Endosulfan, an organochlorine pesticide, has been applied ubiquitously worldwide. However, endosulfan has been identified as a type of persistent organic pollutants (POPs), and its ecotoxicity has drawn attentions from scientists. The present study was implemented to examine the effects of endosulfan on the diversity and structure of soil microorganism communities. A control treatment and three concentrations (0.1, 1.0, and 10.0 mg/kg) were set up in laboratory experiments and sampled on days 7, 14, 21, and 28. The results revealed that the populations of bacteria and actinomycetes decreased significantly after 1.0 and 10.0 mg/kg treatments and that the soil microbial biomass carbon (MBC) was increased by endosulfan compared with the control. Terminal restriction fragment length polymorphism (T-RFLP) results revealed that the soil bacterial diversity was decreased by endosulfan and that the soil microbial community structure became unstable after endosulfan application. Moreover, the results of a 16S rRNA clone library revealed that the phyla Proteobacteria, Actinobacteria, Bacteroidetes, Spirochaetes, and Firmicutes showed an obvious advantage and closely relative. In conclusion, the results of the present study indicated that 0.1–10.0 mg/kg endosulfan showed obvious influences on the diversity and structure of the soil microbial community.

Although phosphorus (P) enrichment alone or in combination with other nutrients such as nitrogen (N) and potassium (K) due to anthropogenic activities may modify the nutrient pools and nutrient elemental ratios of terrestrial ecosystems, few studies have revealed the global effects of P alone or in combination with N and K enrichment on terrestrial ecosystems. In this study, we conducted a meta-analysis of the impacts of P addition alone or in combination with N and K on the C, N, and P pools and C/N/P ratios of plants, soils, and microbial biomass in terrestrial ecosystems. The results suggest that the following changes occurred: (1) P addition resulted in a significantly larger plant C pool, which was further enhanced when extra N and K were added. (2) The soil and microbial biomass C pools and the plant, soil, and microbial biomass N pools were minimally affected by P addition at the global scale but were noticeably affected when N and K were simultaneously added. (3) The P pools of the plants, soil, and microbial biomass were significantly and consistently enhanced by the addition of P, NP, and NPK. (4) The plant C/N, N/P, and C/P ratios were significantly reduced when P was added, while the C/N/P ratios in the soil and microbial biomass were minimally affected. These results, which show the inconsistent responses of plant, soil, and microbial biomass nutrient pools and elemental ratios to P, NP, and NPK addition, improve our understanding of terrestrial ecosystem functions under global change scenarios.

The functional classification of β-lactamases is done through assessing their ability to hydrolyze specific β-lactams and its inactivation by inhibitors. This study investigated the β-lactamases encoding genes present in soil samples from different origins (landfill, preservation area, and soil from a farm). Genes codifying for ESBL enzymes bla SHV, bla TEM₋₁₁₆ and bla OXA₋₁ were found in all analyzed samples. Gene for ESBL bla CTX₋M₋₁₄ was detected in the landfill and farm soil samples, but they were not found in the preservation area, while bla OXA₋₄₈₋ₗᵢₖₑ was present just in the soil from the landfill. The gene for the MBL bla VIM was found in the soil sample from a farm. The results indicate that bla SHV, bla TEM₋₁₁₆, and bla OXA₋₁ genes are scattered in soils with and without potential contaminants; however, genes bla CTX₋M₋₁₄, bla OXA₋₄₈, and bla VIM were detected just in polluted areas.

Wastewater treatments can eliminate or remove a substantial amount of pharmaceutical active compounds (PhACs), but there may still be significant concentrations of them in effluents discharged into surface water bodies. Beirolas wastewater treatment plant (WWTP) is located in the Lisbon area and makes its effluent discharges into Tagus estuary (Portugal). The main objective of this study is to quantify a group of 32 PhACs in the different treatments used in this WWTP. Twelve sampling campaigns of wastewater belonging to the different treatments were made in 2013–2014 in order to study their removal efficiency. The wastewaters were analysed by solid phase extraction (SPE) and ultra-performance liquid chromatography coupled with tandem mass detection (UPLC–MS/MS). The anti-diabetics were the most frequently found in wastewater influent (WWI) and wastewater effluent (WWE) (208 and 1.7 μg/L, respectively), followed by analgesics/antipyretics (135 μg/L and < LOQ, respectively), psychostimulants (113 and 0.49 μg/L, respectively), non-steroidal anti-inflammatory drugs (33 and 2.6 μg/L, respectively), antibiotics (5.2 and 1.8 μg/L, respectively), antilipidemics (1.6 and 0.24 μg/L, respectively), anticonvulsants (1.5 and 0.63 μg/L, respectively) and beta blockers (1.3 and 0.51 μg/L, respectively). A snapshot of the ability of each treatment step to remove these target PhACs is provided, and it was found that global efficiency is strongly dependent on the efficiency of secondary treatment. Seasonal occurrence and removal efficiency was also monitored, and they did not show a significant seasonal trend.

