anaerobic digestion of sludge with low organic content

doi:10.11949/j.issn.0438-1157.20161235

Abstract

Abstract:

The large amounts of municipal sludge are generated from waste water treatment plants.The organic compounds in sludge are helpful for methane production. While the most of municipal sludge in China is of low organic matter. Thus this paper explored the effect of different additive agents combined with thermal hydrolysis on organics solubilization of sludge with low organic and subsequent anaerobic digestion. The results showed that additive combined with low temperature thermal hydrolysis is helpful not only for the dissolution and the production of organics, including soluble sugar, soluble protein and TVFA(total volatile organic acids) but also for anaerobic digestion. The effect of organic dissolution under the thermal pretreatment condition(the solid content, the temperature and the time were 8%, 90℃ and 24 h, respectively) and the additive concentration[the concentration of NaOH, Ca(OH)₂ and CaCl₂ were 0.018 g·(g DS)^-1, 0.016 g·(g DS)^-1 and 0.0375(g·g DS)^-1, respectively] was arranged in descending order, which were NaOH, Ca(OH)₂ and CaCl₂ in turn, namely the addition of NaOH had obvious effects on soluble sugar, soluble protein and TVFA, and the concentrations were 3051 mg·L^-1, 10686 mg·L^-1 and 5740 mg·L^-1 respectively. The ranking of efficiency of anaerobic digestion was NaOH, CaCl₂ and Ca(OH)₂ in turn, and the maximum gas production was acquired and up to 101.9 ml·(g VS)^-1 with the addition of NaOH.

Key words: sludge, low organic content, chemicalthermal pretreatment, anaerobic digestion

摘要：

污水厂污泥量日益增加，所含的有机物可用于厌氧发酵产甲烷，但目前多数污水处理厂多为低有机质污泥。本文围绕低有机质污泥投加不同药剂联合低温热水解对污泥溶解性物质变化及厌氧发酵规律的影响情况进行研究。结果表明，投加药剂联合低温热水解不仅有助于有机物[可溶糖、可溶蛋白和TVFA（挥发性有机酸（]的溶出与生成，而且有助于后续厌氧发酵产甲烷。在本实验所研究的低温热水解（污泥含固率为8%，热水解处理温度为90℃，处理时间为24 h）及药剂投加量[NaOH：0.018 g·（g DS（^-1、Ca（OH（₂：0.016 g·（g DS（^-1、CaCl₂：0.0375g·（g DS（^-1]的条件下，有机物溶出与生成的效果为NaOH> Ca（OH（₂> CaCl₂，其中热水解联合NaOH中可溶糖、可溶蛋白和TVFA浓度分别达到3051 mg·L^-1、10686 mg·L^-1和5740 mg·L^-1。对于产甲烷促进效果为NaOH> CaCl₂> Ca（OH（₂，其中投加NaOH后最大累积产甲烷量可达到101.9 ml·（g VS（^-1。

关键词: 污泥, 低有机质, 药剂联合低温热水解, 厌氧发酵

CLC Number:

X799.3

LIU Changqing, WANG Yulan, LIN Hong, ZHAO Youcai, ZHENG Yuyi, WU Chunshan. Chemicalthermal pretreatment and subsequent anaerobic digestion of sludge with low organic content[J]. CIESC Journal, 2017, 68(4): 1608-1613.

刘常青, 王玉兰, 林鸿, 赵由才, 郑育毅, 吴春山. 低有机质污泥投加药剂联合低温热水解及后续厌氧发酵研究[J]. 化工学报, 2017, 68(4): 1608-1613.

