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Wu J, Fu X, Zhao L, Lv J, Lv S, Shang J, Lv J, Du S, Guo H, Ma F. Biochar as a partner of plants and beneficial microorganisms to assist in-situ bioremediation of heavy metal contaminated soil. Sci Total Environ 2024; 923:171442. [PMID: 38453085 DOI: 10.1016/j.scitotenv.2024.171442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 02/19/2024] [Accepted: 03/01/2024] [Indexed: 03/09/2024]
Abstract
Synergistic remediation of heavy metal (HM) contaminated soil using beneficial microorganisms (BM) and plants is a common and effective in situ bioremediation method. However, the shortcomings of this approach are the low colonisation of BM under high levels of heavy metal stress (HMS) and the poor state of plant growth. Previous studies have overlooked the potential of biochar to mitigate the above problems and aid in-situ remediation. Therefore, this paper describes the characteristics and physicochemical properties of biochar. It is proposed that biochar enhances plant resistance to HMS and aids in situ bioremediation by increasing colonisation of BM and HM stability. On this basis, the paper focuses on the following possible mechanisms: specific biochar-derived organic matter regulates the transport of HMs in plants and promotes mycorrhizal colonisation via the abscisic acid signalling pathway and the karrikin signalling pathway; promotes the growth-promoting pathway of indole-3-acetic acid and increases expression of the nodule-initiating gene NIN; improvement of soil HM stability by ion exchange, electrostatic adsorption, redox and complex precipitation mechanisms. And this paper summarizes guidelines on how to use biochar-assisted remediation based on current research for reference. Finally, the paper identifies research gaps in biochar in the direction of promoting beneficial microbial symbiotic mechanisms, recognition and function of organic molecules, and factors affecting practical applications.
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Affiliation(s)
- Jieting Wu
- School of Environmental Science, Liaoning University, Shenyang 110036, China.
| | - Xiaofan Fu
- School of Environmental Science, Liaoning University, Shenyang 110036, China
| | - Lei Zhao
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Jin Lv
- School of Environmental Science, Liaoning University, Shenyang 110036, China
| | - Sidi Lv
- School of Environmental Science, Liaoning University, Shenyang 110036, China
| | - Jing Shang
- School of Environmental Science, Liaoning University, Shenyang 110036, China
| | - Jiaxuan Lv
- School of Environmental Science, Liaoning University, Shenyang 110036, China
| | - Shuxuan Du
- School of Environmental Science, Liaoning University, Shenyang 110036, China
| | - Haijuan Guo
- School of Environmental Science, Liaoning University, Shenyang 110036, China.
| | - Fang Ma
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
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Qiu J, De Souza MF, Wang X, Ok YS, Meers E. Influence of biochar addition and plant management (cutting and time) on ryegrass growth and migration of As and Pb during phytostabilization. Sci Total Environ 2024; 913:169771. [PMID: 38176551 DOI: 10.1016/j.scitotenv.2023.169771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 12/21/2023] [Accepted: 12/28/2023] [Indexed: 01/06/2024]
Abstract
Phytostabilization of metal-contaminated soils can be enabled or improved by biochar application. However, biochar-aided effects vary on biochar types, and little attention has been paid to plant management (time and cutting) to enhance phytostabilization efficiency in synergy with biochar. Therefore, biochars derived from pig manure (PM), Japanese knotweed (JK), and a mixture of both (P1J1) were applied to Pb and As mining soil with ryegrass cultivation to assess the biochar-induced effects on plant growth, dissolved organic matter (DOM), As and Pb mobility, and bioaccumulation within a phytostabilization strategy. Additional treatments involving the combined biochar (P1J1) and ryegrass were conducted to explore the influence of sequential cutting and growing time on facilitating phytostabilization efficacy. Biochar applications promoted plant growth, progressively increasing over time, but were not enhanced by cutting. Short and long-wavelength humic-like DOM substances identified in the soil pore water after biochar application varied depending on the biochar types used, providing evidence for the correlation among DOM changes, biochar origin, and metal immobilization. Biochar-treated soils exhibited reduced Pb availability and enhanced As mobility, with P1J1 stabilizing Pb significantly similar to PM while causing less As mobilization as JK did. The mobilized As did not result in increased plant As uptake; instead, all biochar-added plants showed a significant decrease in As and Pb concentrations compared to those without biochar. Soil available As decreased while available Pb increased with time, and cutting did not influence soil As behavior but did reduce soil Pb release. Nevertheless, plant As and Pb concentrations decreased over time, whereas those in multiple-cut plants were generally higher than those without cuts. Biochar, especially P1J1, along with growth time, holds promise in promoting plant biomass, reducing plant Pb and As concentrations, and minimizing the migration of PbAs within the soil.
