To understand the boundary layer characteristics and pathways of aerosol–cloud interaction, an Integrated Ground Observational Campaign, concurrent with Cloud Aerosol Interaction and Precipitation Enhancement Experiment, was conducted by the Indian Institute of Tropical Meteorology, Pune, under Ministry of Earth Sciences at Mahabubnagar (a rural environment, which is ~100 km away from an urban city Hyderabad in Andhra Pradesh), during the period of July–November 2011. Collected samples of PM₂.₅and PM₁₀were analyzed for water-soluble ionic species along with organic carbon (OC) and elemental carbon (EC). During study period, the average mass concentrations of PM₂.₅and PM₁₀were about 50(±10) and 69(±14) μg m⁻³, respectively, which are significantly higher than the prescribed Indian National Ambient Air Quality Standards values. The chemical species such as sum of anions and cations from measured chemical constituents were contributed to be 31.27 and 38.49 % in PM₂.₅and 6.35 and 5.65 % to the PM₁₀, whereas carbonaceous species contributed ~17.3 and 20.47 % for OC and ~3.0 and 3.10 % for EC, respectively. The average ratio of PM₂.₅/PM₁₀during study period was ~0.73(±0.2), indicating that the dominance of fine size particles. Carbonaceous analysis results showed that the average concentration of OC was 14 and 8.7 μg m⁻³, while EC was 2.1 and 1.5 μg m⁻³for PM₁₀and PM₂.₅, respectively. The ratios between OC and EC were estimated, which were 6.6 and 5.7 for PM₁₀and PM₂.₅, suggesting the presence of secondary organic aerosol. Total carbonaceous aerosol accounts 23 % of PM₁₀in which the contribution of OC is 20 % and EC is 3 %, while 20 % of PM₂.₅mass in which the contribution of OC is 17 % and EC is 3 %. Out of the total aerosols mass, water-soluble constituents contributed an average of 45 % in PM₁₀and 38 % in PM₂.₅including about 39 % anions and 6 % cations in PM₁₀, while 31 % anions and 7 % cations in PM₂.₅aerosol mass collectively at study site.

The future growing demand of fossil fuels likely will lead to an increased deployment of liquefied natural gas terminals. However, some concerns exist about their possible effects on the marine environment and biota. Such plants showed to cause the production of foam, as occurred at the still operative terminal of Porto Viro (northern Adriatic Sea). Here, we present results from two microcosm experiments focused on the effects of such foam on microbially mediated degradation processes and its consequent incorporation within the pelagic food web. Such material could be considered as a heterogeneous matrix of both living and non-living organic matter, which constitutes an important substrate for exoenzymes as suggested by the faster hydrolytic rates measured in the treatment microcosms. In the second experiment, a quite immediate and efficient carbon transfer to planktonic biomass through prokaryotic incorporation and consequent predation by heterotrophic flagellates was highlighted. Although no negative effect was evidenced on the overall microbes’ growth and foam-derived C seemed to be easily reworked and transferred to higher trophic levels, an important reduction in biodiversity was evidenced for microalgae. Among them, mixotrophic organisms seemed to be favoured suggesting that the addition of foam could cause a modification of the microbial community structure.

The trace element selenium has an essential role for human health. It is involved in redox center functions, and it is related to the immune system response. Legumes are among the main suppliers of selenium into the human food chain. Not only Se concentration as such but also more the chemical species of Se is of higher importance for successful Se supply to the human diet and its bioavailability. The current study was focused on the investigation of the Se species present in chickpea plants exposed to 0, 10, 25, 50, and 100 μM selenite in short- and long-term treatment studies. The linear increase of total Se concentration could be linked to the increased concentrations of Se exposure. The selenium species (SeMet, SeCys, selenite, selenate, GPx) detected in varying concentrations in shoots and roots depend on the exposure’s concentration and duration. The investigation showed that chickpea can accumulate Se in favorable concentrations and its transformation to bioavailable Se species may have positive impacts on human health and aid to implement Se into the diet.

