Spontaneous growth of plants enhances phytoextraction on abandoned coal mine wastes in Central Alborz coalfield, Iran.

Coal mining disperses heavy metals into the environment, necessitating the identification of metal-tolerant plants for ecosystem restoration. This study evaluated the phytoremediation potential of plant species in abandoned coal wastes in northern Iran. Pollution indices indicated moderate contamination of Cu, Ni, V, Zn, Pb, Cr, and As in coal wastes. The plants varied in their ability to accumulate and translocate these metals, with most showing efficient root-to-shoot translocation. Artemisia scoparia (41.06 mg.kg-1) and Capparis spinosa (42.48 mg.kg-1) were effective for Cu phytoextraction. Most species, notably Cynodon dactylon (3.4 mg.kg-1), showed promise for phytoextraction of Cr. Capparis spinosa (7.67 mg.kg-1) exhibited potential for Pb phytoextraction. Most plants, particularly Hordeum vulgare and Melica persica, were effective phytoextractors of Ni. Sylibum marianum accumulated V beyond phytotoxic levels. Chenopodium album and Glaucium fimbriligerum were identified as phytoextractors of Zn while Cynodon dactylon and Hordeum vulgare, accumulating >100 mg.kg-1 Zn in roots, showed potential for phytostabilization. Sylibum marianum and Glaucium fimbriligerum, acted as excluders for As. Kochia prostrata and Artemisia aucheri were excluders for Cu, Cr, Ni, and Pb. This study provided the role of multiple indigenous plants, including perennials and annuals with diverse life forms, in metal extraction and stabilization for sustainable coal waste management.

Vertical Light Non-Aqueous Phase Liquid (LNAPL) distribution by Rn prospecting in monitoring wells.

In the frame of a collaboration between the Italian National Research Council (CNR) and Mares s.r.l., a study, about the possibility of determining radon vertical distribution at different soil depths in order to trace light non-aqueous phase liquid (LNAPL) contaminations, was developed. The radon deficit technique, based on the preferential solubility of soil gas radon into non-polar fluids, such as refined hydrocarbons, has been investigated by various theoretical and applied research so far. According to international scientific literature, radon deficit can be used both for geochemical prospection of the spatial irregular NAPL dispersion and for monitoring of remediation activities. Even though it is well known that this type of pollutants can be distributed along the vertical soil profile-firstly due to their density in comparison to water density, and secondly due to fluctuations of shallow aquifers, soil pore size, aging of contamination, and so on-the vertical localization of the plume still represents a scientific challenge. In this article, a method to determine the radon vertical profile is tested and applied to assess the potential use of the radon deficit technique in the vertical detection of pollutant presence for the first time in a fuelling station. Two LNAPL-contaminated sites were selected for a pilot test. Experimental findings seem to support the use of vertical radon geochemical prospection to delimit the depth range of a LNAPL pollution directly. Systematic data collection and modeling may lead to a 3D reconstruction of the dispersion of contaminant in different soil levels.

Measurement of a Vibration on a Robotic Vehicle.

This article deals with the design and construction of a robotic vehicle. The first part of the paper focuses on the selection of suitable variants for the robotic vehicle arrangement, i.e., frame, electric motors with gearboxes, wheels, steering and accumulators. Based on the selection of individual components, the robotic vehicle was built. An important part of the robotic vehicle was the design of the suspension of the front wheels. The resulting shape of the springs was experimentally developed from several design variants and subsequently produced by an additive manufacturing process. The last part of article is devoted to the experimental measurement of the acceleration transfer to the upper part of the frame during the passage of the robotic vehicle over differently arranged obstacles. Experimental measurements measured the accelerations that are transferred to the top of the robotic vehicle frame when the front wheels of the vehicle cross over the obstacle (obstacles). The maximum acceleration values are 0.0588 m/s2 in the x-axis, 0.0149 m/s2 in the y-axis and 0.5755 m/s2 in the z-axis. This experimental solution verifies the stiffness of the designed frame and the damping effect of the selected material of the designed springs on the front wheels of the robotic vehicle.

Assessment of heavy metals concentration in soils and plants from electronic waste dumpsites in Lagos metropolis.