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Affiliation(s)
- Jing Qiu
- Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium.
| | - Marcella Fernandes De Souza
- Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium
| | - Xiaolin Wang
- Future Energy Center, School of Business, Society and Engineering, Mälardalen University, 722 23 Västerås, Sweden
| | - Yong Sik Ok
- Korea Biochar Research Center, APRU Sustainable Waste Management Program & Division of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Erik Meers
- Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium
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Schommer VA, Nazari MT, Melara F, Braun JCA, Rempel A, Dos Santos LF, Ferrari V, Colla LM, Dettmer A, Piccin JS. Techniques and mechanisms of bacteria immobilization on biochar for further environmental and agricultural applications. Microbiol Res 2024; 278:127534. [PMID: 37944206 DOI: 10.1016/j.micres.2023.127534] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 10/02/2023] [Accepted: 10/19/2023] [Indexed: 11/12/2023]
Abstract
Bacteria immobilization on biochar is a promising approach to achieve high concentration and stability of microbial cells for several applications. The present review addressed the techniques utilized for bacteria immobilization on biochar, discussing the mechanisms involved in this process, as well as the further utilization in bioremediation and agriculture. This article presents three immobilization techniques, which vary according to their procedures and conditions, including cell growth, adsorption, and adaptation. The mechanisms for cell immobilization are primarily adsorption and biofilm formation on biochar. The favorable characteristics of biochar immobilization depend on the pyrolysis methods, raw materials, and properties of biochar, such as surface area, pore size, pH, zeta potential, hydrophobicity, functional groups, and nutrients. Scanning electron microscope (SEM) and colony forming unit (CFU) are the analyses commonly carried out to verify the efficiency of bacteria immobilization. The benefits of applying biochar-immobilized bacteria include soil decontamination and quality improvement, which can improve plant growth and crop yield. Therefore, this emerging technology represents a promising solution for environmental and agricultural purposes. However, it is important to evaluate the potential adverse impacts on native microbiota by introducing exogenous microorganisms.
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Affiliation(s)
- Vera Analise Schommer
- Graduate Program in Civil and Environmental Engineering (PPGEng), University of Passo Fundo (UPF), Passo Fundo, RS, Brazil.
| | - Mateus Torres Nazari
- Graduate Program in Civil and Environmental Engineering (PPGEng), University of Passo Fundo (UPF), Passo Fundo, RS, Brazil.
| | - Flávia Melara
- Graduate Program in Civil and Environmental Engineering (PPGEng), University of Passo Fundo (UPF), Passo Fundo, RS, Brazil
| | - Julia Catiane Arenhart Braun
- Graduate Program in Civil and Environmental Engineering (PPGEng), University of Passo Fundo (UPF), Passo Fundo, RS, Brazil
| | - Alan Rempel
- Graduate Program in Civil and Environmental Engineering (PPGEng), University of Passo Fundo (UPF), Passo Fundo, RS, Brazil
| | - Lara Franco Dos Santos
- Graduate Program in Mining, Metallurgical and Materials Engineering (PPGE3M), Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Valdecir Ferrari
- Graduate Program in Bioexperimentation, University of Passo Fundo (UPF), Passo Fundo, RS, Brazil
| | - Luciane Maria Colla
- Graduate Program in Civil and Environmental Engineering (PPGEng), University of Passo Fundo (UPF), Passo Fundo, RS, Brazil.
