Remediation of organic contaminated soil by Fe-based nanoparticles and surfactants: a review

Surfactants and nanoparticles have been effectively used for environmental remediation for many years. Over the years, various methods have been developed to synthesize nanoparticles using different surfactants to obtain a s higher treatment efficiency for organic contaminated soil. Compared to conventional remediation methods, the in-situ remediation technique provides advantages, such as being more eco-friendly and cost-effective. This review provides an overview of the remediation of organic contaminated soil using surfactant-stabilized Fe-based nanoparticles, mostly surfactant-stabilized nanoscale zero-valent iron (nZVI). In addition, the use of other stabilizers and the mechanisms of stabilization are discussed. The combination of surfactants and Fe-based nanoparticles can be effectively used to remediate organic contaminants from soil, such as trichloroethylene (up to 99%), polychlorinated biphenyls (up to 80%), perchloroethylene (up to 93%). The treatment efficiency organic contaminants in soil by surfactant-stabilized nanoparticles is higher than only surfactant (less than 90%) or nanoparticles (less than 80%) due to the synergistic effects between surfactants and nanoparticles. This technique is generally more effective to use as a strong reductant, such as reductive dehalogenation or reductive immobilization of metals, while less cost-effective as an adsorbent. In addition, the remediation rate depends on various factors, such as pH, temperature, natural organic matter, ionic strength, type and concentration of stabilizers, site characteristics, contaminant features, nanoparticle and surfactant properties. However, short lifetimes or potential toxicity of nanoparticles are some limitations of this technique.