The sulfide mineral flotation collectors are wildly used in China, whereas their toxic effect on soil microbial activity remains largely unexplored. In this study, isothermal microcalorimetric technique and soil enzyme assay techniques were employed to investigate the toxic effect of typical sulfide mineral flotation collectors on soil microbial activity. Soil samples were treated with different concentrations (0–100 μg•g − 1 soil) of butyl xanthate, butyl dithiophosphate, and sodium diethyldithiocarbamate. Results showed a significant adverse effect of butyl xanthate (p < 0.05), butyl dithiophosphate, and sodium diethyldithiocarbamate (p < 0.01) on soil microbial activity. The growth rate constants k decreased along with the increase of flotation collectors concentration from 20.0 to 100.0 μg•g⁻¹. However, the adverse effects of these three floatation collectors showed significant difference. The IC ₂₀ of the investigated flotation reagents followed such an order: IC ₂₀ (butyl xanthate) > IC ₂₀ (sodium diethyldithiocarbamate) > IC ₂₀ (butyl dithiophosphate) with their respective inhibitory concentration as 47.03, 38.36, and 33.34 μg•g⁻¹. Besides, soil enzyme activities revealed that these three flotation collectors had an obvious effect on fluorescein diacetate hydrolysis (FDA) enzyme and catalase (CAT) enzyme. The proposed methods can provide meaningful toxicological information of flotation reagents to soil microbes in the view of metabolism and biochemistry, which are consistent and correlated to each other.

This study builds upon prior work showing that methane (CH₄) could be utilized as the sole electron donor and carbon source in a membrane biofilm reactor (MBfR) for complete perchlorate (ClO₄ ⁻) and nitrate (NO₃ ⁻) removal. Here, we further investigated the effects of salinity on the simultaneous removal of the two contaminants in the reactor. By testing ClO₄ ⁻ and NO₃ ⁻ at different salinities, we found that the reactor performance was very sensitive to salinity. While 0.2 % salinity did not significantly affect the hydrogen-based MBfR for ClO₄ ⁻ and NO₃ ⁻ removals, 1 % salinity completely inhibited ClO₄ ⁻ reduction and significantly lowered NO₃ ⁻ reduction in the CH₄-based MBfR. In salinity-free conditions, NO₃ ⁻ and ClO₄ ⁻ removal fluxes were 0.171 g N/m²-day and 0.091 g/m²-day, respectively, but NO₃ ⁻ removal fluxes dropped to 0.0085 g N/m²-day and ClO₄ ⁻ reduction was completely inhibited when the medium changed to 1 % salinity. Scanning electron microscopy (SEM) showed that the salinity dramatically changed the microbial morphology, which led to the development of wire-like cell structures. Quantitative real-time PCR (qPCR) indicated that the total number of microorganisms and abundances of functional genes significantly declined in the presence of NaCl. The relative abundances of Methylomonas (methanogens) decreased from 31.3 to 5.9 % and Denitratisoma (denitrifiers) decreased from 10.6 to 4.4 % when 1 % salinity was introduced.

Water pollution has been a major concern for agrarian societies like Pakistan. Pharmaceutical industries are amongst the foremost contributor to industrial waste. Present study addresses the generation of oxidative stress caused by 2 months exposure to pharmaceutical wastewater in rats and their response to oral treatment with vitamin E, a potent antioxidant. The rats were randomized into five groups (n = 5) named as negative control, pharmaceutical wastewater (PEW) 100 %, PEW 10 %, PEW 1 %, and PEW 100 % + vitamin E. Oxidative damage in rats was evaluated by estimation of the activities of total superoxide dismutase (T-SOD), catalase (CAT), and the concentration of hydrogen peroxide (H₂O₂) in the liver, kidney, and blood/plasma. Exposure to pharmaceutical wastewater significantly decreased the activities of T-SOD and CAT and concentration of H₂O₂ in the liver and kidney and blood/plasma. Exposure to 100 % pharmaceutical wastewater exhibited a maximum decline in T-SOD activity, and activity was reduced to only 63.57 U/mL, 32.65, and 43.57 U/mg of protein in the plasma, kidney, and liver, respectively. Exposure to wastewater minimized activity CAT to 89.25 U/g of hemoglobin, 54.36, and 62.95 U/mg of protein in the blood, kidney, and liver, respectively. Treatment with vitamin E significantly increased the activity of T-SOD and CAT. However, increase in concentration of H₂O₂ was also observed in vitamin E exposed rats. Histopathology of the kidney revealed coagulative necrosis of renal epithelial cells and peritubular congestion. Endocardium showed infiltration of inflammatory cells and cellular breakdown in some areas. Lung sections exhibited atelectasis and emphysema of alveoli suggesting decline in lung function. The anatomy of the liver was also compromised due to severe degeneration and cellular swelling. The present study concluded that pharmaceutical wastewater induced severe oxidative stress in Wistar rats and ensued in histopathological lesions in several vital organs suggesting its high toxicity. Non-enzymatic antioxidant vitamin E may ameliorate oxidative stress induced by pharmaceutical wastewater.

