The wide diffusion of Emerging Organic Micropollutants (EOMs) in the environment is receiving increasing attention due to their potential toxicological effects on living organisms. So far, the Wastewater Treatment Plants (WWTPs) have not been designed with the purpose to remove these contaminants; therefore, they can represent the major source of release into the environment both through the effluent and the wasted sludge. The fate of EOMs in the WWTPs is still not completely known; further investigations are therefore needed to assess if it is possible to exploit the existing treatment units to reduce EOM concentrations or which processes must be implemented to this purpose. Among the wide class of EOMs, the present study focused on the following drugs of abuse: amphetamine (AM), methamphetamine (MET), 11-nor-Δ9-THC-9carboxy (THC-COOH) and benzoylecgonine (BEG). Presence and removal efficiency of these drugs in the activated sludge tank of a WWTP for domestic sewage was investigated through analyses at both full-scale and laboratory scale. Determinations conducted in the full-scale WWTP highlighted that, among the searched drugs, AM was found to be the most abundant in the influent and effluent of the biological oxidation tank, while 11-nor-Δ9-THC-9carboxy was present at the lowest concentration. Some removal took place in the units prior to the oxidation tank, although the main reduction was observed to occur in the biological oxidation reactor. All the drugs showed a wide variability of the measured concentrations during the week and the day. Taking into account results from both full-scale observations and batch tests, removals in the biological reactor were found within the following ranges: 33–84% for AM, 33–97% for MET, 33–57% for BEG and 29–83% for THC-COOH. These removals were due to a combination of adsorption and biodegradation mainly, while volatilization did not play a significant role. Other processes, e.g. hydrolysis, were likely to occur.

This paper reviews the current quality of groundwater in Vietnam. In Vietnam, groundwater is obtained primarily from tubewells, which have high concentrations of pollutants such as As, Fe, Mn, and NH₄⁺. In the areas where groundwater tests were conducted, arsenic levels ranged from 0.1–3050 μg/L, which substantially exceed the standard of 10 μg/L which has been established by the WHO. Contamination sources are distributed over a large area from the Red River Delta in the north to the Mekong River Delta in the south, putting as many as ten million people at risk of adverse health effects. Levels of arsenic and iron in sediment are strongly correlated, which indicate that the presence of arsenic in groundwater results from the reduction of arsenic bound to iron oxyhydroxides. It is important to raise awareness of these issues among the Vietnamese public by disseminating information about the negative effects of contaminated drinking water, as well as carrying out long-term research projects to identify other sources of contamination and improving water treatment technology and water management capabilities.

Globalization is increasingly a driving force behind vibrant economies around the world. This paper discusses the impact of globalization and natural resources on economic growth from 1970 to 2014 in Pakistan. Based on an auto-regressive distributive lag (ARDL) model, the paper infers that globalization promotes economic growth in Pakistan. Natural resources also contribute to economic growth, as the causality results suggest bi-directional causality between globalization and use of natural resources. Policy implications are that countries should emphasize security, increase exports, encourage technological strength, and increase its intellectual management capacity.

A linear-dendric copolymer containing polyethylene glycol-polycitric acid used as a capping agent to the green inter-matrix synthesis of silver/silver oxide core-shell quantum dots (Ag@AgO QDs). Water-soluble Ag@AgO QDs were synthesized with high yield and narrow size distribution. Here, Ag ions were trapped in the polymer branches and covalently bonded to it. Another sample of Ag@AgO QDs was synthesized through the same method and conditions without any capping agent (raw nanoparticles). Structure, size distribution, and morphology of raw and copolymer-grafted nanoparticles were identified using X-Ray diffraction, field emission scanning electron microscopy (FESEM), and high-resolution transmission electron microscopy (HRTEM). The results from XRD pattern and UV spectra confirmed the Ag@AgO structure of both nanoparticles. From the FESEM image, the size of Ag nanoparticles obtained at the range of 1–20 nm. HRTEM image of grafted nanoparticles directly showed that these nanoparticles have very tiny size in the range of 1–2 nm and presented in the form of core-shell Ag@AgO. Thus, both raw and polymer-grafted samples are in the range of quantum dots (QDs). Raw and polymer-grafted Ag@AgO QDs which take the advantage of water solubility and biosafety, were used as photocatalyst for degradation of cationic methylene blue (MB) and anionic methyl orange (MO) dyes at low and high concentrations of each dye. Results shows using polymer-grafted QDs leads to a significant enhancement both in the efficiency and rate of dye degradation, compared to the case of using raw nanoparticles.

