Submit to Toxics Review for Toxics Propose a Special Issue

Journal Menu

Journal Browser

Safe Utilization and Ecological Restoration of Heavy Metal Polluted Farmland

Print Special Issue Flyer
Special Issue Editors
Special Issue Information
Keywords
Benefits of Publishing in a Special Issue
Published Papers

A special issue of Toxics (ISSN 2305-6304). This special issue belongs to the section "Toxicity Reduction and Environmental Remediation".

Deadline for manuscript submissions: closed (25 October 2024) | Viewed by 6223

Share This Special Issue

Special Issue Editors

Dr. Bin Guo

E-Mail Website
Guest Editor

Institute of Environment, Resource, Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
Interests: heavy metal; contamination; phytoremediation; soil; cadmium

Prof. Dr. Ying Feng

E-Mail Website
Guest Editor

College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China
Interests: heavy metals; plant-microbe interaction; bioavailability; endophytic bacteria; phytoremediation; soil pollution and food safety
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Heavy metals are naturally occurring elements that have a high density and are toxic to living organisms, including humans. Some common heavy metals include lead, mercury, cadmium, arsenic, nickel, copper and chromium. They can persist in the environment for long periods, and have been a significant environmental concern posing high risks to both ecosystems and human health.

To address heavy metal pollution, regulations and guidelines are implemented to control and minimize the release of heavy metals into the environment. This includes the enforcement of emission standards for industries, the proper management and disposal of hazardous waste, and the implementation of monitoring programs to assess the levels of heavy metal contamination in different environmental compartments.

The remediation of heavy metal-contaminated soil is crucial to mitigate the risks posed by this pollution. Several techniques are employed to remove or reduce heavy metals from the soil. Physical methods, such as excavation and soil capping, involve physically removing the contaminated soil or covering it with a barrier to prevent further contamination. Chemical methods, such as soil washing and chemical immobilization, aim to change the chemical properties of heavy metals in the soil, making them less mobile and less available to plants and organisms. Biological methods, such as the use of plants in phytoremediation, utilize certain plant species that can accumulate and remove heavy metals from the soil.

Dr. Bin Guo
Prof. Dr. Ying Feng
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Toxics is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

heavy metal
environment
phytoremediation
utilization
ecological restoration
toxicity
safe utilization

Benefits of Publishing in a Special Issue

Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
e-Book format: Special Issues with more than 10 articles can be published as dedicated e-books, ensuring wide and rapid dissemination.

Further information on MDPI's Special Issue polices can be found here.

Published Papers (5 papers)

Download All Papers

Order results

Result details

Show export options Show export options

Select all

Export citation of selected articles as:

Research

21 pages, 2558 KiB

Open AccessArticle

Rice Husk as a Sustainable Amendment for Heavy Metal Immobilization in Contaminated Soils: A Pathway to Environmental Remediation

by Riccardo Cecire, Aleandro Diana, Agnese Giacomino, Ornella Abollino, Paolo Inaudi, Laura Favilli, Stefano Bertinetti, Simone Cavalera, Luisella Celi and Mery Malandrino

Toxics 2024, 12(11), 790; https://doi.org/10.3390/toxics12110790 - 29 Oct 2024

Viewed by 824

Abstract

Rice husk is a waste byproduct of rice production. This material has a moderate cost and is readily available, representing 20–22% of the biomass produced by rice cultivation. This study focused on the properties of rice husk in the remediation of soils contaminated by heavy metals. The effect of particle size, pH, and the presence of organic ligands on sorption efficiency was evaluated for Cd, Cu, and Mn. The continuous flow method was used to select suitable operative conditions and maximize the retention of heavy metals. Subsequently, pot experiments were carried out by growing two broadleaf plants, Lactuca sativa and Spinacia oleracea, in aliquots of soil collected in a Piedmont (Northwest Italy) site heavily contaminated by Cu, Cr, and Ni. Rice husk was added to the contaminated soil to evaluate its effectiveness in immobilizing heavy metals. The availability of Cr, Mn, Ni, Cu, Zn, Cd, and Pb in soil was studied using Tessier’s sequential extraction protocol. The content of the elements was also analyzed in plants and the uptake of heavy metals was evaluated in relation to the addition of rice husk. The growth of both plants was more efficient in the presence of rice husk due to its ability to reduce the mobility of heavy metals in the soil. The simplicity, cost-effectiveness, and scalability of its employment make the use of rice husk suitable for practical applications in soil remediation. Full article

