Use In Phytoremediation Research Articles

Physiological and biochemical characterization of copper-toxicity tolerance mechanism in grass species native to Pampa Biome and Atlantic Forest for use in phytoremediation.

Orchards and vineyards account for significant copper (Cu) accumulation in the soil due to frequent Cu fungicide applications to control leaf diseases. Although grass species are distributed in these areas likely because of their physiological mechanisms to combat Cu toxicity-related stress, the aim of the present study is to identify grass species presenting biochemical-physiological responses that feature adaptive Cu toxicity tolerance mechanisms. Three grass species native to the Pampa and Atlantic Forest biomes (Paspalum notatum, P. plicatulum, and P. urvillei) and an exotic species (Cynodon dactylon) were tested. Plants were cultivated in pots filled with 4kg of typic Hapludalf soil, under two Cu availability, control, and toxicity conditions (80mg Cu kg soil-1). Photosynthetic parameters, relative growth rate, root dry matter, shoot dry matter, the activity of stress-fighting enzymes (superoxide dismutase and guaiacol peroxidase), root biometry, soluble organic carbon, soil pH, and electrical conductivity were evaluated. P. notatum and P. urvillei have physiological characteristics that allow high translocation factor and Cu accumulation in the root and shoot, and it allows their use in phytoremediation processes due to (1) greater activity of stress-fighting enzymes such as POD in the shoot; (2) to larger diameter roots, which allow greater Cu complexation in them - they are lesser sensitive to stress caused by Cu than the other species; and (3) greater soluble organic carbon exudation in the rhizosphere than species P. plicatulum and C. dactylon, which can complex Cu2+ and reduce the presence of forms toxic to plants.

Mitigation of lead toxicity in Vigna radiata genotypes by silver nanoparticles

Heavy metal (HM) contamination of the soil through anthropogenic activities influences the living systems and drastically impacts food chain. This study examined the application of silver nanoparticles (AgNPs) in two genotypes (G1 and G2) of Mung bean (Vigna radiata) for ameliorating the Pb toxicity. Different doses of Pb (0, 25, 50 μM) were differentially tackled by AgNPs with the aim of ameliorating the plant attributes. Both genotypes displayed statistically significant quantitative and qualitative modulations for Pb tolerance. In G2, the most prominent increase in plant height (43.79%), fresh biomass (49.56%) and total chlorophyll (20%) was observed at L2 (AgNPs 10 mg/L) in comparison with the control. Overall, photosynthetic rate was increased by 26% in G2 at L6 (AgNPs 25 mg/L + Pb 25 μM). In addition, the results presented 78.5% increase in water use efficiency of G2 while G1 experienced a maximum internal CO2 concentration (209.8%) at L8 (Pb 50 μM). AgNPs triggered balanced uptake of minerals and improved growth of Vigna genotypes. 50 μM Pb was most hazardous and caused maximum reduction in growth of Vigna plants along with a significant suppression in photosynthetic activity, increase in MDA (199.7%) in G1 and H2O2 (292.8%) in G2. In comparison to control, maximum superoxide dismutase (376%), peroxidase (659.8%) and catalase (9.3%) activity was observed in G2 at L11. The application of AgNPs substantially enhanced plant growth and helped them in surviving well in absence as well as presence of Pb. G2 genotype exhibited substantial tolerance capability and revealed less impairment in the studied attributes than G1 and treatment of AgNPs i.e. 25 mg/L was the best level that yielded best results in both genotypes. The results demonstrate that AgNPs mediate response(s) of plants under Pb stress and particularly contributed to HM tolerance of plants and thus showing great promise for use in phytoremediation.

Assessment of the antioxidative response and culturable micro-organisms of Lygeum spartum Loefl. ex L. for prospective phytoremediation applications

