Loading...

Bench-scaled nano-Fe 0 permeable reactive barrier for nitrate removal

Hosseini, S. M ; Sharif University of Technology

1733 Viewed
  1. Type of Document: Article
  2. DOI: 10.1111/j.1745-6592.2011.01352.x
  3. Abstract:
  4. There are many fundamental problems with the injection of nano-zero-valent iron (NZVI) particles to create permeable reactive barrier (PRB) treatment zone. Among them the loss of medium porosity or pore blocking over time can be considered which leads to reduction of permeability and bypass of the flow and contaminant plume up-gradient of the PRB. Present study provides a solution for such problems by confining the target zone for injection to the gate in a funnel-and-gate configuration. A laboratory-scale experimental setup is used in this work. In the designed PRB gate, no additional material from porous media exists. NZVI (d 50 = 52 ± 5 nm) particles are synthesized in water mixed with ethanol solvent system. A steady-state condition is considered for the design of PRB size based on the concept of required contact time to obtain optimum width of PRB gate. Batch experiment is carried out and the results are used in the design of PRB gate width (~50 mm). Effect of high initial NO 3 --N concentration, NZVI concentration, and pore velocity of water in the range of laminar groundwater flow through porous media are evaluated on nitrate-N reduction in PRB system. Results of PRB indicate that increasing the initial NO 3 --N concentration and pore velocity has inhibitor effect-against the effect of NZVI concentration-on the process of NO 3 --N removal. Settlement velocity (S.V.) of injected NZVI with different concentrations in the PRB is also investigated. Results indicate that the proposed PRB can solve the low permeability of medium in down-gradient but increasing of the S.V. especially at higher concentration is one of the problems with this system that needs further investigations
  5. Keywords:
  6. Contact time ; Groundwater ; Contaminant plume ; Experimental setup ; Fundamental problem ; Funnel-and-gate ; Gate widths ; Laboratory scale ; Low permeability ; N removal ; Nano-Fe ; Nitrate removal ; Nitrate-N ; Permeable reactive barriers ; Pore blocking ; Pore velocity ; Solvent system ; Steady-state condition ; Concentration (process) ; Ethanol ; Batch experiments ; Groundwater flow ; Groundwater geochemistry ; Organic solvents ; Porous materials ; Reduction ; Bypass ; Inhibitor ; Laboratory method ; Laminar flow ; Nanotechnology ; Nitrate ; Permeability ; Plume ; Pollutant removal ; Pollutant transport ; Porous medium ; Reactive barrier ; Settling velocity ; Steady-state equilibrium
  7. Source: Ground Water Monitoring and Remediation ; Volume 31, Issue 4 , 2011 , Pages 82-94 ; 10693629 (ISSN)
  8. URL: http://onlinelibrary.wiley.com/doi/10.1111/j.1745-6592.2011.01352.x/abstract