Due to the high volume of crude oil released by the Deepwater Horizon oil spill, the salt marshes along the gulf coast were contaminated with crude oil. Biodegradation of crude oil in salt marshes is primarily limited by oxygen availability due to the high organic carbon content of the soil, high flux rate of S²⁻, and saturated conditions. Chlorate, nitrate, and perchlorate were evaluated for use as electron acceptors in comparison to oxygen by comparing oil transformation and mineralization in mesocosms consisting of oiled salt marsh sediment from an area impacted by the BP Horizon oil spill. Mineralization rates were determined by measuring CO₂ production and δ ¹³C of the produced CO₂ and compared to transformation evaluated by measuring the alkane/hopane ratios over a 4-month period. Total alkane/hopane ratios decreased (~55–70 %) for all treatments in the following relative order: aerated ≈ chlorate > nitrate > perchlorate. Total CO₂ produced was similar between treatments ranging from 550–700 mg CO₂-C. The δ ¹³C-CO₂ values generally ranged between the indigenous carbon and oil values (−17 and −27 ‰, respectively). Oil mineralization was greatest for the aerated treatments and least for the perchlorate amended. Our results indicate that chlorate has a similar potential as oxygen to support oil mineralization in contaminated salt marshes, but nitrate and perchlorate were less effective. The use of chlorate as a means to promote oil mineralization in situ may be a promising means to remediate contaminated salt marshes while preventing unwanted secondary impacts related to nutrient management as in the case of nitrate amendments.

Irrigation with wastewater is a promising option to improve crop yields and to reduce pressure on freshwater sources. However, heavy metal concentrations in wastewater may cause health concerns. A greenhouse pot experiment was conducted in order to determine cadmium (Cd) and zinc (Zn) concentrations in sandy soil and plant tissues of tomato (Lycopersicon esculentum L.) and alfalfa (Medicago sativa L.). A 2 × 2 × 4 × 2 factorial treatment arrangement was utilized. Two water sources, fresh (FW) or treated wastewater (TWW), at two salinity levels (1 and 3 dS m⁻¹) containing different levels of Cd and Zn were used. Samples were collected after a 90-day growth period. It was observed that the growth of both plants was depressed at the highest metal level (L3). Metal accumulation in plant parts increased with the increase of metal concentration and salinity in irrigation water. At low salinity, water source was the main factor which controlled metal accumulation, whereas, at high salinity, chloride appeared to be the principal factor controlling metal uptake regardless of water source. Metal translocation from roots to shoots increased in TWW-irrigated plants, even in the controls. Tomatoes accumulated Cd up to and above critical levels safe for human consumption, even though Cd concentration in irrigation water did not exceed the current recommended values. Therefore, food production in sandy soils may well pose a health hazard when irrigated with TWW containing heavy metals. Complexation with dissolved organic compounds (DOC) in TWW may be to be the principal factor responsible for increased metal uptake and transfer at low salinity, thereby increasing the risk of heavy metal contamination of food and forage crops.

Technological, agricultural, and medical advances have improved the lifestyle of humankind. However, these advances have caused new problems that affect the environment and future generations. Emerging contaminants display properties such as low degradation potential and environmental persistence. In addition, most contaminants are lipophilic, which culminates in high bioaccumulation. The disposal of pharmaceuticals and personal care products into the environment underlies microbial and bacterial resistance. Plasticizers change several characteristics of industrialized materials, such as flexibility, but they are potentially carcinogenic and disrupt the endocrine system. Pesticides prevent the propagation of numerous kinds of pests; nevertheless, they exert neurotoxic and mutagenic effects, and they impact the environment negatively. Addition of flame retardants to a number of materials prevents flame propagation; however, after their release into the environment, these chemicals may bioaccumulate in organisms and disrupt the endocrine system, too. Surfactants can change the surface and interfacial properties of liquids, but their presence in the environment can interfere with countless enzymes and can even impair the endocrine system of various organisms and induce the feminization of species. Hence, gaining knowledge about emerging contaminants is increasingly important to minimize future damage and enable proper monitoring of each class of compounds in the environment which will help to improve legislation on this matter.