References 36

[1]	?AHINKAYA S, SEVIMLI M F. Sono-thermal pretreatment of waste activated sludge before anaerobic digestion[J]. Ultrasonics Sonochemistry, 2013, 20(1):587-594.
[2]	高永青, 彭永臻, 王建龙, 等. 剩余污泥水解酸化过程中胞外聚合物的影响因素研究[J]. 中国环境科学, 2010, 30(1):58-63. GAO Y Q, PENG Y Z, WANG J L, et al. Influential factors of extracellular polymer substances in activated sludge hydrolysis and acidification[J]. China Environment Science, 2010, 30(1):58-63.
[3]	COLIN F, GAZBAR S. Distribution of water in sludges in relation to their mechanical dewatering[J]. Water Research, 1995, 29(8):2000-2005.
[4]	NEYENS E, BAEYENS J. A review of thermal sludge pre-treatment processes to improve dewaterability[J]. Journal of Hazardous Materials, 2003, 98(1/2/3):51-67.
[5]	MARTINS S I F S, JONGEN W M F, BOEKEL M A J S V. A review of Maillard reaction in food and implications to kinetic modeling[J]. Trends in Food Science & Technology, 2000, 11 (9/10):364-373.
[6]	XUE Y, LIU H, CHEN S, et al. Effects of thermal hydrolysis on organic matter solubilization and anaerobic digestion of high solid sludge[J]. Chemical Engineering Journal, 2015, 264:174-180.
[7]	APPELS L, DEGRÈVE J, UGGEN B V D, 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.
[8]	LIAO X C, LI H, ZHANG Y Y, et al. Accelerated high-solids anaerobic digestion of sewage sludge using low-temperature thermal pretreatment[J]. International Biodeterioration & Biodegradation, 2016, 106:141-149.
[9]	刘巍, 蒲文晶, 饶辉凯, 等. 低温热水解提高污泥厌氧消化性能的研究[J]. 油气田环境保护, 2014, 24(2):38-40.LIU W, PU W J, RAO H K, et al. Research on the enhancement of sludge anaerobic digestibility by low-temperature thermal hydrolysis[J]. Environmental Protection of Oil & Gas Fields, 2014, 24(2):38-40.
[10]	BOUGRIER C, DELGENÈS J P, CARRÈRE H. Effects of thermal treatments on five different waste activated sludge samples solubilisation, physical properties and anaerobic digestion[J]. Chemical Engineering Journal, 2008, 139 (2):236-244.
[11]	ZHANG S, GUO H, DU L, et al. Influence of NaOH and thermal pretreatment on dewatered activated sludge solubilisation and subsequent anaerobic digestion:focused on high-solid state[J]. Bioresource Technology, 2015, 185:171-177.
[12]	SUN R, XING D, JIA J, et al.Methane production and microbial community structure for alkaline pretreated waste activated sludge[J]. Bioresource Technology, 2014, 169(5):496-501.
[13]	LI H, LI C, LIU W, et al. Optimized alkaline pretreatment of sludge before anaerobic digestion[J]. Bioresource Technology, 2012, 123(3):189-194.
[14]	RAJAN R V, RAY B T. Low-level chemical pretreatment for enhanced sludge solubilization[J]. Research Journal of the Water Pollution Control Federation, 1990, 61(11/12):1678-1683.
[15]	CHEN W H, HAN S K, SUNG S. Sodium inhibition of thermophilic methanogens[J]. Journal of Environmental Engineering, 2003, 129(6):506-512.
[16]	陈蓓蓓. 碱热处理破解污泥效果及脱水性能研究[D]. 合肥:安徽工业大学, 2013.CHEN B B. Investigation on sludge hydrolysis and dewaterability by alkaline-thermal treatment[D]. Hefei:Anhui University of Technology, 2013.
[17]	于洁. 热水解联合氯化钙改善活性污泥脱水性能[D]. 杭州:浙江大学, 2013.YU J. Improvement of activated sludge dewaterability by thermal hydrolysis with calcium chloride[D]. Hangzhou:Zhejiang University, 2013.
[18]	LI H, JIN Y, MAHAR R B, et al. Effects and model of alkaline waste activated sludge treatment[J]. Bioresource Technology, 2008, 99 (11):5140-5144.