Complete bioremediation of soils containing multiple volatile organic compounds (VOCs) remains a challenge. To explore the possibility of complete bioremediation through integrated anaerobic-aerobic biodegradation, laboratory feasibility tests followed by alternate anaerobic-aerobic and aerobic-anaerobic biodegradation tests were performed. Chlorinated ethylenes, including tetrachloroethylene (PCE), trichloroethylene (TCE), cis-dichloroethylene (cis-DCE), and vinyl chloride (VC), and dichloromethane (DCM) were used for anaerobic biodegradation, whereas benzene, toluene, and DCM were used for aerobic biodegradation tests. Microbial communities involved in the biodegradation tests were analyzed to characterize the major bacteria that may contribute to biodegradation. The results demonstrated that integrated anaerobic-aerobic biodegradation was capable of completely degrading the seven VOCs with initial concentration of each VOC less than 30 mg/L. Benzene and toluene were degraded within 8 days, and DCM was degraded within 20 to 27 days under aerobic conditions when initial oxygen concentrations in the headspaces of test bottles were set to 5.3% and 21.0%. Dehalococcoides sp., generally considered sensitive to oxygen, survived aerobic conditions for 28 days and was activated during the subsequent anaerobic biodegradation. However, degradation of cis-DCE was suppressed after oxygen exposure for more than 201 days, suggesting the loss of viability of Dehalococcoides sp., as they are the only known anaerobic bacteria that can completely biodegrade chlorinated ethylenes to ethylene. Anaerobic degradation of DCM following previous aerobic degradation was complete, and yet-unknown microbes may be involved in the process. The findings may provide a scientific and practical basis for the complete bioremediation of multiple contaminants in situ and a subject for further exploration.

A simple and green preconcentration method of hydrophobic to hydrophilic switchable liquid-solid dispersive microextraction (HSL-SDM) has been first time introduced as separation method for arsenic ion in real water samples. Multiwall carbon nanotube (MWCNT) was immobilized with diethylenetriamine (DETA) and then used as solid phase adsorbent for the determination of trace level of arsenic ion by HSL-SDM method prior to analysis by hydride generation atomic absorption spectrometry. Reversibly hydrophobic-hydrophilic switchable of functionalized MWCNT can occur due to the exposing of carbon dioxide (CO₂) as anti-solvent trigger. The reversibly hydrophobic-hydrophilic switchable phenomena of immobilized MWCNT in the liquid-solid dispersive microextraction were checked by using FT-IR and SEM. The optimized analytical condition for arsenic ion analysis such as enrichment factor and limits of detection were obtained 83 and 3.05 ng L⁻¹, respectively. Accuracy of the developed HSL-SDM method was confirmed by the analysis of certified reference materials. Our developed HSL-SDM method was successfully applicable for measurements of arsenic ions in real water samples.

Sulfur (S) is one of the most redox-sensitive elements and has a marked impact on the geochemical cycling of biogenic elements in freshwater sediments. Current understanding of the speciation of sedimentary S, and of the processes regulating it, is insufficient. In this study, the speciation and spatial variations of S and iron (Fe) in sediments (soils) from Lake Hongfeng, one of the largest freshwater lakes in Southwest China, were investigated using X-ray absorption near-edge structure (XANES) spectroscopy and diffusive gradient in thin film technique (DGT). The results show that S in sediments and soils was composed of seven fractions in different electronic oxidation states (EOSs), including (i) reduced S (R-S, G1, EOS = − 1), (ii) lowly oxidized S (LO-S, including G2-G5; EOS = 0, 0.5, 2, and 3.7), and (iii) highly oxidized S (HO-S, including G6 and G7; EOS = 5 and 6). Proportional differences of S speciation in sediments and soils indicated that HO-S is largely reduced to LO-S and R-S during depositional processes. The HO-S fraction decreased in the top surface sediments and then increased in the deeper layers, whereas the R-S fraction showed the opposite trend, suggesting that sulfate reduction and re-oxidation processes occurred in the sediments. High ratios of soluble Fe/S provided a favorable foundation for the reduction and burial of sedimentary S. The speciation and spatial variations of S in freshwater sediments are controlled by complex environmental factors, including terrigenous material discharges, water redox conditions, and porewater chemistry (such as for pH, Eh, and reactive Fe). Our study will help to deepen the understanding of the geochemical dynamics of S in the sediments of freshwater ecosystems.

