Abstract:To realize deep-dewatering of municipal sewage sludge, the combined alternating electric field (AEF) electroosmosis technology was developed with iron modified biomass as the skeleton for disposal of sludge. Based on a single-factor experiment, the effect of the combined technology on sludge dewatering behavior was studied. Moreover, technical parameters of sludge dewatering were optimized with the response surface method (RSM). After mixing the sludge with corn stalks modified by FeCl3 of 0.03g/mL, in the AEF of unequal duty cycle at 4.33:1, voltage at 17.22V/cm, modified biomass dosage at 96.81mg/g DS, modified biomass moisture at 61.91%, biomass particle size at 1.05mm, and anode-cathode distance at 2.10cm, the dewatered sludge with a moisture content of 58.21% could be obtained, and the dewatering energy consumption was 0.0148kW·h/kg RW (Removed water). According to scanning electron microscope (SEM) characterization of the dewatered sludge, iron modified biomass well supports the sludge as the skeleton, which was conducive to the mechanical strength and permeability of the sludge. According to thermogravimetric analysis (TGA), the upper and lower combustion process in the dewatered sludge could be divided into the stage of precipitation of free water and bond water, the stage of precipitation and combustion of volatile, and the stage of decomposition of inorganic salts. The dewatered sludge mixed with iron modified biomass showed higher organic content and faster combustion.
李亚林, 陈高昂, 孙丽莉, 王恩赐, 宋雨晴, 孙趁心. 交变电场-铁改性生物质强化城市污泥深度脱水[J]. 中国环境科学, 2022, 42(7): 3140-3148.
LI Ya-lin, CHEN Gao-ang, SUN Li-li, WANG En-ci, SONG Yu-qing, SUN Chen-xin. Alternating electric field combined with iron-modified biomass to enhance the deep-dewatering of municipal sludge. CHINA ENVIRONMENTAL SCIENCECE, 2022, 42(7): 3140-3148.
戴晓虎.我国污泥处理处置现状及发展趋势[J].科学, 2020, 72(6):30-34. Dai X H. Applications and perspectives of sludge treatment and disposal in China[J]. Science, 2020,72(6):30-34.
[2]
Conraydy J, Vaxelaire J, Olivier J. Electro-dewatering of activated sludge:Electrical resistance analysis[J]. Water Research, 2016,100:194-200.
[3]
Deng W, Lai Z, Hu M, et al. Effects of frequency and duty cycle of pulsating direct current on the electro-dewatering performance of sewage sludge[J]. Chemosphere, 2020,243:125372.
[4]
Qian X, Zhou X, Wu J, et al. Electro-dewatering of sewage sludge:Influence of combined action of constant current and constant voltage on performance and energy consumption[J]. Science of the Total Environment, 2019,667:751-760.
[5]
Xiao J, Wu X, Yu W, et al. Migration and distribution of sodium ions and organic matters during electro-dewatering of waste activated sludge at different dosages of sodium sulfate[J]. Chemosphere, 2017,189:67-75.
[6]
Guo X, Wang Y, Wang D. Permanganate/bisulfite (PM/BS) conditioning-horizontal electro-dewatering (HED) of activated sludge:Effect of reactive Mn (III) species[J]. Water Research, 2017,124:584-594.
[7]
Guo S, Liang H, Bai L, et al. Synergistic effects of wheat straw powder and persulfate/Fe (II) on enhancing sludge dewaterability[J]. Chemosphere, 2019,215:333-341.
[8]
Wu J, Lu T, Bi J, et al. A novel sewage sludge biochar and ferrate synergetic conditioning for enhancing sludge dewaterability[J]. Chemosphere, 2019,237:124339.
[9]
Liu H, Xiao H, Fu B, et al. Feasibility of sludge deep-dewatering with sawdust conditioning for incineration disposal without energy input[J]. Chemical Engineering Journal, 2017,313:655-662.
[10]
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.
