Abstract:Biochar and AlCl3-modified biochar were prepared by using corn stalks as materials to enhance the dewatering of the sludge. The performances of these two biochar for the enhancement of the dewatering of the sludge and possible enhancing mechanisms were discussed. Results showed that SRF, MC, SV30 and CST of the sludge were decreased and YN was increased after conditioned by the two biochar, indicating higher sludge dewaterability. Furthermore, dewatering of the sludge conditioned by the AlCl3-modified biochar was significantly better than that conditioned by the biochar that without modification. Especially, when the dosage of the biochar modified by 3mol/L of AlCl3 solution was adjusted to 3g/L, SRF, MC, SV30 and CST were decreased to 1.3×1012m/kg, 81.9%, 78.6% and 35s, respectively, YN was increased to 17.8kg/(m2·h). For the enhancing mechanism, on the one hand, after conditioned by the biochar, certain skeleton structures were formed in sludge cake to make water cut across easily by decreasing the sludge EPS; on the other hand, charge neutralization occurred when the AlCl3-modified biochar (loaded with positively charged aluminum species on its surface) was dosed into the sludge system, thus destroying the stable sludge colloidal system, thus far easier to congregate the sludge particles, which enhanced the dewatering of the sludge.
郭俊元, 文小英, 羊润锦, 林越, 赖雨隆, 周育玉, 杨红. 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 Jun-yuan, WEN Xiao-ying, YANG Run-jin, LIN Yue, LAI Yu-long, ZHOU Yu-yu, YANG Hong. Preparation of corn stalks biochar and improvement of dewatering performance of sludge. CHINA ENVIRONMENTAL SCIENCECE, 2019, 39(8): 3316-3322.
Chen Z, Zhang W J, Wang D S, et al. Enhancement of activated sludge dewatering performance by combined composite enzymatic lysis and chemical re-flocculation with inorganic coagulants:Kinetics of enzymatic reaction and re-flocculation morphology[J]. Water Research, 2015,83:367-376.
[2]
Yu G H, He P J, Shao L M, et al. Stratification structure of sludge flocs with implications to dewaterability[J]. Environmental Science and Technology, 2008,42:7944-7949.
[3]
Thapa K B, Qi Y, Clayton S A, et al. Lignite aided dewatering of digested sewage sludge[J]. Water Research, 2009,43:623-634.
[4]
张娜,尹华,秦华明,等.微生物絮凝剂改善城市污水厂浓缩污泥脱水性能的研究[J]. 环境工程学报, 2009,3(3):525-528. Zhang N, Yin H, Qin H M, et al. Study on application of bioflocculant to improvement of thickened sludge dewaterability in municipal waste water treatment plant[J]. Chinese Journal of Environmental Engineering, 2009,3(3):525-528.
[5]
郭俊元,能子礼超,刘杨杨,等.污泥预处理对微生物絮凝剂制备及性能的影响[J]. 环境科学学报, 2015,35(7):2077-2082. Guo J Y, Nengzi L C, Liu Y Y, et al. Effects of sludge pre-treatments on the preparation and performances of bioflocculants from sludge[J]. Acta Scientiae Circumstantiae, 2015,35(7):2077-2082.
[6]
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.
[7]
Wu Y, Zhang P Y, Zeng G M, et al. Enhancing sewage sludge dewaterability by a skeleton builder:biochar produced from sludge cake conditioned with rice husk flour and FeCl3[J]. ACS Sustainable Chemistry Engineering, 2016,4:5711-5717.
[8]
Liu H, Yang J, Zhu N, et al. A comprehensive insight into the combined effects of Fenton's reagent and skeleton builders on sludge deep dewatering performance[J]. Journal of Hazardous Materials, 2013,258:144-150.
[9]
Li J, Lv G, Bai W, et al. Modification and use of biochar from wheat straw (Triticum aestivum L.) for nitrate and phosphate removal from water[J]. Desalination Water Treatment, 2016,57:4681-4693.
