Enhanced remediation of arsenic-contaminated excavated soil using a binary blend of biodegradable surfactant and chelator

• Published in: Journal of hazardous materials Vol. 431; p. 128562
• Main Authors: Rahman, Shafiqur, Rahman, Ismail M.M., Ni, Shengbin, Harada, Yasuhiro, Kasai, Shuto, Nakakubo, Keisuke, Begum, Zinnat A., Wong, Kuo H., Mashio, Asami S., Ohta, Akio, Hasegawa, Hiroshi
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 05.06.2022
• Subjects: Animals; Arsenic; Biodegradable surfactant; Chelating Agents; Ecosystem; Enhanced remediation; Environmental Restoration and Remediation; Excavated soil; Green chelator; Isopoda; Metals, Heavy - analysis; Sodium; Soil; Soil Pollutants - analysis; Surface-Active Agents; Excavated soil; Green chelator; Biodegradable surfactant; Arsenic; Enhanced remediation
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2022.128562

The reclamation of geogenic As-contaminated excavated soils as construction additives can reduce the post-disposal impact on the ecosystem and space. Although retaining soil characteristics while reducing contaminant load is a challenging task, washing remediation with biodegradable surfactants or chelators is a promising alternative to non-biodegradable counterparts. In this study, newly synthesized biodegradable surfactants (SDG: sodium N-dodecanoyl-glycinate, SDBA: sodium N-dodecanoyl-β-alaninate, SDGBH: sodium N-dodecanoyl-α,γ-glutamyl-bis-hydroxyprolinate, SDT: sodium N-dodecanoyl-taurinate, and DCPC: N-dodecyl-3-carbamoyl-pyridinium-chloride) and biodegradable chelators (EDDS: ethylenediamine N,N’-disuccinic acid, GLDA: L-glutamate-N, N’-diacetic acid, and HIDS: 3-hydroxy-2,2′-imino disuccinic acid) are evaluated for the remediation of As-contaminated soil. The operating variables, such as washing duration, solution pH, and surfactant or chelator concentration, are optimized for maximum As extraction. SDT shows the highest As-extraction efficiency irrespective of solution pH and surfactant variants, while HIDS is the superior chelator under acidic or alkaline conditions. A binary blend of SDT and HIDS is evaluated for As extraction under varying operating conditions. The SDT–HIDS binary blend demonstrates 6.9 and 1.6-times higher As-extraction rates than the SDT and HIDS-only washing, respectively, under acidic conditions. The proposed approach with a binary blend of a biodegradable surfactant and chelator is a green solution for recycling As-contaminated excavated soils for geotechnical applications. [Display omitted] •Newly synthesized biodegradable surfactants are used to treat As-contaminated soil.•Biodegradable chelators are evaluated for the washing removal of soil-bound As.•Surfactant or chelator-induced As extraction correlated with washing variables.•Cationic surfactant was incompatible and displayed lowest As-extraction efficiency.•A binary blend of surfactant and chelator significantly enhanced As-removal rate.