Abundant plant species in arid industrial areas are mining phyto-resources for sustainable phyto-management. However, the association with their rhizosphere is still poorly known for phytoremediation purposes. This study aims to assess the heavy metals (HMs) and metalloids uptake of Lygeum spartum Loefl. ex L. growing in cement plant vicinity and screen associated culturome for potential phytoremediation use. Bioaccumulation factor (BAF), the translocation factor (TF), and the mobility ratio (MR) were studied along with four sites. Lipid peroxidation (MDA), free proline (Pro), Non-protein thiols (NPTs), and reduced glutathione (GSH) were tested for evaluating the plant antioxidative response. Bacteria and fungi associated with L. spartum Loefl. ex L. were identified by 16S rRNA and fungal internal transcribed spacer (ITS1-ITS2) gene sequencing. Our results showed an efficient uptake of As, Pb, and Zn and enhanced GSH (0.34 ± 0.03) and NPTs (528.7 ± 14.4 nmol g−1 FW) concentrations in the highly polluted site. No significant variation of Arbuscular Mycorrhizal Fungi (AMF) was found. Among 29 bacterial isolates, potential bioremediation were Bacillus simplex and Bacillus atrophaeus. Thus, L. spartum Loefl. ex L. and its associated microbiota have the potential for phytoremediation applications. Novelty statement: This work has been set in line with the investigation of the integrative biology of Lygeum spartum Loefl ex L. and the screening of its associated microbiome for potential phytoremediation applications. This work is the first work conducted in a cement plant vicinity investigating the associated fungi and bacteria of L. spartum Loefl. ex L. and been part of a sectorial research project since 2011, for assessing the impact of industrial pollution and recognizing the accumulation potential of plant species for further phyto-management applications.

Efficiency of heterogeneous chelating agents on the phytoremediation potential and growth of Sasa argenteostriata (Regel) E.G. Camus on Pb-contaminated soil

Ethylenediaminetetraacetic acid (EDTA) is one of the most effective chelating agents for enhancing lead (Pb) accumulation in various plant organs. However, it has a higher risk of causing secondary pollution than other chelating agents. To reduce such environmental risks and increase remediation efficiency, EDTA can be combined with degradable chelating agents for use in phytoremediation, but there are few reports on the combination of EDTA and nitrilotriacetic acid (NTA). This study evaluated the effects of combined EDTA and NTA application at different concentrations (900, 1200, or 1500 mg/kg) and with different methods (1 application or 3 applications) on dwarf bamboo (Sasa argenteostriata (Regel) E.G. Camus) growth and phytoremediation efficiency and on the soil environment in pot experiments with Pb-contaminated soil. Applying EDTA and NTA together resulted in lower soil water-soluble Pb concentrations than applying EDTA alone and therefore resulted in lower environmental risk. The increased availability of soil Pb produced a stress response in the dwarf bamboo plants, which increased their biomass significantly. Moreover, under the chelating treatments, the soil Pb availability increased, which promoted Pb translocation in plants. The Pb content in the aerial parts of the dwarf bamboo increased significantly in all treatments (translocation factors increased by 300~1500% compared with that in CK). The Pb content increase in the aerial parts caused high proline accumulation in dwarf bamboo leaves, to alleviate Pb toxicity. Maximum Pb accumulation was observed in the EN1500 treatment, which was significantly higher than that in the other treatments except the EN900 treatment. This study elucidates the choice of remediation techniques and the physiological characteristics of the plants used in such studies. In conclusion, the EN900 treatment resulted in the lowest environmental risk, greatest biomass production, and highest phytoremediation efficiency of all treatments, indicating that it has great potential for application in phytoremediation with dwarf bamboo in Pb-contaminated soil.

Physiological, nutritional, and biochemical indicators of lead tolerance in sunflower genotypes

This study aimed to select and classify sunflower genotypes tolerant to lead (Pb) stress and evaluate their capacity of phytoextraction based on physiological, nutritional, and biochemical responses. Two experiments were carried out under lead stress. In the first experiment, out of 21 genotypes studied three showed higher relative biomass yield and were characterized as Pb-tolerant and five showed lower relative biomass production and were considered Pb-sensitive. In the second experiment, one Pb-tolerant (BRS-G27) and two Pb-sensitive (H251 and AG963) genotypes were studied. In this experiment, Pb stress reduced the growth and contents photosynthetic pigments in all genotypes, but more pronouncedly in sensitive genotypes. There were no substantial changes in micronutrient levels in the leaves and stem, but the levels of Cu and Mn in the stressed roots of sensitive genotypes were much lower than in BRS-G27. The contents of organic solutes in the roots suggest that sensitive genotypes have higher energy costs for osmoregulation by carbohydrates and amino acids synthesis. However, the accumulation of proline may be related to a greater Pb tolerance. Considering the results of dry mass yield, transfer coefficient, translocation factor, and tolerance index, the BRS-G27 genotype can be recommended for use in phytoremediation of Pb-contaminated soils.

