Plant Species For Phytoremediation Research Articles

Antioxidant defense strategies of urban ornamental plants in southern Iran against heavy metals

One of the effective approaches to reduce heavy metals (HMs) contamination is phytoremediation. The concentration of 10 HMs was measured in 10 ornamental plants grown in the city of Bushehr, located in southern Iran. The concentration of HMs was determined by ICP-MS. Some physiological parameters and antioxidant enzymes activity were measured. Bougainvillea had greater amount of Zn (61.86 mg/kg D.W.), Cu (45.52 mg/kg D.W.), and Cr (14.71 mg/kg D.W.) than the other HMs. Greatest amount of Co (0.686 mg/kg D.W.), Fe (428.00 mg/kg D.W.), and Ni (6.44 mg/kg D.W.) was obtained in Conocarpus erectus. Also, Clerodendrom inerme had maximum As (0.0087 mg/kg D.W.) and Sn (2.516 mg/kg D.W.). The POD activity (1.462 and 1.214 U/g F.W./min) was highest in leaves of C. inerme and Ficus elastica containing the highest concentrations of As, Sn, and Pb, respectively. The SOD activity was high in these two species. Synthesis of osmolytes increased under Co and Sn stresses. The selected plant species followed a defensive strategy (enzymatic or non-enzymatic) against excess of HMs. Overall, shrubs were much more suitable than trees for absorption and accumulation of HMs, and C. inerme, F. elastica, and Bougainvillea are the best plant species for phytoremediation.

Enhanced Phytoremediation and Physicochemical Parameters of Crude Oil Polluted Soil Using Pseudomonas fluorescens and Bacillus substilis

There have been worry over the Niger Delta's environmental contamination. Bacteria and other microorganisms have shown to be very helpful in the breakdown of hydrocarbons generated from petroleum. The goal of this research is to use elbow bufallow grass and sedge plants for phytoremediation of soil affected by crude oil. Standard microbiological techniques were applied to the contaminated soil once it was gathered. Using a hand auger, contaminated soil samples were taken twice a month for three months from two separate locations in Rivers State at two distinct depths: 0–15 cm and 15–30 cm. The following physicochemical parameters of samples were analysed using Standard Laboratory Procedures: pH, Temperature, Nitrogen, Phosphorus, Potassium available in the polluted soil and the total hydrocarbon content (THC). Two plant species common in the Ogoni region of Rivers state, i.e. Sedge plant (Schoenoplectus), Elbow buffalo grass (Panicum subalbidum) were used for phytoremediation monitoring. A combination of treatment consisting of the application of Pseudomonas fluorescens Bacillus substilis, Panicum subalbidum and Schoenoplectus senegalensis was evaluated during 28 days of remediation. Each pot contained crude oil mixture in the soil as a sole source of carbon and energy. THB counts ranged from 2.35 to 4.15 cfu/g. The statistical analysis revealed that there was no significant difference (p>0.05) in the total heterotrophic bacteria counts between the samples. HUB counts range from 0.7 to 1.45cfu/g. The total bacterial population counts obtained from soil sample during bioremediation monitoring ranged from 17+1.41 (CS+PAN) to 40+1.412cfu/g (CS+PSE+BAC+PAN) in Day 1. Results of Day 14 range from 13+1.41 (CS+PAN) to 35.5+3.542cfu/g (CS+BAC+SCH). Results of Day 28 ranged from 8.5+0.71 (CS+PAN) to 27+1.412cfu/g (CS+PSE+BAC+PAN). The presence of microbial activity was determined by the enumeration and isolation of total heterotrophic and hydrocarbon utilizing bacteria. The results of physicochemical parameters before bioremediation is as follows: pH (5.43), Temperature (27oC), Electrical conductivity (9), Moisture content (7.80%), Total organic carbon (0.93%), Soil organic matter (1.60%), Nitrogen (56.695mg/kg), Phosphorus (0.621mg/kg), Potassium (7.125mg/kg) and Total Hydrocarbon content (700mg/kg). Results revealed amount of soil hydrocarbon removed and percentage (%) Bioremediation remediated after 28 days of monitoring to be higher in set up with CS+PSE+SCH (3454mg/kg; 85.28%) and lowest in set up with US+SCH (434mg/kg: 62%) and the amount of root hydrocarbon content removed and percentage (%) Bioremediation remediated after 28 days of monitoring to be higher in set up with CS+BAC+SCH (632Mg/kg; 15.6%) and lowest in set up with US+SCH (12.2mg/kg; 1.74%).
 Three (3) most occurring hydrocarbon utilizing bacterial isolates were isolated and identified culturally and phenotypically from the soil samples these bacteria isolates were confirmed to be Peudomonas, Priestia megaterium and Bacillus spp molecularly via sequencing of the 16SrRNA gene. The most common bacteria isolated were Bacillus spp at a dilution of 104. This research revealed and recommend that Panicum subalbidum as a suitable plant species for phytoremediation of crude oil-contaminated soil.