E-waste is a global environmental problem that must not be underestimated. To ascertain the environmental pollution status of electronic waste dumpsites, an assessment of seasonal variation in concentrations of heavy metals in the soils and plants in electronic waste dumpsites in Lagos metropolis was undertaken during the two major seasons (wet and dry seasons) in Nigeria. The soils and plants samples collected in August during the rainy season and December during the dry season were digested using aqua regia, a wet digestion method. The heavy metal concentrations were quantified with flame atomic absorption spectrophotometer (FAAS) fitted with a hollow cathode lamp (Perkin-Elmer AA Analyst 200) using an air-acetylene flame. The soil samples and the plants analyzed were found to have high concentrations of heavy metals. All the plants analyzed were identified and classified as excluders and accumulators of heavy metals based on their shoot/root quotients. The results obtained experimentally were analyzed using statistical and multivariate techniques. The soil quality of the study area was evaluated using correlation factor, pollution load index, and geoaccumulation index. The heavy metal assessment in comparison with the EU and Canadian standards for both agricultural and residential soils showed that the e-waste dumping sites are highly polluted. The results obtained for both the soil and plants analyzed confirmed the great impact of the hazardous components of e-waste on the ecosystem.

Field-scale monitoring of nitrate leaching in agriculture: assessment of three methods.

Deterioration of groundwater quality due to nitrate loss from intensive agricultural systems can only be mitigated if methods for in-situ monitoring of nitrate leaching under active farmers' fields are available. In this study, three methods were used in parallel to evaluate their spatial and temporal differences, namely ion-exchange resin-based Self-Integrating Accumulators (SIA), soil coring for extraction of mineral N (Nmin) from 0 to 90 cm in Mid-October (pre-winter) and Mid-February (post-winter), and Suction Cups (SCs) complemented by a HYDRUS 1D model. The monitoring, conducted from 2017 to 2020 in the Gäu Valley in the Swiss Central Plateau, covered four agricultural fields. The crop rotations included grass-clover leys, canola, silage maize and winter cereals. The monthly resolution of SC samples allowed identifying a seasonal pattern, with a nitrate concentration build-up during autumn and peaks in winter, caused by elevated water percolation to deeper soil layers in this period. Using simulated water percolation values, SC concentrations were converted into fluxes. SCs sampled 30% less N-losses on average compared to SIA, which collect also the wide macropore and preferential flows. The difference between Nmin content in autumn and spring was greater than nitrate leaching measured with either SIA or SCs. This observation indicates that autumn Nmin was depleted not only by leaching but also by plant and microbial N uptake and gaseous losses. The positive correlation between autumn Nmin content and leaching fluxes determined by either SCs or SIA suggests autumn Nmin as a useful relative but not absolute indicator for nitrate leaching. In conclusion, all three monitoring techniques are suited to indicate N leaching but represent different transport and cycling processes and vary in spatio-temporal resolution. The choice of monitoring method mainly depends (1) on the project's goals and financial budget and (2) on the soil conditions. Long-term data, and especially the combination of methods, increase process understanding and generate knowledge beyond a pure methodological comparison.

Lattice-Based Logarithmic-Size Non-Interactive Deniable Ring Signatures.

Deniable ring signature can be regarded as group signature without group manager, in which a singer is capable of singing a message anonymously, but, if necessary, each ring member is allowed to confirm or disavowal its involvement in the signature via an interactive mechanism between the ring member and the verifier. This attractive feature makes the deniable ring signature find many applications in the real world. In this work, we propose an efficient scheme with signature size logarithmic to the cardinality of the ring. From a high level, we adapt Libert et al.'s zero-knowledge argument system (Eurocrypt 2016) to allow the prover to convince the verifier that its witness satisfies an additional condition. Then, using the Fait-Shamir transformation, we get a non-interactive deniable ring signature scheme that satisfies the anonymity, traceability, and non-frameability under the small integer solution assumption in the random oracle model.

The Comparison of Different Types of Heat Accumulators and Benefits of Their Use in Horticulture.

