Remediation of Smelter Contaminated Soil by Sequential Washing Using Biosurfactants

Remediation of Smelter Contaminated Soil by Sequential Washing Using Biosurfactants

Článek WoS

This paper presents experimental results from the use of biosurfactants in the remediation of a soil from a smelter in Poland. In the soil, concentrations of Cu (1659.1 mg/kg) and Pb (290.8 mg/kg) exceeded the limit values. Triple batch washing was tested as a soil treatment. Three main variants were used, each starting with a different plant-derived (saponin, S; tannic acid, T) or microbial (rhamnolipids, R) biosurfactant solution in the first washing, followed by 9 different sequences using combinations of the tested biosurfactants (27 in total). The efficiency of the washing was determined based on the concentration of metal removed after each washing (C-R), the cumulative removal efficiency (E-cumulative) and metal stability (calculated as the reduced partition index, I-r, based on the metal fractions from BCR sequential extraction). The type of biosurfactant sequence influenced the C-R values. The variants that began with S and R had the highest average E-cumulative for Cu and Pb, respectively. The E-cumulative value correlated very strongly (r > 0.8) with the stability of the residual metals in the soil. The average E-cumulative and stability of Cu were the highest, 87.4% and 0.40, respectively, with the S-S-S, S-S-T, S-S-R and S-R-T sequences. Lead removal and stability were the highest, 64-73% and 0.36-0.41, respectively, with the R-R-R, R-R-S, R-S-R and R-S-S sequences. Although the loss of biosurfactants was below 10% after each washing, sequential washing with biosurfactants enriched the soil with external organic carbon by an average of 27-fold (S-first variant), 24-fold (R first) or 19-fold (T first). With regard to environmental limit values, metal stability and organic carbon resources, sequential washing with different biosurfactants is a beneficial strategy for the remediation of smelter-contaminated soil with given properties.

This paper presents experimental results from the use of biosurfactants in the remediation of a soil from a smelter in Poland. In the soil, concentrations of Cu (1659.1 mg/kg) and Pb (290.8 mg/kg) exceeded the limit values. Triple batch washing was tested as a soil treatment. Three main variants were used, each starting with a different plant-derived (saponin, S; tannic acid, T) or microbial (rhamnolipids, R) biosurfactant solution in the first washing, followed by 9 different sequences using combinations of the tested biosurfactants (27 in total). The efficiency of the washing was determined based on the concentration of metal removed after each washing (C-R), the cumulative removal efficiency (E-cumulative) and metal stability (calculated as the reduced partition index, I-r, based on the metal fractions from BCR sequential extraction). The type of biosurfactant sequence influenced the C-R values. The variants that began with S and R had the highest average E-cumulative for Cu and Pb, respectively. The E-cumulative value correlated very strongly (r > 0.8) with the stability of the residual metals in the soil. The average E-cumulative and stability of Cu were the highest, 87.4% and 0.40, respectively, with the S-S-S, S-S-T, S-S-R and S-R-T sequences. Lead removal and stability were the highest, 64-73% and 0.36-0.41, respectively, with the R-R-R, R-R-S, R-S-R and R-S-S sequences. Although the loss of biosurfactants was below 10% after each washing, sequential washing with biosurfactants enriched the soil with external organic carbon by an average of 27-fold (S-first variant), 24-fold (R first) or 19-fold (T first). With regard to environmental limit values, metal stability and organic carbon resources, sequential washing with different biosurfactants is a beneficial strategy for the remediation of smelter-contaminated soil with given properties.

remediation; soil; copper; lead; saponin; tannic acid; rhamnolipids; organic carbon

remediation; soil; copper; lead; saponin; tannic acid; rhamnolipids; organic carbon

Zygmunt Mariusz Gusiatin, Jurate Kumpiene, Ivan Carabante, Maja Radziemska, Martin Brtnický

2022

07.12.2021

MDPI

BASEL

1660-4601

International Journal of Environmental Research and Public Health

18

12875

Švýcarská konfederace

1

21

21

https://www.mdpi.com/1660-4601/18/24/12875