[11]
杨艳坤,李激,陈晓光,等.竹粉骨架构建体对污泥脱水性能的影响[J].中国给水排水, 2017,33(19):63-67. Yang Y K, Li J, Chen X G. Effect of using bamboo powder as skeleton builder on sludge dewatering processs[J]. China Water&Wastewater, 2017,33(19):63-67.
[12]
李修渠,李里特,植村邦彦,等.不同电场下豆渣的电渗透脱水[J].农业工程学报, 2000,16(3):100-103. Li X Q, Li L T, Kunihiko U, et al. Electroosmotic dewatering of Okaro in different electric fields[J]. Transactions of the Chinese Society of Agricultural Engineering, 2000,3:100-103.
[13]
李亚林,刘蕾,周涛,等.电渗透交变电场联合双氧化技术污泥深度脱水研究[J].现代化工, 2020,40(8):180-184. Li Y L, Liu L, Zhou T, et al. Study on deep-dewatering of sludge by electro-osmosis under alternating electric field combined with double oxidation technology[J]. Modern Chemical Industry, 2020,40(8):180-184.
[14]
Yu W, Yang J, Xu W, et al. Study on dewaterability limit and energy consumption in sewage sludge electro-dewatering by in-situ linear sweep voltammetry analysis[J]. Chemical Engineering Journal, 2017,317:980-987.
[15]
Li Y, Liu J, Chen J, et al. Reuse of dewatered sewage sludge conditioned with skeleton builders as landfill cover material[J]. International Journal of Environmental Science and Technology, 2014,11(1):233-240.
[16]
Phamanh T, Sillanpaa M. Fractionation of macro and trace metals due to off-time interrupted electrodewatering[J]. Drying Technology, 2010,28(6):762-772.
[17]
Mahmoud A, Olivier J, Vaxelaire J, et al. Electro-dewatering of wastewater sludge:Influence of the operating conditions and their interactions effects[J]. Water Research, 2011,45(9):2795-2810.
[18]
Wójcik M. Investigation of filtration properties and microbiological characteristics of sewage sludge after physical conditioning with the use of ground walnut shells[J]. Powder Technology, 2020,361:491-498.
[19]
Wu Y, Zhang P Y, Zhang H B, et al. Possibility of sludge conditioning and dewatering with rice husk biochar modified by ferric chloride[J]. Bioresource Technology, 2016,205:258-263.
[20]
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.
[21]
陈巍,邢奕,陈月,等. O3-脱硫灰-FeCl3联合调理对污泥脱水性能的影响[J].环境工程, 2016,34(3):121-127. Chen W, Xing Y, Chen Y, et al. Effect of ozone-desulfurization ashFeCl3on sludge dewatering performance[J]. Environmental Engineering, 2016,34(3):121-127.
[22]
吴彦.稻壳基骨架颗粒制备及调理城市污泥脱水作用和机理分析[D].长沙:湖南大学, 2016. Wu Y. Preparation of rice husk-based skeleton builders and their effects and mechanisms on sewage sludge conditioning and dewatering[D]. Changsha:Hunan University, 2016.
[23]
Cao B D, Zhang W J, Du Y J, et al. Compartmentalization of extracellular polymeric substances (EPS) solubilization and cake microstructure in relation to wastewater sludge dewatering behavior assisted by horizontal electric field:Effect of operating conditions[J]. Water Research, 2018,130:363-75.
[24]
Qi Y, Thapa K B, Hoadley A F A. Application of filtration aids for improving sludge dewatering properties-A review[J]. Chemical Engineering Journal, 2011,171(2):373-384.
[25]
王瑞露,刘相汝,曹秉帝,等.炭材料强化污泥电脱水效果及同步燃料化处理[J].中国环境科学, 2018,38(11):4120-4129. Wang R L, Liu X R, Cao B D, et al. Carbon material reinforced sludge electric-dewatering synchronous fuel treatment[J]. China Environmental Science, 2018,38(11):4120-4129.