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Mine Site Restoration Using Silvicultural Approach

  • January 2018
DOI:10.1016/B978-0-12-812986-9.00007-5
  • In book: Bio-Geotechnologies for Mine Site Rehabilitation (pp.115-130)
  • Edition: 1st Edition
  • Chapter: 7
  • Publisher: Elsevier
  • Editors: M.N.V. Prasad, Paulo Jorge de Campos Favas, Subodh Kumar Maiti
Authors:
Milan Borišev at University of Novi Sad
Milan Borišev
Slobodanka Pajević at University of Novi Sad
Slobodanka Pajević
Nataša P Nikolić at University of Novi Sad
Nataša P Nikolić
Andrej Pilipovic at University of Novi Sad
Andrej Pilipovic
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Abstract

Tree plantations remain to be a viable option for reclamation of abandoned mine lands, either as a use-only method or as a polishing procedure to be used as an add-up technology at already restored sites. It permits restoration of sites by conserving and improving basic soil biological and physical properties. At the same time it is cost-effective and can even bring some economical return through commercial valorization of obtained biomass and aesthetic recovery of the landscape. Its application should be advised more for moderate to low contaminated sites, otherwise the period of restoration could last for decades. This technology is in continuous development providing new possibilities but also some important restrictions in its potential applications. Additional modifications such as adding different amendments like chelating agents or acidifying amendments, organic fertilizers or composts could significantly improve soil properties and thus increase the efficiency of the remediation process. New horizons in the area are emerging by further development of transgenic plants as improved tools for the restoration process, and also by new nanomaterials applied to different plant commercial species
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Bio-Geotechnologies for Mine Site Rehabilitation. http://dx.doi.org/10.1016/B978-0-12-812986-9.00007-5
Copyright © 2018 Elsevier Inc. All rights reserved.
CHAPTER
MINE SITE RESTORATION
USING SILVICULTURAL
APPROACH
Milan Borišev, Slobodanka Pajević, Nataša Nikolić, Andrej Pilipović,
Danijela Arsenov, Milan Župunski
University of Novi Sad, Novi Sad, Serbia
7
7.1 INTRODUCTION
Among various ways that mankind affects environment, surface mining presents one of the most
extreme technologies. Surface mining results in the excavation of different materials such as coal,
metals, minerals and peat, and soil and rock overlying or hosting a shallow ore during which deposit
is physically removed to access the resource (Lima et al., 2016). Hence, opencast coal mining dam-
ages 2–11 times more land than underground mining (Bai et al., 1999). According to various authors
(Miller and Zegre, 2014; Mummey et al., 2002a), surface mining disturbs the landscape; impacts
habitat integrity, environmental flows, and ecosystem functions; and raises concerns about water, air,
and soil quality and often, public health. Overburden dumps created for the accommodation of mine
waste have major effects such as deterioration of aesthetics and reduction in land productivity.
Complete destruction of landform (landscape) and habitat acts as a continuous source of air and
water pollution (Mukhopadhyay et al., 2013). Concerning the mining activities, presently mines are
specifically designed with mitigation methods to manage potential environmental impacts; however,
in former mines the extracted mineral deposits may remain after mines have been abandoned and
usually become a large and uncontrolled source of metal and metalloid contamination (Moreno-
Jiménez et al., 2011). Therefore, to reduce the environmental risks of mining waste, revegеtation has
been recommended as the most promising approach (Bradshaw and Johnson, 1992). Fortunately,
unlike other industries, mining is a temporary user of a specific land site, and proper reclamation can
restore the productivity of land and may bring better landscape (Maiti, 2013). Afforestation of mine
wastes by the establishment of permanent plant cover is an alternative practice for remediation
(Kramer et al., 2000; Mains et al., 2006), rather than to abandon sites or give physicochemical treat-
ment (Ortega-Larrocea et al., 2010). Depending on the type of surface mining, technologies used,
type of the material excavated, and the overall impact on the environment and expected end-point,
the biological recovery activities, according to Lima et al. (2016), can be defined as R4 terminology:
(1) remediation (cleaning of particular target, i.e., soil, water, health with decontamination as end
target), (2) reclamation (recovering ecosystem services, but not all, use of other species), (3) restora-
tion (bring back preexisting ecosystem), and (4) rehabilitation (land management for some uses such
as agriculture, forestry, or urbanization).

Supplementary resource (1)

BioGeoTechnologies Ch7
Data
January 2018
Milan Borišev · Slobodanka Pajević · Nataša P Nikolić · Andrej Pilipovic · Milan Župunski
... Moreover, using tree species for reclamation treatment is one of the oldest methods used in reclamation, especially in areas under an open cast mining method. Afforestation's influence on soil format is a process for the evolution of a postmining ecosystem [25,26]. Additionally, the afforestation of degraded areas with diverse tree species allows for sequestering more carbon, is more resistant, and gives a bigger biomass production [21,25]. ...
... Afforestation's influence on soil format is a process for the evolution of a postmining ecosystem [25,26]. Additionally, the afforestation of degraded areas with diverse tree species allows for sequestering more carbon, is more resistant, and gives a bigger biomass production [21,25]. Some tree species (pioneer species) are resistant to heavy conditions by using a mechanism against the stressful conditions that occur in degraded areas [25]. ...
... Additionally, the afforestation of degraded areas with diverse tree species allows for sequestering more carbon, is more resistant, and gives a bigger biomass production [21,25]. Some tree species (pioneer species) are resistant to heavy conditions by using a mechanism against the stressful conditions that occur in degraded areas [25]. Soil is a crucial element, and has the ability to influence restored and newly created ecosystems [21]. ...
Reclaimed Area Land Cover Mapping Using Sentinel-2 Imagery and LiDAR Point Clouds
Article
Full-text available
  • Jan 2020
This paper investigates the possibility of using fusion Sentinel-2 imageries (2016, ESA) and light detection and ranging (LiDAR) point clouds for the automation of land cover mapping with a primary focus on detecting and monitoring afforested areas and deriving precise information about the spatial (2D and 3D) characteristics of vegetation for reclaimed areas. The study was carried out for reclaimed areas – two former sulfur mines located in Southeast Poland, namely, Jeziórko, where 216.5 ha of afforested area was reclaimed after borehole exploitation, and Machów, where 871.7 ha of dump area was reclaimed after open cast strip mining. The current land use and land cover (LULC) classes at the Machów and Jeziórko former sulfur mines are derived based on Sentinel-2 image processing, and confirmed the applied type of reclamation for both analysed areas. The following LULC classes showed a significant spatial range: broad-leaved forest, coniferous forest, and transitional woodland shrub. The progress of afforested areas, not only in terms of the occupied area, but also in terms of the growth of trees and shrubs, was confirmed. The results of the study showed differences in vegetation parameters, namely, height and canopy cover. Various stages of vegetation growth were also observed. This indicates an ongoing process of vegetation development, as an effect of the reclamation treatment for these areas.
... Unfavorable conditions for plant growth at mining sites present the most crucial limitation in using revegetation for soil remediation (Mulligan et al., 2001). In particular, contamination levels, low-soil fertility, lack of organic matter, disturbance of soil chemical and physical properties, and disappearance of soil microbiota comprise the most common obstacles in revegetation (Borišev et al., 2018). Considering these limitations, selection of proper plant species (and genotypes, where applicable) is a prerequisite for future success of surface mine reclamation. ...
Bioremediation and soils
Chapter
  • Jan 2021
Anthropogenic activities worldwide have caused ecological degradation that has resulted in the need to mitigate damage to essential ecosystem services in rural and urban areas. Plant-based technologies, such as phytoremediation and associated phytotechnologies, are ideal for such applications but require extensive knowledge of soil–plant interactions for restoration to be successful. Here we describe remediation of contaminated soils using plants, focusing on the selection of appropriate plant materials and soil factors important for designing remediation systems. The last section of the chapter contains five real-world examples of such systems, including (1) grasslands used for phytoremediation of soil phosphorus, (2) urban afforestation used to create forests in cities, (3) riparian buffer systems used to reduce agrichemical transport from agroecosystems, (4) short rotation woody crops used to enhance ecosystem services at landfills, and (5) woody species used for surface mine reclamation.
... The negative impact of mining disturbance on the surrounding area exceeded 10-15 times the area of mine sites. Tree planting remains one of the most effective strategies in re-establishing ecosystems [4][5][6][7][8] Forest reclamation and restoration of mine sites helps to prevent erosion and to return the land to productive capability [9]. ...
Betula pendula Roth. survival and growth on mine sites of the Kursk Magnetic Anomaly
Article
Full-text available
  • Nov 2019
The study sites is located in an iron-mining district of European part of Russia, called The Kursk Magnetic Anomaly. Birch tree (Betula pendula Roth) plantation was created in 1972 in two different types of heap dumps (hydraulic-mine dumps and mining dumps). Afforested dumps are mainly consisted of cenomanian and aptian sands with the admixture of mesozoic carbonate rocks. In particular hydraulic-mine dumps are formed with sand material and mining dumps are formed with sandy-lime material. For improving poor properties of sand substrate before the planting birch trees on hydraulic-mine dumps were used the technique of soil transfer. The re-spreading fertile layer of soil varies from 30 to 80 cm. Substrate quality varied considerably. Long-term growth and survival of birch tree were analyzed and volume per ha were calculated in different slope parts. Study results show that double-layer substrate with fertile layer (30-40 cm) on the top would not appear to be the best way to rehabilitate mine ecosystems and it has significant disadvantages. At the age of 38 years, common birch is characterized by sufficiently high growth parameters, but low survival.
... At present, the greatest attention is paid to agricultural land reclamation. Grain and legume crops are grown on the open-air lands, perennial grasses are sown, and garden agro-crops are created [9,10]. Since mining activity negatively affects the physical and chemical properties of the soil and the survival of plants, their restoration can be achieved by using such plant species that are able to tolerate specific soil properties within the mine workings. ...
The Prospect of the Use of Energy Crops for Biological Reclamation of Disturbed Lands
Article
  • Jan 2019
Senegalia senegal (L.) Britton Response to Microbial and Manure Amendments for the Rehabilitation of Waste Rock Dumps in the Essakane Gold Mining Site, Burkina Faso
Article
  • Feb 2022
Senegalia senegal (L.) Britton (Fabaceae) is a widespread, multipurpose tree capable of colonizing disturbed Sub-Saharan mining sites given its adaptations to arid lands. The purpose of this study was to determine the potential of the association of microbial and/or manure amendments with S. senegal seedlings for the effective rehabilitation of the environment post mining. A multi-year factorial experiment involving this species was conducted in a nursery and on waste rock dumps (Essakane gold mine, NE Burkina Faso). Inoculation with arbuscular mycorrhizal (AM) fungi (native isolate Rhizophagus aggregatus DAOM2277128; commercial isolate Rhizophagus irregularis DAOM197198) and Mesorhizobium plurifarium strain ORS3588 was conducted on S. senegal seedlings. These were planted in black polythene bags filled with three substrate types: 100% sandy soil (substrate A); 75% sandy soil, 25% manure (substrate B); and 50% sandy soil, 50% manure (substrate C). Seedlings were then out-planted on waste rock to determine whether microbial inoculation improves their growth and survival rates. Under nursery conditions, manure-enriched substrates harboured less nodulation and AM colonization, but substantially increased plant height, and dry mass compared to un-amended substrate. Inoculation on manure-enrich substrates did not consistently increase root AM colonization and plant growth parameters among treatments. Plants that were inoculated with R. aggregatus alone or with R. irregularis or Mesorhizobium plurifarium ORS3588 showed the greatest increase in growth variables. On un-amended substrates, inoculation with R . aggregatus in combination with M. plurifarium or R. irregularis significantly enhanced root colonization rates, without altering plant growth parameters. Yet, inoculation with R. irregularis or M. plurifarium alone did not elicit increases in these parameters, although nodulation was greatly improved by the latter treatment. In field conditions, plant growth and survival were reduced under high rate manure amendments, likely due to less AM colonization and root nodulation that was observed for these treatments in nursery before out-planting. Strongly colonized plants on the un-amended substrate and moderately amended substrate showed greater survival after out-planting. Our results support the general conclusion that microbial inoculation and manure-enriched substrates are a viable option for mining site rehabilitation using S. senegal . They also suggest that manure amendments in forest nurseries should be cautiously applied given that high rates may impede establishment of plant symbioses, thereby affecting their performance on waste rock dumps following out-planting.
Restoring coal mine degraded lands in India for achieving the UN‐sustainable development goals
Article
  • Nov 2021
Anthropogenic activities substantially altered the ecosystem's functioning and most of them are directly or indirectly responsible for biodiversity loss, land degradation, and climate change. Therefore, maximizing the conservation of natural capital and restoring the potential of the natural ecosystems are essential to sustain life on this planet. Where most of the economic activities are coupled with environmental degradation, the re-establishment of ecosystem attributes is a vital part of global conservation strategies. Mining activities cause inevitable loss of ecological structure and functions, while restoration of mine degraded lands provides an opportunity to reinstate ecological integrity and to develop a self-sustaining ecosystem. However, it cannot be possible without learning from our experience, scientific research, community participation, traditional knowledge, political support, and economic backup. Here, we summarize some of the field observations explicitly based on the restoration of coal mine degraded lands in India. Experiences based on the practical approaches of ecosystem restoration highlight the key role of physical aspects of restoration, selection of plant species for biological restoration, and its combined effect on generating socioeconomic and environmental benefits. We recommend the inclusion of a site-specific restoration plan, native species for reforestation, and involvement of the local community in restoration programs. Moreover, they are essential to attain the United Nations Sustainable Development Goals (UN-SDGs) particularly, reduce poverty and hunger, provide affordable and clean energy, mitigate climate change and reestablish life on degraded lands. This article is protected by copyright. All rights reserved.
Plant species selection and biomass nutrient content on post-mine sites of the Kursk magnetic anomaly, Russia
Article
  • Oct 2021
The article presents data on the assessment of the different tree and shrubs species for a reclamation of the hydraulic dump of the Kursk Magnetic Anomaly, Russia. The purpose of the work is to identify highly productive tree and shrub species with the maximum content of nitrogen and ash elements in the biomass. The objects of research are protective plantations of Robinia pseudoacacia L., Caragana arborescens L., Betula pendula L., Hippophae rhamnoides L., Pínus sylvestris L., Populus balsamifera L. Under the influence of different type of vegetation, the fertility of the dump substrates increases and the initial substrates gradually turns into soil. The rate of formation of primary soils depends on the biomass of plantations and the content of chemical elements in it. The article analyzes data on the content of the main chemical elements in different parts of plants aged 8-9 years. Trees and shrubs are arranged in sequential rows in terms of nitrogen accumulation, ash elements and overall biological productivity. The authors identified sea-buckthorn and robinia pseudoacacia, which, already at a young age, are characterized by high productivity (146.2 and 118.0 dt/ha) and have a positive effect on the fertility of the dump substrates.
land Managing and Reforesting Degraded Post-Mining Landscape in Indonesia: A Review
Article
Full-text available
  • Jun 2021
Citation: Pratiwi; Narendra, B.H.; Siregar, C.A.; Turjaman, M.; Hidayat, A.; Rachmat, H.H.; Mulyanto, B.; Suwardi; Iskandar; Maharani, R.; et al.
Soil Properties and Biomass Attributes in a Former Gravel Mine Area after Two Decades of Forest Restoration
Article
Full-text available
  • Jun 2020
The ongoing global deforestation resulting from anthropogenic activities such as unsustainable agriculture and surface mining threatens biodiversity and decreases both soil carbon and above-ground biomass stocks. In this study, we assessed soil properties and below- and above-ground biomass attributes in a restored former gravel mine area in Ghana two decades after active restoration with potted plants and fresh topsoil. We compared conditions to four alternative land-use types (unrestored abandoned gravel mine, arable land, semi-natural forest, and natural forest) representing pre- and post-disturbance as well as natural reference states. We hypothesized that soil properties and related levels of below- and above-ground biomass in the restored area share similarities with the natural reference systems and thereby are indicative of a trajectory towards successful restoration. Eight replicated subareas in each land-use type were assessed for a set of soil parameters as well as below- and above-ground biomass attributes. The soil properties characteristic for the restored area differed significantly from pre-restoration stages, such as the abandoned gravel site, but did not differ significantly from properties in the natural forest (except for bulk density and base saturation). Above-ground biomass was lower in the restored area in comparison to the reference natural forests, while differences were not significant for below-ground biomass. Silt and effective cation exchange capacity were closely related to above-ground biomass, while below-ground biomass was related to soil organic carbon, bulk density, and potassium concentration in soils. Our results suggest that major steps towards successful restoration can be accomplished within a relatively short period, without the wholesale application of topsoil. Improving soil conditions is a vital tool for the successful development of extensive vegetation cover after surface mining, which also affects carbon sequestration by both above- and below-ground biomass. We emphasize that the use of reference systems provides critical information for the monitoring of ecosystem development towards an expected future state of the restored area.
Nanotechnology and remediation of agrochemicals
Chapter
  • Jan 2020
Preliminary assessment of growth and survival of green alder (Alnus viridis), a potential biological stabilizer on fly ash disposal sites
Article
Full-text available
  • Mar 2015
This paper presents preliminary assessment of seedling survival and growth of green alder (Alnus viridis (Chaix) DC. in Lam. & DC.) planted on fly ash disposal sites. This kind of post-industrial site is extremely hard to biologically stabilize without top-soiling. The experiment started with surface preparation using NPK start-up mineral fertilizer at 60–36–36 kg ha−1 followed by initial stabilization through hydro-seeding with biosolids (sewage sludge 4 Mg ha−1 dry mass) and a mixture of grasses (Dactylis glomerata L. and Lolium multiflorum Lam.) (200 kg ha−1). Subsequently, three-years-old green alder seedlings were planted in plots on two substrate variants: the control (directly on combustion waste) and plots with 3 dm3 lignite culm from a nearby mine introduced into the planting pit. Five years of preliminary monitoring show good survival seedling rates and growth parameters (height (h), average increase in height (Δh), number of shoots (Lo) and leaf nitrogen supply in the fly ash disposal habitat. Treatment of the site with a combination of lignite culm in planting pits and preliminary surface preparation by hydro-seeding and mineral fertilization had the most positive effect on green alder seedling parameters. The results indicate that it is possible and beneficial to use green alder for biological stabilization on fly ash disposal sites.
Identification and application of amino acids as chelators in phytoremediation of rare earth elements lanthanum and yttrium
Article
Full-text available
  • Dec 2013
Aims This study aimed to identify amino acids that could act as chelators in enhancing absorption and translocation capabilities of a rare earth element (REE) lanthanum and yttrium in a non-hyperaccumulator plant. Methods We analysed correlations between amino acid, La and Y concentrations in xylem saps of the REE hyperaccumulator Phytolacca americana L., to identify functional amino acids in long-distance transportation processes. These were used as chelators to observe the efficacy of La uptake and translocation in REE non-hyperaccumulator tomato seedlings. Pot culture experiments were conducted using modified Hoagland solution artificially contaminated with REEs. Results Eighteen xylem sap amino acids were identified and measured in the xylem sap, using reversed-phase high-performance liquid chromatography. Aspartic acid, asparagine, histidine and glutamic acid may be related to xylem La and Y long-distance transportion in P. americana L. Extraneous aspartic acid, asparagine, histidine and glutamic acid enhanced La absorption in the whole tomato, compared with La alone. Moreover, the whole tomato La content increased by 449 μg and 139 μg in the presence of aspartic acid and asparagine as compared to P. americana L. Tryptophan insignificantly affected La uptake and translocation in tomato seedlings. Conclusions Aspartic acid and asparagine could potentially promote remediation of La contamination in soil when used as a chelator.
EDTA-Enhanced Phytoremediation of Heavy Metals: A Review
Article
Full-text available
  • Mar 2014
Increase in heavy metal terrestrial ecosystems contamination through anthropogenic activities is a widespread and serious global problem due to their various environmental and human implications. For these reasons, several techniques, including phytoremediation of heavy metals, have been extensively studied. In spite of significant recent advancement, ethylene diamine tetraacetic acid (EDTA)-enhanced heavy metal phytoextraction as well as related ecological risks are still topical and remain an important area of research. Actually, EDTA favours the solubilization of metals and metalloids in soils, and was therefore extensively studied during the last two decades in order to improve phytoextraction efficiency and reduce in consequence treatment duration. This review highlights the recent findings (2010-2012) and mechanisms behind EDTA31 enhanced (i) solubilization of heavy metals in soil, (ii) mobilization/transport of soluble metals towards plant root zone (iii) metal absorption by plant roots and translocation towards aerial parts. The review also presents potential risks associated with EDTA-enhanced phytoextraction: (i) environmental persistence of EDTA and/or metal-EDTA complex, (ii) potential toxicity of EDTA and/or metal-EDTA complex to plants and (iii) leaching and contamination to groundwater. Moreover, field scale cost of EDTA-enhanced remediation and the role of EDTA in time required for heavy metal remediation is discussed.
Effects of citric acid and the siderophore desferrioxamine B (DFO-B) on the mobility of germanium and rare earth elements in soil and uptake in Phalaris arundinacea
Article
  • Feb 2017
Effects of citric acid and desferrioxamine B (DFO-B) on the availability of Ge and selected REEs (La, Nd, Gd, Er) to P. arundinacea were investigated. A soil dissolution experiment was conducted to elucidate the effect of citric acid and DFO-B at different concentrations (1 and 10 mmol l−1 citric acid) on the release of Ge and REEs from soil. In a greenhouse plants of P. arundinacea were cultivated on soil and on sand cultures to investigate the effects of citric acid and DFO-B on the uptake of Ge and REEs by the plants. Addition of 10 mmol l−1 citric acid significantly enhanced desorption of Ge and REEs from soil and uptake into soil–grown plants. Applying DFO-B enhanced the dissolution and the uptake of REEs, while no effect on Ge was observed. In sand cultures, presence of citric acid and DFO-B significantly decreased the uptake of Ge and REEs, indicating a discrimination of the formed complexes during uptake. This study clearly indicates that citric acid and the microbial siderophore DFO-B may enhance phytoextraction of Ge and REEs due to the formation of soluble complexes that increase the migration of elements in the rhizosphere.
Hydroponic screening of black locust families for heavy metal tolerance and accumulation
Article
  • Sep 2015
Present work examines phytoextraction potential of four black locust families (half-sibs 54, 56, 115 and 135) grown hydroponically. Plants were treated with 6 ppm of cadmium (Cd), 100 ppm of nickel (Ni) and 40 ppm of lead (Pb) added in Hoagland nutrient solution, accompanying with simultaneously applied all three metals. Responses to metals exposure among families were different, ranging from severe to slight reduction of root and shoot biomass production of treated plants. Calculated tolerance indices are indicating tested families as highly tolerant (Ti > 60). Family 135 had the lowest tolerance index, pointing that it was highly susceptible to applied metals. Comparing photosynthetic activities of tested families it has been noticed that they were highly sensitive to stress induced by heavy metals. Net photosynthetic rate of nickel treated plants was the most affected by applied concentration. Cadmium and nickel concentrations in stems and leaves of black locust families exceeded 100 mg Cd kg-1 and 1000 mg Ni kg-1, in both single and multipolution context. On the contrary, accumulation of lead in above ground biomass was highly affected by multipolution treatment. Tf and BCF significantly varied between investigated treatments and families of black locust. Concerning obtained results of heavy metals accumulation and tolerance of black locust families can be concluded that tested families might be a promising tool for phytoextraction purposes, but it takes to be further confirmed in field trials.
Magnesium and iron deficiencies alter Cd accumulation in Salix viminalis L
Article
  • Aug 2015
Evidence exists that Cd and certain nutrient elements, such as Fe and Mg, could share similar mechanisms of plant uptake and accumulation. Here we report that Mg and Fe deficiency in mature plants of Salix viminalis, grown in hydroponic solutions containing 5 µg ml(-1) of Cd, caused a significant increase in Cd accumulation in roots, stems and leaves. Cd (µg g(-1) dry weight) was determined following three treatments: 1) Cd treatment in complete nutrient solution; 2) Cd treatment with Fe deficiency; and 3) Cd treatment with Mg deficiency, yielding, respectively: in young leaves (65.3, 76.1 and 92.2), mature leaves (51.5 to 76.3 and 87.1), upper stems (80.6, 116.8 and 130.6) lower stems (67.2, 119 and 102.3), roots (377.1, 744.8 and 442,5). Our results suggest that Cd utilizes the same uptake and transport pathways as Mg and Fe. Evidence exists that Mg and Fe uptake and translocation could be further facilitated by plants as an adaptive response to deficiency of these elements. Such physiological reaction could additionally stimulate Cd accumulation. Although Cd uptake was mostly confined in roots, high Cd content in aerial plant parts (51.5-130.6 µg g(-1)) indicates that the genotype Salix viminalis is suitable for phytoextraction.
Restoration of rare earth mine areas: organic amendments and phytoremediation
Article
Overexploitation of rare earth mine has caused serious desertification and various environmental issues, and ecological restoration of a mining area is an important concern in China. In this study, experiments involving dry grass landfilling, chicken manure broadcasting, and plant cultivation were carried out to reclaim a rare earth mine area located in Heping County, Guangdong Province, China. The prime focus was to improve soil quality in terms of nutrients, microbial community, enzyme activity, and physicochemical properties so as to reclaim the land. After 2 years of restoration, an increase of organic matter (OM), available potassium (K), available phosphorus (P) levels, and acid phosphatase (ACP) activity and a reduction of the available nitrogen (N) level and urease (URE) activity in soil were achieved compared to the original mined land. The nutrients and enzyme activities in soil with 5 years of restoration were close to or surpass those in the unexploited land as control. The bulk density, total porosity, water holding capacity, pH, and electrical conductivity (EC) of soil were improved, and the number of cultivable microorganisms and the bacterial diversity in soil were greatly increased with time during ecological restoration, especially for surface soil. Furthermore, the artificial vegetation stably grew at the restored mining sites. The results indicated that organic amendments and phytoremediation could ecologically restore the rare earth mining sites and the mined land could finally be planted as farmland.
Phytoremediation of Heavy Metals in Contaminated Water and Soil Using Miscanthus sp. Goedae-Uksae 1
Article
  • Dec 2014
The aim of this study is to characterize the heavy metal phytoremediation potential of Miscanthus sp. Goedae-Uksae 1, a hybrid, perennial, bio-energy crop developed in South Korea. Six different metals (As, Cu, Pb, Ni, Cd, and Zn) were used for the study. The hybrid grass effectively absorbed all the metals from contaminated soil. The maximum removal was observed for As (97.7%), and minimum removal was observed for Zn (42.9%). Similarly, Goedae-Uksae 1 absorbed all the metals from contaminated water except As. Cd, Pb, and Zn were completely (100%) removed from contaminated water samples. Generally, the concentration of metals in roots was several folds higher than in shoots. Initial concentration of metals highly influenced the phytoremediation rate. The results of the bioconcentration factor, translocation factor, and enrichment coefficient tests indicate that Goedae-Uksae 1 could be used for phytoremediation in a marginally contaminated ecosystem.
Assessment of Robinia pseudoacacia cultivations as a restoration strategy for reclaimed mine spoil heaps
Article
Abstract Re-forestation with black locust (Robinia pseudoacacia) is considered a successful technique that is often used for the reclamation of open-cast mine areas. An alternative reclamation technique could be the natural regeneration of vegetation with spontaneous grass species. In this study, we compared the concentrations of chemical and biochemical variables in soil samples taken under black locust canopy to those from sites covered by spontaneous grass vegetation (control samples) in a time sequence of spoil deposition (0 to 10 years), in order to assess which of the two reclamation techniques yields higher soil quality. Soil quality refers here to the ability of soils to function ecologically. This has a special interest since the main question for the restored soils is their capacity to perform a range of ecological functions under stress or disturbance. Furthermore, we aimed at identifying the effect of vegetation type on soil ecological succession. The effect of vegetation type on primary succession becomes apparent after two years of reclamation. R. pseudoacacia as a nitrogen-fixing plant enriched soil with organic and inorganic nitrogen and organic matter to a greater extent than the natural grasses. It also increased the amount of soil microbial biomass and the activity of alkaline phosphatase. However, the fact that black locust failed to enhance dehydrogenase activity and actually decreased the activity of urease, activities that represent specialized niche functions and therefore, are more vulnerable to stress or disturbance, suggests that the development of an indigenous grass community in combination with organic supplements might often be more appropriate for the reclamation of similar kinds of mine areas.