This paper presents the results of the analysis of thermal issues and energy efficiency of three types of accumulators; namely stone-bed; water and phase change. Research experiments were carried out during April-October 2013 in a standard commercial semi-cylindrical high plastic tunnel with tomato cultivation of 150 m2. A stone-bed accumulator; with an area of almost 75 m2 was installed in the tunnel below ground level; while a water accumulator with a volume of 4 m3 was installed outside the tunnel. A phase change material (PCM) accumulator, with a volume of 1 m3 containing paraffin, was located inside the tunnel. The heat storage capacity of the tested accumulators and the energy efficiency of the process were determined based on the analyses of the 392 stone-bed charging and discharging cycles, the 62 water accumulator charging cycles and close to 40 PCM accumulator charging and discharging cycles. Dependencies in the form of easily measurable parameters; have been established to determine the amount of stored heat; as well as the conditions for which the effectiveness of these processes reaches the highest value. The presented analysis falls under the pro-ecological scope of replacing fossil fuels with renewable energy. As a result of the analysis; it was found that; in the case of a stone-bed; such an accumulator shows higher efficiency at lower parameters; that is, temperature difference and solar radiation intensity. In turn; a higher temperature difference and a higher value of solar radiation intensity are required for the water accumulator. The energy storage efficiency of the PCM accumulator is emphatically smaller and not comparable with either the stone-bed or the water accumulator.

Mixed plantation of wheat and accumulators in arsenic contaminated plots: A novel way to reduce the uptake of arsenic in wheat and load on antioxidative defence of plant.

Wheat (W) and accumulators (A) were planted in plots (arsenic amended soil and without arsenic) designed with ecotoxicological concern for arsenic safe-grains. For the study sixteen plots of 2 × 2 × 0.5 m (l × b × h) size were prepared. Arsenic (As) in the form of sodium arsenate was applied at 50 mg/kg in plots. Out of these sixteen plots eight plots had arsenic amended soil and rest 8 without any arsenic (C). Accumulator's viz. Pteris vittata (PV), Phragmites australis (PA) and Vetiveria zizanioides (VZ) were planted along with wheat in combination (W + PV, W + PA and W + VZ) in twelve plots (6 AWAs plots and 6 AWC plots). In the rest 4 plots (2 WAs plots and 2 WC plots), only wheat was planted. The study was conducted for two cropping seasons, where accumulators were left in the plots between the cropping seasons except that before 2nd cropping accumulators were properly pruned and extra tillers were removed. The germination % of wheat in WAs in 1st and the 2nd cropping season was found to be 55 and 57%, while in AWAs and AWC plots it was between 86 and 92% (W + VZ, 56 and 73%). The physiological activity was found to be reduced in WAs plots compared to AWAs (except for vetiver combination) and AWC plots in both cropping seasons. The antioxidant activity was enhanced in WAs compared with AWAs. The arsenic concentration in grains of wheat was within the permissible limit set by WHO and GOI in AWAs plots while it exceeded the limit in W + VZ (in 1st cropping) and WAs in both cropings.

Heavy metal (Pb) accumulation in metallophytes as influenced by the variations in rhizospheric and non-rhizospheric soils physico-chemical characteristics.

Activities at root-soil interface determine the solubility and uptake of metals by plants. Metal accumulation in plant species (Imperata cylindrical, Cynodon dactylon, Eleucine indica, Gomphrena celosoides, Sporobolus pyramidalis, Chromolaena odorata and Rhynchospora corymbosa) growing on Pb contaminated site as influenced by variations in physico-chemical characteristics, dissolved organic matter (DOM), Pb fractionation and different functional groups (using Fourier Transmittance Infra-red) of rhizospheric and non-rhizospheric soils was assessed. The electrical conductivity (2660-5520 µs) and Pb concentrations (51390.0-64080.0 mg/kg) were more in non-rhizospheric than rhizospheric soils having 276 µs to 3160 µs EC and 3289.0 to 44850.0 mg/kg Pb. More nutrients, DOM and carbohydrates functional groups (C-O; 1100 -1000 and O-H; 3700-3600) were found in rhizospheric compared to non-rhizospheric soils. The pH was slightly acidic (5.0-5.54) and E. indica with the lowest pH (5.0) accumulated highest Pb concentrations in shoot (8030 mg/kg) and root (16380 mg/kg) while C. odorata with highest values of pH, P, Ca and Mg in rhizospheric soil accumulated the least (root; 331.6 and shoot: 209.0 mg/kg). Pb was more in organic and residual fractions of rhizospheric and non-rhizospheric soils respectively. Reduction in pH, EC coupled with nutrients and DOM availability increased Pb uptake by plants.

