Phytoremediation has been proven to be an environmentally sound alternative for the recovery of contaminated soils, and the economic profit that comes along with the process might stimulate its field use. This study investigated cadmium (Cd) transfer and detoxification mechanisms in a soil–mulberry–silkworm system to estimate the suitability of the mulberry and silkworm as an alternative method for the remediation of Cd-polluted soil; it also explored the underlying mechanisms regulating the trophic transfer of Cd. The results show that both the mulberry and silkworm have high Cd tolerance. The transfer factor suggests that the mulberry has high potential for Cd extraction from polluted soil. The subcellular distribution and chemical forms of Cd in mulberry leaves show that cell wall deposition and vacuolar compartmentalization play important role in Cd tolerance. In the presence of increasing Cd concentrations in silkworm food, detoxification mechanisms (excretion and homeostasis) were activated so that excess Cd was excreted in fecal balls, and metallothionein levels in the mid-gut, the posterior of the silk gland, and the fat body of silkworms were enhanced. And, the Cd concentrations in silk are at a low level, ranging from 0.02 to 0.21 mg kg⁻¹. Therefore, these mechanisms of detoxification can regulate Cd trophic transfer, and mulberry planting and silkworm breeding has high phytoremediation potential for Cd-contaminated soil.

Pig farms have achieved importance in the last few decades from the perspective of environment protection as a consequence of the intensive rearing systems in livestock production. Ammonia (NH₃) and greenhouse gases (GHG), such as methane (CH₄), carbon dioxide (CO₂), and nitrous oxide (N₂O), are emitted from slurry storage at farm prior to land application, but little is known about these losses under on-farm conditions in Spain. This study assessed the influence of management and environmental parameters on NH₃ and GHG emissions from slurry storage in spring and autumn. Gas emissions were measured in a commercial pig-fattening farm from two lagoons (1000 and 768 m³ capacity, respectively) during 30 days by the floating dynamic chamber system in spring and autumn 2011 (average temperature 19 and 9 °C, respectively). Low NH₃ and CH₄ emissions were registered in spring (range 10–406 and 3–17 mg m⁻² min⁻¹, respectively) probably as a result of low pH values of stored slurry (6.5 to 7.0) and rainfall. High variability on NH₃, CH₄, and CO₂ emissions was observed as a result of differences in temperature and rainfall. No NH₃ emission and low CH₄ and CO₂ emissions were observed in autumn (average 1.2 ± 0.9 and 27 ± 22 mg m⁻² min⁻¹, respectively). Slurry loading operations increased NH₃ losses from storage.

Roadside plants have the potential to accumulate pollutants and safeguard waterways. To assess growth and pollutant accumulation of roadside plants, the willow Salix miyabeana was grown (a) in a greenhouse on soil collected at different distances from an interstate highway to test the longer-term effects of pollutant deposition as manifested in soil, and (b) in the field on reference soil placed at different distances from that highway to test the shorter-term effects of proximity to pollutant sources during a single growing season. In the first experiment, relative growth rate (RGR) increased 150 % with distance of soil collection from the roadway, from a baseline near the highway to 100 m away. Relative nitrogen and phosphorus accumulation rates were positively correlated with RGR (P <0.0001), and total contents of zinc, strontium, copper, nickel, cadmium, and lead in new shoots were also positively correlated with RGR (P <0.05). Thus more rapidly growing plants accumulated more N, P, and metals. Reduced growth for plants grown on soils collected near the roadway was associated with very high tissue concentrations of sodium and soil concentrations of chloride, implicating the deposition of deicing agents in this northern temperate roadside ecosystem. In contrast, S. miyabeana showed the opposite pattern on reference soil in the field, with RGR decreasing 31 % as distance from the roadside increased. The latter trend appears to have resulted from greater soil moisture and reduced shading near the highway. We suggest that reducing road salt applications will promote growth and pollutant accumulation by roadside vegetation.

Photosynthetic process is a good approach to discriminate cadmium-tolerant species, because it is reported as one of the most sensitive processes. Our goal was to measure Elephantopus mollis Kunth (Asteraceae) tolerance, determining the interference of Cd on the photosynthetic process. For this, a hydroponic experiment design was conducted in nutrition solution with concentrations of 0 (control), 10, 50, and 100 μM of cadmium (Cd). Measures of photosynthesis performance were obtained, for example, gas exchange, photosystem integrity, chlorophyll content, leaf growth rate, root length, and dry weight. In addition, cadmium and zinc concentrations were measured. Furthermore, results were linked to phytoremediation potential. Our specific questions were as follows: (1) Can the photosynthetic apparatus of E. mollis deal with cadmium stress? (2) Is E. mollis able to accumulate cadmium and maintain zinc level? (3) Is E. mollis a tolerant or sensitive species? (4) Can any phytoremediation practice be suggested from these results? Our results showed that E. mollis can deal with cadmium toxicity up to 10 μM Cd. Moreover, this plant is a potential hyperaccumulator, which can accumulate 248 mg Cd kg⁻¹ dry weight. However, at concentrations of 50 and 100 μM Cd, this species was sensitive and cadmium toxicity affected both biochemistry and photochemistry phases of photosynthesis on account of negative changes on gas exchange, fluorescence chlorophyll, and chlorophyll content. Nevertheless, these results did not compromise the research about its tolerance at lower concentrations of cadmium.

