Bosten Lake, a typical rump lake in an oasis in northwest China, was chosen to evaluate the distribution, sources, pollution status, and potential ecological risk of heavy metals. Sediment samples were collected from the lake, and results showed that the values of the eight heavy metals all fell within the Second Soil National Standard, while the average and maximum values of the metals were higher than the background values of the study. Multivariate statistical analysis showed that sediment concentrations of Cd, Pb, Hg, and Zn were mainly influenced by man sources. In comparison, Cu, Ni, Cr, and As were primarily natural in origin. Enrichment factor analysis (EF) and the geo-accumulation index evaluation method (I gₑₒ) showed that Cd, Hg, and Pb fell under low and partial serious pollution levels, while Zn, As, Cr, Ni, and Cu mainly were characterized under no pollution and low pollution levels. The potential ecological hazards index (RI) showed that among the eight heavy metals, Pb, Hg, and Cd posed the highest potential ecological risk, with potential ecological hazards indices (RI) of 29.06, 27.71, and 21.54 %, respectively. These findings demonstrated that recent economic development in the area of the basin has led to heavy metal accumulation in the surface sediments of the lake.

ANT is a commonly occurring polycyclic aromatic hydrocarbon (PAH) in natural eutrophic waters where Microcystis blooms break out usually. In this study, effects of ANT at different concentrations (0.02, 0.06, 0.18, 0.54, and 1.62 μg/mL) on the growth, microcystin-LR (MC-LR) production, and expression of three key mcy genes in Microcystis aeruginosa were investigated. The results showed that all the tested concentrations of ANT inhibited M. aeruginosa growth significantly except 0.02 μg/mL ANT in the early stage of the experiment. In the culture media, initially applied ANT concentrations decreased significantly after 3 days of incubation. ANT stimulated MC-LR production in a concentration-dependent manner. After exposure to ANT for 1 day, the expression of mcyB gene was inhibited and the inhibitory effects increased with ANT concentrations. ANT at higher concentrations (above 0.02 μg/mL) stimulated gene expression of mcyD (P < 0.05) and mcyH (P < 0.01) significantly, and 0.02 μg/mL of ANT inhibited their expression significantly (P < 0.01). With increasing culture time, 0.18 μg/mL of ANT inhibited mcyB gene expression first and then stimulated it while gene expressions of mcyD and mcyH were stimulated throughout the experiment. Our results suggested that ANT in natural waters could affect not only Microcystis growth but also MC production via modifying mcy gene expressions.

Synthesis parameters of nano manganese oxide (NMO) were tuned in order to maximize Cs and Co sorption efficiencies. The prepared oxide was characterized using various techniques including x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), SEM, and surface area analyzer. The sorption characteristics with respect to uptake of Cs, Co, and Pb were evaluated. An α − phase nano manganese oxide with a surface area of 165 m² g⁻¹ was synthesized. Maximum adsorption capacities were 230 mg g⁻¹ for Pb²⁺, 73 mg g⁻¹ for Cs⁺, and 26 mg g⁻¹ for Co²⁺. The intra-particle diffusion was the rate-limiting step in the case of Pb²⁺, whereas both intra-particle diffusion and film diffusion contribute to the rate-determining step in the adsorption process in the case of Cs⁺ and Co²⁺. FT-IR analyses reveled that Cs⁺ and Co²⁺ coordinated to vacancy sites of NMO as inner-sphere complexes, while Pb²⁺ formed bidentate corner-sharing complexes. NMO had high affinity for Pb²⁺ but was also effective for sorption of Cs⁺ and Co²⁺ over a wide pH range, even in the presence of Na⁺. HCl (0.5 mol L⁻¹) solution could regenerate the adsorbent successfully, and the NMO could be efficiently reused with lower production of residues. Thus, the prepared NMO can be efficiently used in wastewater treatment in terms of high adsorption capacity, easy availability, and low cost.

The mass spectrometric analysis of the impact of sulfur dioxide and dust emission on carbon and oxygen stable isotopic compositions of glucose hydrolysed from α-cellulose samples extracted from Scots pine growing in the vicinity of “Huta Katowice” steelworks was the main aim of this study. The annual rings covered the time span from 1975 to 2012 AD. The relationships between climatic conditions, sulfur dioxide, and industrial dust emission and oxygen and carbon isotopic compositions were analyzed using correlation function methods. This study shows the first analysis of carbon and oxygen stable isotopes in glucose as the bio-indicators of CO₂, sulfur dioxide, and industrial dust emission. The anticoincidence trend of δ¹⁸O and δ¹³C and dust and sulfur dioxide confirms that the decreases of dust and sulfur dioxide industrial emission increase δ¹⁸O and δ¹³C values in glucose.

Various inorganic and organic pollutants in industrial soils may adversely affect soil microorganisms and terrestrial ecosystem functioning. The aim of the study was to explore the relationship between the microbial activity, microbial biomass, and functional diversity of soil bacteria and the metals and total petroleum hydrocarbons (TPHs) in the Upper Silesian Industrial Region (Poland). We collected soil samples in pine-dominated forest stands and analyzed them according to a range of soil physicochemical properties, including metal content (cadmium, lead, and zinc) and TPH content. Metal concentrations were normalized to their toxicity to soil microorganisms and integrated in a toxicity index (TI). Soil microbial activity measured as soil respiration rate, microbial biomass measured as substrate-induced respiration rate, and the bacterial catabolic activity (area under the curve, AUC) assessed using Biolog® ECO plates were negatively related to TPH pollution as shown in multiple regressions. The canonical correspondence analysis (CCA) showed that both TPH and TI affected the community-level physiological profiles (CLPPs) of soil bacteria and the pollutants’ effects were much stronger than the effects of other soil properties, including nutrient content.

