Anthropogenic pollution results in high concentrations of heavy metals in the environment. Due to their persistence and a high potential for bioaccumulation, metals are a real threat for birds breeding in industrial areas. The aim of the present study has been to explore the contents of heavy metals (arsenic As, cadmium Cd, chromium Cr, copper Cu, iron Fe, nickel Ni, lead Pb and zinc Zn) in the excreta of Whitethroat (Sylvia communis) nestlings living in polluted environment and to investigate the relationship between these contents and the nestlings’ condition. Excrement samples contained all the studied elements. The contents of arsenic, cadmium, copper and zinc in the excreta of nestlings from nests located close to a slag dump were several times higher than in the soil near the dump, which suggested accumulation in food consumed by the birds. Condition parameters (body mass and haemoglobin concentration) were not related to heavy metal concentrations in the nestlings’ excreta, except of Zn. It is possible that Whitethroats are able to detoxicate heavy metals to a certain extent. Detailed, multi-element analysis of the environment, food and bird tissues or excreta should be performed to explore relations between different chemicals and bird condition.

The phosphorus (P)-buffering ability of suspended particulate matter (SPM) from the Ziya River Mainstream (ZRM) and the Luanhe River (LR) of northern China was investigated in this study. Forty samples of SPM from the ZRM and LR were collected in October and November of 2016. The ZRM has slow flow and poor water quality, while the LR has fast flow and reasonably good water quality. Under a scanning electron microscope, the SPM from the ZRM had a more complex microstructure than that from the LR, perhaps because of the slower flow and heavier pollution in the ZRM. P fractions in both SPM and water samples were determined using standard measurement and testing program methods. The equilibrium P concentration was used to determine the influence of SPM on soluble reactive P (SRP) concentrations. These SRP fractions were used to evaluate the P-buffering intensity of the two rivers. Differences in SPM microstructure resulted in the SPM from ZRM having a stronger P-buffering ability than the LR, making SPM an effective vector for SRP. Anthropogenic activities likely contributed to the differences in both microstructures of the SPM and P-buffering intensity of the rivers. A conceptual model was developed to show how anthropogenic activities influence the P-buffering intensity of the two rivers. As far as we know, this is the first time that the P-buffering intensity has been compared between two rivers that have been severely impacted by anthropogenic activities. Our findings provide an important reference for similar rivers worldwide.

Four vertical-flow constructed wetland systems were set up in the field in order to study the removal efficiency and possible enzymatic mechanism of the constructed wetlands in treating sewage containing different concentrations of dibutyl phthalate (DBP). Under DBP spiked concentrations of 0.5, 1.0, and 2.0 mg/L, good DBP removal rates of 62.08, 82.17, and 84.17% were achieved, respectively. Meanwhile, certain removal effects of general water quality parameters were observed in all four constructed wetlands: with high average removal rates of nitrate nitrogen (NO₃⁻-N) and chemical oxygen demand (COD) of 91.10~93.89 and 82.83~89.17%, respectively, with moderate removal efficiencies of total nitrogen (TN), total phosphorus (TP), ammonia nitrogen (NH₄⁺-N) of 44.59~49.67, 30.58~37.18, and 28.52~37.45%, respectively. Compared to the control, an increase of enzyme activities of urease, phosphatase, dehydrogenase, and nitrate reductase was observed in the treatments with DBP addition. In the presence of 0.5 mg/L of DBP concentration, the urease, phosphatase, and dehydrogenase activities reached the highest levels, with an increase of 350.02, 36.57, and 417.88% compared with the control, respectively. It appeared that the low concentration of DBP might better stimulate the release of enzymes.