| | - Aline Dettmer
- Graduate Program in Food Science and Technology (PPGCTA), University of Passo Fundo (UPF), Passo Fundo, RS, Brazil
| | - Jeferson Steffanello Piccin
- Graduate Program in Civil and Environmental Engineering (PPGEng), University of Passo Fundo (UPF), Passo Fundo, RS, Brazil
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Ndour PMS, Bargaz A, Rchiad Z, Pawlett M, Clark IM, Mauchline TH, Harris J, Lyamlouli K. Microbial Catabolic Activity: Methods, Pertinence, and Potential Interest for Improving Microbial Inoculant Efficiency. Microb Ecol 2023; 86:2211-2230. [PMID: 37280438 DOI: 10.1007/s00248-023-02250-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 05/24/2023] [Indexed: 06/08/2023]
Abstract
Microbial catabolic activity (MCA) defined as the degrading activity of microorganisms toward various organic compounds for their growth and energy is commonly used to assess soil microbial function potential. For its measure, several methods are available including multi-substrate-induced respiration (MSIR) measurement which allow to estimate functional diversity using selected carbon substrates targeting specific biochemical pathways. In this review, the techniques used to measure soil MCA are described and compared with respect to their accuracy and practical use. Particularly the efficiency of MSIR-based approaches as soil microbial function indicators was discussed by (i) showing their sensitivity to different agricultural practices including tillage, amendments, and cropping systems and (ii) by investigating their relationship with soil enzyme activities and some soil chemical properties (pH, soil organic carbon, cation exchange capacity). We highlighted the potential of these MSIR-based MCA measurements to improve microbial inoculant composition and to determine their potential effects on soil microbial functions. Finally, we have proposed ideas for improving MCA measurement notably through the use of molecular tools and stable isotope probing which can be combined with classic MSIR methods. Graphical abstract describing the interrelation between the different parts and the concepts developed in the review.
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Affiliation(s)
- Papa Mamadou Sitor Ndour
- College for Sustainable Agriculture and Environmental Sciences, AgroBioSciences, Mohammed VI Polytechnic University, Ben Guerir, Morocco.
- Cranfield Soil and AgriFood Institute, School of Applied Sciences, Cranfield University, Cranfield, MK43 0AL, UK.
| | - Adnane Bargaz
- College for Sustainable Agriculture and Environmental Sciences, AgroBioSciences, Mohammed VI Polytechnic University, Ben Guerir, Morocco
| | - Zineb Rchiad
- Institute of Biological Sciences (ISSB), Faculty of Medical Sciences, Mohammed VI Polytechnic University, Ben Guerir, Morocco
| | - Mark Pawlett
- Cranfield Soil and AgriFood Institute, School of Applied Sciences, Cranfield University, Cranfield, MK43 0AL, UK
| | - Ian M Clark
- Sustainable Agriculture Sciences, Rothamsted Research, Harpenden, Hertfordshire, UK
| | - Tim H Mauchline
- Sustainable Agriculture Sciences, Rothamsted Research, Harpenden, Hertfordshire, UK
| | - Jim Harris
- Cranfield Soil and AgriFood Institute, School of Applied Sciences, Cranfield University, Cranfield, MK43 0AL, UK
| | - Karim Lyamlouli
- College for Sustainable Agriculture and Environmental Sciences, AgroBioSciences, Mohammed VI Polytechnic University, Ben Guerir, Morocco
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Schommer VA, Vanin AP, Nazari MT, Ferrari V, Dettmer A, Colla LM, Piccin JS. Biochar-immobilized Bacillus spp. for heavy metals bioremediation: A review on immobilization techniques, bioremediation mechanisms and effects on soil. Sci Total Environ 2023; 881:163385. [PMID: 37054796 DOI: 10.1016/j.scitotenv.2023.163385] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 04/04/2023] [Accepted: 04/05/2023] [Indexed: 04/15/2023]
Abstract
Heavy metals contamination present risks to ecosystems and human health. Bioremediation is a technology that has been applied to minimize the levels of heavy metals contamination. However, the efficiency of this process varies according to several biotic and abiotic aspects, especially in environments with high concentrations of heavy metals. Therefore, microorganisms immobilization in different materials, such as biochar, emerges as an alternative to alleviate the stress that heavy metals have on microorganisms and thus improve the bioremediation efficiency. In this context, this review aimed to compile recent advances in the use of biochar as a carrier of bacteria, specifically Bacillus spp., with subsequent application for the bioremediation of soil contaminated with heavy metals. We present three different techniques to immobilize Bacillus spp. on biochar. Bacillus strains are capable of reducing the toxicity and bioavailability of metals, while biochar is a material that serves as a shelter for microorganisms and also contributes to bioremediation through the adsorption of contaminants. Thus, there is a synergistic effect between Bacillus spp. and biochar for the heavy metals bioremediation. Biomineralization, biosorption, bioreduction, bioaccumulation and adsorption are the mechanisms involved in this process. The application of biochar-immobilized Bacillus strains results in beneficial effects on the contaminated soil, such as the reduction of toxicity and accumulation of metals in plants, favoring their growth, in addition to increasing microbial and enzymatic activity in soil. However, competition and reduction of microbial diversity and the toxic characteristics of biochar are reported as negative impacts of this strategy. More studies using this emerging technology are essential to improve its efficiency, to elucidate the mechanisms and to balance positive and negative impacts, especially at the field scale.
