We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
The Behavior of Cadmium Leaching from Contaminated Soil by Nitrilotriacetic Acid: Implication for Cd-Contaminated Soil Remediation.
- Authors
Xie, Xianjun; Yang, Sen; Liu, Hongxing; Pi, Kunfu; Wang, Yanxin
- Abstract
To determine the leaching behavior and mechanism of cadmium (Cd) from contaminated soil by nitrilotriacetic acid (NTA), batch leaching experiments and chemical extraction in combination with Fourier transform infrared spectroscopy (FTIR) analyses were conducted to investigate the changes of Cd species, the organic matter content, the functional groups of soil particles in the course of leaching. The batch experiment was conducted using one cadmium level (12.49 mg/kg), different levels of NTA (1, 5, 10, 100, 150, 200, 300, 400, and 500 mmol/L), different pH levels (6–11), and different contact times (10, 30, 60, 120, 240, 480, 1440 min). Moreover, based on the experiment results, factors like the input NTA concentration, the eluent pH values, as well as the leaching time for the amount of leached Cd were evaluated via a multiple linear regression simulation. The results showed that the leached Cd from contaminated soils increased with increasing input NTA concentration and absorbed NTA in soils. At the beginning of the leaching experiment, the functional groups of the soil particles changed from hydroxyl to ester, resulting in the release of Cd from soil particles. At the same time, the esterification reaction caused an increase of eluent pH. However, after Cd released into the liquid phase, the complexation reaction between NTA and Cd continually consumed NTA, and this resulted in a minor decrease in eluent pH. As the result, some amounts of Cd could be precipitated as Cd(OH)2 and immobilized again under high pH condition. Multiple linear regression results showed that the input NTA concentration is the main factor that influences the removal efficiency of Cd from contaminated soils. The study results provide vital support for the practice of Cd-contaminated soil remediation using NTA as chemical eluent.
- Subjects
SOIL pollution; SOIL remediation; NITRILOTRIACETIC acid; ACID soils; FOURIER transform infrared spectroscopy
- Publication
Water, Air & Soil Pollution, 2020, Vol 231, Issue 4, p1
- ISSN
0049-6979
- Publication type
Article
- DOI
10.1007/s11270-020-04545-7