Metal pollution is a subject of growing concern as it affects the whole food chain of an ecosystem by bioaccumulation. Growing industrialization and anthropogenic intervention have put tremendous pressure on self-sustaining ecosystems worldwide. Sundarbans mangrove estuary, being a UNESCO World Heritage site, suffers severely from anthropogenic stress, urbanization, ecotourism, overexploitation of natural resources and discharges of industrial as well as municipal waste products. Our study unfolds the extent of metal pollution in the sediment of this estuarine mangrove ecosystem and also investigates the source and distribution of these metals. Extensive samplings were performed during three major seasons, namely pre-monsoon, monsoon, and post-monsoon for two consecutive years at ten sampling stations along the major river networks of the mangrove estuary. Seasonal variations of these metals, physicochemical properties, and soil texture studies were performed to explore the sediment quality of the study area. Positive correlation was observed between the pollutants and siltation. Several environmental indices were investigated to explore the degree of metal pollution which revealed contamination of Cd, Cr, and Pb to cross the permitted safe index in the study area. Pollution load index indicates the spatial as well as seasonal variation of eco toxic metal load along the course of the rivers. Statistical analyses such as principal component analysis and correlation matrix identified different sources for metal contamination. Almost 700 tannery industries are located in the upstream region of the rivers, and several small- and large-scale battery industries seem to be the main possible source for Cd, Cr, and Pb pollution. Analysis of the results indicates the alarming condition of this heritage site. The metal concentrations beyond toxicity thresholds are responsible for gradual deterioration of this estuarine mangrove which may only be protected by developing sustainable management planning.

We evaluated the agronomic quality of loam to clay–loam soils from a Mediterranean area, which have been submitted for more than 10 years to irregular and poorly controlled treated wastewater (TWW) irrigation and sewage sludge (SS) amendment, both TWW and SS issuing from a domestic effluent treatment plant. A soil was submitted to SS amendment only, another to TWW irrigation only, another to both treatments, and another was not submitted to any of these treatments. We found that the agronomic quality of the treated soils has not decreased. In treated soils, it was observed a slight increase of pH, an increase of the cation exchange capacity, and no change of either salinity or electrical conductivity. Sodium adsorption ratio and exchangeable sodium percentage remained satisfactory, below 13 and 15, respectively, and no infiltration problems were observed, indicating that rainwater percolation was sufficient to leach the salt brought by SS or TWW. The soil organic matter (SOM) increased in all SS-amended and/or TWW-irrigated soils, the increase being higher in SS-amended soils. The SOM kept a satisfactory C/N ratio, lower than 15; the SUVA (Specific UV Absorbance) and E2/E3 index showed normal characteristics of the water-extracted organic matter (WEOC). Both SS amendment and TWW irrigation brought high amounts of nutrients in the considered soils and increased the nutrients disponibility, especially regarding K and P, as shown by the nutrient concentrations in the soil water extracts. The pH increase does not seem to be a problem for the bioavailability of trace elements, at least regarding Cu, Zn, Co, and Fe. Complementary studies should be undertaken for Ni. These observations highlight the potential agronomical benefits of application of wastewater and sewage sludge, even without great technicality, the better results being obtained using both SS amendment and TWW irrigation.

The aim of this study is to examine the role of oil price changes in the effects of services trade and tourism on real income growth in Turkey. Time series analysis using the 1960–2017 annual period has been adapted with this respect. Results confirm the long-term impacts of tourism and services trade sectors on real income growth in Turkey. Tourism and trade (both services and manufacturing) exert positively significant effects on the long-term performance of macroeconomic activity as measured by gross domestic product. Oil prices negatively impact on real income growth of Turkey. It is also found that oil prices negatively moderate the effects of foreign trade, services trade, and tourism on real income growth in Turkey. This finding reveals that significant effects of foreign trade, services trade, and tourism on real income are negatively influenced from oil price changes.

Heavy metal concentrations in agricultural fields and their ecological risks are a source of extensive concern worldwide. A field survey was conducted to investigate the present situation and health risks of heavy metals (Mn, Pb, Zn, Cu, and Cd) and crops (corn, green soybean, sweet potato, persimmon, cassava, and Chinese chestnut) around the Pingle manganese (Mn) mine site in Guangxi Province, China, which was abandoned 20 years ago. The results showed that the ranges of Mn, Pb, Zn, Cu, and Cd were 2706.54–6760.16, 229.37–275.84, 160.39–215.48, 58.11–75.30, and 5.78–6.98 mg kg⁻¹, respectively, which were approximately 15.38–38.41, 11.76–14.15, 2.12–2.85, 2.09–2.71, and 21.64–28.75 times greater than their respective background values. Most of these concentrations exceeded the national standard for soil quality (grade 2) developed by the Ministry of Environmental Protection of China (1995). Contamination assessments based on the single contamination index (Pᵢ), Nemerow multi-factor index (Pcₒₘ), and potential ecological risk index (RI) showed that the sampled soils were severely polluted with these heavy metals, especially Pb and Cd. Similarly, the crops were enriched with Pb and Cd, with concentrations of 10.22–41.78 and 2.33–5.37 mg kg⁻¹, respectively, which were much higher than the threshold values of the national food standards. Contamination assessments with Pᵢ and Pcₒₘ also showed that the crops were severely polluted with Pb and Cd. The bioaccumulation factor values for Cd were highest among the heavy metals, with an average mean of 0.66 in these six crops, demonstrating that Cd readily accumulates in these crops. An assessment showed that the health risk for adults living in the mining-impacted areas was significant. Our study strongly recommends that heavy metal contamination in agricultural soils and crops grown around the Pingle Mn mining-affected areas should be treated to mitigate the health risks.

