上下流室宽度比对厌氧折流板反应器水力特性的影响
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摘要
借助计算流体力学技术(CFD)获取四组厌氧折流板反应器(ABR,上下流室宽度比分别为2:1、3:1、4:1及5:1)的停留时间分布(RTD),并计算串联数(N)、扩散数(D/μL)及水力死区容积占比(V_d/V)等参数,以分析反应器流动、混合等水力特性;在此基础上选择最佳上下流室宽度比值,优化ABR反应器的设计。结果表明:当容积和理论水力停留时间(HRT)相同时,提高上下流室宽度比,N随之降低,最低值为4.80,而D/μL呈上升趋势,最大值为0.118;V_d/V随上下流室宽度比的增大,呈先下降后升高的趋势,比值为4:1时V_d/V最小,仅为3.13%。选取水力效率(λ)作为反应器的水力评价指标,在2:1~4:1的流室宽度比范围内,λ相差不大,属于理想范围。综合考虑反应器流动混合特性、死区占比及水力效率,确定反应器的最佳上下流室宽度比为4:1。
Four different anaerobic baffled reactors(ABRs) with the width ratios of upstream to downstream chamber set as 2:1,3:1,4:1 and 5:1 respectively were studied in this paper.The computational fluid dynamics(CFD) technique was employed to obtain the residence time distributions(RTD),and parameters like number of continuous stirred tanks in series(N),dispersion number(D/μL) and fraction of hydraulic dead space(V_d/V) were calculated.By analyzing the RTD curve,the flow mixing pattern and other hydraulic characteristics of the four ABRs could be achieved to determine the optimal width ratio to improve the design of ABR.Results showed that under the same volume and ideal hydraulic retention time(HRT),with the increase of width ratios,the value of N decreased(the minimum value was 4.80) while D/μL was on the rise(the maximum value was 0.118),and the fraction of hydraulic dead space tended to decrease at first and then increase.The dimension of the dead zone could be restricted to the minimal(only 3.13%of the total volume) when the width ratio was 4:1.The hydraulic efficiency(λ) was introduced as the hydraulic evaluation indicator,and the values of A were similar when the width ratios were 2:1,3:1 and 4:1,which indicated that good performances were achieved under these hydraulic conditions.Comprehensively considering the flow mixing pattern,fraction of hydraulic dead space and hydraulic efficiency of the ABRs,the optimal width ratio of upstream to downstream chamber is suggested as 4:1.
Four different anaerobic baffled reactors(ABRs) with the width ratios of upstream to downstream chamber set as 2:1,3:1,4:1 and 5:1 respectively were studied in this paper.The computational fluid dynamics(CFD) technique was employed to obtain the residence time distributions(RTD),and parameters like number of continuous stirred tanks in series(N),dispersion number(D/μL) and fraction of hydraulic dead space(V_d/V) were calculated.By analyzing the RTD curve,the flow mixing pattern and other hydraulic characteristics of the four ABRs could be achieved to determine the optimal width ratio to improve the design of ABR.Results showed that under the same volume and ideal hydraulic retention time(HRT),with the increase of width ratios,the value of N decreased(the minimum value was 4.80) while D/μL was on the rise(the maximum value was 0.118),and the fraction of hydraulic dead space tended to decrease at first and then increase.The dimension of the dead zone could be restricted to the minimal(only 3.13%of the total volume) when the width ratio was 4:1.The hydraulic efficiency(λ) was introduced as the hydraulic evaluation indicator,and the values of A were similar when the width ratios were 2:1,3:1 and 4:1,which indicated that good performances were achieved under these hydraulic conditions.Comprehensively considering the flow mixing pattern,fraction of hydraulic dead space and hydraulic efficiency of the ABRs,the optimal width ratio of upstream to downstream chamber is suggested as 4:1.
引文
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[4]Zhu G,Zou R,Jha A K,et al.Recent developments and future perspectives of anaerobic baffled bioreactor for wastewater treatment and energy recovery[J].Critical Reviews in Environmental Science and Technology,2015,45(12):1243-1276.
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[6]耿亚鸽,张翔,张浩勤,等.ABR反应器工程设计的技术探讨[J].水处理技术,2009,35(2):103-107.
[7]周冬卉,吴时强,祝龙,等.折流式厌氧反应器水力特性分析[J].水利水运工程学报,2015(4):37-42.
[8]戴友芝,施汉昌,钱易.有毒物冲击负荷对厌氧折流板反应器的影响[J].中国环境科学,2000,20(1):40-44.
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[11]李慧莉,刘紫璇,赵红花.厌氧折流板反应器处理废水的研究进展[J].工业水处理,2015,35(11):5-8.
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[14]张寿通,郭海燕,费庆志,等.斜板式ABR水力特性及生活污水的处理[J].环境化学,2009,28(4):492-496.
[15]Li S,Nan J,Li H,et al.Comparative analyses of hydraulic characteristics between the different structures of two anaerobic baffled reactors(ABRs)[J].Ecological Engineering,2015,82(4):138-144.
[16]Liotta F,Chatellier P,Esposito G,et al.Hydrodynamic mathematical modelling of aerobic plug flow and nonideal flow reactors:A critical and historical review[J].Critical Reviews in Environmental Science and Technology,2014,44(23):2642-2673.
[17]Xie H,Yang J,Hu Y,et al.Simulation of flow field and sludge settling in a full-scale oxidation ditch by using a two-phase flow CFD model[J].Chemical Engineering Science,2014,109(16):296-305.