Disposal and management of abattoir wastewater have been a long-term concern in a high meat-consuming country like Australia. Land-based application of wastewater is considered to be the most economically viable disposal method and is widely used by abattoirs. In this study, we assessed the effects of long-term abattoir wastewater irrigation on soil physical and chemical characteristics of calcareous soils. Soil samples were collected from 16 different locations with seven 5 cm depths intervals down to 35 cm. Soil properties including soil type, bulk density, moisture holding capacity, pH, electrical conductivity (EC), nitrogen (N), phosphorus (P), carbon (C) and micronutrients were measured. Soil characteristics were compared with non-irrigated soils. The study area receives annually about 327 ML of wastewater with high concentration of N and P (186 and 30.4 mg/L). Overall, the site retained 0.6 t N/ha, 0.1 t P/ha and 0.4 t of K per hectare. Irrigation for over a decade onto the study site has caused a significant change in the soil fertility. Soil total N was increased by 82% compared to non-irrigated. Similarly, soil total P concentration was increased more than sixfold. The overall results showed that the abattoir wastewater irrigation to soil caused very significant changes in soil nutrient levels. These changes indicate need to recapture the surplus nutrient, in particular N, to avoid potential leaching and off-site effects.

The inhibitory effect of seven different metals on the specific anammox activity of granular biomass, collected from a single stage partial nitritation/anammox reactor, was evaluated. The concentration of each metal that led to a 50% inhibition concentration (IC₅₀) was 19.3 mg Cu⁺²/L, 26.9 mg Cr⁺²/L, 45.6 mg Pb⁺²/L, 59.1 mg Zn⁺²/L, 69.2 mg Ni⁺²/L, 174.6 mg Cd⁺²/L, and 175.8 mg Mn⁺²/L. In experiments performed with granules mechanically disintegrated (flocculent-like sludge), the IC₅₀ for Cd⁺² corresponded to a concentration of 93.1 mg Cd⁺²/L. These results indicate that the granular structure might act as a physical barrier to protect anammox bacteria from toxics. Furthermore, the presence of an external layer of ammonia oxidizing bacteria seems to mitigate the inhibitory effect of the metals, as the values of IC₅₀ obtained in this study for anammox activity were higher than those previously reported for anammox granules. Additionally, the results obtained confirmed that copper is one of the most inhibitory metals for anammox activity and revealed that chromium, scarcely studied yet, has a similar potential inhibitory effect.

Polycyclic aromatic hydrocarbons (PAHs) are scavenged from the atmosphere during snowfall, stored in the seasonal snowpack, and exchanged with PAHs in atmosphere. Thus, the PAHs in fresh snow and snowpack could reflect the PAH levels in atmosphere. This study investigated the concentrations and compositions of 16 priority-controlled PAHs in fresh snow and seasonal snowpack, as well as PAH levels in underlying soils before and after snow melting. The total concentrations of PAHs in fresh snow and snowpack ranged from 26.6 ± 4.2 to 36.9 ± 1.7 μg L⁻¹ and from 40.3 ± 4.4 to 105.9 ± 6.9 μg L⁻¹, respectively. The higher concentrations of PAHs in fresh snow compared with other areas indicated a high PAH level in atmosphere in Changchun city, presenting a potential risk to human health. Higher concentrations of total PAHs in snowpack than those in fresh snow indicated the prominent deposition of PAHs from atmosphere to snowpack in winter. In contrast, a specific reduction of five- to six-ring PAHs in the snowpack suggested that strong photolysis of five- to six-ring PAHs occurred in snowpack. The variation of PAHs in different snowpacks suggested that the deposition may be largely affected by local environment. The results of diagnostic ratios and principal component analysis (PCA) suggested that the PAHs in fresh snow and snowpack are both from a mixed source of coal combustion and from vehicle emissions. However, nonmetric multidimensional scaling (NMDS) divided fresh snow and snowpack into two groups, indicating the different contributions of coal combustion and vehicle emissions to PAHs in fresh snow and snowpack. After snowpack melting, three- to four-ring PAH levels in underlying soils showed no change, indicating that the three- to four-ring PAHs were volatilized to the atmosphere. This study indicated a risk of atmospheric PAHs in Changchun city in winter and in the beginning of spring.