Evaluation of Phytoremediation, Physicochemical and Heavy Metal Assessment of Crude Oil Polluted Soil Using Pseudomonas and Bacillus spp, Rivers State, Nigeria

Crude oil exploration has been beneficial to our economy but detrimental to our environment with the artisanal `refineries further compounding the challenge. This research was aimed at investigating the phytoremediation, physicochemical and heavy metal assessment of crude oil polluted soil using Peudomonas spp. and Bacillus spp. as augmenting microorganism, in Rivers state, Nigeria. This study was carried out in in south-south Nigeria (B-dere in Gokana Local government of `Rivers State). Contaminated Soil were collected and subjected to standard microbiological methods. Contaminated Soil samples were collected from two different area of Rivers state with sterilized soil auger at two depths of 0-15cm and 15-30cm. The contaminated soil sampled were analyzed for heavy metal (Cadium Chromium, Lead and Zinc) using Atomic Absorption spectrophotometric method. Microbiological analysis was carried out on the soil samples. Ten (10) treatments consisiting of contaminated soil (CS), uncontaminated soil (US), uncontaminated soil(US), Panicum subalbidum and Schoenoplectus senegalensis were setup for a period of 28 days. Physicochemical parameters were analyzed for uncontaminated soil and contaminated soil. The physicochemical parameters analyzed were pH, Temperature, Nitrogen, Phosphorus, Potassium and Total Hydrocarbon Content. The physiochemical parameters of the uncontaminated soil were pH (5.43), temperature (27oC), Electrical conductivity (9uS/cm), Moisture content (7.80%), Total organic carbon (0.93%), Soil organic matter (1.60%), total Nitrogen (56.695mg/kg), available phosphorus (0.621mg/kg), potassium (7.125mg/kg) and total hydrocarbon content (700mg/kg). Results revealed that the amount of hydrocarbon remediated and percentage (%) bioremediation in the soil after 28 days of monitoring from the initial THC value of (4050 mg/kg), is higher in set up with CS+PSE+SCH (3454mg/kg; 85.28%) and lowest in set up with US+SCH (434mg/kg: 62%) and the amount uptake of phytoremediation in the root after 28 days of monitoring to be higher in set up with CS+BAC+SCH (632Mg/kg; 15.6%) and lowest in set up with US+SCH (12.2mg/kg; 1.74%). The heavy metals assessed were cadium (Cd), chromium (Cr), lead (Pb) and zinc (Zn). This research revealed and recommend that Schoenoplectus senegalensis as a suitable plant species for phytoremediation of crude oil contaminated soil. Hydrocarbon utilizing bacteria identified in this study were; Pseudomonas and Bacilus spp.

Responses of microbial communities in rhizocompartments of king grass to phytoremediation of cadmium-contaminated soil

King grass has been recognized as a potential phytoremediation plant species due to its high biomass and resistance to heavy metals (HMs). However, the possible impacts of cadmium (Cd) contamination on rhizocompartments' microbial activities in association with king grass have not been extensively explored. The utilization of 16S rRNA gene and ITS sequencing was carried out to examine alterations in the bacterial and fungal communities in the rhizosphere and rhizoplane of king grass in response to low and high Cd stress. Results demonstrated that both bacterial and fungal communities' diversity and richness were negatively impacted by Cd stress, regardless of its concentration. However, evenness did not exhibit any significant response to either of the concentrations. Additionally, nonmetric multidimensional scaling (NMDS) ordination demonstrated a significant difference (p < 0.001) in microbial communities under different treatments. The abundance of bacterial taxa such as Steroibacter, Nitrospira, Pseudoxanthomonas, Cellvirio, Phenylobacterium, Mycobacterium, Pirellula and Aquicella was adversely affected under Cd stress while Flavobacterium, Gemmata, Thiobacillus and Gemmatimonas showed no prominent response, indicating their resistance to Cd stress. Like that, certain fungal taxa for instance, Cladosporium, Cercophora, Acremonium, Mortierella, Aspergillus, Penicillium, Glomus and Sebacina were also highly reduced by low and high Cd stress. In contrast, Fusarium, Thanatephorus, Botrytis and Curvularia did not show any response to Cd stress. The identified taxa may have a crucial role in the growth of king grass under heavy metal contamination, making them promising candidates for developing bioinoculants to encourage plant performance and phytoremediation capability in HM-contaminated soils.

