The formation of a common mycorrhizal network (CMN) between roots of different plant species enables nutrient transfers from one plant to another and their coexistence. However, almost all studies on nutrient transfers between CMN-connected plants have separately, but not simultaneously, been demonstrated under the same experimentation. Both conspecific and heterospecific seedlings of Cinnamomum camphora, Bidens pilosa, and Broussonetia papyrifera native to a karst habitat in southwest China were concurrently grown in a growth microcosm that had seven hollowed compartments (six around one in the center) being covered by 35.0-μm and/or 0.45-μm nylon mesh. The Ci. camphora in the central compartment was supplied with or without Glomus etunicatum and ¹⁵N to track N transfers between CMN-connected conspecific and heterospecific seedlings. The results showed as follows: significant greater nitrogen accumulations, biomass productions, ¹⁵N content, % Nₜᵣₐₙₛfₑᵣ, and the Nₜᵣₐₙₛfₑᵣ amount between receiver plant species ranked as Br. papyrifera≈Bi. pilosa > Ci. camphora under both M⁺ and M⁻, and as under M⁺ than under M⁻ for Ci. camphora but not for both Bi. Pilosa and Br. papyrifera; the CMN transferred more nitrogen (¹⁵N content, % Nₜᵣₐₙₛfₑᵣ, and Nₜᵣₐₙₛfₑᵣ amount) from the donor Ci. camphora to the heterospecific Br. papyrifera and Bi. pilosa, with a lower percentage of nitrogen derived from transfer (%NDFT). These findings suggest that the CMN may potentially regulate the nitrogen transfer from a donor plant to individual heterospecific receiver plants, where the ratio of nitrogen derived from transfer depends on the biomass strength of the individual plants.

Due to its adverse impact on health, as well as its global distribution, long atmospheric lifetime and propensity for deposition in the aquatic environment and in living tissue, the US Environmental Protection Agency (US EPA) has classified mercury and its compounds as a severe air quality threat. Such widespread presence of mercury in the environment originates from both natural and anthropogenic sources. Global anthropogenic emission of mercury is evaluated at 2000 Mg year⁻¹. According to the National Centre for Emissions Management (Pol. KOBiZE) report for 2014, Polish annual mercury emissions amount to approximately 10 Mg. Over 90% of mercury emissions in Poland originate from combustion of coal.The purpose of this paper was to understand mercury behaviour during sub-bituminous coal and lignite combustion for flue gas purification in terms of reduction of emissions by active methods. The average mercury content in Polish sub-bituminous coal and lignite was 103.7 and 443.5 μg kg⁻¹. The concentration of mercury in flue gases emitted into the atmosphere was 5.3 μg m⁻³ for sub-bituminous coal and 17.5 μg m⁻³ for lignite. The study analysed six low-cost sorbents with the average achieved efficiency of mercury removal from 30.6 to 92.9% for sub-bituminous coal and 22.8 to 80.3% for lignite combustion. Also, the effect of coke dust grain size was examined for mercury sorptive properties. The fine fraction of coke dust (CD) adsorbed within 243–277 μg Hg kg⁻¹, while the largest fraction at only 95 μg Hg kg⁻¹. The CD fraction < 0.063 mm removed almost 92% of mercury during coal combustion, so the concentration of mercury in flue gas decreased from 5.3 to 0.4 μg Hg m⁻³. The same fraction of CD had removed 93% of mercury from lignite flue gas by reducing the concentration of mercury in the flow from 17.6 to 1.2 μg Hg m⁻³. The publication also presents the impact of photochemical oxidation of mercury on the effectiveness of Hg vapour removal during combustion of lignite. After physical oxidation of Hg in the flue gas, its effectiveness has increased twofold.

Cotton crops generate millions of tons of lignocellulosic waste in Brazil that could be used in energy generation; however, the main destination of this raw material is soil incorporation. The aim of this work was to perform an energetic characterization and evaluation of briquettes produced from different agricultural waste of naturally colored cotton for power generation. The cultivars Brasil Sementes (BRS) Jade and Topazio were studied, with white cotton (BRS 286) as standard for comparison purposes. Two different parts of each species, stalk and cotton shell, were analyzed by bulk density, proximate analysis, higher heating value, cellulose, hemicellulose, protein, fat and lignin content, thermogravimetric analysis, and briquette mechanical strength. The results of the energetic characterization indicated a higher energetic potential of the colored species when compared with the white cotton, especially because of the volatile matter content, fixed carbon, and higher heating value. The briquette mechanical strength was higher in the samples formulated by a mixture of stalk and shell. Finally, it was concluded that the waste from colored cotton cultivars, Jade and Topazio, is capable to generate briquettes with good mechanical and physico-chemical characteristics, especially those formed by the mixture of stalk and shell.