Phytoremediation of Heavy-Metals-Contaminated Soils: A Short-Term Trial Involving Two Willow Species from Gloucester WillowBank in the UK

Phytoremediation, as a bioremediation process in which plants are used to remove contaminants from an environment, has proved to be a practical and low-cost strategy for recovering mining-affected areas. This study aims to assess the potential for use in phytoremediation of two willow species, Salix viminalis and Salix dasyclados, by testing their potential for cleaning-up a range of soils with differing heavy metal concentrations: Pb (111, 141, 192 and 249 mg /kg), Zn (778.6, 1482, 2734 and 4411 mg/kg) and Cd (3.00, 5.03, 9.14 and 16.07 mg/kg). The extracted metals were preferentially translocated to the leaves with considerably higher concentrations and relative BAFs in the case of S. viminalis. The highest recorded Zn concentration of over 0.5% was found in the leaves of S. viminalis growing in soil 4. However, under the conditions of the experiments, S. dasyclados showed greater potential for use in phytoremediation, especially if coupled with use of biomass for energy production. An assessment of the suitability of willow species in this role, with regard to wider aspects involved, such as use of resultant biomass and/or waste management, revealed good potential. Willows are fast growing, grow vigorously from coppiced stumps and have extensive root systems. Therefore, their use in bioenergy production through pyrolysis or combustion, coupled with flue gas screening, is strongly advised.

Biomedical waste management in Panchakarma practice: Present scenario and scope

Ayurveda is a traditional medical system of India. In Ayurveda, Panchakarma (fivefold detoxification treatment) procedures are designed for internal purification and cleansing. As per the Indian government’s initiative (launched in September 2014), Ayurveda is part of wellness industry. There is a constant rise in the number of Ayurveda clinics, hospitals, wellness centers, and spas in India. The various Panchakarma procedures performed in these hospitals, clinics, wellness centers, and spas generate biomedical wastes (BMW). Metropolitan areas in India bring about 62 million tonnes of wastes annually, and this figure is predicted to rise to 165 million tonnes by 2030. Forty-three million tonnes of the municipal solid waste are collected every year, of which 31 million are disposed of in landfills and only 11.9 million are treated. Pharmaceutical wastes are one among them. Reports from the Indian medicinal plant industries indicate that presently more than 9000 plant industries are registered in India, which produces a huge amount of waste each year. This has created a need in the proper management of waste generated. Here is the description and discussion of categorization, classification, and treatment options for waste generated during Panchakarma procedures in Ayurveda hospitals. Effective and proper management of the BMW is necessary to maintain personal as well as environmental health. The current available techniques for the treatment of waste generated during Panchakarma procedure are sewage drainage, incineration, and landfill. Nothing turns around to be waste until it is being not used further with intelligence. The natural cycles of life taught us the same through science: utilizing of three Rs of ideal waste management. While further advancement can include the use of phytoremediation, composting, vermicomposting, biofiltration, bioaugmentation and use of solar energy in waste management.

Determination of the Heavy Metal Contents and the Benefit/Cost Analysis of Hypericum salsugineum in the Vicinity of Salt Lake

In this study, Hypericum salsugineum, an endemic halophytic plant growing around Salt Lake, was analyzed to determine the heavy metals (chromium, lead, copper, zinc and nickel) on it and on the soil it grew. The phytoremediation potential of H. salsugineum was evaluated. In addition, the benefit cost (B/C) analysis was performed for its potential use in phytoremediation. The plant and soil samples were collected from Eskil and Cihanbeyli between May and September in 2016. A total of 300 soil and plant samples were analysed for heavy metal content. Statistical and standard benefit/cost analyses were performed for assessment. The capacity of accumulating the aforementioned heavy metals was found to be high in H. salsugineum. It was found that Ni and Pb ratio exceeded optimum values in its habitat, and H. salsugineum accumulated available Ni and Pb. When the plant was evaluated in terms of benefit/cost, B/C ratio was greater than 1 during the useful life of the study. This conclusion increases the ecological and economical values of H. Salsugineum, effecting its potential use in phytoremediation.