[10]
APHA. Standard methods for the examination of water and wastewater, 20th ed[M]. American Public Health Association:Washington, DC, 1998.
[11]
Guo J Y, Zhang Y Z, Zhao J, et al. Characterization of a bioflocculant from potato starch wastewater and its application in sludge dewatering[J]. Applied Microbiology and Biotechnology, 2015,99:5429-5437.
[12]
Rebhun M, Zall J, Galil N. Net sludge solids yield as an expression of filterability for conditioner optimization[J]. Journal of Water Pollution Control Federation, 1989,61:52-54.
[13]
罗曦,雷中方,张振亚,等.好氧/厌氧污泥胞外聚合物(EPS)的提取方法研究[J]. 环境科学学报, 2005,25(12):1624-1629. Luo X, Lei Z F, Zhang Z Y, et al. Study on the extraction of extracellular polymeric substances (EPS) from aerobic anaerobic sludges[J]. Acta Scientiae Circumstantiae, 2005,25(12):1624-1629.
[14]
薛秀玲,樊国峰,李吉安.活性污泥中EPS的2中测定方法及其对膜通量的影响[J]. 环境工程学报, 2013,7(9):3466-3470. Xue X L, Fan G F, Li J. Two methods for determination of extracellular polymeric substances in active sludge and its effects on membrane fouling[J]. Chinese Journal of Environmental Engineering, 2013,7(9):3466-3470.
[15]
Guo J Y, Chen C, Jiang S L, et al. Feasibility and mechanism of combined conditioning with coagulant and flocculant to enhance sludge dewatering[J]. ACS Sustainable Chemistry Engineering, 2018, 6:10758-10765.
[16]
Xia C, Yue Q Y, Song F Y, et al. A study on the deep dewatering of urban dewatered-sewage sludge by aluminum chloride[J]. Desalination and Water Treatment, 2016,57:545-552.
[17]
Guo J Y, Nengzi L C, Zhao J, et al. Enhanced dewatering of sludge with the composite of bioflocculant MBFGA1and P(AM-DMC) as a conditioner[J]. Applied Microbiology and Biotechnology, 2015,99:2989-2998.
[18]
Chen Z, Zhang W, Wang D, et al. Enhancement of activated sludge dewatering performance by combined composite enzymatic lysis and chemical re-flocculation with inorganic coagulants:kinetics of enzymatic reaction and re-flocculation morphology[J]. Water Research, 2015,83:367-376.
[19]
Guo J Y, Jiang S L, Pang Y J. Rice straw biochar modified by aluminum chloride enhances the dewatering of the sludge from municipal sewage treatment plant[J]. Science and Total Environment, 2019,654:338-344.
[20]
Chen C, Zhang P, Zeng G, et al. Sewage sludge conditioning with coal fly ash modified by sulfuric acid[J]. Chemical Engineering Journal, 2010,158:616-622.
[21]
Li L Z, Mao L Y, Wang X L, et al. Synthesis and flocculation property of chitosan-acrylamide graft copolymer[J]. Chemical Research in Chinese Universities, 2004,20:221-224.
[22]
Zhen G Y, Lu X Q, Li Y Y, et al. Novel insights into enhanced dewaterability of waste activated sludge by Fe(Ⅱ)-activated persulfate oxidation[J]. Bioresource Technology, 2012,119:7-14.
[23]
Liu J, Yang Q, Wang D, et al. Enhanced dewaterability of waste activated sludge by Fe(Ⅱ)-activated peroxymonosulfate oxidation[J]. Bioresource Technology, 2016,206:134-140.
[24]
Liu T, Chen ZL, Yu WZ, et al. Characterization of organic membrane foulants in a submerged membrane bioreactor with pre-ozonation using three-dimensional excitation-emission matrix fluorescence spectroscopy[J]. Water Research, 2011,45:2111-2121.