Tool For Phytoremediation Research Articles

Nature's Clean-Up Crew: Unlocking the Potential of Water Hyacinth as a Phytoremediation Wonder for Eutrophication Reduction in Aquatic Environments

This study aims to determine whether water hyacinth can be a phytoremediation tool to mitigate eutrophication in water bodies. Specifically, it seeks to observe the morphological changes in the leaves and stems of water hyacinth in terms of length and width, to describe the similarities and differences of water hyacinth from eutrophic and normal water aquariums, and to determine the efficacy of water hyacinth in mitigating eutrophication. The research employed an experimental research design, which constitutes a structured set of protocols and procedures tailored for conducting experimental investigations scientifically, employing two distinct sets of variables. In conclusion, the study found significant changes in water hyacinth's morphology when exposed to eutrophic water, with signs of distress observed after ten days due to high nutrient levels. Despite this, the findings support the potential of water hyacinth to mitigate eutrophication in water bodies, offering promise for enhanced water quality management.

Nature's Clean-Up Crew: Unlocking the Potential of Water Hyacinth as a Phytoremediation Wonder for Eutrophication Reduction in Aquatic Environments

This study aims to determine whether water hyacinth can be a phytoremediation tool to mitigate eutrophication in water bodies. Specifically, it seeks to observe the morphological changes in the leaves and stems of water hyacinth in terms of length and width, to describe the similarities and differences of water hyacinth from eutrophic and normal water aquariums, and to determine the efficacy of water hyacinth in mitigating eutrophication. The research employed an experimental research design, which constitutes a structured set of protocols and procedures tailored for conducting experimental investigations scientifically, employing two distinct sets of variables. In conclusion, the study found significant changes in water hyacinth's morphology when exposed to eutrophic water, with signs of distress observed after ten days due to high nutrient levels. Despite this, the findings support the potential of water hyacinth to mitigate eutrophication in water bodies, offering promise for enhanced water quality management.

Integrated Phytobial Remediation of Dissolved Pollutants from Domestic Wastewater through Constructed Wetlands: An Interactive Macrophyte-Microbe-Based Green and Low-Cost Decontamination Technology with Prospective Resource Recovery

Macrophytes have the potential to withstand pollutant-induced stress and can be used to clean contaminated water using phyto-extraction, phyto-degradation, phyto-filtration, phyto-stimulation, and phyto-volatilization technique(s). Phytoremediation through constructed wetlands (CWs) for eliminating inorganic and organic pollutants from household sewage and wastewater has attracted scientific attention. CWs are artificially engineered treatment systems that utilize natural cycles or processes involving soils, wetland vegetation, and plant and soil-associated microbial assemblages to remediate contaminated water and improve its quality. Herein, we present a detailed assessment of contaminant removal effectiveness in different CW systems, i.e., free-water surface or surface-flow constructed wetlands (FWSCWs/SFCWs), subsurface-flow constructed wetlands (SSFCWs), and hybrid constructed wetlands (HCWs). Several wetland floral species have been reported as potential phytoremediators, effectively reducing aquatic contamination through biodegrading, biotransforming, and bioaccumulating contaminants. Water hyacinth (Pontederia crassipes) is one of the most resistant macrophytes, capable of tolerating high nitrate (NO3−) and phosphate (PO42−) concentrations. Other aquatic weeds also effectively alleviate biological oxygen demand (BOD), chemical oxygen demand (COD), total dissolved solids (TDS), and pathogen levels and ameliorate the impact of different ionic forms of nitrogen (N), phosphorus (P), and trace elements (TEs). The review primarily focuses on using hydrophyte(s)-microbe(s) associations in different CWs as an essential phytoremediation tool for sustainable management of freshwater ecosystems, ecorestoration, and prospective resource recovery, favoring a circular bioeconomy (CBE).

