Abstract:In this study, to improve the dewatering performance of waste sludge, single-factor experiments on the oxalic acid, chitosan and CaO were applied to determine the range and levels of their various factors. The prediction model of water content of dewatered sludge (WC) reduction efficiency was established using the response surface methodology (RSM). In addition, this prediction model was calculated and solved using the computing method of particle swarm optimization (PSO), which was used to optimize the optimal ratio of oxalic acid, chitosan and CaO for regulating the ratio of sludge dewatering. Finally, the characteristics of extracellular polymeric substance (EPS) were deeply analyzed to learn the key mechanism of sludge dewatering. The results showed that the combined treatment of sludge dewatering with oxalic acid, chitosan and CaO can significantly improve the sludge dewatering performance. The optimum values for oxalic acid, chitosan and CaO were 0.377, 0.029 and 0.040g/g. Under this condition, the WC was 64.017%. And the prediction model fitted well (R2=0.9651). The model variance analysis showed that oxalic acid was the main factor influencing the WC. Dosage of oxalic acid had a significant positive correlation with soluble EPS (SL-EPS) contents. However, the opposite trend was demonstrated with tightly bound EPS (TB-EPS). The research results can provide technical and method references for improving the dewatering performance of waste sludge.
贺明星, 程文, 任杰辉, 万甜, 吕涛涛, 闫幸幸, 杨鹤云. 草酸、壳聚糖与CaO联合调理对污泥脱水性能的影响[J]. 中国环境科学, 2020, 40(7): 3029-3036.
HE Ming-xing, CHENG Wen, REN Jie-hui, WAN Tian, LÜ Tao-tao, YAN Xing-xing, YANG He-yun. Effects of dewatering performance of sludge under the co-conditioning of oxalic acid, chitosan and CaO. CHINA ENVIRONMENTAL SCIENCECE, 2020, 40(7): 3029-3036.
Yang G, Zhang G, Wang H. Current state of sludge production, management, treatment and disposal in China[J]. Water Research, 2015,78:60-73.
[2]
Wang Q L, Wei W, Gong Y Y, et al. Technologies for reducing sludge production in wastewater treatmentplants:State of the art[J]. Science of the Total Environment, 2017,587-588:510-521.
[3]
Zhang W J, Chen Z, Cao B D, et al. Improvement of wastewater sludge dewatering performance using titanium salt coagulants (TSCs) in combination with magnetic nano-particles:significance of titanium speciation[J]. Water Research, 2017,110:102-111.
[4]
张维宁,肖智华,马彬,等.过硫酸盐对城市污泥脱水和重金属去除的影响[J]. 中国环境科学, 2017,37(12):4605-4613. Zhang W N, Xiao Z H, Ma B, et al. Effects of persulfate oxidation on dewatering performance and removing heavy metals in municipal sludge[J]. China Environmental Science, 2017,37(12):4605-4613.
[5]
Guo J Y, Chen C. Sludge conditioning using the composite of a bioflocculant and PAC for enhancement in dewaterability[J]. Chemosphere, 2017,185:277-283.
[6]
牛美青,张伟军,王东升,等.不同混凝剂对污泥脱水性能的影响研究[J]. 环境科学学报, 2012,32(9):2126-2133. Niu M Q, Zhang W J, Wang D S, et al. Study on effect of chemical conditioning using different coagulants on sludge dewatering performance[J]. Acta Scientiae Circumstantiae, 2012,32(9):2126-2133.
[7]
郭俊元,文小英,羊润锦,等.玉米秸秆生物炭改善污泥脱水性能[J]. 中国环境科学, 2019,39(8):3316-3322. Guo J Y, Wen X Y, Yang R J, et al. Preparation of corn stalks biochar and improvement of dewatering performance of sludge[J]. China Environmental Science, 2019,39(8):3316-3322.
[8]
郑怀礼,陈新,黄文璇,等.改性壳聚糖絮凝剂及其应用研究进展[J]. 水处理技术, 2019,45(11):1-6. Zheng H L, Chen X, Huang W X, et al. Research progress of modified chitosan flocculant and its application[J]. Technology of Water Treatment, 2019,45(11):1-6.
[9]
毛玉红,冯俊杰,常青,等.壳聚糖助凝对PAC混凝过程的影响[J]. 中国环境科学, 2015,35(4):1096-1102. Mao Y H, Feng J J, Chang Q, et al. Influence of chitosan coagulat aid on the coagulation process of polyaluminum chloride[J]. China Environmental Science, 2015,35(4):1096-1102.