[19]	SMITH G, GORANSSON J. Generation of an effective internal carbon source for denification through thermal hydrolysis of pre-precipitated sludge[J]. Water Science and Technology, 1992, 25(4/5):211-218.
[20]	NEYENS E, BAEYENS J, CREEMERS C.Alkaline thermal sludge hydrolysis[J]. Journal of Hazardous Materials, 2003, 97(1/2/3):295-314.
[21]	宜慧, 韩芸, 李玉友, 等. 碱解+低温水热预处理改善剩余污泥中温厌氧消化性能工艺[J]. 环境工程学报, 2014, 8(9):3927-3932.YI H, HAN Y, LI Y Y, et al. Enhancement of mesophilic anaerobic digestion of waste activated sludge using alkaline-low temperature thermal pretreatment[J]. Chinese Journal of Environmental Engineering, 2014, 8(9):3927-3932.
[22]	TANAKA S, KOBAYASHI T, KAMIYAMA K I, et al. Effects of thermochemical pretreatment on the anaerobic digestion of waste activated sludge[J]. Water Science & Technology, 1997, 35(8):209-215.
[23]	郑育毅, 林鸿, 林志龙, 等. 不同碱剂对污泥与餐厨垃圾联合厌氧发酵产氢余物产甲烷的影响[J]. 环境工程学报, 2016, 10(1):393-398.ZHENG Y Y, LIN H, LIN Z L, et al. Impact of different alkali agents on methanogenesis of residue from anaerobic fermentative hydrogen production using combined sludge and food waste[J]. Chinese Journal of Environmental Engineering, 2016, 10(1):393-398.
[24]	FANG W, ZHANG P, ZHANG G. Effect of alkaline addition on anaerobic sludge digestion with combined pretreatment of alkaline and high pressure homogenization[J]. Bioresource Technology, 2014, 168(3):167-172.
[25]	LIN J G, CHANG C N, CHANG S C. Enhancement of anaerobic digestion of waste activated sludge by alkaline solubilization[J]. Bioresource Technology, 1997, 62(3):85-90.
[26]	AHN J H, DO T H, KIM S D, et al. The effect of calcium on the anaerobic digestion treating swine wastewater[J]. Biochemical Engineering Journal, 2006, 30(1):33-38.
[27]	奚旦立. 环境监测[M]. 北京:高等教育出版社, 1996.XI D L. Environmental Monitoring[M]. Beijing:Higher Education Press, 1996.
[28]	林加涵, 魏文玲, 彭宣宪. 现代生物学实验[M]. 北京:高等教育出版社, 2001.LIN J H, WEI W L, PENG X X. Modern Biology Experiment[M]. Beijing:Higher Education Press, 2001.
[29]	任南琪, 马放. 污染控制微生物学原理与应用[M]. 北京:化学工业出版社, 2003.REN N Q, MA F. Pollution Control Microbiology Principle and Application[M]. Beijing:Chemical Industry Press, 2003.
[30]	陆源. 市政污泥预处理厌氧发酵产氢机理研究[D]. 福州:福建师范大学, 2014. LU Y. The mechanism of biohydrogen production by anaerobic fermentation using pretreated municipal sludge[D]. Fuzhou:Fujian Normal University, 2014.
[31]	陈晓玲. 城市污泥厌氧发酵产酸条件优化及其机理研究[D]. 无锡:江南大学, 2008. CHEN X L. The condition optimization of sewage for producing volatile fatty acids and the investigation of acidogenic mechanism[D]. Wuxi:Jiangnan University, 2008.
[32]	HIGGINS M J, NOVAK J T. The effect of cations on the settling and dewatering of activated sludges:laboratory results[J]. Water Environment Research, 1997, 69(2):215-224.
[33]	HIGGINS M J, NOVAK J T. Characterization of exocellular protein and its role in bioflucculation[J]. Journal of Environment Engineering, 1997, 123(5):479-485.
[34]	URBAINETAL V. Bioflocculation in actived sludge:an analystic approach[J]. Water Research, 1993, 27(5):829-838.
[35]	ROY R, CONRAD R. Effect of methanogenic precursors (acetate, hydrogen, propionate) on the supression of methane production by nitrate in anoxic rice field soil[J]. FEMS Microbiology Ecology, 1999, 28(1):49-61.
[36]	KOSTER I W, LETTINGA G. The influence of ammonium-nitrogen on the specific activity of pelletized methanogenic sludge[J]. Agricultural Wastes, 1984, 9(3):205-216.