The objective of the present study was to investigate the responses of the chironomid communities (Diptera: Chironomidae) to environmental variables in four moderately and highly disturbed rivers located in one of the most degraded watersheds in South America. Sampling campaigns were carried out during 2014–2016 in four sites of the Matanza-Riachuelo basin. The physical-chemical and hydrological variables were measured and, the ecological indices were calculated and evaluated by ANOVA. The responses of Chironomidae to the environmental variables were evaluated by redundancy analysis (RDA), and the sampling sites were grouped according to the populations of chironomids and the main environmental variables. Finally, the Spearman correlation was made to determine which of these variables were significant. In total, 13 chironomid taxa were found in 36 samples during the study period. The greatest density registered belongs to Rheotanytarsus and Cricotopus. The ANOVA detected the greatest Chironomidae density and taxonomic richness in the sites with agricultural-urban impact. The changes in the distribution of Rheotanytarsus, Thienemanniella, and Polypedilum were mainly explained by the increase in current velocity, organic matter, and hardness, and the decrease of NH3 and BOD. On the other hand, Goeldichironomus, Chironomus, Parachironomus, Dicrotendipes, and Cricotopus were explained by the increase in conductivity, dissolved oxygen, and temperature, and the decrease of the variables NO3, BOD, and Cu. In addition to this, the sites with urban-agricultural impact were clearly separated from sites with urban-industrial impact. The last one was more related to the increase in BOD, Cu, and NO3 that indicates moderate to poor water quality. In conclusion, we can infer that the physical and chemical variables are correlated with changes in the structure and distribution of the chironomid community and there are genera that respond differently at high and intermediate situations of disturbances. This knowledge contributes to the execution of strategies for the conservation and restoration of the lotic ecosystems.

The insecticide λ-cyhalothrin was incubated with planktonic and biofilm cultures of the fungus Cunninghamella elegans. ¹⁹F nuclear magnetic resonance spectroscopy demonstrated that the compound was initially biosorbed to the biomass and more slowly degraded by the fungus. Furthermore, the presence of trifluoromethyl-containing metabolites was observed. Analysis of culture extracts by gas chromatography-mass spectrometry (GC-MS) identified non-fluorinated metabolites that suggested the likely catabolic pathway. The hydroxylated metabolites were probably generated from the action of cytochromes P450 (CYPs), as the presence of CYP inhibitors resulted in the absence of biodegradation. Planktonic cells were measurably faster at degrading the pesticide compared with biofilm.

Investigating whether the same hyperaccumulator shows a high accumulation potential for different species of the same heavy metal in the soil has rarely been considered until now. In this experiment, Cd accumulation by a hyperaccumulator Bidens pilosa L. from soils spiked with 3 and 9 mg Cd kg⁻¹ in the form of Cd(NO₃)₂, CdCl₂, CdBr₂, CdI₂, CdSO₄, CdF₂, Cd(OH)₂, CdCO₃, Cd₃(PO₄)₂, and CdS and effect of soil amendment with EDTA were determined. The results showed that the Cd concentrations in B. pilosa for high-solubility species were basically higher. But the enrichment factors (EFs) (shoot to soil Cd concentration ratio) and translocation factors (TFs) (shoot to root Cd concentration ratio) of low-solubility Cd species were all greater than 1, either indicating that there was a high Cd hyperaccumulative potentials of B. pilosa without considering on Cd species in soil. EDTA significantly improved B. pilosa Cd hyperaccumulation, especially for low-solubility Cd forms in soils. These results can perfectly explain the accumulation properties of one hyperaccumulator to different species of the same heavy metal. Phytoremediation may be applied for a wide scope for different Cd species–contaminated soil. Moreover, the total amount of Cd in soil was important when assessing the risk of Cd-contaminated soils.