Screening of new native metallophytes from copper abandoned mining site: Promising tool for phytoremediation

AbstractA field survey on abandoned mining site ‘Bir Nehass‐Morocco’ was conducted to identify new native metallophytes as a promising tool for phytoremediation. The spatial distribution of metals in tailings and mining soils was investigated and metal accumulation in plant tissues was analyzed and compared. The results indicated that the studied area was polluted by Cu, Zn, Pb and Cd Cadmium with maximum values of 2892, 27868.3, 6982 and 63.03 mg.kg−1, respectively, which are higher than background levels for agricultural soils. The concentrations of Cu, Zn, Pb and Cd decreased with the distance from the mine tailings. Thirteen species (11 families) were identified and mainly native and therophyte plants. Significant difference (p < 0.05) was observed among the average concentrations of metals in plant tissues and most values exceeded the normal concentration range. Based on the comparative analysis of heavy metals content, translocation and bioconcentration factors in plants, Aizoon canariense L, Hirschfeldia incana (L.) L. Fossat, Citrullus colocynthis (L.) Schrader and Peganum harmala L had a high accumulation ability and showed a remarkable phytoremediation potential which could be identified as promising candidates for phytoremediation techniques.

Sarcocornia fruticosa recovery capacity after exposure to co-existed water and salinity stress

The capacity of halophytes species to resist abiotic stress has been tested on multiple occasions. The ability of these species such as Sarcocornia fruticosa to cope with severe stress conditions has been shown, as well as their utility as a phytoremediation tool or even as potential crop species. However, there is a lack of literature on the effect that these abiotic factors have on their physiological response after a recovery period. In a greenhouse experiment, S. fruticosa plants were subjected to a combination of water regimen (water stress/field capacity) and salinity concentration (171/510 mM NaCl) grown conditions for 30 days. After these stress periods, plants were left 15 days in recovery conditions (field capacity and 171 mM NaCl). To study the effect of stress during both periods, osmotic potential, net photosynthetic rate, stomatal conductance, intercellular CO2 concentration, quantum efficiency of PS II, OJIP-derived parameters and photosynthetic pigment concentrations were measured. Our results show the already known resistance of this species to drought and salinity stress. However, the combination of both factors did affect the ability of S. fruticosa to maintain its level of carbon assimilation due to a decrease in stomatal conductance. In addition, the recovery period helped us to describe a synergic effect of both abiotic factors showing that plants subjected to both stresses received a better response during the recovery period than those only affected by salinity stress.

High boron stress leads to sugar beet (Beta vulgaris L.) toxicity by disrupting photosystem Ⅱ

This sugar beet acts as a soil remediator in areas where there are high levels of boron (B) in the soil, since it has a high requirement of boron (B) for growth, and has strong resistance to high B levels. Although B toxicity in different plants has been widely researched, little is known about the response of photosystem II (PSII) activity in sugar beet leaves to B toxicity at present.To clarify the growth and photosynthetic physiological response of sugar beet to B toxicity, the effects of different concentrations of H3BO3 (0.05, 1.5, 2.5,3.5 mM) on the growth, photosynthetic characteristics and antioxidant defense system of sugar beet seedlings were investigated by hydroponic experiments. In the present study, high B stress inhibited the growth of sugar beet and significantly decreased the biomass of the plants. There was a remarkable increase in the accumulation of B in the shoots, which affected photosynthesis and decreased the photosynthetic pigments. As B toxicity increased, leaf PSII activities and maximum photochemical efficiency of PSII (Fv/Fm) showed a tendency to decrease; at the same time, the photosynthetic performance index based on absorbed light energy (PIABS) decreased as well. Meanwhile, the energy allocation parameters of the PSII reaction center were changed, the light energy utilization capacity and the energy used for electron transfer were reduced and the thermal dissipation was increased at the same time. Furthermore, B toxicity decreased catalase (CAT) activity, increased peroxidase (POD) and superoxide dismutase (SOD) activities, and increased malondialdehyde (MDA) accumulation. According to the results obtained in this study, high B concentrations reduced the rate of photosynthesis and fluorescence, thus weakened antioxidant defense systems, and therefore inhibited the growth of sugar beet plants. Thus, in high B areas, sugar beet possesses excellent tolerance to high B levels and has a high B translocation capacity, so it can be used as a phytoremediation tool. This study provides a basis for the feasibility of sugar beet resistant to high B environments.