The Use of Plants, Nanotechnology and Surfactants in Lindane Remediation: A Mini Review

Lindane is an organochlorine chemical and an isomer of hexachlorocyclohexane that has been used both as an agricultural insecticide and as a pharmaceutical treatment for lice and scabies. Lindane accumulates in the agricultural soil and plants thereby causing environmental and health deteriorative effects. A lot of soil remediation methods used are highly expensive and require a lot of expertise. Phytoremediation (rhizofiltration, phytostabilization), which involve the use of the plant to stabilize or remove environmental toxicants is presently much in use because of its cost-effectiveness and ecological friendliness. Adsorption has emerged as the most efficient, easy, and promising nanotechnology method of wastewater treatment out of the several approaches now employed. Recently, biosurfactants are used for the production of nanoparticles which will be further applied in the area of pesticide remediation. The use of phytoremediation is the most important fully green approach as no new chemicals are added to the polluted soil. Other emerging technologies where phytoremediation might not be applicable especially groundwater has begun to evaluate the use of green nanobiotechnology.

Use of phytoremediation for pollution removal of hexavalent chromium-contaminated acid agricultural soils

<p>Chromium is a common heavy metal pollutant found in industrial wastewaters which may pollute agricultural soils through groundwater and watering. Phytoremediation is an economical and highly applicable method for removal of pollutants from agricultural soils. This research was carried out for the removal of hexavalent chromium (Cr (VI)) contamination from the soil with the phytoremediation method. For this purpose, only 30 mg kg-1 hexavalent chromium (Cr (VI) as Chromium CrO3, only 10 mL bacteria Rhodobacter capsulatus DSM1710 and chromium plus bacteria applied to the pots and Malabar spinach (Basella alba L.) grown in the pots. At the end of experiment the results showed that side branching, leaf width, plant dry weights were the highest agro-morphological traits when bacteria were applied to chromium polluted soil. Some macro and micro nutrient elements which are essential for plant nutrition were analyzed (N, P, K, Ca, Mg, Fe, Cu, Mn and Zn). Among them, N, P, Fe, Cu, Mn and Zn were found to be statistically significant at the level of 5%. The Cr content of Malabar spinach in control soil was 0.31mgkg-1, but it was 2.33mgkg-1 when the soil was contaminated with Cr at the end of experiment. Moreover, when bacteria were additionally applied the Cr content increased to 4.02 mgkg-1 of Malabar spinach. Chromium pollution antagonistically affected both some nutrient element (P, K, Ca; Mg) and some heavy metals (Fe, Cu, Zn, Mn) in the soil. This study shows that phytoremediation can be used to remove the soil pollution caused by containing high hexavalent chromium. For this reason, the nitrogen fixing bacterium Rhodobacter capsulatus and the hyperaccumulator Malabar spinach plant can be used. It is the first study where Malabar spinach was used a hyperaccumulator plant for chromium pollution in the soils.</p>

Comparison of the single and combined effects of arsenic and antimony on growth and physiology of giant reed (Arundo donax L.).

Fast-growing plant, giant reed (Arundo donax L.) has been gaining a lot of popularity in the phytoremediation of metal-polluted soils. However, information regarding the physiological background of tolerance and accumulation capacity of A. donax with respect to antimony (Sb), arsenic (As), and their co-contamination are very limited. Rooted stem cuttings were grown for 5 months in hydroponics exposed to Sb (10 mg L-1), As (10 mg L-1), and their combined toxicity (Sb 5 mg L-1 + As 5 mg L-1) wherein treatment without As/Sb served as control. Effect of these treatments on key photosynthetic parameters (rate of net photosynthesis, effective quantum yield of photosystem II, chlorophyll fluorescence, and photosynthetic pigments), phytoextraction ability of metalloids, nutrient uptake, root growth, and lignification were analyzed. Arsenic-containing treatments severely affected root morphology of A. donax compared to Sb/control and plants exposed to As showed intensive lignification already in young apical part of the root in the present study. Shoot concentration was found to be 11.35±0.75 Sb mg kg-1 and 8.97±0.52 As mg kg-1 compared to root concentration of 1028.3±19.1 Sb mg kg-1 and 705.3±69.9 As mg kg-1 in the treatments of Sb and As. Even though Sb and As were translocated to the shoots in relatively small amount, both metalloids significantly decreased the shoot and root growth of A. donax and negatively affected the photosynthetic parameters. Moreover, co-contamination of Sb and As proved to be severely toxic to growth and physiology of A. donax even though the magnitudes of the metalloids used were lower than those of Sb/As alone treatments. In conclusion, Sb and As caused a marked reduction in growth and physiological characteristics of A. donax, opposing its use in phytoremediation of highly contaminated soils. Tolerance capacity of plants to simultaneous presence of As and Sb in the environment is crucial for the successful implementation of phytoremediation since the co-contamination by As and Sb might reduce the efficiency of phytoremediation when using this fast-growing and high biomass-producing plant species.

