Investigating the efficiency of microscale zero valent iron-based in situ reactive zone (mZVI-IRZ) for TCE removal in fresh and saline groundwater.
Sci Total Environ
; 626: 638-649, 2018 Jun 01.
Article
in En
| MEDLINE
| ID: mdl-29898552
ABSTRACT
In this study, long-term column experiments were conducted in three media (Milli-Q water, fresh groundwater and saline groundwater) to evaluate the trichloroethylene (TCE) removal performance, electron efficiency (EE), and permeability loss of a microscale zero valent iron-based in situ reactive zone (mZVI-IRZ) under different field conditions. A potential scenario of in situ contamination plume remediation was simulated by adding a TCE-containing influent to columns filled with mixed mZVI particles and silica sand at a flow rate of 4â¯mLâ¯h-1 for 6â¯months. Results showed that, over the course of 100 pore volumes (PV) for 6â¯months, mZVI displayed the lowest TCE breakthrough rate (0.0026 PV-1) and highest TCE removal capacity (43.72â¯mg) but the poorest EE value (25-40%) in saline groundwater. Mineral characterization (SEM, XRD), ion concentration analysis, and geochemical modeling corroborated that different dominant solid precipitates (magnetite, siderite, dolomite/magnetite) were identified inside the three columns. The column containing saline groundwater experienced the greatest porosity loss, approximately 30.23â¯mL over the course of 100 PVs. This study illustrates that, to improve designs of mZVI-IRZs, EE as well as hydraulic conductivity should be taken into consideration for predictive evaluations.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Trichloroethylene
/
Water Pollutants, Chemical
/
Groundwater
/
Environmental Restoration and Remediation
Type of study:
Prognostic_studies
Language:
En
Journal:
Sci Total Environ
Year:
2018
Type:
Article