Metal and metalloid containing natural products and a brief overview of their applications in biology, biotechnology and biomedicine.

Bioinorganic natural product chemistry is a relatively unexplored but rapidly developing field with enormous potential for applications in biology, biotechnology (especially in regards to nanomaterial development, synthesis and environmental cleanup) and biomedicine. In this review the occurrence of metals and metalloids in natural products and their synthetic derivatives are reviewed. A broad overview of the area is provided followed by a discussion on the more common metals and metalloids found in natural sources, and an overview of the requirements for future research. Special attention is given to metal hyperaccumulating plants and their use in chemical synthesis and bioremediation, as well as the potential uses of metals and metalloids as therapeutic agents. The potential future applications and development in the field are also discussed.

Controls on foliar nutrient and aluminium concentrations in a tropical tree flora: phylogeny, soil chemistry and interactions among elements.

Foliar elemental concentrations are predictors of life-history variation and contribute to spatial patterns in biogeochemical cycling. We examined the contributions of habitat association, local soil environment, and elemental interactions to variation in foliar elemental concentrations in tropical trees using methods that account for phylogeny. We sampled top-soils and leaves of 58 tropical trees in heath forest (HF) on nutrient-poor sand and mixed dipterocarp forest (MDF) on nutrient-rich clay soils. A phylogenetic generalized least squares method was used to determine how foliar nutrient and aluminium (Al) concentrations varied in response to habitat distribution, soil chemistry and other elemental concentrations. Foliar nitrogen (N) and Al concentrations were greater for specialists of MDF than for specialists of HF, while foliar calcium (Ca) concentrations showed the opposite trend. Foliar magnesium (Mg) concentrations were lower for generalists than for MDF specialists. Foliar element concentrations were correlated with fine-scale variation in soil chemistry in phylogenetically controlled analyses across species, but there was limited within-species plasticity in foliar elemental concentrations. Among Al accumulators, foliar Al concentration was positively associated with foliar Ca and Mg concentrations, and negatively associated with foliar phosphorus (P) concentrations. The Al-accumulation trait and relationships between foliar elemental and Al concentrations may contribute to species habitat partitioning and ecosystem-level differences in biogeochemical cycles.

Creation of products made from honey based on the content of elements determined by ICP-OES.

People of different age can consume honey, but the taste is often not accepted easily. Therefore, products made from honey with a pleasant taste and high nutritional and health benefits are highly demanded on the market. Honey is a bioindicator of environmental pollution. Certain plants are known as high accumulators of toxic elements. Here on the example of three honey-based prototypes, with sesame, shelled pumpkin, sunflower seeds, plums, walnut, almond, hazel, and cinnamon as minor ingredients, we demonstrated the creation of new products putting the accent on the content of toxic and potentially toxic elements, usually treated as irrelevant in making products. Nineteen elements (Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, Se, Si, and Zn) were determined by ICP-OES after oven-based and wet digestion methods in blossom honey and prototypes samples. Among the investigated elements, the most abundant element in blossom honey for the products and the investigated products was potassium in most cases. Investigated honey (used for the products) and two of the products contain small quantities of toxic and potentially toxic elements. However, the second product, containing besides honey two accumulators of toxic metals (sesame, sunflower seeds), shows higher values for toxic elements. Therefore, the ICP-OES analysis can be a good step in making new products with high nutritional and health values but almost free from toxic and potentially toxic elements.

Optimal Allocation of Finite Sampling Capacity in Accumulator Models of Multialternative Decision Making.

When facing many options, we narrow down our focus to very few of them. Although behaviors like this can be a sign of heuristics, they can actually be optimal under limited cognitive resources. Here, we study the problem of how to optimally allocate limited sampling time to multiple options, modeled as accumulators of noisy evidence, to determine the most profitable one. We show that the effective sampling capacity of an agent increases with both available time and the discriminability of the options, and optimal policies undergo a sharp transition as a function of it. For small capacity, it is best to allocate time evenly to exactly five options and to ignore all the others, regardless of the prior distribution of rewards. For large capacities, the optimal number of sampled accumulators grows sublinearly, closely following a power law as a function of capacity for a wide variety of priors. We find that allocating equal times to the sampled accumulators is better than using uneven time allocations. Our work highlights that multialternative decisions are endowed with breadth-depth tradeoffs, demonstrates how their optimal solutions depend on the amount of limited resources and the variability of the environment, and shows that narrowing down to a handful of options is always optimal for small capacities.