As a global pollutant, Hg (Hg) since the turn of the last century has received increased attention. Decreasing the emission of Hg into the food chain and the atmosphere is an effective way to reduce the Hg damage. The current study provided information about pilot-scale horizontal subsurface flow (HSSF) constructed wetlands (CWs) to remove different Hg species in polluted water. Synthetic wastewater was fed to two HSSF CWs, one was planted with Acorus calamus L and the other was unplanted as a control. The total Hg (THg), dissolved Hg (DHg), and particulate Hg (PHg) from five sites along the HSSF CWs were analyzed to describe the process of Hg removal. Results show that the CWs have high removal efficiency of Hg which is more than 90%. The removal efficiencies of THg and DHg from the unplanted CW were 92.1 ± 3.6% and 72.4 ± 13.1%, respectively. While, the removal efficiencies of THg and DHg in planted CW were 95.9 ± 7.5% and 94.9 ± 4.9%, which were higher than that in blank CW. The PHg was mainly removed in the first quarter of the CWs, which was also revealed by the partition coefficient Kd. To a certain extent, the effect of plants depends on the hydraulic retention time (HRT). The results in the current study show the potential of the HSSF-CWs for restoration from Hg-contaminated water.

Phytoremediation of heavy metal-contaminated soil is considered to be one ecological environmental protection way that is effective and economical. The selection of suitable hyperaccumulators is a key issue for phytoremediation of heavy metal-contaminated soil. Pot experiments were conducted to study the effects of different Cd levels (0, 75, 150, 300, and 600 mg kg⁻¹ Cd) on the dry weight, antioxidant enzyme activities, malondialdehyde (MDA) contents, Cd concentration, Cd accumulation, and soil Cd form distribution ratio (FDC) of alfalfa (Medicago sativa L.) and Indian mustard (Brassica juncea L.). The correlations between Cd concentration in shoots and roots of alfalfa and Indian mustard and soil Cd form were also investigated. The results showed that with the increase of soil Cd levels, dry weight of shoot and root of alfalfa and Indian mustard significantly decreased, which decreased by 50.0–71.8% and 29.6–59.3% (alfalfa), 59.6–89.0% and 64.3–74.8% (India mustard), respectively, compared with the control. With the increase of soil Cd level, superoxide dismutase (SOD) activity in shoot of alfalfa significantly increased. Catalase (CAT) activity and malondialdehyde contents in shoots and roots of alfalfa and Indian mustard, as well as superoxide dismutase activity in the roots of alfalfa and Indian mustard increased first and then decreased with the increase of soil Cd level. With increasing Cd stress, Cd concentration in shoots and roots of alfalfa and Indian mustard significantly increased. At soil Cd level of 75 mg kg⁻¹, Cd concentrations in shoots of alfalfa and Indian mustard exceeded the critical value of Cd-hyperaccumulator (100 mg kg⁻¹), which was 356.46 mg kg⁻¹ and 308.74 mg kg⁻¹, respectively. Cadmium concentrations in shoots and roots of plants were in the order of that of alfalfa > Indian mustard; total Cd accumulation in the aboveground tissues and roots of the plants was in the order of that of Indian mustard > alfalfa at the same Cd level. With increasing soil Cd level, Cd concentrations of exchangeable form (EXC-Cd), carbonate-bound form (CAB-Cd), iron-manganese oxide-bound form (FeMn-Cd), organic-bound form (OM-Cd), and residual form (RES-Cd) showed an increasing trend. The form distribution ratio of soil Cd forms in alfalfa’s rhizosphere was in the order of that of exchangeable form Cd > carbonate-bound form Cd > iron-manganese oxide-bound form Cd > residual form Cd > organic-bound form Cd. Except for organic-bound form Cd, soil Cd forms were significantly positively correlated with Cd concentration in shoot and root (P < 0.01). Comprehensively considering the biomass and Cd accumulation, Indian mustard is more suitable as remediation material for soil Cd pollution.

Purification effects of constructed rapid infiltration system with two main fillers (coarse sand or medium coarse sand) and different addition proportion (5%, 10%, or 15%) modifiers (sponge iron, blast furnace slag, or zeolite) on rainwater runoff were studied through filter column tests. A set of constructed rapid infiltration system test device was designed, which included 9 rainwater filter columns. The test results showed that the permeability of artificial fillers blended with modifiers could have the promotion with varying degrees. There were differences in the characteristics of the modifiers, so the artificial fillers blended with different modifiers had a significant difference for the purification effects on each pollutant. In view of the overall situations, the pollutant removal effects of artificial fillers with two or more modifiers had a smaller gap, and the reduction effects were good, ranging from 38.95 to 46.25% when the main filler is coarse sand and from 46.29 to 49.46% while main filler is medium coarse sand. It was worth noting that the artificial fillers blended with sponge iron showed a slight harden after prolonged used; however, it had little influence on the permeability and water purification effects.