Remediation Opportunities for Arsenic-Contaminated Gold Mine Waste

Arsenic (As)-contaminated gold mine waste is a global problem and poses a significant risk to the ecosystem and community (e.g., carcinogenic, toxicity). Arsenic concentrations of 77,000 mg/kg and 22,000 mg/kg in mine waste have been reported for Canada and Australia, respectively. Research is investigating environmentally sustainable techniques to remediate As-rich mine waste. Biological techniques involving plants (phytoremediation) and soil amendments have been studied to bioaccumulate As from soil (phytoextraction) or stabilise As in the rhizosphere (phytostabilisation). Identified plant species for phytoremediation are predominately fern species, which are problematic for arid to semi-arid climates, typical of gold mining areas. There is a need to identify native plant species that are compatible with arid to semi-arid climates. Arsenic is toxic to plants; therefore, it is vital to assess soil amendments and their ability to reduce toxicity, enhance plant growth, and improve soil conditions. The effectiveness of a soil-amending phytoremediation technique is dependent on soil properties, geochemical background, and As concentrations/speciation; hence, it is vital to use field soil. There is a lack of studies involving mine waste soil collected from the field. Future research is needed to design soil-amending phytoremediation techniques with site-specific mine waste soil and native plant species.

Enhanced Phytoremediation of Crude Oil Polluted Soil Using Pseudomonas fluorescens

Environmental pollution in the Niger Delta has been a huge concern. Bacteria have proven to be of great benefit in the degradation of petroleum hydrocarbons. This research is aimed at enhanced phytoremediation of crude oil polluted soil using Pseudomonas fluorescens. Soil was collected from oil spill polluted site at B-dere, Rivers State. Six (6) treatments consisting of contaminated soil (CS), uncontaminated soil (US), augmenting organisms Pseudomonas fluorescens (Pse), and phytoremediation grasses (Elbow buffalo grass (Panicum subalbidum) (PAN-G) and Sedge plant Schoenoplectus senegalensis (SCH-G)) were evaluated during a period of 28 days. Total Heterotrophic Bacteria (THB) and Hydrocarbon Utilizing Bacteria (HUB) were monitored. Physicochemical parameters monitored were pH, Temperature, Nitrogen, Phosphorus, Potassium and Total Hydrocarbon Content (THC). Baseline results of physicochemical parameters carried out in the uncontaminated soil were pH, temperature (oC), Moisture content (%), Electrical conductivity (uS/cm), Total Organic Carbon (TOC), Soil Organic Matter, Total Hydrocarbon Content (THC), Nitrogen, Phosphorus and Potassium (mg/kg). The amount of hydrocarbon remediated and percentage bioremediation in the soil after 28 days were: CS+PSE+SCH (3454mg/kg; 85.28%) &gt; CS + BAC + SCH-G (3264mg/kg; 80.59%) &gt; CS +PSE + BAC + SCH-G (3210mg/kg; 79.26%) and CS + SCH-G had the lowest (434mg/kg: 62%). This research revealed that Schoenoplectus senegalensis (sedge plant) is a suitable plant species for phytoremediation of crude oil polluted soil than Panicum subalbidum. Moreso, Schoenoplectus senegalensis (sedge plant) has a higher phytoremediation potential when augmented with Psuedomonas. it is therefore recommended that Schoenoplectus senegalensis (sedge plant) in combination with augmenting organism (Psuedomonas) is best option for remediation of crude oil polluted.

Assessing the Native Plant Species for Phytoremediation of Freshwater Bodies in Southern Ontario, Canada

