用于人工湿地的基质净水除磷静态实验与渗流模拟综合研究

doi:10.7523/j.issn.2095-6134.2021.04.006

摘要/Abstract

摘要： 为有效解决人工湿地基质除磷普遍存在的去除率不断下降问题和基质结构优化设计与维护问题，需针对不同介质掌握其对具体含磷污水的吸附特性及实际去磷效果的演变趋势与规律。选取人工湿地可选用的除磷性能较好的沸石、麦饭石和磁铁矿3种基质，首先通过静态实验研究它们对磷的吸附动力学过程和等温吸附特征，并考察不同基质和粒径对磷吸附的影响。进而选取其中磷吸附性能最好的沸石进行去除磷的砂箱渗流模拟试验，获取潜流湿地的基质除磷净化效果。通过磷吸附静态实验和磷去除砂箱渗流模拟试验综合研究，查明不同粒径的沸石基质实际去磷效果的主要机制与演变趋势和规律。研究结果表明：3种基质对磷的吸附过程都包括快速吸附、缓慢吸附和逐渐平衡3个过程，Langmuir方程准确地描述基质吸附磷的等温吸附过程。当含磷水在砂箱基质中呈渗流状态时，不同粒径的沸石吸附除磷及总体除磷效率呈现较大差异，各粒径沸石基质的除磷效率具有波动现象，且总体呈先上升再明显下降趋势。分析表明，除明显的吸附除磷机制，微生物除磷作用也产生相当的去磷效果。

关键词: 基质, 磷, 吸附, 物理模型模拟, 除磷效率

Abstract: In order to solve the problem of decreasing for the removal rate of phosphorus and consider the optimal design and maintenance of the substrate structure in constructed wetlands, it is necessary to understand the phosphorus adsorption characteristics for different substrates and obtain the evolution trend and law regarding the actual dephosphorization effect for specific phosphorus-containing wastewater. In this study, three substrates including zeolite, medical stone, and magnetite, were selected, which are commonly used in constructed wetlands with good phosphorus removal performance, to study their adsorption kinetics and isothermal adsorption characteristics of phosphorus and to investigate the effects of different substrates and particle sizes on phosphorus adsorption. Further, zeolite with the best phosphorus adsorption performance among the three substrates was selected to carry out the seepage sand tank test for phosphorus removal, so as to simulate and obtain the phosphorus removal and purification effects of the subsurface flow wetland. By integrating the static experiment with seepage sand tank test for the phosphorus removal, the mechanisms of dephosphorization and the evolution trend and law of actual dephosphorization effects of the zeolite substrates with different particle sizes were identified. The results show that the adsorption process of phosphorus on the three substrates consists of the fast adsorption, slow adsorption, and gradual equilibrium. Furthermore, the Langmuir equation can accurately describes the isothermal process of phosphorus adsorption on the substrates. The adsorption phosphorus removal efficiency and the overall phosphorus removal efficiency of the zeolite substrate with different particle sizes are significantly different. Additionally, the phosphorus removal efficiency of the zeolite substrates fluctuates with the particle size, and the overall phosphorus removal efficiency initially increases and then decreases considerably. The analysis of the achieved data sets indicates that, in addition to the significant mechanism of phosphorus adsorption removal, the microbial effect is also considerable on the phosphorus removal. Based on this type of integrated investigations, the phosphorus removal mechanisms with their relative importance and the overall phosphorus removal efficiency can be identified.

Key words: substrate, phosphorus, adsorption, physical model simulation, phosphorus removal efficiency

中图分类号:

X703

王迪, 王明玉. 用于人工湿地的基质净水除磷静态实验与渗流模拟综合研究[J]. 中国科学院大学学报, 2021, 38(4): 478-485.

WANG Di, WANG Mingyu. Substrate phosphorus removal for contaminated water treatment in constructed wetlands by integrating static adsorption experiments with seepage sand tank tests[J]. Journal of University of Chinese Academy of Sciences, 2021, 38(4): 478-485.