In the present paper, the inter-seasonal Hg variability in snow cover was examined based on multivariate statistical analysis of chemical and meteorological data. Samples of freshly fallen snow cover were collected at the semi-urban site in Poznań (central Poland), during 3-month field measurements in winter 2013. It was showed that concentrations of atmospherically deposited Hg were highly variable in snow cover, from 0.43 to 12.5 ng L⁻¹, with a mean value of 4.62 ng L⁻¹. The highest Hg concentration in snow cover coincided with local intensification of fossil fuel burning, indicating large contribution from various anthropogenic sources such as commercial and domestic heating, power generation plants, and traffic-related pollution. Moreover, the variability of Hg in collected snow samples was associated with long-range transport of pollutants, nocturnal inversion layer, low boundary layer height, and relatively low air temperature. For three snow episodes, Hg concentration in snow cover was attributed to southerly advection, suggesting significant contribution from the highly polluted region of Poland (Upper Silesia) and major European industrial hotspots. However, the peak Hg concentration was measured in samples collected during predominant N to NE advection of polluted air masses and after a relatively longer period without precipitation. Such significant contribution to the higher Hg accumulation in snow cover was associated with intensive emission from anthropogenic sources (coal combustion) and atmospheric conditions in this area. These results suggest that further measurements are needed to determine how the Hg transformation paths in snow cover change in response to longer/shorter duration of snow cover occurrence and to determine the interactions between mercury and absorbing carbonaceous aerosols in the light of climate change.

Petrochemical industries generate wastewaters containing pollutants that can severely impact the biological treatment systems. Some streams from specific production units may contain nonbiodegradable or toxic compounds that impair the performance of the wastewater treatment plant and should be segregated and treated by specific techniques. In this work, the utilization of chemical oxidation (H₂O₂/UV) was investigated for removing 4-vinylcyclohexene (VCH) from a liquid stream coming from the production of hydroxylated liquid polybutadiene (HLPB). Besides VCH, this stream also contains ethanol, hydrogen peroxide, and many other organic compounds. Experiments were carried out in a small-scale photochemical reactor (0.7 L) using a 25-W low-pressure mercury vapor lamp. The photochemical reactor was operated in batch, and the reaction times were comprised between 10 and 60 min. Assays were also performed with a synthetic medium containing VCH, H₂O₂, and ethanol to investigate the removal of these substances in a less complex aqueous matrix. By-products formed in the reaction were identified by gas chromatography and mass spectroscopy (GC-MS). VCH was significantly removed by the oxidation process, in most assays to undetectable levels. Ethanol removal varied from 16 to 23 % depending on the reaction conditions. Acetic acid, acetaldehyde, and diols were detected as by-products of the industrial wastewater stream oxidation. A drop on the toxicity of the industrial stream was also observed in assays using the organism Artemia salina.

Knowledge on the dynamics and the durability of the processes governing the mitigation of pesticide loads by aquatic vegetation in vegetated streams, which are characterized by dynamic discharge regimes and short chemical residence times, is scarce. In a static long-term experiment (48 h), the dissipation of five pesticides from the aqueous phase followed a biphasic pattern in the presence of aquatic macrophytes. A dynamic concentration decrease driven by sorption to the macrophytes ranged from 8.3 to 60.4 % for isoproturon and bifenox, respectively, within the first 2 h of exposure. While the aqueous concentrations of imidacloprid, isoproturon, and tebufenozide remained constant thereafter, the continuous but decelerated concentration decrease of difenoconazole and bifenox in the water-macrophyte systems used here was assumed to be attributed to macrophyte-induced degradation processes. In addition, a semi-static short-term experiment was conducted, where macrophytes were transferred to uncontaminated medium after 2 h of exposure to simulate a transient pesticide peak. In the first part of the experiment, adsorption to macrophytes resulted in partitioning coefficients (logK D_Adₛₒᵣₚ) ranging from 0.2 for imidacloprid to 2.2 for bifenox. One hour after the macrophytes were transferred to the uncontaminated medium, desorption of the compounds from the macrophytes resulted in a new phase equilibrium and K D_Dₑₛₒᵣₚ values of 1.46 for difenoconazole and 1.95 for bifenox were determined. A correlation analysis revealed the best match between the compound affinity to adsorb to macrophytes (expressed as K D_Adₛₒᵣₚ) and their soil organic carbon-water partitioning coefficient (K OC) compared to their octanol-water partitioning coefficient (K OW) or a mathematically derived partitioning coefficient.