Bio-Mercury Remediation Suitability Index: A Novel Proposal That Compiles the PGPR Features of Bacterial Strains and Its Potential Use in Phytoremediation.

Soil pollution from heavy metals, especially mercury, is an environmental problem for human health. Biological approaches offer interesting tools, which necessarily involve the selection of organisms capable of transforming the environment via bioremediation. To evaluate the potential use of microorganisms in phytorhizoremediation, bacterial strains were isolated from rhizospheric and bulk soil under conditions of chronic natural mercury, which were identified and characterized by studying the following: (i) their plant growth promoting rhizobacteria (PGPR) activities; and (ii) their maximum bactericide concentration of mercury. Information regarding auxin production, phosphate solubilization, siderophore synthesis and 1-aminocyclopropane-1-carboxylic acid deaminase (ACCd) capacity of the isolates was compiled in order to select the strains that fit potential biotechnological use. To achieve this objective, the present work proposes the Bio-Mercury Remediation Suitability Index (BMR-SI), which reflects the integral behavior of the strains for heavy metal polluted soil bioremediation. Only those strains that rigorously fulfilled all of the established criteria were selected for further assays.

Phytoremediation and Microorganisms-Assisted Phytoremediation of Mercury-Contaminated Soils: Challenges and Perspectives.

Mercury (Hg) pollution is a global threat to human and environmental health because of its toxicity, mobility and long-term persistence. Although costly engineering-based technologies can be used to treat heavily Hg-contaminated areas, they are not suitable for decontaminating agricultural or extensively-polluted soils. Emerging phyto- and bioremediation strategies for decontaminating Hg-polluted soils generally involve low investment, simple operation, and in situ application, and they are less destructive for the ecosystem. Current understanding of the uptake, translocation and sequestration of Hg in plants is reviewed to highlight new avenues for exploration in phytoremediation research, and different phytoremediation strategies (phytostabilization, phytoextraction and phytovolatilization) are discussed. Research aimed at identifying suitable plant species and associated-microorganisms for use in phytoremediation of Hg-contaminated soils is also surveyed. Investigation into the potential use of transgenic plants in Hg-phytoremediation is described. Recent research on exploiting the beneficial interactions between plants and microorganisms (bacteria and fungi) that are Hg-resistant and secrete plant growth promoting compounds is reviewed. We highlight areas where more research is required into the effective use of phytoremediation on Hg-contaminated sites, and conclude that the approaches it offers provide considerable potential for the future.

Prevention of Hydrosphere’s Pollution by Aluminium

The environmental hazard is the transport of toxic ions and aluminium oxides entering the hydrosphere. In addition to solving global issues of maintaining environmental wellbeing through sustainable development, it is necessary to solve the technological problems of cleaning water bodies from excessive aluminium. One of the effective measures to solve such problems is the use of phytoremediation - a set of methods for treating wastewater and water bodies with the help of aquatic plants. The study of aquatic organisms (hydrobionts) ecology shows how do they affect the physical and chemical parameters of the environment, including the hydrosphere. Our study in measuring the concentration and toxicity of aluminium ions in the aquatic environment based on the results of experiments with aquatic plants (macrophytes) Ceratophyllum and Chara fragilis, as well as with the higher aquatic plant Callitriche palustris Linne showed the possibility in initiating self-purification processes of hydrosphere objects from mentioned pollutants. Another option in preventing hydrosphere pollution by aluminium compounds should be based on implementation the noospheric transformation of the educational system for national economy specialists in accordance with proposals, given in the paper.

Nickel tolerance and biosorption potential of rhizobia associated with horse gram [Macrotyloma uniflorum (Lam.) Verdc.