Vetiver Floating Wetlands for Dyeing Effluent

As a result of industrialization, the degree of global water contamination has drastically grown in recent decades. Both rich and developing nations are seeing this worldwide trend, although the later are experiencing it more pronouncedly. Due to its extraordinary and distinctive morphological and physiological characteristics, the Vetiver Floating Wetlands (VFWs), which is based on Vetiver grass (Chrysopogon zizanioides), has been successfully used as a phytoremediation tool to remediate both polluted water like municipal wastewater such as sewage effluent, landfill leachate, urban runoff, drainage channels, industrial wastewater such as food processing factories, and contaminated land (mine overburden and tailings, solid waste dumps). This study focuses on the use of hydroponics and floating wetlands to clean contaminated dyeing effluent. This study aims to find the efficiency of Vetiver Floating wetlands over various physio-chemical parameters in Dyeing effluent. The study was laid down in Tamil Nadu Agricultural University, Coimbatore in 2022 during the month of April- May. The effluent was diluted to different concentrations namely 25%, 50%, 75% and 100%. Various parameters were analyzed in these treatments in Dyeing effluent. The samples were collected at 15 days interval analyzed for one month. In Dyeing effluent, 50% concentration of the effluent showed better results over Vetiver Floating Wetlands and the removal efficiency was greater at this particular concentration.

Presence and Plant Uptake of Heavy Metals in Tidal Marsh Wetland Soils.

Marsh grasses have been used as efficient tools for phytoremediation and are known to play key roles in maintaining ecosystem functions by reducing the contamination of coastlines. This study was initiated to understand how human activities in wetlands can impact ion-heavy metal concentrations in relation to native and invasive marsh grasses. The study site, Blackbird Creek (BBC) is a tidal wetland that experiences agricultural, fishing, recreational, residential and other anthropogenic activities throughout the year. Heavy metals cadmium, arsenic, and lead in the soils and marsh grasses were monitored along with the ion compositions of soils. The main objective of this study was to understand if the marsh soils containing monotypic stands of native (Spartina) and non-native (Phragmites) vegetation display similar levels of heavy metals. Differences were observed in the concentrations of heavy metals at study sites with varying marsh vegetation types, and in soils containing vegetation and no vegetation. The soils with dense Spartina and Phragmites stands were anaerobic whereas soil at the boat ramp site was comparatively less anaerobic and also had increased levels of cadmium. Heavy metal concentrations in soil and Phragmites leaves were inversely correlated whereas they were positively correlated in Spartina sites. Electrical conductivity and pH levels in soil also showed increased cadmium and arsenic concentrations. These findings collectively infer that human activities and seasonal changes can increase soil complexities affecting the bioavailability of metals.

Can Pesticides Dissolved in Runoff and Exposed to Maturing Rice (Oryza sativa) Plants be Transferred to Seeds?

Agriculture's global challenge to feed an estimated 7.7 billion people is further exacerbated by less available cropland for production and rapidly changing climate patterns. Pesticides are often utilized to minimize crop losses due to pest infestations; however, problems arise when these chemicals are transported off production acreage, either by storm or irrigation events, and into nearby water bodies. Innovative management practices are needed to not only reduce the volume of runoff, but also to mitigate various pollutants, such as pesticides, within the runoff. One such practice being evaluated involves using rice (Oryza sativa) as a pesticide mitigation tool. While rice plants may serve as a mechanism for phytoremediation, whether the seeds harvested from exposed plants could then be utilized as a human food source is an unanswered question. Thirty round mesocosms (55 L volume; 56cm diameter; six replicates per treatment) were established with rice and exposed to aqueous concentrations of the pesticides clomazone, propanil, or cyfluthrin, as well as a mixture of the three pesticides. Six replicates with rice and no pesticide exposure served as controls. Initial pesticide exposure took place 8weeks post-planting and continued once a week for 5weeks. Rice plants, unmilled seeds, and mesocosm sediment were collected from each mesocosm 2weeks after seed formation began and analyzed for pesticide concentrations using gas chromatography. Concentrations of pesticides in unmilled seed were below detection for individual exposures of clomazone, propanil, and cyfluthrin. When rice was exposed to the pesticide mixture, the mean ± SE unmilled seed cyfluthrin concentration was 14.8 ± 1.25µgkg-1. These small-scale, preliminary studies offer insight into the possibility of using immature rice plants as a phytoremediation tool, while harvesting its grain after plant maturation for human consumption. Further research is needed to address this question on a larger scale and with multiple pesticide mixtures.

Rossellomorea arthrocnemi sp. nov., a novel plant growth-promoting bacterium used in heavy metal polluted soils as a phytoremediation tool.