Phytoextraction of metal(loid)s from contaminated soils by six plant species: A field study.

Phytoextraction is an in situ remediation technique that uses (hyper)accumulator plant species to extract metal(loid)s from contaminated soils. Field studies can help in selecting appropriate plants for phytoextraction and in better understanding their phytoextraction performance. Hence, a field study was conducted using six (hyper)accumulator species (Solanum nigrum L., Bidens pilosa L., Xanthium strumarium L., Helianthus annuus L., Lonicera japonica T. and Pennisetum sinese R.) over two years in Jiaoxi town, Liuyang city, Hunan Province, China, to determine the effect of the (hyper)accumulator rhizospheres on field soils contaminated with multiple metal(loid)s and to analyze the variations in rhizosphere soil microbial community diversity and composition. After two years of field experiments, compared to the other four (hyper)accumulators, Bidens pilosa L. and Xanthium strumarium L. exhibited not only better metal(loid) phytoextraction abilities but also higher shoot biomasses. The contents of diethylenetriaminepentaacetic acid (DTPA)-extractable Pb, Cd and Zn decreased in the rhizosphere soils of all six (hyper)accumulators after repeated phytoextraction. Moreover, our findings illustrated that hyperaccumulator planting helps improve and rebuild the soil bacterial community composition and structure in contaminated soils by shifting the soil physiochemical properties. After repeated planting, the soil bacterial communities were reconstructed and dominated by Proteobacteria, Actinobacteriota, Chloroflexi and Acidobacteriota at the phylum level. The soil fungal communities were dominated by Ascomycota, Basidiomycota and Mortierellomycota at the phylum level. The reconstruction of soil microbial communities may help (hyper)accumulators adapt to metal(loid)-contaminated environments and improve their phytoextraction abilities.

A review on global metal accumulators-mechanism, enhancement, commercial application, and research trend.

The biosphere is polluted with metals due to burning of fossil fuels, pesticides, fertilizers, and mining. The metals interfere with soil conservations such as contaminating aqueous waste streams and groundwater, and the evidence of this has been recorded since 1900. Heavy metals also impact human health; therefore, the emancipation of the environment from these environmental pollutants is critical. Traditionally, techniques to remove these metals include soil washing, removal, and excavation. Metal-accumulating plants could be utilized to remove these metal pollutants which would be an alternative option that would simultaneously benefit commercially and at the same time clean the environment from these pollutants. Commercial application of pollutant metals includes biofortification, phytomining, phytoremediation, and intercropping. This review discusses about the metal-accumulating plants, mechanism of metal accumulation, enhancement of metal accumulation, potential commercial applications, research trends, and research progress to enhance the metal accumulation, benefits, and limitations of metal accumulators. The review identified that the metal accumulator plants only survive in low or medium polluted environments with heavy metals. Also, more research is required about metal accumulators in terms of genetics, breeding potential, agronomics, and the disease spectrum. Moreover, metal accumulators' ability to uptake metals need to be optimized by enhancing metal transportation, transformation, tolerance to toxicity, and volatilization in the plant. This review would benefit the industries and environment management authorities as it provides up-to-date research information about the metal accumulators, limitation of the technology, and what could be done to improve the metal enhancement in the future.

Strategies of heavy metal uptake by three Armeria species growing on different geological substrates in Serbia.