Many Canadian freshwater ecosystems are polluted by agricultural runoff, impairing their function with increased nutrient levels. Here, we simulated the water filtration function of wetlands, which uses aquatic plant species to create a phytoremediation system that can address the contamination of freshwater ecosystems with excess nutrients. We collected the water samples from three of Ontario’s freshwater bodies: the Holland Marsh, a highly agricultural area; the Nottawasaga River, a river in a rural area and part of a greater Nottawasaga watershed and Lake Ontario, near industrial sites in the Niagara region. To filter nitrogen (N), phosphorus (P) and potassium (K) from the collected samples, we determined the effectiveness of five local wetland and agricultural plant species: duckweed (Lemnoideae), watercress (Nasturtium officinale), coontail (Ceratophyllum demersum), thyme (Thymus praecox) and parsley (Petroselinum crispum). During a five-month experiment, plants were grown in collected water samples to determine their ability to uptake N, P and K. Along with monitoring their effectiveness in lowering nutrient levels, we tracked the health and growth of each plant species. The results showed that duckweed was the most tolerant to high nutrient concentrations and the most effective at overall nutrient reduction. From the Holland Marsh sample with the highest nutrient concentrations among all collected samples, the duckweed reduced N, P, and K by 11%, 53%, and 21%, respectively, compared to the control sample (i.e., with no plant). This filtration system allows for ecosystem restoration and prevention of further damage and contamination from agricultural runoff and nutrient pollution.

Status of Phytoremediation of Domestic Wastewater in India – A Review

After the industrial revolution, human beings are utilizing natural resources in an accelerated and alarming rate, which has resulted into the release of very harmful substances into the environment. Along with industrialization, there was the growth of urban centers with changed lifestyles having an additional burden on the environment posing a serious threat to the delicate ecological balance. For cleaning this waste, especially domestic wastewater by conventional treatment methods, all governments, and local civic bodies have to incur huge capital expenditures on them. Some alternative green technologies, such as the technique of phytoremediation for the treatment of domestic wastewater are much promising. This review article focuses on a selection of plant species for phytoremediation which are indigenous, have the potential of cleaning domestic wastewater, and can easily adapt to local ecosystems without harming them along with some socio-economic and ecological benefits.

Enolase, a cadmium resistance related protein from hyperaccumulator plant Phytolacca americana, increase the tolerance of Escherichia coli to cadmium stress

Phytolacca americana is a Cd hyperaccumulator plant that accumulates significant amounts of Cd in leaves, making it a valuable phytoremediation plant species. Our previous research found enolase (ENO) may play an important part in P. americana to cope with Cd stress. As a multifunctional enzyme, ENO was involved not only in glycolysis but also in the response of plants to various environmental stresses. However, there are few studies on the function of PaENO (P. americana enolase) in coping with Cd stress. In this study, the PaENO gene was isolated from P. americana, and the expression level of PaENO gene significantly increased after Cd treatment. The enzymatic activity analysis showed PaENO had typical ENO activity, and the 42-position serine was essential to the enzymatic activity of PaENO. The Cd resistance assay indicated the expression of PaENO remarkably enhanced the resistance of E. coli to Cd, which was achieved by reducing the Cd content in E. coli. Moreover, both the expression of inactive PaENO and PaMBP-1 (alternative translation product of PaENO) can improve the tolerance of E. coli to Cd. The results indicated PaENO may be alternatively translated into the transcription factor PaMBP-1 to participate in the response of P. americana to Cd stress.

Calorific Value of Festuca rubra Biomass in the Phytostabilization of Soil Contaminated with Nickel, Cobalt and Cadmium Which Disrupt the Microbiological and Biochemical Properties of Soil

The choice of optimal plant species for phytoremediation and organic fertilization plays an important role in stabilizing the functions of soils contaminated with heavy metals. The influence of nickel, cobalt and cadmium on the biomass yield and calorific value of Festuca rubra, heavy metal concentrations in soil and plants and the microbiological, biochemical and physicochemical proprieties of soil were analyzed in a pot experiment. The tolerance index (TI) describing Festuca rubra’s ability to tolerate heavy metals, as well as the translocation (TF), accumulation (AF) and bioaccumulation (BF) factors of heavy metals in Festuca rubra were calculated. The experiment was conducted in two series: In soil fertilized and not fertilized with compost. Nickel and cobalt significantly inhibited the growth and development of Festuca rubra. The experiment demonstrated that this plant species can be grown on soil contaminated with heavy metals. Festuca rubra contained on average 46.05% C, 34.59% O, 5.91% H, 3.49% N, 0.19% S and 9.76% ash. Festuca rubra has a stable calorific value which is not affected by heavy metals; therefore, biomass harvested from heavy metal-polluted soil can be used for energy generation. The calorific value of Festuca rubra ranged from 15.924 to 16.790 MJ kg−1 plant d.m., and the heat of combustion from 17.696 to 18.576 MJ kg−1. It has a stable calorific value which is not affected by heavy metals, therefore biomass harvested from heavy metal-polluted soil can be used for energy generation. Festuca rubra is particularly useful for the phytostabilization of soil contaminated with cadmium and cobalt. Compost minimizes the adverse effects of heavy metal pollution on the microbiological, biochemical and physicochemical properties of soil.