Copper (Cu) contamination has become a global concern because of industrial, agricultural, and other anthropogenic activities. In the present experiments, the toxicological effects, mechanisms, and potential toxicity thresholds were investigated in the roots of Vicia faba L. seedlings that were cultivated in Cu-amended soils (0, 6.25, 12.5, 25, 50, 100, 200, 400, and 600 mg kg⁻¹) for 20 days, based on an analysis of the soil physicochemical properties, native Cu, available Cu, and root-enriched Cu contents. The superoxide dismutase (SOD), ascorbate peroxidase (APX), and guaiacol peroxidase (POD) isozymes and activities, as well as glutathione (GSH) and heat shock protein 70 (HSP70), changed like biphasic dose-response curves, cooperating to control the redox homeostasis. The APX and POD enzymes exhibited enhanced activities and became H₂O₂ scavengers primarily when the catalase (CAT) activities tended to decrease. Endoprotease (EP) isozymes and activities might be enhanced to degrade carbonylated proteins and alleviate metabolic disturbance in the roots. Additionally, HSP70 may not be suitable as a biomarker for relatively higher soil Cu concentrations and relatively longer exposure times for the roots. As a result, the isozymes and activities of SOD, CAT, and EP, as well as GSH, can be adopted as the most sensitive biomarkers. The toxicity threshold is estimated as 0.76–1.21 mg kg⁻¹ of available Cu in the soils or 25.04–36.65 μg Cu g⁻¹ dry weights (DW) in the roots.

The occurrence and migration of heavy metal in coastal aquifer incorporating tidal effects were investigated in detail by the field geological survey and observation. The continuous groundwater sampling, field observation (for groundwater potentiometric surface elevation, pH, dissolved oxygen, temperature, and salinity), and laboratory analysis (for Cr, Ni, Cu, Zn, Cd, and Pb concentration) were conducted through eight monitoring wells located around the landfill in the northern part of Chongming Island, China. The results showed that the unconfined aquifer medium was estuary-littoral facies deposit of Holocene, mainly gray clayey silt and grey sandy silt, and the groundwater flow was mainly controlled by topography condition of the aquifer formation strike. The background values of Cr, Ni, Cu, Zn, Cd, and Pb in Chongming Island were 3.10 ± 3.09, 0.81 ± 0.25, 1.48 ± 1.09, 43.32 ± 33.06, 0.08 ± 0.16, and 0.88 ± 1.74 μg/L, respectively. Compared with the groundwater samples around the study area, the drinking water was qualified and was free from the seawater intrusion/estuarine facies contaminant encroachment. Pollutant discharge was reflected in water quality parameters, the Cr and Cu concentrations elevated to the peak of 50.07 and 46.00 μg/L, respectively, and meanwhile specific migration regularity was embodied in observation time series as well as other elements. This migration regularity was not fully identical according to correlations between these analyzed elements. Ambient watery environment, anthropogenic disturbance, regional hydrogeological condition, and biogeochemical reactivity on heavy metals reduced/altered the significance of elements correlation in the migration pathway in coastal aquifer.

This study aimed to determine the Pb⁺²adsorption capacities of hazelnut shell and activated carbon obtained from hazelnut shell. It also aimed to determine the effect of ZnCl₂in the activation process. The hazelnut was pyrolyzed at 250 and 700 °C. For determining the capture speed of the adsorbents, the pseudo-first- and second-order kinetic studies were performed. The Freundlich and Langmuir isotherm models were used to determine adsorption equilibrium. The surface characterization of hazelnut shell and activated carbon was determined by Brunauer-Emmett-Teller (BET) analysis and FTIR spectrum. Pb⁺²adsorption capacity of obtaining activated carbon was determined by ICP-OES analysis. The raw hazelnut shell’s BET surface area is 5.92 m²/g and the surface area of activated carbons which is pyrolyzed at 250 and 700 °C were determined (270.2 and 686.7 m²/g, respectively. The surface area of hazelnut shell, which pyrolyzed at 700 °C after being activated with ZnCl₂, was determined to be 736.49 m²/g. Results show that physical adsorption process is dominant for the activated carbon pyrolysis at 700 °C but the chemical adsorption is dominant for the activated carbon pyrolysis at lower degrees and for raw hazelnut shell.