Influence of permeability on nanoscale zero-valent iron particle transport in saturated homogeneous and heterogeneous porous media

详细信息    查看全文

• 作者：Tessa J. Strutz ; Götz Hornbruch…
• 关键词：Nanoscale zero ; valent iron ; Transport ; Permeability ; Homogeneous and heterogeneous porous media ; Groundwater remediation
• 刊名：Environmental Science and Pollution Research
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：23
• 期：17
• 页码：17200-17209
• 全文大小：1,732 KB
• 刊物类别：Earth and Environmental Science
• 刊物主题：Environment
  Environment
  Atmospheric Protection, Air Quality Control and Air Pollution
  Waste Water Technology, Water Pollution Control, Water Management and Aquatic Pollution
  Industrial Pollution Prevention
  
• 出版者：Springer Berlin / Heidelberg
• ISSN：1614-7499
• 卷排序：23

文摘

Nanoscale zero-valent iron (NZVI) particles can be used for in situ groundwater remediation. The spatial particle distribution plays a very important role in successful and efficient remediation, especially in heterogeneous systems. Initial sand permeability (k₀) influences on spatial particle distributions were investigated and quantified in homogeneous and heterogeneous systems within the presented study. Four homogeneously filled column experiments and a heterogeneously filled tank experiment, using different median sand grain diameters (d₅₀), were performed to determine if NZVI particles were transported into finer sand where contaminants could be trapped. More NZVI particle retention, less particle transport, and faster decrease in k were observed in the column studies using finer sands than in those using coarser sands, reflecting a function of k₀. In heterogeneous media, NZVI particles were initially transported and deposited in coarse sand areas. Increasing the retained NZVI mass (decreasing k in particle deposition areas) caused NZVI particles to also be transported into finer sand areas, forming an area with a relatively homogeneous particle distribution and converged k values despite the different grain sizes present. The deposited-particle surface area contribution to the increasing of the matrix surface area (θ) was one to two orders of magnitude higher for finer than coarser sand. The dependency of θ on d₅₀ presumably affects simulated k changes and NZVI distributions in numerical simulations of NZVI injections into heterogeneous aquifers. The results implied that NZVI can in principle also penetrate finer layers.