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Affiliation(s)
- Vera Analise Schommer
- Graduate Program in Civil and Environmental Engineering (PPGEng), University of Passo Fundo (UPF), Passo Fundo, RS, Brazil
| | - Ana Paula Vanin
- Graduate Program in Civil and Environmental Engineering (PPGEng), University of Passo Fundo (UPF), Passo Fundo, RS, Brazil
| | - Mateus Torres Nazari
- Graduate Program in Civil and Environmental Engineering (PPGEng), University of Passo Fundo (UPF), Passo Fundo, RS, Brazil
| | - Valdecir Ferrari
- Graduate Program in Mining, Metallurgical and Materials Engineering (PPGE3M), Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Aline Dettmer
- Graduate Program in Food Science and Technology (PPGCTA), University of Passo Fundo (UPF), Passo Fundo, RS, Brazil
| | - Luciane Maria Colla
- Graduate Program in Civil and Environmental Engineering (PPGEng), University of Passo Fundo (UPF), Passo Fundo, RS, Brazil.
| | - Jeferson Steffanello Piccin
- Graduate Program in Civil and Environmental Engineering (PPGEng), University of Passo Fundo (UPF), Passo Fundo, RS, Brazil
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Abstract
The genus Bacillus has been widely applied in contemporary agriculture as an environmentally-friendly biological agent. However, the real effect of commercial Bacillus-based fertilizers and pesticides varies immensely in the field. To harness Bacillus for efficient wheat production, we reviewed the diversity, functionality, and applicability of wheat-associated native Bacillus for the first time. Our main findings are: (i) Bacillus spp. inhabit the rhizosphere, root, stem, leaf, and kernel of wheat; (ii) B. subtilis and B. velezensis are the most widely endophytic species that can be isolated from both below and aboveground tissues; (iii) major functions of these representative strains are promotion of plant growth and alleviation of both abiotic and biotic stresses in wheat; (iv) stability and effectiveness are 2 major challenges during field application; (v) a STVAE pipeline that includes 5 processes, namely, Screen, Test, Validation, Application, and Evaluation, has been proposed for the capture and refinement of wheat-associated Bacillus spp. In particular, this review comprehensively addresses possible solutions, concerns, and criteria during the development of native Bacillus-based inoculants for sustainable wheat production.
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Vlajkov V, Pajčin I, Vučetić S, Anđelić S, Loc M, Grahovac M, Grahovac J. Bacillus-Loaded Biochar as Soil Amendment for Improved Germination of Maize Seeds. Plants (Basel) 2023; 12:1024. [PMID: 36903885 PMCID: PMC10004800 DOI: 10.3390/plants12051024] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 02/20/2023] [Accepted: 02/21/2023] [Indexed: 06/18/2023]
Abstract
Biochar is considered one of the most promising long-term solutions for soil quality improvement, representing an ideal environment for microorganisms' immobilization. Hence there is a possibility to design microbial products formulated using biochar as a solid carrier. The present study was aimed at development and characterization of Bacillus-loaded biochar to be applied as a soil amendment. The producing microorganism Bacillus sp. BioSol021 was evaluated in terms of plant growth promotion traits, indicating significant potential for production of hydrolytic enzymes, indole acetic acid (IAA) and surfactin and positive tests for ammonia and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase production. Soybean biochar was characterised in terms of physicochemical properties to evaluate its suitability for agricultural applications. The experimental plan for Bacillus sp. BioSol021 immobilisation to biochar included variation of biochar concentration in cultivation broth and adhesion time, while the soil amendment effectiveness was evaluated during maize germination. The best results in terms of maize seed germination and seedling growth promotion were achieved by applying 5% of biochar during the 48 h immobilisation procedure. Germination percentage, root and shoot length and seed vigour index were significantly improved when using Bacillus-biochar soil amendment compared to separate treatments including biochar and Bacillus sp. BioSol021 cultivation broth. The results indicated the synergistic effect of producing microorganism and biochar on maize seed germination and seedling growth promotion, pointing out the promising potential of this proposed multi-beneficial solution for application in agricultural practices.