Screening the six plant species for phytoremediation of synthetic textile dye waste water

Most of the dyes are carcinogenic and mutagenic in nature. Plants are potential candidates to remediate textile dye wastewater from contaminated sites. The present study aimed to design an efficient hydroponic system to screen potential ornamental plant species for removal of synthetic dye solution of triarylmethane dye Methylene Blue (MB) and diazo dye Congo Red (CR). The plants selected for screening are Trachyspermum ammi, Tagetes erecta, Hibiscus rosa-sinensis, Chrysanthemum indicum, Bryophyllum fedtschenkoi, and Catharanthus roseus. The phytotreatment of dyes was done up to 40 h for two different concentrations of dyes, i.e., 10 and 20 mg L−1. Among screened plant species, the maximum decolorization was obtained from T. ammi followed by B. fedtschenkoi. Both plant species showed active growth in indigenous designed hydroponic system even after the phytoremediation process. T. ammi decolorized the MB dye 99 % (10 mg L−1) and 86 % (20 mg L−1) while the decolorization of the CR dye solution was up to 95 % (10 mg L−1) and 84 % (20 mg L−1). T. ammi was found to have maximum potential among screened plants for the removal of MB and CR dye from synthetic dye solution and can be used for phytoremediation of wastewater contaminated with synthetic dyes.

Assessment of heavy metal and metalloid levels and screening potential of tropical plant species for phytoremediation in Singapore

Heavy metal or metalloid contamination is a common problem in soils of urban environments. Their introduction can be due to unpremeditated anthropogenic activities like atmospheric deposition produced by diffuse sources, construction activities and landscape maintenance. Phytoremediation is a rapidly evolving, sustainable approach to remediate the contaminated lands where metals and metalloids are highly persistent in the environment. The present work sets out to determine the level of 12 heavy metals and metalloids (As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb and Zn) in soil and their accumulation by plant foliage found in nature parks and industrial sites in Singapore. The latter also involve the investigation of the remediation capacity of selected tropical plant species found at the sampling sites. The study is done using digestion and inductively coupled plasma-optical emission spectrometry. Eleven soil sampling sites across Singapore with 300 sampling points were selected, where soil (0–10 cm) and plant foliage samples were collected. Bioconcentration factors were determined to assess the phytoremediation potential of the collected plant species. Toxicity risk of heavy metals were assessed by comparing the target and intervention values from the soil quality guidelines by the Dutch Standard. Results of the study revealed there were regions where levels of heavy metals and metalloids were relatively high and could affect the environment and the health of flora and fauna in Singapore. Our study discovered that there were available tropical plant species (e.g., wildflowers, ferns and shrubs) which could potentially play a significant role in the remediation of contaminated lands that could open up a huge possibility of developing a sustainable and environmentally-friendly way of managing this emerging urban problem. Results showed that 12 plant species, including hyperaccumulator like Pteris vittata, Centella asiatica, were effective for the accumulation of heavy metals and metalloids.

Potential of indigenous plant species for phytoremediation of arsenic contaminated water and soil

The presence of arsenic (As) and heavy metals in soil and water resources has serious impact on ecosystem as well as human health. In India, West Bengal (W.B.) is severely contaminated by higher levels of As in water, soil and growing plants/crops. The present study was designed to examine the remediation ability of indigenous plant species, growing naturally in the As contaminated Dakshin Panchpota village of Nadia district (W.B.). Soil and water samples, collected from the site, showed higher levels of arsenic and heavy metals. For the study, total twenty eight plants (eighteen terrestrial, ten aquatic) were collected from the contaminated area and among them ten terrestrial and seven aquatic plants showed bioaccumulation factor (BCF) > 1, suggesting their role in As remediation and site restoration. Althernanthera ficoides demonstrated highest accumulation as well as translocation of As (TF > 1) among all the terrestrial plants tested, showing its suitability for remediation of As contaminated soil. More As was recorded in shoots than the roots in Phyllanthus amarus and Cyanodon dactylon, showing their feasibility for phytoextraction purpose. Among aquatic plants, Eicchornia crassipes and Marsilea quadrifolia were found most effective for As remediation. Besides As, plants have also shown potential to tolerate and accumulate Fe, Zn, Cu and Cr in their tissues. Thus, the results of this study showed that the naturally growing plant species have potential to remediate As contaminated site in the presence of elevated concentrations of heavy metals and can play an important role in ecological restoration, however, care should be taken owing to medicinal properties possessed by some of the accumulators.