参考文献

[1] 王荣, 贺锋, 徐栋, 等. 人工湿地基质除磷机理及影响因素研究[J]. 环境科学与技术, 2010, 33(S1):12-18.
[2] Cui L H, Zhu X Z, Ma M, et al. Phosphorus sorption capacities and physicochemical properties of nine substrate materials for constructed wetland[J]. Archives of Environmental Contamination and Toxicology, 2008, 55(2):210-217.
[3] Tsihrintzis V A. The use of vertical flow constructed wetlands in wastewater treatment[J]. Water Resources Management, 2017, 31(10):3245-3270.
[4] 马琳, 贺锋. 我国农村生活污水组合处理技术研究进展[J]. 水处理技术, 2014, 40(10):1-5.
[5] Dai H L, Hu F P. Phosphorus adsorption capacity evaluation for the substrates used in constructed wetland systems:a comparative study[J]. Polish Journal of Environmental Studies, 2017, 26(3):1003-1010.
[6] Bubba M D, Arias C A, Brix H. Phosphorus adsorption maximum of sands for use as media in subsurface flow constructed reed beds as measured by the Langmuir isotherm[J]. Water Research, 2003, 37(14):3390-3400.
[7] 袁东海, 景丽洁, 张孟群, 等. 几种人工湿地基质净化磷素的机理[J]. 中国环境科学, 2004, 24(5):614-617.
[8] Mann R A, Bavor H J. Phosphorus removal in constructed wetlands using gravel and industrial waste substrata[J]. Water Science and Technology, 1993, 27(1):107-113.
[9] 王振华, 朱波, 何敏, 等. 紫色土泥沙沉积物对磷的吸附-解吸动力学特征[J]. 农业环境科学学报, 2011, 30(1):154-160.
[10] 赵桂瑜, 秦琴, 周琪. 几种人工湿地基质对磷素的吸附作用研究[J]. 环境科学与技术, 2006(6):84-85,120.
[11] Li Y C, Yang J, Zhou X R, et al. Elimination of phosphorous from phosphorus-rich farmyard wastewater using reeds bed system containing steel furnace slag[J]. Desalination and Water Treatment, 2014, 52(46):6648-6654.
[12] 袁东海, 高士祥, 景丽洁, 等. 几种粘土矿物和粘土对溶液中磷的吸附效果[J]. 农村生态环境, 2004, 20(4):60-63,72.
[13] Barca C, Meyer D, Liira M, et al. Steel slag filters to upgrade phosphorus removal in small wastewater treatment plants:removal mechanisms and performance[J]. Ecological Engineering, 2014, 68:214-222.
[14] 路沙沙, 麻凤海, 刘书贤. 天然沸石特性对含磷废水净化效果的影响[J]. 环境工程学报, 2015, 9(6):2711-2716.
[15] Cui L J, Li W, Zhou J, et al. Influence of substrate depth and particle size on phosphorus removal in a surface flow constructed wetland[J]. Water Science and Technology, 2017, 75(10):2291-2298.
[16] Li L Y, Zhang H, Wang D Q. Influencing factors of limestone sorption and its usage in advanced wastewater treatment for phosphorus removal[J]. International Journal of Nanoscience, 2012, 11(6):316-321.
[17] 赵林丽, 邵学新, 吴明, 等. 人工湿地不同基质和粒径对污水净化效果的比较[J]. 环境科学, 2018, 39(9):4236-4241.
[18] Jiang C, Jia L Y, He Y L, et al. Adsorptive removal of phosphorus from aqueous solution using sponge iron and zeolite[J]. Journal of Colloid and Interface Science, 2013, 402:246-252.
[19] Njau K N, Minja R J A, Katima J H Y. Pumice soil:a potential wetland substrate for treatment of domestic wastewater[J]. Water Science and Technology, 2003, 48(5):85-92.
[20] 张修稳, 李锋民, 卢伦, 等. 10种人工湿地填料对磷的吸附特性比较[J]. 水处理技术, 2014, 40(3):49-52,56.
[21] 蒋卫刚. 人工湿地技术在景观水处理中的应用案例研究[J]. 环境污染与防治, 2011, 33(7):87-89,93.
[22] 朱加宾, 李冰, 侯诒然, 等. 人工湿地不同植物根系及基质重金属富集特征及其与环境因子相关性[J]. 上海海洋大学学报, 2018, 27(4):531-542.
[23] 王生福, 李伟斯, 苏庆梅. 基于实地调查研究的湿地水质提升与功能恢复对策探讨:以临沂市罗庄区武河湿地为例[J]. 环境与可持续发展, 2018, 43(5):112-115.
[24] 贺婷婷. 石子河人工湿地水质净化工程设计[J]. 中国给水排水, 2018, 34(14):50-53.