[10]
郭俊元,文小英,贾晓娟,等.磁性壳聚糖改善污泥脱水性能的研究[J]. 中国环境科学, 2019,39(7):2944-2952. Guo J Y, Wen X Y, Jia X J, et al. Preparation of magnetic chitosan and improvement of dewatering performance of sludge[J]. China Environmental Science, 2019,39(7):2944-2952.
[11]
Chen N, Tao S, Xiao K, et al. A one-step acidification strategy for sewage sludge dewatering with oxalic acid[J]. Chemosphere, 2020, 238:124598.
[12]
苏建文,郑浩,王彩冬,等.超声波或生石灰单独及联合作用对污泥脱水性能的影响[J]. 净水技术, 2014,33(3):48-51,57. Su J W, Zheng H, Wang C D, et al. Individual or combined effect of ultrasonic and calcium oxide on performance of sludge dewatering[J]. Water Purification Technology, 2014,33(3):48-51,57.
[13]
Tony M A, Zhao Y Q, Fu J F, et al. Conditioning of aluminium-based water treatment sludge with Fenton's reagent:Effectiveness and optimising study to improve dewaterability[J]. Chemosphere, 2008, 72(4):673-677.
[14]
邢奕,王志强,洪晨,等.芬顿试剂与DDBAC联合调理污泥的工艺优化[J]. 中国环境科学, 2015,35(4):1164-1172. Xing Y, Wang Z Q, Hong C, et al. Technological optimization of sludge conditioned by Fenton's reagent combined with surfactant[J]. China Environmental Science, 2015,35(4):1164-1172.
[15]
张丽平.粒子群优化算法的理论及实践[D]. 杭州:浙江大学, 2005. Zhang L P. The theorem and practice upon the particle swarm optimization algorithm[D]. Hangzhou:Zhejiang University, 2005.
[16]
孙洪伟,陈翠忠,高宇学,等.碳氮比对活性污泥胞外聚合物的长期影响[J]. 中国环境科学, 2018,38(3):950-958. Sun H W, Chen C Z, Gao Y X, et al. Effect of C/N ratio on extracellular polymeric substance (EPS) in the sequencing batch reactor (SBR)[J]. China Environmental Science, 2018,38(3):950-958.
[17]
袁冬琴,王毅力.活性污泥胞外聚合物(EPS)的分层组分及其理化性质的变化特征研究[J]. 环境科学, 2012,33(10):3522-3528. Yuan D Q, Wang Y L. Study on the stratification components of extracellular polymeric substances (EPS) in activated sludge and their variation characteristics in Physicochemical Properties[J]. Environmental Science, 2012,33(10):3522-3528.
[18]
夏晶,田永静,王骁,等.生物淋滤中硫粉对污泥EPS组分和脱水性的影响[J]. 中国环境科学, 2019,39(2):619-624. Xia J, Tian Y J, Wang X, et al. Effect of S0on fractions of EPS in sludge and dewaterability by bioleaching[J]. China Environmental Science, 2019,39(2):619-624.
[19]
段亮,夏四清,宋永会,等.活性污泥胞外聚合物提取动力学模型[J]. 中国环境科学, 2009,29(9):951-954. Duan L, Xia S Q, Song Y H, et al. Kinetics model of extracellular polymeric substances extraction[J]. China Environmental Science, 2009,29(9):951-954.
[20]
任杰辉,程文,万甜,等.缓冲液盐度对热提取活性污泥胞外聚合物的影响[J]. 环境科学学报, 2018,38(8):3054-3060. Ren J H, Cheng W, Wan T, et al. Effect of buffer salinity on heat extraction of extracellular polymeric substances from activated sludge[J]. Acta Scientiae Circumstantiae, 2018,38(8):3054-3060.
[21]
Dai Q, Ma L, Ren N, et al. Investigation on extracellular polymeric substances, sludge flocs morphology, bound water release and dewatering performance of sewage sludge under pretreatment with modified phosphogypsum[J]. Water Research, 2018,142:337-346.
[22]
邢奕,王志强,洪晨,等.基于RSM模型对污泥联合调理的参数优化[J]. 中国环境科学, 2014,34(11):2866-2873. Xing Y, Wang Z Q, Hong C, et al. Parameter optimization of sludge co-conditioning based on RSM model[J]. China Environmental Science, 2014,34(11):2866-2873.