Strain EAR8T is a root endophyte isolated from Arthrocnemum macrostachyum plants collected from the Odiel marshes, Huelva (Spain). It presented in vitro plant growth-promoting properties and improved the plant growth and heavy metal accumulation in polluted soils playing an important role in phytoremediation strategies. Phenotypically, strain EAR8T cells were Gram-positive, aerobic and non-motile rods with terminal oval endospores and non-swollen sporangia which form beige, opaque, butyrous, raised and irregular colonies with undulate margins. The strain was able to grow between 15–45 °C, at pH 6.0–9.0 and tolerated 0–25 % NaCl (w/v) showing optimal growth conditions on trypticase soy agar plates supplemented with 2.5 % NaCl (w/v) at pH 7.0 and 37 °C for 24 h. Chemotaxonomic analyses showed that the isolate has meso-diaminopimelic acid as the peptidoglycan in the cell wall and MK-7 as the major respiratory quinone. The predominant fatty acids were anteiso-C15 : 0 and iso-C15 : 0 and the polar lipid profile was composed of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Phylogenetic analyses based on the whole proteomes of closest sequenced relatives confirmed that strain EAR8T is affiliated to the genus Rossellomorea and forms a clade with Rossellomorea vietnamensis 15-1T with maximum support. Genome analyses showed that EAR8T has indole-3-acetic acid and siderophore biosynthesis and transporters genes and genes related to resistance against heavy metals. Phenotypic and phylogenomic comparative studies suggested that strain EAR8T is a new representative of the genus Rossellomorea and the name Rossellomorea arthrocnemi sp. nov. is proposed. Type strain is EAR8T (=CECT 9072T=DSM 103900T).

Ecological Risk Assessment of Potential Toxic Elements in Salt Marshes on the East Coast of the Red Sea: Differential Physiological Responses and Adaptation Capacities of Dominant Halophytes

The impact of the mutual interactions between salinity and the phytoavailability of potential toxic elements (PTEs) on the adaptation of halophytes in their natural habitat is complex and far from clear. Herein, we aimed to evaluate salinity- and PTE-induced oxidative stress in selected halophytes and the antioxidant responses of these plants. For that, five salt marshes were selected, and the physiological responses of dominant halophytes (Tamarix nilotica, Heliotropium crispum, Zygophyllum coccineum, Halopeplus perfoliata, and Avicennia marina) were evaluated against the physicochemical features of their rhizosediments. The tested locations varied in their physicochemical properties and showed various levels of salinity stress and a low fertility status. Distinct variations in ten PTE concentrations were recognized among locations and within plants, with Cr and Co showing the highest ecological risk indices. The high levels of salinity and PTEs were associated with higher foliar levels of malondialdehyde, particularly in A. marina and Z. coccineum. The bio-concentration ratio revealed hyperaccumulating potentials of PTEs by the tested halophytes. Z. coccineum showed effective accumulation of Co, Fe, and Pb, while T. nilotica exhibited effective accumulation of Cu, Cd, and Zn. H. perfoliate had higher accumulation of Cr and Hg, whereas A. marina accumulated a significant amount of Hg, Cd, Zn, and Mn. H. crispum leaves accumulated the highest Ni levels among the tested halophytes. Altogether, our results highlight the potential risk of pollution of the tested areas with PTEs and the efficient physiological adaptation of each of the tested halophytes as a unique biological system. They also reflect the high capabilities of the tested halophytes as phytoextractors of their corresponding PTEs and their potential as efficient tools for phytoremediation of salt- and PTE-affected lands.

Nodulated White Lupin Plants Growing in Contaminated Soils Accumulate Unusually High Mercury Concentrations in Their Nodules, Roots and Especially Cluster Roots

Two white lupin (Lupinus albus L.) cultivars were tested for their capacity to accumulate mercury when grown in Hg-contaminated soils. Plants inoculated with a Bradyrhizobium canariense Hg-tolerant strain or non-inoculated were grown in two highly Hg-contaminated soils. All plants were nodulated and presented a large number of cluster roots. They accumulated up to 600 μg Hg g−1 DW in nodules, 1400 μg Hg g−1 DW in roots and 2550 μg Hg g−1 DW in cluster roots. Soil, and not cultivar or inoculation, was accountable for statistically significant differences. No Hg translocation to leaves or seeds took place. Inoculated L. albus cv. G1 plants were grown hydroponically under cluster root-promoting conditions in the presence of Hg. They accumulated about 500 μg Hg g−1 DW in nodules and roots and up to 1300 μg Hg g−1 DW in cluster roots. No translocation to the aerial parts occurred. Bioaccumulation factors were also extremely high, especially in soils and particularly in cluster roots. To our knowledge, Hg accumulation in cluster roots has not been reported to date. Our results suggest that inoculated white lupin might represent a powerful phytoremediation tool through rhizosequestration of Hg in contaminated soils. Potential uptake and immobilization mechanisms are discussed.