(This article belongs to the Special Issue Safe Utilization and Ecological Restoration of Heavy Metal Polluted Farmland)

► Show Figures

Graphical abstract

17 pages, 3202 KiB

Open AccessArticle

Quantitative Soil Characterization for Biochar–Cd Adsorption: Machine Learning Prediction Models for Cd Transformation and Immobilization

by Muhammad Saqib Rashid, Yanhong Wang, Yilong Yin, Balal Yousaf, Shaojun Jiang, Adeel Feroz Mirza, Bing Chen, Xiang Li and Zhongzhen Liu

Toxics 2024, 12(8), 535; https://doi.org/10.3390/toxics12080535 - 24 Jul 2024

Viewed by 1212

Abstract

Soil pollution with cadmium (Cd) poses serious health and environmental consequences. The study investigated the incubation of several soil samples and conducted quantitative soil characterization to assess the influence of biochar (BC) on Cd adsorption. The aim was to develop predictive models for Cd concentrations using statistical and modeling approaches dependent on soil characteristics. The potential risk linked to the transformation and immobilization of Cd adsorption by BC in the soil could be conservatively assessed by pH, clay, cation exchange capacity, organic carbon, and electrical conductivity. In this study, Long Short-Term Memory (LSTM), Bidirectional Gated Recurrent Unit (BiGRU), and 5-layer CNN Convolutional Neural Networks (CNNs) were applied for risk assessments to establish a framework for evaluating Cd risk in BC amended soils to predict Cd transformation. In the case of control soils (CK), the BiGRU model showed commendable performance, with an

R^{2}

value of 0.85, indicating an approximate 85.37% variance in the actual Cd. The LSTM model, which incorporates sequence data, produced less accurate results (

R^{2} = 0.84)

, while the 5-layer CNN model had an R² value of 0.91, indicating that the CNN model could account for over 91% of the variation in actual Cd levels. In the case of BC-applied soils, the BiGRU model demonstrated a strong correlation between predicted and actual values with

R^{2}

(0.93), indicating that the model explained 93.21% of the variance in Cd concentrations. Similarly, the LSTM model showed a notable increase in performance with BC-treated soil data. The

R^{2}

value for this model stands at a robust

R^{2} (0.94)

, reflecting its enhanced ability to predict Cd levels with BC incorporation. Outperforming both recurrent models, the 5-layer CNN model attained the highest precision with an

R^{2}

value of 0.95, suggesting that 95.58% of the variance in the actual Cd data can be explained by the CNN model’s predictions in BC-amended soils. Consequently, this study suggests developing ecological soil remediation strategies that can effectively manage heavy metal pollution in soils for environmental sustainability. Full article

(This article belongs to the Special Issue Safe Utilization and Ecological Restoration of Heavy Metal Polluted Farmland)

► Show Figures

Graphical abstract

18 pages, 3413 KiB

Open AccessArticle

Evaluating the Response of the Soil Bacterial Community and Lettuce Growth in a Fluorine and Cadmium Co-Contaminated Yellow Soil

by Mei Wang, Xiangxiang Chen, Yasir Hamid and Xiaoe Yang

Toxics 2024, 12(7), 459; https://doi.org/10.3390/toxics12070459 - 25 Jun 2024

Viewed by 1005

Abstract

The impact of cadmium (Cd) and fluorine (F) on plant and human health has provoked significant public concern; however, their combined effects on plant and soil bacterial communities have yet to be determined. Here, a pot experiment was conducted to evaluate the effects of exogenous F, Cd, and their combination (FCd) on lettuce growth and soil bacterial communities. The results revealed that F and Cd concentrations in lettuce ranged from 63.69 to 219.45 mg kg⁻¹ and 1.85 to 33.08 mg kg⁻¹, respectively, presenting lower values in shoots than in the roots. Moreover, low contamination levels had no discernable influence on lettuce growth, but showed a synergistic negative on plant biomass when exogenous F and Cd exceeds 300 and 1.0 mg kg⁻¹, respectively. The results of 16S rRNA gene sequencing indicated that the most abundant bacterial community at the phylum level was Proteobacteria, with the relative abundance ranging from 33.42% to 44.10% across all the treatments. The contaminants had little effect on bacterial richness but impacted the structure of bacterial communities. The PCoA showed that compartment and contaminants were the primary contributors to the largest source of community variation, while the VPA indicated that F and Cd synergistically affected the bacterial communities. In turn, lettuce plants could enhance the resistance to the combined stress by increasing the relative abundance of Oxyphotobacteria, Subgroup 6, Thermoleophilia, and TK10 classes in the rhizosphere. Full article

