Mass balance of metals during the phytoremediation process using Noccaea caerulescens : a pot study
- PDF / 560,958 Bytes
- 10 Pages / 595.276 x 790.866 pts Page_size
- 59 Downloads / 198 Views
RESEARCH ARTICLE
Mass balance of metals during the phytoremediation process using Noccaea caerulescens: a pot study Wenxiang He 1 & Aogui Long 1 & Chunming Zhang 1 & Min Cao 2 & Jie Luo 1 Received: 29 February 2020 / Accepted: 11 October 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract There are two widely used methods to estimate the time taken for phytoremediation for the removal of the target pollutants, i.e., using the data of metal uptake by the harvested parts of the selected plant or using the decrement in average element content between the beginning and end of the remediation. The latter not only depends on sampling points but is also determined by sampling time because even if the soil is initially perfectly homogenized, plant growth itself heterogenizes the soil as time goes by. In this study, phytoremediation was tested on one homogenized soil obtained from various soil samples taken within an ewaste dismantling and recycling site, and the remediation time for different points of bulk and rhizosphere soil was estimated using the two methods. Phytoremediation efficiency, as assessed by the change in soil metal concentrations over 100 days, widely varied depending on which of the six soil compartments of the pot was sampled, and the standard deviations of Cd, Zn, Pb, and Cu increased as the experiment proceeded, indicating the inaccuracy of this method. When applied to rhizosphere soil, this method led to a large overestimation of phytoremediation efficiency for Cd and Zn, which was 81- and 77-fold that was obtained by measuring the actual amount of metals taken up by Noccaea caerulescens. The significant difference between the two methods indicated that the blended soil became heterogeneous during the phytoremediation process because the species extracted metals from different soil parts, manifested by the variation in the metal content. The gap between these two estimation methods decreased when the soil was mixed thoroughly at the end of the experiment. This work shows that calculating the metal decontamination efficiency based on the measurement of the actual amount of metal taken by the plant is more robust than estimating it based on the evolution of soil metal concentration over time. In addition, our study reveals that using N. caerulescens may not be appropriate in Pb- or Cu-polluted soil, since this species mobilized these metals but did not extract them. Keywords Phytoremediation . Spatial variability . Heavy metal . Remediation time . Rhizosphere soil
Introduction With the development of urbanization and industry, different toxicants have been released into the soil, river, and atmosphere. A recent national environmental pedological and geochemical investigation showed that 16.1% of the national territorial area has been influenced by different pollutants, and heavy metal pollution is involved in 82% of such contaminated area (Wang et al. 2018). Besides the high geochemistry
Responsible Editor: Elena Maestri * Jie Luo [email protected] 1
KLETOR Ministry of E
Data Loading...