Physicochemical Indices of Phyto Remediated Hydrocarbon Polluted Soil and the Effect of Bio-nutrient Amendment

Aim: To assess the Physicochemical indices of Phytoremediated Crude Oil polluted amended soil using grass plant Cyperus esculentus (Cyp) and Phyllanthus amarus (Phy).&#x0D; Study Design: The study employs experimental design, statistical analysis of the data and interpretation.&#x0D; Place and Duration of Study: Rivers State University demonstration farmland in Nkpolu- Oroworukwo, Mile 3 Diobu area of Port Harcourt, was used for this study. The piece of land is situated at Longitude 4°48’18.50” N and Latitude 6ᵒ58’39.12” E measuring 5.4864 m x 5.1816 m with a total area of 28.4283 square meter. Phytoremediation process monitoring lasted for 240 days; analyses were carried out monthly at 30 days’ interval.&#x0D; Methodology: The study was carried out on Crude Oil Polluted soil (PS) amended with bio-nutrient supplements (Spent Mushroom Substrate (SMS) and selected fungi (Aspergillus niger(AN) andMucor racemosus (MR)) used to stimulate and augment the indigenous microbial population present in a crude oil polluted soil thereby enhancing hydrocarbon reduction in pari per sue with phytoremediation (uptake of Crude oil by test plants) over a period of 240 days. Ten (10) experimental plots (two Control (Unpolluted and polluted soil without amendment) and eight polluted amended/treated plots) employing Randomized Block Design (each having dimensions: 100 x 50 x 30 cm LxBxH); formed and mapped out on agricultural soil and left fallow for 6 days before contamination on the seventh day; after which it was allowed for 21 days for proper contamination and exposure to natural environmental factors (to mimic soil crude oil spill site); thereafter nutrients/organics (biostimulating agents) and bioaugmenting organisms were applied. Baseline studies were carried out on soil profile before and after contamination, major parameters monitored and assayed were Total Petroleum Hydrocarbon (TPH) uptake by plant roots and stem, Polycyclic Aromatic Hydrocarbons (PAHs) and TPH reduction in soil. Other physicochemical properties analyzed in the soil from different plots were pH, Electrical Conductivity, Moisture Content, Total Nitrogen, Available Phosphorus, Potassium, Total Organic Carbon, Plant Height, Iron, Lead and Zinc at regular intervals; days 1, 60, 90, 120, 150, 180, 210 &amp; 240. The rate of phytoremediation was estimated from percentage (%) uptake of Total petroleum hydrocarbon (TPH) in plant roots and stem from day 1 -240; while percentage (%) reduction of TPH and PAHs in soil was estimated from day 1 to the residual at day 240.&#x0D; Results: The test plants decreased significant amount of crude oil as revealed in TPH uptake in their roots and Stem. Mean amount and percentage Total Petroleum Hydrocarbon (TPH) uptake by Cyperus esculentus roots and stem were; 152.33±50.34mg/kg, 12.57±4.16% and 201.13±8.80mg/kg, 13.27±0.58% respectively; while that of Phyllanthus amarusroots and stem were 141.50±35.62mg/kg, 11.68±2.94% and 174.44±19.98mg/kg, 11.51±1.32% respectively; revealing higher Uptake of TPH in plant stem than roots. From the initial TPH contamination value of 5503.00mg/kg, it was observed that plots planted with Cyperus esculentus (TPH 5492.75±76.36mg/kg) showed higher reduction of TPH from soil than those planted with Phyllanthus amarus(TPH 5449.72±18.27mg/kg); while PAHs degradation/reduction showed a reverse trend with plots planted with Phyllanthus amarus (PAHs 28.72±2.74mg/kg; 60.46±5.77%) higher than plots planted with Cyperus esculentus&#x0D; s (PAHs 25.77±2.12mg/kg, 54.24±4.47%).&#x0D; Conclusion: Plots planted with Cyperus esculentus showed higher reduction of TPH from soil than those planted with Phyllanthus amarus while PAHs degradation/reduction in plots planted with Phyllanthus amarus was higher than plots planted with Cyperus esculentus. TPH uptake was higher in plant stems than roots; more so, plots amended with nutrient supplements showed significant higher percentage reduction in hydrocarbon in the polluted soil than unamended polluted soil. It is therefore recommended that Cyperus esculentus is a suitable plant species for phytoremediation of crude oil contaminated soil with high TPH value while Phyllanthus amarusis the best option in phytoremediation of polluted soil with high PAHs value, both in combination with bio-nutrient supplement.

