流化床结晶软化高硬度地下水及其晶体生长动力学
Softening of high hardness groundwater and crystal growth kinetics in a fluidized bed crystallization reactor
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摘要: 采用流化床结晶软化的方法对北京市城区某地下水进行软化处理，研究考察了软化药剂投加量、诱晶颗粒粒径、诱晶颗粒填料高度、入水流速、碳酸钙过饱和度等参数对水质硬度去除的影响。研究发现，当药剂投加量为220 mg·L-1时，出水钙硬度去除率可达90%以上，总硬度去除率达到60%，出水总硬度可达300 mg·L-1左右。使用石英砂颗粒作为诱晶材料，粒径为0.21~0.43 mm。当诱晶材料填料高度为40 cm，入水流速控制在40~70 m·h-1时，均可得到较好的出水水质。优化反应参数，可控制处理后的出水总硬度在300 mg·L-1左右，即去除235 mg·L-1的暂时硬度，煮沸的水不再浑浊，无水垢生成，并且出水pH可控制在8.5以下。此外，探究了多相流化过程中诱晶颗粒的线性增长速率以及床层增长速率与过饱和度、颗粒粒径、入水流速的关系，通过计算得到晶体线性增长速率相关表达式。Abstract: The softening of high hardness groundwater was carried out using fluidized bed induced crystallization. The groundwater source is in Beijing urban area. In the present study, the influence of processing parameters such as the dosage of softening agent, the size and amount of crystallization seeds, the inlet velocity and super-saturation on the removal of hardness were investigated. The results showed that when the dosage of NaOH was 220 mg·L-1, the removal of calcium hardness could reach to more than 90%, and the total hardness removal reached about 60%.Silica sands were used as crystal seeds and loaded in the fluidized bed reactor beforehand.A good water quality could be achieved when the height of fixed bed is about 40 cm and the particle size of the silica seedsis in the range of 0.21 to 0.43 mm under the flow velocity of 40 to 70 m·h-1. By optimizing the reaction parameters, the total hardness of the treated water was controlled to be 300 mg·L-1and pH below 8.5, and the remove of the temporary hardness from the source water was 235 mg·L-1. No incrustation formed in the treated water after boiling. In addition, the relationship of the linear growth rate of induced crystals and the growth rate of the bed layer between the super-saturation, the seeds size and the water flow velocity were studied.The expression of the linear growth rate of crystals is proposed based on calculation.
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[1] 姜体胜, 杨忠山, 黄振芳,等. 北京郊区浅层地下水总硬度变化趋势及其机理浅析[J]. 水文地质工程地质,2010,37(4):33-37 10.3969/j.issn.1000-3665.2010.04.007 [2] 吴芳. 南方地区典型城市水源水及饮用水水质特征分析与评价[D].武汉:武汉大学,2005 [3] 维锐. 高效结晶除硬技术处理高盐废水的研究[D]. 呼和浩特: 内蒙古大学,2014 [4] 陈涛. 用石灰软化-絮凝法处理地下水水源硬度试验研究[D]. 武汉: 华中科技大学,2012 [5] 顾艳梅, 许航, 孙宇辰, 等. 造粒反应器处理高硬度水试验研究[J]. 土木建筑与环境工程,2015,37(3):151-155 10.11835/j.issn.1674-4764.2015.03.020 [6] 石玉. 浓水中总硬度及钙镁离子的去除实验研究[D]. 太原: 太原理工大学,2013 [7] 熊娅, 阎中, 陈坚, 等. 诱导结晶反应器运行性能研究[J]. 环境工程,2013,31(2):46-48 [8] 陈平. 载体诱导沉淀结晶法软化水及脱氟的研究[D]. 西安: 西安建筑科技大学,2004 [9] 胡瑞柱, 黄廷林, 文刚, 等. 造粒流化床反应器去除地下水中硬度试验研究[J]. 中国给水排水,2016,32(21):39-44 [10] PAOLO B, BARBARA P, FRANCESCO F, et al.Phosphorus removal from anaerobic supernatants: Start-up and steady-state conditions of a fluidized bed reactor full-scale plant[J].Industrial & Engineering Chemistry Research,2006,45(2):663-669 10.1021/ie050796g [11] 国家环境保护总局. 水和废水监测分析方法[M]. 4 版. 北京: 中国环境科学出版社,2002 [12] KRAMER O, JOBSE M A, BAARS E T, et al.Model-based prediction of fluid bed state in full-scale drinking water pellet softening reactors[C]//The Royal Dutch Water Association and the International Water Association.IWC International Water Conferences,2015 [13] 黄廷林, 孙田, 邓林煜. 诱导结晶法去除地下水中氟离子[J]. 环境工程学报,2014,8(1):1-5 [14] 姜科. 诱导结晶法回收和去除氟化盐工业废水中的氟[D]. 长沙: 中南大学,2014 [15] ALDACO R, GAREA A, IRABIEN A.Modeling of particle growth: Application to water treatment in a fluidized bed reactor[J].Chemical Engineering Journal,2007,134(1):66-71 10.1016/j.cej.2007.03.068 [16] TAI C Y, CHANG M C, WU C K, et al.Interpretation of calcite growth data using the two-step crystal growth model[J].Chemical Engineering Science,2006,61(16):5346-5354 10.1016/j.ces.2006.03.047 -
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