This study surveyed three species of the genus Armeria Willd. from five ultramafic outcrops, two non-ultramafic (schist) soils, and one tailing heap of an abandoned iron-copper mine from Serbia. Similarities and differences among the three Armeria species growing on different geological substrates in the ability to control uptake and translocate nine metals were examined. Chemical characteristics of the soil and plant samples (concentrations of P2O5, K2O, Ca, Fe, Mn, Ni, Zn, Cu, Cr, Co, Cd, and Pb) are presented. In order to assess accumulative potential of these three Armeria species, biological concentration, accumulation, as well as translocation factors were used. Three investigated Armeria species growing on eight different localities showed large differences in heavy metal uptake, translocation, and accumulation. The differences were present among the plant samples of the same species and even more among three different Armeria species and were primarily the result of the different contents of available heavy metals in the investigated soils. Additionally, differences might be the consequence of diverse responses and possible presence of supplementary resistance mechanisms in the plants from the ultramafic soils. None of the three Armeria species showed shoot hyperaccumulative potential for any of the investigated heavy metals and they could be considered as root accumulators, considering their potential to accumulate medium to large amounts of Zn (BCF up to 134), Cr (BCF up to 148), and Cd (BCF up to 9) in their roots.

Rice planted along with accumulators in arsenic amended plots reduced arsenic uptake in grains and shoots.

An experiment was designed using phytoremadiation technology to obtain grains of rice safe for consumption. Sixteen plots of size 2 × 2 m were prepared (8 plots were treated with 50 mg kg-1 of sodium arsenate and rest 8 without any treatment). The study was done for two plantations (1st and 2nd plantation). Rice was planted with three accumulators (Phragmites australis, Vetiveria zizanioides and Pteris vitatta) in treated and untreated plot. Arsenic in grains of Actr (R + Pt, R + Ph and R + Vt) for 1st plantation was 0.4, 0.2 and 0.2 mg kg-1 where as in the case of wActr (Ras) it was 3 mg kg-1. In 2nd plantation the concentration of arsenic in grain of Actr (R + Pt, R + Ph and R + Vt) was 0.1, 0.1 and 0.1 mg kg-1 where as in the case of wActr (Ras) it was 2 mg kg-1. Significant differences in growth and yield parameters of rice between Actr and wActr in 1st plantation, while for 2nd plantation the activity was reduced in combinations except R + Pt and no significant difference was observed between Actr, Acntr and wActr. The study concluded that combinations of accumulators with crops could be useful for the survival and safe grains in As-contaminated soils but with some amendments in long-term remediation.

Cadmium accumulation and growth response to cadmium stress of eighteen plant species.

This study investigated the cadmium (Cd) accumulation and growth response to Cd stress of 18 plant species. After growth for 30 days in the sand containing 0, 2, or 10 mg Cd kg-1, seedlings were evaluated for growth parameters, specific root length, and Cd accumulation. The 18 species differ greatly in Cd accumulation and resistance to Cd stress, depending on Cd concentrations in the sand. Under high Cd condition (10 mg kg-1), the 18 species were classified into two groups: (1) Indian mustard and rapeseed having high Cd tolerance and increased accumulation capacity in shoots could be considered as Cd accumulators, and (2) the remaining 16 non-accumulators constitute a species continuum from the indicators to excluders. Shoot Cd concentration showed exponential decay relationships with biomass production, absolute growth rate, and growth ratio, indicating that biomass production negatively relates to the shoot Cd concentration in non-accumulators via dilution or concentration effect. Species with high biomass generally accumulate low Cd in the shoots and display high Cd-tolerant capacity. Indian mustard and rapeseed are promising species for long-term phytoextraction of Cd-contaminated farmlands for bioenergy production.

Motor-Learning-Based Adjustment of Ambulatory Feedback on Vocal Loudness for Patients With Parkinson's Disease.

OBJECTIVES: To investigate how the direct biofeedback on vocal loudness administered with a portable voice accumulator (VoxLog) should be configured, to facilitate an optimal learning outcome for individuals with Parkinson's disease (PD), on the basis of principles of motor learning. STUDY DESIGN: Methodologic development in an experimental study. METHODS: The portable voice accumulator VoxLog was worn by 20 participants with PD during habitual speech during semistructured conversations. Six different biofeedback configurations were used, in random order, to study which configuration resulted in a feedback frequency closest to 20% as recommended on the basis of previous studies. RESULTS: Activation of feedback when the wearer speaks below a threshold level of 3 dB below the speaker's mean voice sound level in habitual speech combined with an activation time of 500 ms resulted in a mean feedback frequency of 21.2%. CONCLUSIONS: Settings regarding threshold and activation time based on the results from this study are recommended to achieve an optimal learning outcome when administering biofeedback on vocal loudness for individuals with PD using portable voice accumulators.