[18]黄远东,顾静,赵树夫,等.CFD在水处理反应器研究中的应用进展[J].水资源与水工程学报,2011,22(6):11-15.
[19]许明,冯骞,刘伟京,等.ABR反应器的结构参数对流动及混合特性的影响[J].环境科学研究,2014,27(7):758-762.
[20]Ji J,Zheng K,Xing Y,et al.Hydraulic characteristics and their effects on working performance of compartmentalized anaerobic reactor[J].Bioresource Technology,2012,116(4):47-52.
[21]Crittenden J C,Trussell R R,Hand D W,et al.MWH's water treatment:principles and design[M].New Jersey:John Wiley&Sons,2012.
[22]张濂,许志美,袁向前.化学反应工程原理[M].上海:华东理工大学出版社,2000.
[23]Yu J,Chen H,Guo Q,et al.Response of perfonnance of an anammox anaerobic baffled reactor(ABR)to changes in feeding regime[J],Ecological Engineering,2015,83(6):19-27.
[24]Thackston E L,Shields Jr F D,Schroeder P R.Residence time distributions of shallow basins[J].Journal of Environmental Engineering,1987,113(6):1319-1332.
[25]Pereson J,Somes N,Wong T.Hydraulics efficiency of constructed wetlands and ponds[J].Water Science and Technology,1999,40(3):291-300.
[2]宋铁红,张芳,董利鹏,等.厌氧折流板反应器(ABR)的应用研究进展[J].中国资源综合利用,2015,33(1):29-32.
[3]邹然,朱葛夫,张净瑞,等.厌氧折流板反应器处理土霉素废水的潜能和运行特性研究[J].环境科学学报,2014,34(11):2746-2753.
[4]Zhu G,Zou R,Jha A K,et al.Recent developments and future perspectives of anaerobic baffled bioreactor for wastewater treatment and energy recovery[J].Critical Reviews in Environmental Science and Technology,2015,45(12):1243-1276.
[5]Barber W P,Stuckey D C.The use of the anaerobic baffled reactor(ABR)for wastewater treatment:A review[J].Water Research,1999,33(7):1559-1578.
[6]耿亚鸽,张翔,张浩勤,等.ABR反应器工程设计的技术探讨[J].水处理技术,2009,35(2):103-107.
[7]周冬卉,吴时强,祝龙,等.折流式厌氧反应器水力特性分析[J].水利水运工程学报,2015(4):37-42.
[8]戴友芝,施汉昌,钱易.有毒物冲击负荷对厌氧折流板反应器的影响[J].中国环境科学,2000,20(1):40-44.
[9]Sarathai Y,Koottatep T,Morel A.Hydraulic characteristics of an anaerobic baffled reactor as onsite wastewater treatment system[J].Journal of Environmental Sciences,2010,22(9):1319-1326.
[10]耿亚鸽,张浩勤,陈吴,等.ABR反应器在不同HRT下的流态特征分析[J].郑州大学学报(工学版),2008,29(3):92-94.
[11]李慧莉,刘紫璇,赵红花.厌氧折流板反应器处理废水的研究进展[J].工业水处理,2015,35(11):5-8.
[12]周磊,陈朱蕾,廖波,等.厌氧折流板反应器性能研究进展[J].工业水处理,2005,22(6):1-5.
[13]胡细全,刘大银,蔡鹤生.ABR反应器结构对水力特性的影响[J].地球科学,2004,29(3):369-374.
[14]张寿通,郭海燕,费庆志,等.斜板式ABR水力特性及生活污水的处理[J].环境化学,2009,28(4):492-496.
[15]Li S,Nan J,Li H,et al.Comparative analyses of hydraulic characteristics between the different structures of two anaerobic baffled reactors(ABRs)[J].Ecological Engineering,2015,82(4):138-144.
[16]Liotta F,Chatellier P,Esposito G,et al.Hydrodynamic mathematical modelling of aerobic plug flow and nonideal flow reactors:A critical and historical review[J].Critical Reviews in Environmental Science and Technology,2014,44(23):2642-2673.
[17]Xie H,Yang J,Hu Y,et al.Simulation of flow field and sludge settling in a full-scale oxidation ditch by using a two-phase flow CFD model[J].Chemical Engineering Science,2014,109(16):296-305.
[18]黄远东,顾静,赵树夫,等.CFD在水处理反应器研究中的应用进展[J].水资源与水工程学报,2011,22(6):11-15.
[19]许明,冯骞,刘伟京,等.ABR反应器的结构参数对流动及混合特性的影响[J].环境科学研究,2014,27(7):758-762.
[20]Ji J,Zheng K,Xing Y,et al.Hydraulic characteristics and their effects on working performance of compartmentalized anaerobic reactor[J].Bioresource Technology,2012,116(4):47-52.
[21]Crittenden J C,Trussell R R,Hand D W,et al.MWH's water treatment:principles and design[M].New Jersey:John Wiley&Sons,2012.
[22]张濂,许志美,袁向前.化学反应工程原理[M].上海:华东理工大学出版社,2000.
[23]Yu J,Chen H,Guo Q,et al.Response of perfonnance of an anammox anaerobic baffled reactor(ABR)to changes in feeding regime[J],Ecological Engineering,2015,83(6):19-27.
[24]Thackston E L,Shields Jr F D,Schroeder P R.Residence time distributions of shallow basins[J].Journal of Environmental Engineering,1987,113(6):1319-1332.
[25]Pereson J,Somes N,Wong T.Hydraulics efficiency of constructed wetlands and ponds[J].Water Science and Technology,1999,40(3):291-300.