Tolerance and detoxification mechanisms to cadmium stress by hyperaccumulator Erigeron annuus include molecule synthesis in root exudate

Cadmium (Cd) is one of the most toxic environmental pollutants affecting the growth and reproduction of various plants. Analysis of the biological adaptation and tolerance mechanisms of the hyperaccumulator Erigeron annuus to Cd stress may help identify new plant species for phytoremediation and in optimizing the process. This study is to the first to analyze the molecular composition and diversity of dissolved organic matter (DOM) secreted by roots using FT-ICR MS, and multiple physiological and biochemical indexes of E. annuus seedlings grown in solutions containing 0–200 Cd μmol L−1. The results showed that E. annuus had strong photosynthetic adaptation and protection ability under Cd stress. Cd was immobilized or compartmentalized by cell walls and vacuoles in the plant, thus alleviating Cd stress. Activation of anti-oxidation defense mechanisms also played an important role in alleviating or eliminating Cd toxicity in E. annuus. High Cd stress promoted production of a higher proportion of new molecules in DOM secreted by E. annuus roots compared to low Cd stress. DOM secreted by roots contributed to plant resistance to Cd-induced stress via producing more carbohydrates, aromatic structures and tannins. Results indicate the mechanisms underpinning the potential use of E. annuus as a phytoremediator in environments with moderate Cd pollution.

Trace Element Levels in Native Plant Species around the Industrial Site of Puchuncaví-Ventanas (Central Chile): Evaluation of the Phytoremediation Potential

The present work investigates the uptake of selected trace elements (Cu, Sb, As, Pb, Cd, Zn, Cr, Mn, Ni, V, and Co) from soil and their accumulation in the biomass samples (leaves and flowers) of three selected native plants (namely Oenothera picensis, OP; Sphaeralcea velutina, SV; and Argemone subfusiformis, AS) around an industrial area (Puchuncaví-Ventanas) located in the Puchuncaví valley, in the central region of Chile. Primary emission sources in the area come from a copper refinery, coal-fired power plants, and a set of 14 other different industrial facilities. Trace element measurements in the native plants of this area and the ability to transfer of these pollutants from soil to plants (transfer factor) have been assessed in order to identify the potential use of these plant species for phytoremediation. Preliminary results showed a high concentration of trace elements in the OP, SV, and AS samples. The concentration of these elements in the plants was found to be inversely correlated to the distance of the primary emission sources. Moreover, the high concentrations of trace elements such as Cu, As, Cr and V, upon the toxic limits in the native plant species, suggest the need for continuous monitoring of the region. The OP species was identified as the plant with the highest capacity for trace elements accumulation, which also showed higher accumulation potential in whole aerial parts than in leaves. Transfer factor values suggested that these native plants had phytoremediation potential for the elements Cu, Pb, As, Ni, and Cr. This study provides preliminary baseline information on the trace element compositions of important native plants and soil in the Puchuncaví-Ventanas area for phytoremediation purposes.

Uptake Kinetics of \({\text{NH}_{4}^{+} }\), \({\text{NO}_{3}^{-} }\) and \({\text{H}_{2}\text{PO}_{4}^{-} }\) by Typha orientalis, Acorus calamus L., Lythrum salicaria L., Sagittaria trifolia L. and Alisma plantago-aquatica Linn

The emergent plants may differ in their capacity to assimilate nutrients from eutrophic water bodies, so the utilization of suitable emergent plants is the key part for successful restoration of shallow eutrophic lakes and rivers. This research applied the depletion method to study the kinetics of uptake of nutrient (H2PO4−, NH4+, NO3−) in different nutrient stresses by the five emergent aquatic plants (Acorus calamus L., Typha orientalis, Lythrum salicaria L., Sagittaria trifolia L., Alisma plantago-aquatica Linn) in the riverine zones of Dashi River (39°30′–39°40′ N, 115°59′–116°5′ E), a shallow eutrophic river located in Fangshan District, Beijing. The results showed that at the three phosphorus levels, A. calamus and A. plantago-aquatica had the highest maximum uptake rate values for NH4+ under low to moderate phosphorus conditions, and high phosphorus, respectively. T. orientalis had the highest maximum uptake rate values for NO3− at all phosphorus concentrations, while the Michaelis-Menten constant values of L. salicaria and A. plantago-aquatica were smaller. At the three nitrogen levels, the maximum uptake rate values for H2PO4− were the greatest for A. plantago-aquatica at the low to moderate nitrogen levels and L. salicaria at high levels. Meanwhile, T. orientalis and L. salicaria had the smallest Michaelis-Menten constant values. In this study, nitrogen microbial transformations, such as nitrification, denitrification and their coupling were not measured and their role in measuring kinetics was not assessed. Thus, achieved results shall be considered as a synthesis of several processes mediated by plants, a theoretical guidance to the selection of plant species for phytoremediation of polluted water bodies with different nutrient stresses for quality improvement around the diverse rivers in Haihe River basin.