[23]
Montgomery D C. Design and analysis of experiments[M]. New York:John Wiley, 1991:576-579.
[24]
杨维,李歧强.粒子群优化算法综述[J]. 中国工程科学, 2004, 6(5):87-94. Yang W, Li Q Q. Survey on particle swarm optimization algorithm[J]. Engineering Science, 2004,6(5):87-94.
[25]
易柯欣,邹长武,刘伟,等.基于粒子群算法的混合尘溯源解析技术改进[J]. 中国环境科学, 2015,35(11):3247-3250. Yi K X, Zou C W, Liu W, et al. Improvement of source apportionment by exploring origin of mixed dust source with particle swarm optimization[J]. China Environmental Science, 2015,35(11):3247-3250.
[26]
Li X Y, Yang S F. Influence of loosely bound extracellular polymeric substances (EPS) on the flocculation, sedimentation and dewaterability of activated sludge[J]. Water Research, 2007,41(5):1022-1030.
[27]
刘翔,黄映恩,刘燕,等.活性污泥和生物膜的胞外聚合物提取方法比较[J]. 复旦学报(自然科学版), 2011,50(5):556-562. Liu X, Huang Y E, Liu Y, et al, The comparison of effectiveness of different methods in extracting extracellular polymeric substance (EPS) from biofilm and activated sludge[J]. Journal of Fudan University (Natural Science), 2011,50(5):556-562.
[28]
Yu G H, He P J, Shao L M. Characteristics of extracellular polymeric substances (EPS) fractions from excess sludges and their effects on bioflocculability[J]. Bioresource Technology, 2009,100(13):3193-3198.
[29]
Ren J H, Cheng W, Wan T, et al. Characteristics of the extracellular polymeric substance composition in an up-flow biological aerated filter reactor:The impacts of different aeration rates and filter medium heights[J]. Bioresource Technology, 2019,289:121664.
[30]
何文远,杨海真,顾国维.酸处理对活性污泥脱水性能的影响及其作用机理[J]. 环境污染与防治, 2006,(9):680-682+706. He W Y, Yang H Z, Gu G W. Acid treatment of waste activated sludge for better dewaterability[J]. Environmental Pollution & Control, 2006,(9):680-682,706.
[31]
申亮.壳聚糖和溶菌酶联用强化污泥脱水性能研究[D]. 长沙:湖南大学, 2015. Shen L. Study on enhancing sludge waterability by combining chitosan with lysozyme[D]. Changsha:Hunan University, 2015.
[32]
林霞亮.壳聚糖复合调理剂改善污泥脱水性能的试验研究[D]. 广州:华南理工大学, 2015. Lin X L. Experimental study on effect of complex chitosan conditioners on sewage sludge dewatering[D]. Guangzhou:South China University of Technology, 2015.
[33]
李圭白,张杰.水质工程学[M]. 北京:中国建筑工业出版社, 2005:54-56. Li G B, Zhang J. Water quality engineering[M]. Beijing:China Architecture & Building Press, 2005:54-56.
[34]
李莉,张赛,何强,等.响应面法在试验设计与优化中的应用[J]. 实验室研究与探索, 2015,34(8):41-45. Li L, Zhang S, He Q, et al. Application of response surface methodology in experiment design and optimization[J]. Research and Exploration in Laboratory, 2015,34(8):41-45.
[35]
胡德秀,张艳,张聪.EDTA对剩余污泥磷释放及MAP法磷回收影响[J]. 中国环境科学, 2019,39(4):1611-1618. Hu D X, Zhang Y, Zhang C. Effects of EDTA on phosphorus release in excess sludge and phosphorus recovery by MAP[J]. China Environmental Science, 2019,39(4):1611-1618.
[36]
洪晨,邢奕,司艳晓,等.芬顿试剂氧化对污泥脱水性能的影响[J]. 环境科学研究, 2014,27(6):615-622. Hong C, Xing Y, Si Y X, et al. Influence of Fenton's reagent oxidation on sludge dewaterability[J]. Research of Environmental Sciences, 2014,27(6):615-622.
[37]
邢奕,王志强,洪晨,等.不同pH值下胞外聚合物对污泥脱水性能及束缚水含量的影响[J]. 工程科学学报, 2015,37(10):1387-1395. Xing Y, Wang Z Q, Hong C, et al. Influence of extracellular polymeric substances on sludge dewaterability and bound water content at various pH values[J]. Chinese Journal of Engineering, 2015,37(10):1387-1395.