Phytoremediation tool for restoration of metal-polluted coal mine soil in Okaba, Nigeria: a hierarchical cluster approach.

Coal mining activities have been ongoing in Okaba for years without adequate attention paid to pollution and reclamation. Soil and plants were sampled from Okaba coal mine to determine the metal content in the soil and to identify the plants that have potential for phytoremediation. The samples were prepared, separated into various tissues, and labeled and taken to the laboratory. Digestion was carried out using acid mixture of nitric acid (HNO3): perchloric acid (HCLO4) for the plants, while the mixture of nitric acid (HNO3): hydrochloric acid (HCl): perchloric acid (HCLO4) was used for the soil. The concentrations of metals from the samples were determined using EDX3600B X-ray fluorescence spectrometer (Sky ray Instruments Inc., USA), a World Bank Assisted Project, Nigeria. Bioconcentration factor (BCF), translocation factor (TF), and bioaccumulation coefficient (BAC) or extraction coefficient (EC) were determined to identify the plants that have potential for hyperaccumulation, phytoextraction, and phytostabilization and ability to store up these metals for harvesting. Hierarchical cluster analysis was performed to highlight the relationship between the variables. This study has revealed that Ageratum conyzoides Linn (ACL), Desmodium velutinum (DV), Triumfetta rhiomdoidea Jacq. (TRJ), Gleichenia linearis (Burns) (GL), Selaginella myosurus (SM), and Sida linifolia juss.excav. (SL) had potential as hyperaccumulators of nickel. Eleven (11) plants have potential for phytoextraction of manganese (Mn), and six (6) plants have stabilization potential for the same metal. Eight (8) phytoextractors and seven (7) stabilizers plants were recorded for Ni. Eclipta alba (L) Hassk (EAH) (location 4) and TRJ were phytostabilizers plants for Pb. Six (6) other plants have potential as phytoextractors of Pb. Eight (8) of the studied plants were suitable for phytoextraction of Ni, and five (5) plants were suitable as phytostabilizers. Most of the plants were found to be useful for phytoremediation of the soil.

Heavy metals and arsenic phytoremediation potential of invasive alien wetland plants Phragmites karka and Arundo donax: Water-Energy-Food (W-E-F) Nexus linked sustainability implications

Heavy metals and arsenic (As) are hazardous to the environment and human health. In concert with the problem of metallic contaminants, certain macrophytes in wetlands are harmful invasive alien plants (IAP). Nevertheless, there exists a knowledge gap, that whether all IAP are nuisance or possess certain beneficial role as bioresource in environmental amelioration. Present study conducted microcosm experiments to investigate the heavy metals and As phytoremediation potential of IAP (Phragmites karka (Retz.) Trin. ex Steud. and Arundo donax L.). The results revealed the significant but differential heavy metals remediation (31.0 to 73.3%; p ≤ 0.01) and anti-oxidative defence potential (in terms of enzymatic activity) of IAP. Highest translocation factor (TF-0.89) was noted in case of P. karaka for Zn. Rhizofiltration (TF < 1) was observed as main phytoremediation mechanism. In the present experimental design, P. karka was noted as better phytoremediation tool than A. donax. In future studies, phytoremediation potential of these IAP can be tested at field scale, in conjunction with ‘Water-energy food (W-E-F) nexus’ and ‘biorefinery’ co-benefits.

Heterologous expression of cyanobacterial PCS confers augmented arsenic and cadmium stress tolerance and higher artemisinin in Artemisia annua hairy roots.