The objective of this study was to investigate the chemisorption mechanisms of Cu(II) on alcohol functionalized carbon nanotubes (OH-CNT) compared to granulated activated carbon (F-400). Two different sizes of OH-CNT were used on both adsorption isotherm experiments and continuous-flow fixed-bed columns. The experiments were conducted as a function of adsorbent type with fixed bed height (5 cm), fixed flow rate (0.035 mL/min), and one initial Cu(II) concentration (10 mg/L) at pH 5.1 and room temperature. Isotherm curves follow Freundlich model with better adsorption capacity for OH-CNT (6.3 and 15.7 mg/g) compared to F-400 (6.0 mg/g). Breakthrough curves for all adsorbents were typical, while OH-CNT showed higher capacity to treat water per amount of adsorbent than F-400. After 5 days of desorption, there was very little Cu(II) leached from the OH-CNT column as compared to F-400 that slowly desorbed 85 % of Cu(II). These results indicated chemisorption process on OH-CNT with low residual release of Cu(II) from adsorbent after reaching saturation. A systematic correlation method using converted FTIR absorbance curves (first derivative analysis) of as-received and hybrid OH-CNT identified new peaks on the spectra for Cu(II) chemisorbed on CNT surface, showing that Cu(II) target acidic functional groups during adsorption.

We investigated the magnetic and chemical properties of the roadside soil samples collected from five European and Asian countries. Spots in which cars slowed down and/or accelerated due to the traffic organization (speed limits, junctions, and traffic lights) were selected for sampling. Apart from the Zabrze site (Poland), the magnetic susceptibility and heavy metal contents decreased with increasing distance from the road edge. The highest mass-specific magnetic susceptibility values (χ) were observed in the samples collected from Mumbai (India) and Zabrze (Poland). Moreover, the high contents of Fe, Ni, Mn, and Co were observed in Mumbai, whereas in Zabrze, all the examined elements demonstrated high contents, except for Co. Analyses revealed that magnetite was the main magnetic mineral in the roadside soil samples. The high correlation coefficients (r = 0.87) between the magnetic susceptibility values and the total Fe content demonstrated that Fe occurred mainly as ferrimagnetic particles of technogenic origin resulting from traffic emissions. The traffic origin of the pollutants was also confirmed by the increased contents of the typically anthropogenic metals (Pb, Zn, Cd, and Cu) and a good correlation (r = 0.83) between the Ti and Mo contents, which do not occur in natural associations. The ratio between particular polycyclic aromatic hydrocarbons (PAHs) and high content of PAHs typical for car exhaust also implied traffic as their main source.

Surface water bodies can be impaired by turbidity and excessive sediment loading due to urban development, construction activities, and agricultural practices. Turbidity has been considered as a proxy for evaluating water quality, aquatic habitat, and aesthetic impairments in surface waters. The US Environment Protection Agency (USEPA) has listed turbidity and sediment as major pollutants for construction site effluent. Recently proposed USEPA regulations for construction site runoff led to increased interest in methods to predict turbidity in runoff based on parameters that are more commonly predicted in runoff–erosion models. In this study, a turbidity prediction methodology that can be easily incorporated into existing runoff–erosion models has been developed using fractions of sand, silt, and clay plus suspended sediment concentration of eight parent soils from locations in Oklahoma and South Carolina, USA.

The paper presents a comprehensive analysis of the most basic features of the air quality of a Mediterranean urban environment area. The impact of meteorology on the air quality is also examined. Observational surface concentrations of the most important air pollutants, recorded at two measuring stations in Patras, Greece, are used. The Weather Research and Forecasting (WRF) meteorological model was employed to produce a series of surface and upper air data and local circulation and ventilation indices. These modeled data along with selected surface meteorological observational data comprise a substantial data set that was used to assess the effect of meteorology on the air quality. Mostly during the summer period, a significant proportion of the particulate matter is transported from sources away from the measuring sites. The synoptic setting of winter and summer seasons represented primarily by the local ventilation and recirculation, the wind, the boundary layer height, and the precipitation has a very strong impact in the overall formation of the air quality status.

In this study, the samples of the spatial soil and organs of the grapevine (Vitis vinifera) cultivar Tamjanika were collected from the selected zones near the Mining and Smelting Complex Bor (East Serbia). They were analyzed by ICP-OES to determine the content of Cu, Zn, Pb, As, Cd, and Ni with the aim of ascertaining if these data may help in the assessment and improvement of the quality of environment in polluted areas such as Bor and its surrounding area. The results obtained from the calculated biological and enrichment factors, as well as from the Pearson correlation study and hierarchical cluster analysis confirmed that very useful information is recorded in plant organs: root, stem, leaves, and fruit. Yet, when the atmospheric pollution is the sphere of interest, the most informative data are found in unwashed leaves. The results of this study indicated also that the investigated plant species has some highly effective strategies involved in tolerance to the stress induced by heavy metals, which makes it an excellent candidate for phytostabilization purposes. Planting of this grapevine cultivar can be recommended in all areas that are severely polluted with heavy metals.

Solid organic carbon and zero-valent iron (ZVI) have been used separately as reactive media in permeable reactive barriers (PRBs) to degrade nitrate in groundwater, but few studies have examined the combination of the two materials in one system for nitrate remediation. In the present study, batch tests are conducted to evaluate three common solid organic carbons and their combination with ZVI for nitrate removal from water. The results show that the combined system achieves better denitrification efficiency than that measured with sawdust or cotton alone. However, no obvious difference is noted between the cornstalk alone and its mixture with ZVI treatment. When complete nitrate removal is achieved in the system that combined ZVI with sawdust or cotton, only 72 and 62.6 % of nitrate removal, respectively, are obtained in which the carbon (C) source is used alone. The results indicate that there are synergistic effects in the combined denitrification system, and the effects depend on the type of carbon material used. Sawdust is an alternative carbon source for nitrate removal in a C-ZVI-combined system. In a sawdust-ZVI system, the accumulation of nitrite and ammonium is affected greatly by nitrate concentration, C/N ratio, and Fe/N ratio.