The present study aimed to assess the level of metal ions [chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), and zinc (Zn)] in the serum of patients with fixed orthodontic appliances. One hundred samples (32 males, 68 females) were collected from patients undergoing fixed orthodontic treatment for different periods. A reference (control) group (24 males, 16 females) who had no appliances was used to properly evaluate the changes in the level of these elements in orthodontic appliance users. The element concentrations were measured using inductively coupled plasma mass spectrometry (ICP-MS). Higher concentrations of metal ions (except for Cr) were found in the serum of the orthodontic group. Bivariate scatter plot showed a highly significant (p < 0.001) correlation between Ni and other elements. The duration of orthodontic treatment increased significantly the Ni levels whereas the bracket type was found to have no significant impact on altering the concentration level of metal ions. The results of the SEM-EDS showed a high variation in the level of metal ions in the brackets and wires. In conclusion, fixed orthodontic appliances increased serum levels of Ni, Zn, Mn, Fe, and Cu but did not change Cr levels.

Freshwater aquatic environment close to cities and industrial areas is more sensitive than marine environment. The freshwater shellfish Semisulcospira cancellate was introduced as a bioindicator to monitor the heavy metal contamination in the river through ionomic profiles and arsenic speciation. The shellfish samples were collected near four cities along the Xiang River in China. The concentrations of elements including Mg, Al, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Sr, Cd, Sn, Sb, Ba, and Pb were determined using ICP-MS. Multivariate statistical analyses such as Pearson’s correlation analysis and principle component analysis (PCA) were employed to identify the possible sources of the elements in the shellfish samples. Three principle components were extracted from the ionomic matrix and were associated with natural existence, biological pathways, and mining and smelting activities, respectively. The ionomic profiles of the shellfish samples were evaluated through hierarchical cluster analysis (HCA) which was exhibited in the form of heatmap. The shellfish samples were categorized according to the sampling sites with different contamination levels. Six As species including arsenite [As(III)], arsenate [As(V)], monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsenobetaine (AsB), and arsenocholine (AsC) were separated and quantified using HPLC-ICP-MS. The concentrations of As(III) and As(V) were linearly increased with total As concentration increasing. However, the proportion of AsB was decreased with total As while the AsB concentration was irrelevant to total As.

Plants are rich in biologically active compounds. They can be explored for the production of bioherbicides. In this context, the present work aimed to evaluate the allelopathic effect of hydroalcoholic extracts from two Solanaceae species: Solanum muricatum Ait. and Solanum betaceum Cav. For this end, we conducted phytochemical screening and biological assays, determining the effects of the extracts on germination, early development, cell cycle, and DNA fragmentation in plantlets and meristematic cells of the plant model Lactuca sativa L. (lettuce). The percentage of seeds germinated under effect of S. muricatum extract did not differ from the control, but plantlet growth was reduced at the highest concentrations. For S. betaceum extract, dose dependence was observed for both germination and plantlet development, with the highest concentrations inhibiting germination. The growth curves revealed the concentrations of 2.06 and 1.93 g/L for S. muricatum and S. betaceum extracts, respectively, as those reducing 50% of root growth (RG). At these concentrations, both extracts presented mitodepressive effect, besides inducing significant increase in the frequency of condensed nuclei, associated to DNA fragmentation and cytoplasmic shrinkage. The frequency of chromosome alterations was not significant. We further discuss the mechanisms of action related to the chemical composition of the extracts, which presented organic acids, reducing sugars, proteins, amino acids, and tannins, besides catechins and flavonoids, only found in the extract of S. betaceum.

We investigated the uptake of microplastic (MP, <5 mm) particles by using freshwater bivalves (Unio pictorum) as biological samplers in the environment. They were exposed either directly to the biologically purified sewage of a North Bavarian sewage treatment plant (STP) or placed in a small river up- and downstream of the wastewater discharge for 28 days and 6 months, respectively. A control group was maintained in a pond. After acid digestion, the soft tissue was analyzed for MP particles by means of Raman microspectroscopy (RM, over 3000 particles individually measured), which allows for identification and quantification of particles down to 1 μm. Only in the bivalve collective exposed to STP effluents MP was found, however a very small amount (maximum of nine MP particles in the bivalve sample exposed for 6 months). In the bivalves up- and downstream of the wastewater discharge and in control organisms from a pond, no microplastic was identified. The amount of microplastic particles was small in absolute terms and small in relative terms (ca. 1:100 (6 months) and below 1:1000 (28 days)) as hundreds of particles per sample were analyzed which turned out to be non-plastic. Including the results for the river, this indicates a rather low MP contamination level for organisms in close vicinity to a sewage treatment plant.