The present study provides the first report of heterologous expression of phytochelatin synthase from Anabaena PCC 7120 (anaPCS) into the hairy roots of Artemisia annua. Transformed hairy roots of A. annua expressing anaPCS gene showed better tolerance to heavy metals, viz., arsenic (As) and cadmium (Cd) owing to 143 and 191% more As- and Cd-accumulation, respectively, as compared to normal roots with a bioconcentration factor (BCF) of 9.7 and 21.1 for As and Cd, respectively. Under As and Cd stresses, transformed hairy roots possessed significantly higher amounts of phytochelatins and thiols probably due to the presence of both AaPCS (Artemisia annua PCS) and anaPCS. In addition, artemisinin synthesis was also induced in transformed hairy roots under heavy metals stresses. In-silico analysis revealed the presence of conserved motifs in both AaPCS and anaPCS sequences as well as structural modelling of PCS functional domain was conducted. Interaction of AaPCS and anaPCS proteins with CdCl2 and sodium arsenate gene ontology analysis gave insights to anaPCS functioning in transformed hairy roots of A. annua. The study provides transformed hairy roots of A. annua as an efficient tool for effective phytoremediation with added advantages of artemisinin extraction from hairy roots used for phytoremediation.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11816-021-00682-5.

PHYTOREMEDIATION OF URANIUM TAILINGS: ROLE OF CHELATORS IN TRIGGERING URANIUM ACCUMULATION IN WHEAT

Chelator-assisted phytoextraction has been proposed as a potential tool for phytoremediation of uranium contaminated tailings. The purpose of the present investigation was to test the efficiency of the four various chelators namely, citric acid (CA), oxalic acid (OA), NTA and EDTA and to screen out the most effective chelator with promising concentration of it in increasing the U uptake and accumulation for phytoremedial programmes. Three kilograms of mixture (25:75; tailing: garden soil) was filled in the earthen pots. Treatment pots were prepared by applying- 0.1, 0.5, 2.5 and 12.5 mmol kg-1 concentrations of each of the chelator (CA, OA, NTA and EDTA). Optimum concentrations of the chelators were recorded considering biomass production, tolerance index and U uptake. Each chelator produced severe toxicity symptoms at 12.5 mmol kg-1 treatment level. Lowest depression in respect of growth was observed with NTA while OA and CA were proved less toxic than EDTA. Highest inhibition was recorded in EDTA treatments at respective levels. U uptake and accumulation was concentration dependent for each of the chelator amendment. Maximum U uptake (3.4-fold) in the roots occurred at 2.5 mmol kg-1 of CA while NTA proved to be the weakest for the same purpose. Not with standing, EDTA and NTA are stronger complexion agents than CA but in contrary, the use of CA proved beneficial in U tailing phytoremediation in the present investigation. The growth of the wheat plants was affected by each of the chelator, which in general follows the order: NTA ? OA ? CA ? EDTA, whereas the order for U accumulation was recorded as- CA &gt; EDTA &gt; OA &gt; NTA. On the basis of this study it can be suggested that the use CA over EDTA is better, as it is easily biodegradable, less toxic and has lower leaching risk..

The phytoremediation potential of water hyacinth: A case study from Hartbeespoort Dam, South Africa

Eutrophication has been a prevalent problem in South African water bodies for many decades, resulting in algal blooms and growth of invasive alien aquatic weeds such as water hyacinth. It was brought under control in the 1990′s, but in recent years this problem has been exacerbated by increasing incidences of untreated sewage entering the river systems, along with other anthropogenic nutrient sources. This study investigated the potential for water hyacinth to be used as a phytoremediation tool to reduce the eutrophic state of Hartbeespoort Dam, and to determine if the water quality, aside from the nutrient concentrations, affects the rate of removal of nutrients by water hyacinth. Water hyacinth plants were grown in both water from the Hartbeespoort Dam and Hoagland Solution to test the effect of growth medium ‘purity’ on hyacinth growth. Another set of vessels containing Hartbeespoort Dam water only, without a hyacinth plant, was used to observe the remediation potential of the plant and its effectiveness at suppressing algal growth. The results show that one plant can absorb up to 7,38 mg of Phosphates and 27 mg of Nitrates within 11 days. Water hyacinth can reduce the nutrient concentration of 3 L of Hartbeespoort Dam water from 0,65 mg/L phosphates to 0,04 mg/L phosphate and from 4,1 mg/L nitrates to 0,5 mg/L nitrates in 4 days. These results suggest that water hyacinth can be employed as a phytoremediation tool to mitigate eutrophication in open water bodies and may have the potential to reduce Microcystis blooms.