Hydrologically controlled moist-soil impoundment wetlands provide critical habitat for high densities of migratory bird populations. Nutrients exported from heavily used impoundments by prescribed seasonal drawdown of surface water may contribute to the eutrophication of aquatic ecosystems. To investigate the relative importance of nutrient export from managed impoundment habitats, we conducted a field study at Mattamuskeet National Wildlife Refuge in North Carolina, USA, which contains 1545 ha of impoundments that drain into hypereutrophic Lake Mattamuskeet. We found that prescribed hydrologic drawdowns of an impoundment exported roughly the same amount of nitrogen (N) as adjacent fertilized agricultural fields on a per-area basis and contributed approximately one fifth of total N load to Lake Mattamuskeet. The prescribed drawdown regime, designed to maximize waterfowl production in impoundments, may be exacerbating the degradation of habitat quality in the downstream lake as an unintended consequence. Few studies of wetland N dynamics have targeted impoundments managed to provide wildlife habitat, but a similar phenomenon may occur in some of the 36,000 ha of similarly managed moist-soil impoundments on National Wildlife Refuges in the southeastern USA, especially those hosting dense concentrations of waterfowl. We suggest an earlier seasonal drawdown could potentially mitigate impoundment N pollution and estimate it could reduce N export from our study impoundment by more than 70 %.

Co-digestion of swine manure and crude glycerine from biodiesel production has been successfully attempted by many authors reporting substantial increments in biogas production. However, the effectiveness of this approach has been questioned recently. The addition of glycerol may cause an improvement in biogas production but at the expense of disturbing the degradation of manure. In the present paper, the organic transformations undergone in the anaerobic digestion of pig manure at increasing amounts of glycerine (2–8 % (v/v)) were analysed using spectroscopy techniques (Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (¹H NMR)). An increase in biogas production was observed with the addition of glycerine up to 8 %, resulting in a volumetric production of methane per litre of reactor (Lr) of 1.4 L CH₄/Lr d. However, the subsequent failure of the system was observed at this glycerine content due to the inhibitory effect caused by high H₂S concentration and foam formation. FTIR and ¹H NMR analysis performed on digestate samples showed that the addition of the co-substrate also caused the preferential degradation of glycerine and accumulation of proteins and aliphatic compounds. A post-stabilisation stage was necessary to complete the degradation process. Modifications in organic matter continued under this last stage although in the previous digestion period, a competition for substrate between sulphate reducing bacteria and methanogens was observed.

In the last 40 years of the twentieth century, as a result of the growth in the exploitation and industrial processing of sulphur, the northern part of the Sandomierz Basin was one of the most polluted areas of Poland. Forests growing in this region, predominantly the Scots pine, offered an opportunity to analyse the degradation of the environment during that period using the dendrochronological method. The study was based on 814 samples, taken from 53 research surfaces belonging to nine linear transects. The investigations demonstrated that the highest reduction in growth occurred during the years 1970–1990. After that period, a considerable improvement in the condition of the pine trees was observed in most of the research plots. The spatial schedule of the trees with reductions reveals a clear relationship with the distance from the emitter i.e. the reductions were significantly lower in more distant sites. A distinct weakening of the trees is also indicated by missing rings, recorded in the years: 1964, 1974, 1978, 1979, 1980, 1985, 1990, and 2002. A definite impact on the condition of the tree stands was also due to the cone of depression around the Jeziórko mine, the post-flotation landfills, as well as pollution on a regional scale.

The population increase has led to the rise of megacities that generate high levels of pollutants. To examine the temporal and spatial trends, the concentration data of total suspended particles (TSP) and coarse particles (particulate matter (PM)10) from the Rio de Janeiro State Environmental Institute (INEA) collected between 1968 and 2013 were used. To our knowledge, this is the study with the longest time series carried out in South America. The results showed that the TSP concentrations for urban and industrial regions exceeded the suggested limit (80 μg m⁻³) for nearly all years examined. PM10 concentrations remained above or very close to the limit (50 μg m⁻³). In several sites, there was a decrease, along the years, in atmospheric particulate matter concentrations, which may be coupled to improvements of fossil fuels and replacement by less-polluting fuels, such as hydrated alcohol and natural gas. However, in other places, high particulate matter concentrations were observed, which are associated with the infrastructure development in the city and for sporting events. The results show a seasonal trend during the study period, which is characterized by high levels of particulates during the austral wintertime. This trend is related to low rainfall and air mass stagnation. Regarding the daily concentrations observed, a tendency for high concentrations in the early morning and late afternoon was observed in urban regions, due mainly to traffic. In the industrial area, the variation was lower and more dependent on industrial activities than on traffic.

The Cumberland Marsh Region (CMR), located on the coast of the Bay of Fundy, is a major feeding ground for waterfowl and contains significant coastal wetland systems. In this study, concentrations of lead (Pb) and arsenic (As) were assessed in the bottom sediments of various open water wetlands across the CMR, and gastropods were sampled from the same wetlands to assess bioaccumulation of these non-essential trace elements and the potential for transfer to higher trophic level species. It was predicted that gastropods would have higher concentrations of Pb and As from wetlands with higher concentrations of these elements in sediments. Although wetland sediments and gastropods had elevated Pb and As concentrations, in some cases above the Canadian Sediment Quality Guidelines for the protection of aquatic life, there were no significant correlations between sediment and gastropod trace element concentrations. Gastropod to sediment ratios of Pb and As concentrations were highest in the brackish wetlands, but overall, levels were not of toxicological concern. Wetland chemistries and gastropod physiologies are hypothesized to be driving factors in determining the level to which Pb and As will bioaccumulate and merit careful consideration when developing wetland management strategies.