The rhizobia isolated from root nodules of horse gram were screened for nickel (Ni) tolerance in vitro. The strain HGR-4 could tolerate 1000 µg g−1 of Ni. It was also observed that horse gram plants associated with HGR-4 have shown Ni stress tolerance in Ni amended soils up to a concentration of 100 µg g−1. In another experiment, the plants associated with HGR-4 have shown higher nodulation, nitrogen level, and leghaemoglobin content at 80 µg g−1 of Ni than control plants without HGR-4 inoculation. Analysis of biosorption potential of Ni in horse gram plants inoculated by the strain HGR-4 was done using atomic absorption spectroscopy revealed maximum biosorption in bacterial root nodules. Besides, there was a reduction in the content of the heavy metal in the soil samples which demonstrates a fair amount of heavy metal extraction and accumulation of Ni by rhizobia associated root nodules of the horse gram. This study demonstrates that the strain HGR-4 (GQ483457 Rhizobium sp. ATCC BAA-2335) could be a potential source for phytoextraction of Ni contaminated soils upon its association with horse gram. The study could be of use in phytoremediation of metal (Ni) contaminated soils in the future. Novelty statement: The phytoremediation of nickel (Ni) using of rhizobia associated with horse gram remains unevaluated till now. Horse gram associated with rhizobia could produce nodules and fix nitrogen even in Ni amended soils. The biosorption potential of the rhizobial strains was analyzed from both root nodules and soil. These findings imply that horse gram plants associated with these rhizobial strains could be used to remediate Ni metal in contaminated soils.

Iron phytostabilization by Leucaena leucocephala

This study investigated the potential for tolerance, absorption, and translocation of iron (Fe) by Leucaena leucocephala, as well as the response of the photosynthetic mechanism and the phytoremediation potential of L. leucocephala grown in soil with concentrations of Fe (0, 100, 200, 300, 400, and 500 mg Fe/dm3 of soil). The chlorophyll content and the photosynthetic apparatus showed a significant difference between treatments: the chlorophyll content, transpiration rate, and stomatal conductance were higher in the treatment 200 mg Fe/dm3 of soil, while the photosynthetic rate was higher in the treatment 500 mg Fe/dm3 of soil in relation to the control. From 300 mg Fe/dm3 of soil onward, there was a significant reduction in the number of leaves, mass, and biomass of L. leucocephala. The species is tolerant to the Fe doses analyzed. Availability of Fe in the soil after the cultivation of L. leucocephala decreased, evidencing the plant capacity of Fe absorption, which accumulated mostly in the roots, and only % of Fe was translocated to the shoots. The highest Fe accumulation per biomass was 9.48 mg, at 200 mg Fe/dm3 of soil. The amount of Fe translocated and accumulated in L. leucocephala is directly related to its biomass production thus the dose 200 mg Fe/dm3 of soil allows the best performance of phytoremediation potential. Although plant growth is affected by treatments of 300, 400 and 500 mg Fe/dm3 of soil and Fe accumulation is less, L. leucocephala is able to tolerate and phytostabilize soil Fe with potential for use in phytoremediation, mainly because it is a kind of phytostabilization of Fe.

Phytoremediation of chromium and manganese by Ipomoea aquatica Forssk. from aqueous medium containing chromium‐manganese mixtures in microcosms and mesocosms

AbstractIpomoea aquatica—an aquatic macrophyte—could remove chromium and manganese from their mixtures after 96 h exposure at a maximum rate of 82.8% and 93.9%, respectively, in microcosms. The removal rates were higher (90.4% and 94.5%, respectively) after 96 h exposure in mesocosms with gravel beds and vertical subsurface flow. The higher removal rates in mesocosm were probably due to a wide range of partitioned micro‐environments close to the root boundaries, and within the biofilms on both root and gravel surfaces. The Cr and Mn removal efficiencies of I. aquatica increased with increasing Cr or Mn concentrations in the medium. The study reveals the potential of I. aquatica—a fast‐growing species that can proliferate by fragmentation—to effectively remove Cr and Mn within a relatively short period of time, thereby raising the prospect of its use in phytoremediation of wastewater contaminated with these metals.

Enhanced Phytoremediation of Bisphenol A in Polluted Lake Water by Seedlings of Ceratophyllum demersum and Myriophyllum spicatum from In Vitro Culture.