Nature-based solutions as tools for air phytoremediation: A review of the current knowledge and gaps.

Monitoring of air quality and the application of strategies for its improvement are perceived as key areas for reducing environmental pollution. The research on Nature Based Solutions for the mitigation of pollutant concentrations in the air has increasingly developed in the last twenty years. The purpose of this review is to evaluate whether the current knowledge about Nature-Based Solutions provides a quantitative answer of the real benefits of air phytoremediation. To address this question, the literature on air phytoremediation over the last twenty years was analyzed. Altogether, 52 variables were selected, grouped into six categories, to briefly characterize the contents, methodology and outcome of the peer-reviewed articles. Altogether, 413 plant species found in the analyzed studies were recorded. The results show the trends about the most studied pollutants and on the methodologies mostly applied, in relation to the study outcomes. The analysis demonstrated that particulate matter (PMx) was the most frequently examined pollutant, most studies on NBS are based on experiments with exposure chambers, and scaling up the results with models has been limited. Although effective reductions in pollutant concentrations have been shown in the majority of studies, there is a strong fragmentation of the approaches, most studies have looked at a single pollutant and detailed information for model parameterization is only available for a few species. Thus, the review highlights that studies of Nature Based Solutions in air phytoremediation require unification of methodologies, and should consider a broader range of pollutants and plant organisms useful for mitigating the impacts of air pollutants in indoor and outdoor human environments.

Can mangroves work as an effective phytoremediation tool for pesticide contamination? An interlinked analysis between surface water, sediments and biota

Mangroves are a unique group of plants growing along tropical and sub-tropical coastlines, with the ability to remove several types of contaminants such as heavy metals and other persistent organic compounds in coastal waters. However, little attention has been given to the possible role of mangroves in the removal of organochlorinated pesticides (OCPs) from the environment. Used worldwide, these pesticides were banned in the late 80s, withal they can still be quantified in aquatic environments due to their high stability. Moreover, as persistent and lipophilic compounds, OCPs are known for their tendency to bioaccumulate and biomagnify through the food chain, affecting local ecosystems, and potentially human health. This work aimed to investigate the potential benefits of mangrove ecosystems as OCP phytoremediators. For this purpose, a total of seventy-three articles from non-mangrove and mangrove areas around the world were gathered, integrated and re-analysed as a whole. These data include information from four different matrices (water, sediment, benthic fauna and mangrove plants). A common trend of less pesticide contamination in mangrove areas was observed for all the selected matrices. As a complement, average concentrations were discussed considering International Directives, such as the European legislation 2013/39/EU for water policy and the Dutch List together with the International Sediment Quality Guideline, for sediments. Additionally, theoretical risk assessments were also included. Since information regarding OCPs in mangroves ecosystem is very scarce compared to non-mangrove areas, this review provides valuable insights regarding these environments, and the importance of preserving them as a relevant remediation unit.

Antioxidant Responses of Phenolic Compounds and Immobilization of Copper in Imperata Cylindrica, a Plant with Potential Use for Bioremediation of Cu Contaminated Environments.

This work examined the capability of Imperata cylindrica to respond, tolerate and accumulate Cu when growing at high Cu concentration (300 mg kg−1 of substrate) at different times of exposure (2, 14 and 21 days). The Cu accumulation in plants was examined by atomic absorption spectroscopy (AAS) and Cu localized by Scanning Electron Microscopy-Energy Dispersive X-Ray spectroscopy. Additionally, the phenolic compound identifications and concentrations were determined using liquid chromatography coupled to mass spectrometry. Our results showed that root biomass decreased significantly at high Cu levels, with a greater decrease at 21 days (39.8% less biomass in comparison to control). The root showed 328 mg Cu kg−1 dry weight at 21 days of exposure to Cu, being the tissue that accumulates most of the Cu. Lipid peroxidation was a clear indicator of Cu stress, principally in shoots. The exposure to Cu significantly increased the synthesis of phenolic compounds in shoots of plants exposed 21 days to Cu, where 5-caffeoylquinic acid reached the highest concentrations. Our results support that I. cylindrica is a Cu accumulator plant in root organs with a medium level of accumulation (between 200–600 mg Cu kg−1 biomass), which can tolerate the exposure to high Cu levels by means of increasing the synthesis of phenolic compound in shoots, suggesting a potential use as phytoremediation tool in Cu polluted environments.