(This article belongs to the Special Issue Safe Utilization and Ecological Restoration of Heavy Metal Polluted Farmland)

► Show Figures

Graphical abstract

12 pages, 2398 KiB

Open AccessArticle

Temporal and Spatial Variation of Toxic Metal Concentrations in Cultivated Soil in Jiaxing, Zhejiang Province, China: Characteristics and Mechanisms

by Mengzhuo Cao, Yanbo Jia, Xin Lu, Jinfa Huang, Yanlai Yao, Leidong Hong, Weijing Zhu, Weiping Wang, Fengxiang Zhu and Chunlai Hong

Toxics 2024, 12(6), 390; https://doi.org/10.3390/toxics12060390 - 26 May 2024

Viewed by 806

Abstract

The toxic metal (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) pollution in 250 agricultural soil samples representing the urban area of Jiaxing was studied to investigate the temporal and spatial variations. Compared to the early 1990s, the pollution level has increased. Industry and urbanization were the main factors causing toxic metal pollution on temporal variation, especially the use of feed containing toxic metals. The soil types and crop cultivation methods are the main factors causing toxic metal pollution on spatial variation. Although the single-factor pollution indices of all the toxic metals were within the safe limits, as per the National Soil Environmental Quality Standard (risk screening value), if the background values of soil elements in Jiaxing City are used as the standard, the pollution index of all the elements surveyed exceeds 1.0, reaching a level of mild pollution. The soil samples investigated were heavily contaminated with toxic metal compounds, and their levels increased over time. This situation poses potential ecological and health risks. Full article

(This article belongs to the Special Issue Safe Utilization and Ecological Restoration of Heavy Metal Polluted Farmland)

► Show Figures

Figure 1

16 pages, 5830 KiB

Open AccessArticle

A Modified Model for Quantitative Heavy Metal Source Apportionment and Pollution Pathway Identification

by Maodi Wang, Pengyue Yu, Zhenglong Tong, Xingyuan Shao, Jianwei Peng, Yasir Hamid and Ying Huang

Toxics 2024, 12(6), 382; https://doi.org/10.3390/toxics12060382 - 23 May 2024

Viewed by 1297

Abstract

Current source apportionment models have successfully identified emission sources and quantified their contributions. However, when being utilized for heavy metal source apportion in soil, their accuracy needs to be improved, regarding migration patterns. Therefore, this work intended to improve the pre-existing principal component analysis and multiple linear regression with distance (PCA-MLRD) model to effectively locate pollution pathways (traffic emissions, irrigation water, atmospheric depositions, etc.) and achieve a more precise quantification. The dataset of soil heavy metals was collected from a typical area in the Chang-Zhu-Tan region, Hunan, China in 2021. The identification of the contribution of soil parent material was accomplished through enrichment factors and crustal reference elements. Meanwhile, the anthropogenic emission was identified with principal component analysis and GeoDetector. GeoDetector was used to accurately point to the pollution source from a spatial differentiation perspective. Subsequently, the pollution pathways linked to the identified sources were determined. Non-metal manufacturing factories were found to be significant anthropogenic sources of local soil contamination, mainly through rivers and atmospheric deposition. Furthermore, the influence of irrigation water on heavy metals showed a more pronounced effect within a distance of 1000 m, became weaker after that, and then gradually disappeared. This model may offer improved technical guidance for practical production and the management of soil heavy metal contamination. Full article

(This article belongs to the Special Issue Safe Utilization and Ecological Restoration of Heavy Metal Polluted Farmland)

► Show Figures

Journal Menu

Journal Browser

Safe Utilization and Ecological Restoration of Heavy Metal Polluted Farmland

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Published Papers (5 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI