Beneficial effects of tobacco biochar combined with mineral additives on (im)mobilization and (bio)availability of Pb, Cd, Cu and Zn from Pb/Zn smelter contaminated soils

2017 ◽  
Vol 145 ◽  
pp. 528-538 ◽  
Author(s):  
Altaf Hussain Lahori ◽  
Zengqiang Zhang ◽  
Zhanyu Guo ◽  
Ronghua Li ◽  
Amanullah Mahar ◽  
...  
2021 ◽  
Author(s):  
Amaia Nogales ◽  
Erika S. Santos ◽  
Gonçalo Victorino ◽  
Wanda Viegas ◽  
Maria Manuela Abreu

<p>Copper-based fungicides are commonly applied in vineyards to control fungal diseases that can severely affect grapevine productivity. Continuous application of this type of fungicides contributes to Cu accumulation in surface horizons of the soil, which can generate toxicity problems in plants, regardless of being an essential nutrient. Several strategies have been proposed to immobilize or counteract the effect of soil contaminants, such as plant inoculation with arbuscular mycorrhizal fungi (AMF). However, depending on the element concentration, this may not be sufficient to avoid its excessive accumulation in belowground and/or aboveground organs. Since Fe is known to have an antagonistic interaction with Cu in plants, Fe application, as an amendment, in vineyard soils, could be a good strategy to avoid excessive Cu uptake by grapevines growing in Cu-contaminated soils. However, little information is available on the combined effects of both strategies.</p><p>In order to reveal the possible beneficial effects of plant mycorrhization and Fe application in Cu-contaminated soils on grapevine growth and nutrition, a mesocosm experiment was established under controlled conditions. Two-year-old plants, previously inoculated or not with two different AMF, were grown in pots filled with 6.5 kg of an Arenosol collected from a wine-growing region. These plants were subjected to three soil treatments: 1) soil contamination with Cu, where the grapevines were watered with a solution containing 5.89 mg/L CuSO<sub>4</sub> to ensure that the soil in each container reached 300 mg Cu/kg; 2) soil contamination with Cu + Fe addition, where the plants were watered with a solution that contained the same amount of CuSO<sub>4</sub> plus 0.38 mg/L of FeNaEDTA·3H<sub>2</sub>O to achieve 100 mg of Fe/kg soil; and 3) non-contaminated soil watered with deionized water. Four months later, at the end of the growing season, plant vegetative growth as well as leaf and root nutrient contents were analyzed.</p><p>Grapevines inoculated with AMF demonstrated a good level of tolerance to high Cu concentrations in soil, as they presented significantly higher root biomass than non-inoculated plants and Cu was mainly accumulated in the roots avoiding its translocation to the aerial part. However, when the Cu-contaminated soil was amended with Fe, a significant decrease was observed in root biomass in all mycorrhizal inoculation treatments and Cu was accumulated in grapevine leaves. Contrastingly, Fe application helped to avoid the excessive increase of Mn concentrations in leaf and roots that is commonly induced in Cu contaminated soils, which can be detrimental for grapevine growth.</p><p>These results demonstrated that mycorrhizal inoculation is a suitable strategy to promote grapevine growth in Cu-contaminated soils. However, special attention needs to be taken when applying amendments to correct Cu contamination, as the mycorrhizal status of plants may alter the expected outcome.</p><p> </p><div> <div> </div> </div>


2005 ◽  
Vol 2 (3) ◽  
pp. 167 ◽  
Author(s):  
Grant Evans ◽  
Julyette Evans ◽  
Andrea Redman ◽  
Nancy Johnson ◽  
Richard D. Foust

Environmental Context. Phytoremediation, the process of using plants to remove metals from contaminated soils, shows promise as a low-technology method for economically removing arsenic, and other toxic metals, from soil. Arsenic transport studies in vascular plants have examined how arsenic is taken up, chemically modified, and transported from roots to other parts of the plant. No studies, to our knowledge, have examined the effect of low-level doses of arsenic on the roots themselves. This paper shows, for the first time, that arsenic at low levels may beneficially affect root development. Abstract. Corn (Zea mays) roots were grown in culture on modified Strullu–Roman medium in two separate experiments. Roots were exposed to one of four treatments combining arsenic (100 µg L−1 or 0.0 µg L−1) and phosphorous (4.8 mg L−1 or 0.0 mg L−1). The cultures were allowed to grow for 18 days or 21 days before they were used for quantitative measurement of root mass, root length, number of branches, and branch length. Results indicate roots grown in medium lacking phosphate but containing arsenic were longer and had greater mass than roots grown in medium with only phosphate. The data presented here suggest that arsenic at low levels might be beneficial for root development.


Author(s):  
Ming Lei ◽  
Min Zeng ◽  
Pu feng Qin ◽  
Bo han Liao ◽  
Bai qing Tie ◽  
...  
Keyword(s):  

2011 ◽  
Vol 63 (3) ◽  
pp. 739-745 ◽  
Author(s):  
B. Lorestani ◽  
M. Cheraghi ◽  
N. Yousefi

Various industrial activities contribute heavy metals to the soil environment directly or indirectly through the release of solid wastes, waste gases, and wastewater. Phytoremediation can be potentially used to remedy metal-contaminated sites. A major step towards the development of phytoremediation of heavy metal-impacted soils is the discovery of the heavy metal hyperaccumulation in plants. This study evaluated the potential of 7 species growing on a contaminated site in an industrial area. Several established criteria to define a hyperaccumulator plant were applied. The case study was represented by an industrial town in the Hamedan province in the central-western part of Iran. This study showed that most of the sampled species were able to grow in heavily metal-contaminated soils and were also able to accumulate extraordinarily high concentrations of some metals such as Pb, Fe, Mn, Cu and Zn. Based on the obtained results and using the most common criteria, Camphorosma monospeliacum for Pb and Fe, and Salsola soda and Circium arvense for Pb can be classified as hyperaccumulators and, therefore, they have suitable potential for the phytoremediation of contaminated soils.


2017 ◽  
Vol 83 (20) ◽  
Author(s):  
Mingmei Lu ◽  
Shuo Jiao ◽  
Enting Gao ◽  
Xiuyong Song ◽  
Zhefei Li ◽  
...  

ABSTRACT The symbiosis of the highly metal-resistant Sinorhizobium meliloti CCNWSX0020 and Medicago lupulina has been considered an efficient tool for bioremediation of heavy metal-polluted soils. However, the metal resistance mechanisms of S. meliloti CCNWSX00200 have not been elucidated in detail. Here we employed a comparative transcriptome approach to analyze the defense mechanisms of S. meliloti CCNWSX00200 against Cu or Zn exposure. Six highly upregulated transcripts involved in Cu and Zn resistance were identified through deletion mutagenesis, including genes encoding a multicopper oxidase (CueO), an outer membrane protein (Omp), sulfite oxidoreductases (YedYZ), and three hypothetical proteins (a CusA-like protein, a FixH-like protein, and an unknown protein), and the corresponding mutant strains showed various degrees of sensitivity to multiple metals. The Cu-sensitive mutant (ΔcueO) and three mutants that were both Cu and Zn sensitive (ΔyedYZ, ΔcusA-like, and ΔfixH-like) were selected for further study of the effects of these metal resistance determinants on bioremediation. The results showed that inoculation with the ΔcueO mutant severely inhibited infection establishment and nodulation of M. lupulina under Cu stress, while inoculation with the ΔyedYZ and ΔfixH-like mutants decreased just the early infection frequency and nodulation under Cu and Zn stresses. In contrast, inoculation with the ΔcusA-like mutant almost led to loss of the symbiotic capacity of M. lupulina to even grow in uncontaminated soil. Moreover, the antioxidant enzyme activity and metal accumulation in roots of M. lupulina inoculated with all mutants were lower than those with the wild-type strain. These results suggest that heavy metal resistance determinants may promote bioremediation by directly or indirectly influencing formation of the rhizobium-legume symbiosis. IMPORTANCE Rhizobium-legume symbiosis has been promoted as an appropriate tool for bioremediation of heavy metal-contaminated soils. Considering the plant-growth-promoting traits and survival advantage of metal-resistant rhizobia in contaminated environments, more heavy metal-resistant rhizobia and genetically manipulated strains were investigated. In view of the genetic diversity of metal resistance determinants in rhizobia, their effects on phytoremediation by the rhizobium-legume symbiosis must be different and depend on their specific assigned functions. Our work provides a better understanding of the mechanism of heavy metal resistance determinants involved in the rhizobium-legume symbiosis, and in further studies, genetically modified rhizobia harboring effective heavy metal resistance determinants may be engineered for the practical application of rhizobium-legume symbiosis for bioremediation in metal-contaminated soils.


Author(s):  
Liu Aiju ◽  
Wang Honghai ◽  
Gao Peiling ◽  
Xu Hong-zhi

Chemical fractionation of Cu and Zn in bulk soil and its effects on soil microbial properties were determined in Cu and Zn contaminated soils (Cu: 35.57~46.37 mg·kg-1, Zn: 74.33~127.20 mg·kg-1) sampled from an agricultural field in outskirts of Zibo, China during the month of September, 2011. A sequential extraction technique (SET) was used for metals chemical fractionation analysis in soils and a correlation analysis was applied to determinate the effects of metal on soil microbial properties. Chemical speciation showed that Cu and Zn were mostly present in the residual fraction and their concentrations in the most labile fraction (acid soluble fraction) were the lowest in the investigated soils. However, the correlation analysis indicated that the labile forms of Cu/Zn, such as its acid soluble, reducible or oxidizable fractions, were usually significantly negatively correlated with the tested microbial activities at 0.05 or 0.01 probability levels. These results indicate that the metal labile fractions could exert an inhibitory effect on the soil microbial parameters even in the minor contaminated soils. Int. J. Agril. Res. Innov. & Tech. 3 (1): 20-25, June, 2013 DOI: http://dx.doi.org/10.3329/ijarit.v3i1.16045


2011 ◽  
Vol 356-360 ◽  
pp. 1716-1718 ◽  
Author(s):  
Yuan Liang ◽  
Xiao Chun Wang ◽  
Xin De Cao ◽  
Ling Zhao

The objective of this study is to immobilize Pb, Cu, and Zn in a multi-metal contaminated soil using triple superphosphate fertilizer (TSP) and phosphate rock tailing (PR) materials, alone and in combination. The treatment effectiveness was evaluated with a column leaching experiment under simulated rainfall conditions. More than 90% of Pb and Cu were stabilized in the upper layer soil (0-10cm) in both untreated and P-treated soil columns. However, the significant downward migration of Zn was observed in either untreated or P-treated column soil profiles though the transport was inhibited by P treatments. In the untreated soil, 27.2% of Zn migrated down to the subsurface soil (10-20cm), while there were 7.45%, 13.0%, and 11.2% of Zn transported down in the TSP, PR, and PR+TSP treatments, respectively. Phosphate reduced the leaching of Pb and Cu from the contaminated soils, with reduction of Pb and Cu in the leachate by up to 71.2% and 34.8%, respectively. However, Zn leaching was enhanced by P treatments except for TSP. The results indicated that triple superphosphate fertilizer and phosphate rock tailing were effective in immobilizing Pb followed by Cu, but less for Zn in a multi-metal contaminated soil.


Sign in / Sign up

Export Citation Format

Share Document