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Affiliation(s)
- Vanja Vlajkov
- Faculty of Technology Novi Sad, University of Novi Sad, Bulevar Cara Lazara 1, 21000 Novi Sad, Serbia
| | - Ivana Pajčin
- Faculty of Technology Novi Sad, University of Novi Sad, Bulevar Cara Lazara 1, 21000 Novi Sad, Serbia
| | - Snežana Vučetić
- Faculty of Technology Novi Sad, University of Novi Sad, Bulevar Cara Lazara 1, 21000 Novi Sad, Serbia
| | - Stefan Anđelić
- Faculty of Technical Sciences, University of Novi Sad, Trg Dositeja Obradovića 6, 21000 Novi Sad, Serbia
| | - Marta Loc
- Faculty of Agriculture, University of Novi Sad, Trg Dositeja Obradovića 8, 21000 Novi Sad, Serbia
| | - Mila Grahovac
- Faculty of Agriculture, University of Novi Sad, Trg Dositeja Obradovića 8, 21000 Novi Sad, Serbia
| | - Jovana Grahovac
- Faculty of Technology Novi Sad, University of Novi Sad, Bulevar Cara Lazara 1, 21000 Novi Sad, Serbia
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Wu C, Zhi D, Yao B, Zhou Y, Yang Y, Zhou Y. Immobilization of microbes on biochar for water and soil remediation: A review. Environ Res 2022; 212:113226. [PMID: 35452667 DOI: 10.1016/j.envres.2022.113226] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 03/05/2022] [Accepted: 03/29/2022] [Indexed: 06/14/2023]
Abstract
Biochar has caught great attention over the last decade with the loose and porous structure, and carbon stability provides suitable living conditions for the growth and activity of microorganisms. This review provided a comprehensive summary of biochar immobilization microbe (BIM) in water and soil decontamination. Firstly, the bacterial immobilization techniques including adsorption, entrapping, and covalence methods were exhibited. Secondly, the applications of BIM in water and soil environmental remediation were introduced, mainly including the treatment of organic pollutants, heavy metals, and N/P, among which the most frequently immobilized microorganism was Bacillus. Then, the mechanisms of adsorption, redox, and degradation were analyzed. Finally, pertinent questions for future research of BIM technology were proposed. The purpose of this paper is to provide useful background information for the selection of better biochar fixation microorganisms for water and soil remediation.
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Affiliation(s)
- Chuchu Wu
- Hunan International Scientific and Technological Cooperation Base of Agricultural Typical Pollution Remediation and Wetland Protection, College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, China
| | - Dan Zhi
- Hunan International Scientific and Technological Cooperation Base of Agricultural Typical Pollution Remediation and Wetland Protection, College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, China
| | - Bin Yao
- Hunan International Scientific and Technological Cooperation Base of Agricultural Typical Pollution Remediation and Wetland Protection, College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, China.
| | - Yuzhou Zhou
- Hunan International Scientific and Technological Cooperation Base of Agricultural Typical Pollution Remediation and Wetland Protection, College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, China
| | - Yuan Yang
- Hunan International Scientific and Technological Cooperation Base of Agricultural Typical Pollution Remediation and Wetland Protection, College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, China
| | - Yaoyu Zhou
- Hunan International Scientific and Technological Cooperation Base of Agricultural Typical Pollution Remediation and Wetland Protection, College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, China.
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Palmeggiani G, Lebrun M, Simiele M, Bourgerie S, Morabito D. Effect of Biochar Application Depth on a Former Mine Technosol: Impact on Metal(Loid)s and Alnus Growth. Environments 2021; 8:120. [DOI: 10.3390/environments8110120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The contamination of soil by potentially toxic elements (PTEs) is a problem resulting from various anthropic activities including the exploitation of mines, which determines an accumulation of metal(loid)s in the surrounding area. It is therefore necessary to use remediation techniques to prevent the potential damage to human health and the ecosystem. One of these techniques is phytoremediation, which involves the revegetation of contaminated areas in such a way as to reduce the spread of contaminants and entry into the groundwater by stabilizing the metal(loid)s in the soil, decreasing their mobility. To increase the ability of plants to grow under the extreme conditions of contaminated soils, it is necessary to use amendments, which can also intervene directly in reducing the mobility of contaminants. In this study, an open-field mesocosm was set up using a former mining technosol contaminated mainly by As. A biochar produced from hardwood was added at two different depths to evaluate the effectiveness of these application modalities for an overall observation duration of 17 months. Iron sulphate was also applied in both non-biochar and biochar amended conditions. In addition, trees of Alnus sp. were planted to examine the effectiveness of these plants for their use in soil remediation and the effect of the treatments used. The results showed an increase in soil pH induced by the biochar, which decreased over time. During the period examined, the application of biochar in the deepest layer was able to retain As more effectively. The Alnus sp. showed similar growth rates among the various treatments, resulting from its tolerance towards arsenic.
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