Phytoremediation has been applied as a promising and cost-effective technique for removing nutrient pollutants from wastewater. In this study, the effect of fullerene C60 was assessed on enhancing the phytoremediation efficiency of teak plants over a period of 1 month. Teak plants were supplied with fullerene C60 (0, 25, or 50 mg L⁻¹) and fed daily with two types of urea plant wastewater (with and without adding optimum ratio of phosphorus and potassium). The required volume of wastewater by the teak plants, nitrogen removal percentage, plant growth parameters (plant height, number of leaves, leaf surface area, and dry biomass), and nutrient content was recorded throughout the study. The results showed that addition of 25 mg L⁻¹ fullerene C60 to urea plant wastewater could increase water uptake and nitrogen recovery of the teak plants. Plant growth and nutrient contents of teak plants were also increased in the presence of 25 mg L⁻¹ fullerene C60. However, addition of 50 mg L⁻¹ fullerene C60 to the wastewater decreased the values for water uptake and nitrogen recovery. The findings indicated that addition of proper amount of fullerene C60 to the teak-based remediation system can increase the efficiency of the plants for nitrogen removal.

Previous studies suggest that biochar has potential to benefit soil when used as an amendment, but only few studies have investigated how the different biochars affect the microbial activity of soil in a calcareous soil. Hence, to study the effect of the biochars obtained from wheat straw and cow manure and produced under different production conditions on two biological soil indicators, dehydrogenase activity and soil respiration, after 0, 60, and 120 days of incubation (DOI), an incubation experiment as a completely randomized design with factorial arrangement in three replicates was conducted in a calcareous soil. The results of the study showed that with increasing the pyrolysis temperature (300 and 500 °C) and pyrolysis residence times (1, 3, and 6 h) of biochars, regardless of feedstock source, the dehydrogenase activity and soil respiration decreased. Both maximum activity of dehydrogenase (20.93 μg TPF g⁻¹ 24 h⁻¹) and maximum soil respiration (0.26 mg CO₂ g⁻¹ 24 h⁻¹) were found in the biochar produced from wheat straw at 300 °C, and the residence time of 1 h at the level of 10 t ha⁻¹ and minimum of these soil biological traits was observed in control treatments (soil). Moreover, the maximum activity of dehydrogenase and soil respiration was observed in 60 DOI. Therefore, when applying biochar as an amendment for increasing microbial activity in calcareous soil, the production conditions of biochar, type of biochar, and long- and short-term effects of different biochars should be taken into consideration.

Sorption of pharmaceuticals onto sediments is frequently related to organic matter content. Thus, the present work aimed to compare the effect of humic substances (HS) extracted from a river sediment versus Aldrich (HS) on the sorption of selected pharmaceuticals onto this river sediment. The results exhibited no “unique” effect of the presence of HS from the same origin. Thus, the sediment HS increased the sorption of sulfamethoxazole (SMX), diclofenac (DCF), and trimethoprim (TMP), but reduced the sorption of atenolol (ATN). The presence of Aldrich HS increased the sorption of TMP and ATN and decreased the sorption of SMX and DCF. Fluorescence quenching measurements revealed that these effects cannot be explained only by the presence of pharmaceutical HS associations. The use of several sorption models suggested that the sorption of SMX, DCF, and ATN involves multilayer mechanisms. Furthermore, it was pointed out that the presence of HS does not change the sorption mechanisms although it was observed interaction between HS and the sediment. Indeed, the sediment HS sorbs onto the sediment whereas the Aldrich HS tends to mobilize organic compounds from the sediment to the solution.