β-N-Methylamino-L-alanine (BMAA), a neurotoxin reportedly produced by cyanobacteria, diatoms and dinoflagellates, is proposed to be linked to the development of neurological diseases. BMAA has been found in aquatic and terrestrial ecosystems worldwide, both in its phytoplankton producers and in several invertebrate and vertebrate organisms that bioaccumulate it. LC-MS/MS is the most frequently used analytical technique in BMAA research due to its high selectivity, though consensus is lacking as to the best extraction method to apply. This study accordingly surveys the efficiency of three extraction methods regularly used in BMAA research to extract BMAA from cyanobacteria samples. The results obtained provide insights into possible reasons for the BMAA concentration discrepancies in previous publications. In addition and according to the method validation guidelines for analysing cyanotoxins, the TCA protein precipitation method, followed by AQC derivatization and LC-MS/MS analysis, is now validated for extracting protein-bound (after protein hydrolysis) and free BMAA from cyanobacteria matrix. BMAA biological variability was also tested through the extraction of diatom and cyanobacteria species, revealing a high variance in BMAA levels (0.0080–2.5797 μg g⁻¹ DW).

This study aims to determine an interactive environmental model for economic growth that would be supported by the “sustainability principles” across the globe. The study examines the relationship between environmental pollutants (i.e., carbon dioxide emission, sulfur dioxide emission, mono-nitrogen oxide, and nitrous oxide emission); population growth; energy use; trade openness; per capita food production; and it’s resulting impact on the real per capita GDP and sectoral growth (i.e., share of agriculture, industry, and services in GDP) in a panel of 34 high-income OECD, high-income non-OECD, and Europe and Central Asian countries, for the period of 1995–2014. The results of the panel fixed effect regression show that per capita GDP are influenced by sulfur dioxide emission, population growth, and per capita food production variability, while energy and trade openness significantly increases per capita income of the region. The results of the panel Seemingly Unrelated Regression (SUR) show that carbon dioxide emission significantly decreases the share of agriculture and industry in GDP, while it further supports the share of services sector to GDP. Both the sulfur dioxide and mono-nitrogen oxide emission decreases the share of services in GDP; nitrous oxide decreases the share of industry in GDP; while mono-nitrogen oxide supports the industrial activities. The following key growth-specific results has been obtained from the panel SUR estimation, i.e., (i) Both the food production per capita and trade openness significantly associated with the increasing share of agriculture, (ii) food production and energy use significantly increases the service sectors’ productivity; (iii) food production decreases the industrial activities; (iv) trade openness decreases the share of services to GDP while it supports the industrial share to GDP; and finally, (v) energy demand decreases along with the increase agricultural share in the region. The results emphasize the need for an interactive environmental model that facilitates the process of sustainable development across the globe.

To evaluate lung function responses to short-term indoor PM₁ and PM₂.₅ concentrations, we conducted a panel study of healthy schoolchildren aged 13–14 years. The following lung function parameters FVC, FEV₁, PEF, and mid expiratory flows MEF₂₅, MEF₅₀, and MEF₇₅ were measured in 141 schoolchildren of the secondary school in Wroclaw, Poland in years 2009–2010. On days when spirometry tests were conducted, simultaneously, PM₁ and PM₂.₅ samples were collected inside the school premises. Information about differentiating factors for children including smoking parents, sex, living close to busy streets, dust, mold, and pollen allergies were collected by means of questionnaires. To account for repeated measurements, the method of generalized estimating equations (GEE) was used. The GEE models for the entire group of children revealed the adverse effects (p < 0.05) of PM₁ and PM₂.₅. Small differences in effects estimates per interquartile range (IQR) of PM₁ and PM₂.₅ on MEF₂₅ (5.1 and 4.8 %), MEF₅₀ (3.7 and 3.9 %), MEF₇₅ (3.5 and 3.6 %) and FEV₁ (1.3 and 1.0 %) imply that PM₁ was likely the component of PM₂.₅ that might have a principal health effect on these lung function parameters. However, the reduction of FVC and PEF per IQR for PM₂.₅ (2.1 and 5.2 %, respectively) was higher than for PM₁ (1.0 and 4.4 %, respectively). Adjustment for potential confounders did not change the unadjusted analysis.