Bacteria-derived biochars from Bucillus sp. biomass under different pyrolysis temperature (250 °C, 350 °C, 450 °C, and 550 °C, respectively) were prepared, forming polyptychial, mesoporous graphite-like structure. The adsorption and sequestration efficiencies of Cd²⁺ by these biochars were evaluated, and the underlying mechanisms were then discussed. Cd²⁺ sorption data could be well described by Langmuir mode while the pseudo-second-order kinetic model and Elovich model best fitted the kinetic data. The functional groups complexation, cation-π interactions, and interaction with minerals (including surface precipitation with phosphorus and ion exchange) jointly contributed to Cd²⁺ sorption and sequestration on biochar, but the interaction with minerals played a dominant role by forming insoluble cadmium salt composed by polycrystalline and/or amorphous phosphate-bridged ternary complex. The maximum sorption capacity of BBC350 in simulated water phase of soil for Cd²⁺ was 34.6 mg/g. Furthermore, the addition of bacteria-derived biochars (1%, w/w) decreased the fractions easily absorbed by plants for Cd in the test paddy soils by 1.9–26% in a 10-day time. Results of this study suggest that bacteria-derived biochar would be a promising functional material in environmental and agricultural application.

This study was conducted to investigate the effects of maternal exposure to bisphenol A (BPA) on testis development of F1 male mice. The BPA exposure model of pregnant mice was prepared by intragastric administration of BPA at the doses of 0, 2.5, 5, 10, 20, and 40 mg/kg/day at gestation day (GD) 0.5–17.5. The testis index of the offspring mice was calculated at postnatal day (PND) 21 and PND 56. The results showed that maternal exposure to 20 mg/kg BPA during pregnancy significantly increased the testicular index of F1 males at PND 21, and 40 mg/kg BPA significantly decreased the testicular index of F1 males at PND 56 (P < 0.01). BPA significantly reduced serum testosterone (T) and estradiol (E₂) levels, and improved testicular ERα and ERβ levels in F1 males at both PND 21 and PND 56. BPA exposure also upregulated transcription of testicular Dnmt1 and inhibited the transcription of testicular Dnmt3A and Dnmt3B in F1 mice at PND 21. BPA reduced the transcriptional level of testicular DNA methyltransferase (Dnmt), increased the expression of testicular caspase-7, caspase-9, and bax, and decreased the expression of bcl-2 in F1 mice at PND 56. Consistent with that, BPA improved the apoptosis rate in the testis at PND 56 (P < 0.01 or P < 0.05). Our study indicates that BPA disrupts the secretion of testosterone, estradiol, and estrogen receptors by interfering with the transcription of testicular DNA methyltransferase (Dnmt) in offspring males, which damages testicular tissues and affects the potential reproductive function.

In 2008, the Mulberry River, a National Wild and Scenic River, was listed as impaired due to low pH (below pH 6.0). Over the last 50 years, the volume of conifers in the Ozark region has increased 115% since 1978 which may result in the acidification of nearby aquatic ecosystems. The objective of this study was to determine if differences exist in soil and litter chemical properties between deciduous and coniferous tree stands. Aboveground litter (n = 200) and soil (n = 400) at 0- to 5- and 5- to 15-cm depths were collected at paired deciduous and coniferous stands at 10 locations within the Mulberry River watershed and analyzed for a suite of chemical parameters. There were no differences (P > 0.05) in several measures of soil acidity between deciduous and coniferous stands. Litter collected from the coniferous stands was more acidic than deciduous litter (4.4 vs 4.7; P < 0.05). Cation exchange capacity, exchangeable Ca and Mg, and water-soluble P and Mg contents differed (P < 0.05) by stand and depth. Cation exchange capacity and exchangeable Ca and Mg were greatest in the 0- to 5-cm depth interval of the coniferous stands. Water-soluble P and Mg contents were greatest within the 0- to 5-cm depth interval which did not differ (P > 0.05) between stand but were greater than the 5- to 15-cm depth interval. Although limited to the top 15-cm of soil, the similarity in soil acidity between stands suggests that conifer growth may not be a substantial source of acidity to the Mulberry River.