Rhizobacteria Communities of Phytoremediation Plant Species in Petroleum Hydrocarbon Contaminated Soil of the Sudd Ecosystem, South Sudan.

The Sudd wetland is one of the oil-rich regions of South Sudan where environmental pollution resulting from oil extraction activities has been unprecedented. Although phytoremediation is the most feasible technique, its efficacy reduces at high TPH concentration in soil. This has made rhizoremediation the most preferred approach. Rhizoremediation involves use of a combination of phytoremediation and biostimulation. The process is catalyzed by the action of rhizobacteria. Therefore, the objective of this study is to characterize rhizobacteria communities prevalent in phytoremediation species growing in hydrocarbon-contaminated soils biostimulated with cattle manure. The treatments studied were plant species only (T1), plant species and hydrocarbons (T2), plant species and manure (T3), and plant species, manure, and hydrocarbons (T4). The rhizobacteria communities were determined using pyrosequencing of 16S rRNA. In the treatment with phytoremediation species, hydrocarbons 75 g · kg−1soil, and cattle manure 5 g · kg−1soil (T4), there was a significant increase (p < 0.05) in rhizobacteria abundance with the highest ASV observed in H. rufa (4980) and the lowest in S. arundinaceum (3955). In the same treatment, bacteria community diversity was high in H. rufa (Chao1, 10310) and the least in S. arundinaceum (Chao 1, 8260) with Proteobacteria, Firmicutes, and Actinobacteria as the dominant phyla. Similarly, in contaminated soil treated with cattle manure, there was a significant increase (p < 0.05) in abundance of rhizobacteria genera with Pseudomonas dominating across phytoremediation species. H. rufa was dominated by Bacillus, Fusibacter, and Rhodococcus; G. barbadense was mainly associated with Luteimonas and Mycobacterium, and T. diversifolia was inhabited by Bacillus and Luteimonas. The rhizosphere of O. longistaminata was dominated by Bacillus, Fusibacter, and Luteimonas, while S. arundinaceum was largely inhabited by Sphingomonas. These rhizobacteria genera ought to be applied in the Sudd region for bioremediation.

Physiological and metabolic alterations induced by phthalates in plants: possible mechanisms of their uptake and degradation

Phthalates or phthalate acid esters (PAEs) belong to a class of chemicals renowned for frequent use in an array of plastic products. Phthalates are basically endocrine disruptors and act as mutagens. These are typical emerging pollutants and are largely debated because of their toxicological implications on living organisms. Phthalates stress is one of the prevailing stress to living organisms nowadays, which is not only limited to animals but also on plants. They interfere with the physiological and morphological characteristics of plants and bring about various metabolic alterations. Therefore, it is essential to explore the exact mechanisms adopted by plants to overcome phthalates induced stress. This review article is a dedicated attempt to unravel the probable mechanisms behind phthalate uptake, accumulation, sequestration, and degradation in plant cells and critically reviewed the plethora of toxicological effects caused by phthalates to plants including agricultural crops. The article will help understand the tolerance strategies adopted by various plants to cope up with stress, which will further help in the identification of plant species for phytoremediation.

Performance of Aquatic Plant Species for Phytoremediation of Heavy Metals Contaminated Water

Heavy metals and organic pollutants are ubiquitous environmental pollutants affecting the quality of soil, water and air. Over the past 5 decades, many strategies have been developed for the remediation of polluted water. Use of aquatic plants to extract, sequester and/or detoxify pollutants and is a new and powerful technique for environmental clean up. Plants are ideal agents for soil and water remediation because of their unique genetic, biochemical and physiological properties. The aim of this work is to evaluate the potential of free floating duck weed Spirodela polyrhiza to remove heavy metals from waste water and the biochemical effect of heavy metals on Spirodela polyrhiza. Approximately 93% of total heavy metal induced – toxicity appears resulting in the reduced activities of nitrate reductase, total chlorophyll and protein content of the plant. The results recommended the use of Spirodela polyrhiza to ameliorate the wastewater contaminated with heavy metals.