Bisphenol A (BPA) is a typical endocrine disruptor that causes problems in waters all around the world. In this study, the effects of submerged macrophytes (Ceratophyllum demersum and Myriophyllum spicatum) cultured in vitro on the removal of BPA at two initial concentrations (0.5 mg L−1 vs. 5.0 mg L−1) from Donghu lake water were investigated, using different biomass densities (2 g L−1 vs. 10 g L−1) under different nutrient conditions (1.85 mg L−1 and 0.039 mg L−1 vs. 8.04 mg L−1 and 0.175 mg L−1 of the total nitrogen and phosphorus concentration, respectively), together with the effect of indigenous microorganisms in the water. The results showed that indigenous microorganisms had limited capacity for BPA removal, especially at higher BPA initial concentration when its removal rate amounted to about 12% in 12 days. Addition with plant seedlings (5 cm in length) greatly enhanced the BPA removal, which reached 100% and over 50% at low and high BPA initial concentration in 3 days, respectively. Higher biomass density greatly favored the process, resulting in 100% of BPA removal at high BPA initial concentration in 3 days. However, increases in nutrient availability had little effect on the BPA removal by plants. BPA at 10.0 mg L−1 significantly inhibited the growth of M. spicatum. Therefore, C. demersum may be a candidate for phytoremediation due to greater efficiency for BPA removal and tolerance to BPA pollution. Overall, seedlings of submerged macrophytes from in vitro culture showed great potential for use in phytoremediation of BPA in natural waters, especially C. demersum.

Phytodesalination and chemical and organic conditioners to recover the chemical properties of saline‐sodic soil

AbstractSemiarid regions’ soils have been degraded by salinization. The use of chemical conditioners makes this management very expensive. As an alternative, organic conditioners can be used with plants adapted to the salts and phytoremediation, such asAtriplex nummulariaLindl. This study aimed to evaluate the use of phytoremediation and chemical and organic conditioners in the recovery of chemical attributes of a saline‐sodic soil in Brazil Northeast. A study was carried out by testingA. nummulariawith the application of chemical (gypsum and anionic polymer) and organic conditioners (bovine and sheep manure), and a control treatment. The experiment was conducted for 18 mo with soil sampling at 6, 12, and 18 mo. The treatments did not modify pH but were effective in reducing the electrical conductivity. All treatments reduced the sodium adsorption ratio and the exchangeable sodium percentage. The use ofA. nummulariaand organic conditioners were as efficient as the use of chemical conditioners to improve soil chemical attributes, suggesting the use of these techniques in the management of soil degradation by salinization. Our study also suggests that local seasonal patterns and physical characteristics of soils influence the effectiveness of Atriplex and conditioners on the extraction and dynamics of salts. Phytoremediation may be complementary to the use of organic conditioners produced on the farm, making management more sustainable.

Potential of hemp (Cannabis sativa L.) for paired phytoremediation and bioenergy production

AbstractHemp (Cannabis sativa L.) is a multi‐use crop that has been investigated for its potential use in phytoremediation of heavy metals, radionuclides, and organic contaminants, and as a feedstock for bioenergy production. A review of research literature indicates that hemp is a suitable crop for phytoremediation, and a competitive option for bioenergy. Coupling phytoremediation and bioenergy production from a single hemp crop is a potential solution to overcoming the economic constraints of phytoremediation projects. The current challenge is ensuring that the extracted contaminants are not introduced into the consumer marketplace. After several decades of limited research on hemp in the United States, the purpose of this review is to identify the knowledge available for hemp applications in phytoremediation or in production of bioenergy, and if and how those two purposes have been combined. The literature shows that hemp growth has been demonstrated successfully at the field scale for phytoremediation and in several bioenergy conversion technologies. Little is known about the fate of contaminants during hemp growth or during post‐harvest processing, especially the relationships between hemp genetics, metabolomics, and contaminant partitioning. Complicating the understanding is the expectation that contaminant fate will be dependent on the contaminant type, the concentration in the material, and the processing methods. Before hemp from phytoremediation applications can be used for bioenergy, the fractionation of heavy metals, radionuclides, and/or organic compounds during transesterification, anaerobic digestion, fermentation, and/or combustion of hemp must be evaluated.