Davenportsteen9890

Ten-fold cross-validation was conducted to evaluate the performance of RF models. We find that the full auxiliary variables model had a better performance for the both periods. POP and GDP were key auxiliary variables affecting spatial variability of SOC stocks in 2015. Over a 25-year period, SOC stocks decreased from 2.77 ± 1.09 kg m-2 to 2.16 ± 0.93 kg m-2, resulting in 3.78 Tg SOC loss in this region. Rapid urbanization led to drastic land- use change, which was the main reason for the decrease of SOC stocks. Additionally, urban-specific variables should be used as the main auxiliary variables when predicting SOC stocks in the areas that experience rapid urbanization. We believe that accurate prediction and mapping of SOC stocks will help manage land use and facilitate soil quality assessment so as to increase soil carbon sequestration in the region. The objective of this study was to evaluate the fractionation of ZnO and CuO engineered nanoparticles (ENPs) in soils with a pH adjusted to 4.0, 6.5, and 9.0 after 1 day and 30 days of incubation. Based on the multi-stage extraction, 5 fractions of metals were determined. Moreover, the effect of ENPs on the activity of acid, neutral and alkaline phosphatase was determined. The results of the study revealed that pH had a dominant effect on the metal participation in soils. The levels of those fractions of metals differed between nano-ZnO and nano-CuO, which could have resulted from differences in the dissolution of the ENPs. After 1 day, the concentration of Zn2+ (0.02-7.4 mg L-1) was 10 times higher than that of Cu2+. The metal fractionation in soil treated with ENPs and metal salts may also confirm the role of ENP dissolution. The concentration of potentially bioavailable fraction of Zn increased with a drop in pH. BAY439006 At a 4 pH concentration of Zn in the treatment with nano-ZnO and ZnCl2 was at a similar level (42.1-45 mg kg-1), whereas the addition of nano-CuO resulted in a lower content of Cu (24.7 mg kg-1) than CuCl2 (36.5 mg kg-1). On the other hand, the concentration of fraction exchangeable of both metals in the alkaline soil did not exceed the level of 5.0 mg kg-1. Sample incubation time was especially important for metal participation in samples with a pH of 6.5. link2 The greatest differentiation of metal fractionation between the soils was also noted at a pH of 6.5, which could also have been a result of other properties of the soils. The strong effect of pH on the lability of ENPs in soils confirmed a need to trace the fate of ENPs in extreme soil conditions as well as in changing environment. V.This review documents recent advances in terrestrial mercury cycling. Terrestrial mercury (Hg) research has matured in some areas, and is developing rapidly in others. We summarize the state of the science circa 2010 as a starting point, and then present the advances during the last decade in three areas land use, sulfate deposition, and climate change. The advances are presented in the framework of three Hg "gateways" to the terrestrial environment inputs from the atmosphere, uptake in food, and runoff with surface water. Among the most notable advances These and other advances reported here are of value in evaluating the effectiveness of the Minamata Convention on reducing environmental Hg exposure to humans and wildlife. Swine wastewater (SW) represents an important source of antibiotic resistance genes (ARGs) in the environment. However, few studies have assessed the occurrence and removal of ARGs in the whole wastewater treatment process followed by its farmland application. This study investigated the ARGs profiles in an integrated SW treatment system and its receiving soil, as well as their relationships with SW parameters and bacterial communities. Results revealed that sulfonamide, tetracycline and aminoglycoside resistance genes were dominant in SW. link3 The relative abundance of total ARGs in SW was reduced by 84% after the treatments. Among the SW treatment units, anaerobic digestion, primary sedimentation and constructed wetland contributed to ARGs removal while secondary sedimentation increased the total ARGs abundance. Farmland irrigation of the treated SW resulted in enrichment of persistent ARGs in the receiving soil, which might be attributed to the propagation of potential bacterial hosts and high horizontal gene transferability. Redundancy analysis indicated that the relative abundance of total ARGs was significantly correlated with total nitrogen, total phosphorus, antibiotics and bacterial communities. The shift in bacterial community was the major driving factor for ARGs alteration during SW treatment process. Our results highlight the effect of treated SW irrigation on the antibiotic resistome in agricultural environment, and can contribute in improving SW treatment system for better antibiotic resistance control. Environmental risk assessment of contaminated soils should ideally be carried out with complementary approaches (chemical and biological) conducted in situ and ex situ. While biological methods based on the assessment of effect and bioaccumulation in bioindicators exist for soil fauna organisms, such as land snails, the methodology is currently limited in the field to 14 metallic elements (MEs). To provide new relevant tools to the stakeholders of polluted fields, the aim of this work is to determine ex situ threshold guide values (ex situ TGVs), for 15 MEs, 16 polycyclic aromatic hydrocarbons (PAHs) and 7 polychlorinated biphenyls (PCBs). These ex situ TGVs are the usual concentration of contaminants found in the viscera of the bioindicator Cantareus aspersus after 28 days of exposure to uncontaminated soils. The second objective was to assess and validate the relevance of these ex situ TGVs for the interpretation of contamination levels in various European contaminated soils based on global index calculations i) The sum of the excess of transfers (SETs) and ii) the weighted SETs based on the general toxicity points of each contaminant used to evaluate the risk of transferred MEs, PAHs and PCBs (ERITMEs, ERITPAHs and ERITPCBs, respectively). In addition, the influence of soil physico-chemical properties on accumulation was modelled to better understand their roles in bioavailability. The presented ex situ TGV and the associated indicators (the global sum of the excess of transfers and global ecotoxicological risk) provide a basis by which stakeholders can prioritize the management of polluted soils depending on the risk they may represent. The determination of ex situ TGVs for organic and inorganic compounds provides new tools to characterize excess contaminant transfers, and it will also allow the use of snails for ERAs, notably for common pollutants, such as PAHs and PCBs for which guide values are not available. Renewable energy plays a vital role in achieving environmental sustainability, however, the mitigating effect varies across countries depending on the share of renewables in the energy mix. Herein, we analyze the effect of renewable energy consumption, energy prices, and trade on emissions in G-7 countries. The results demonstrate that renewable energy and energy prices exert negative pressure on CO2 emissions while trade volume exerts a robust positive pressure on CO2 emissions. The country-specific estimation results provide evidence of a negative effect of energy prices on CO2 emissions. While the environmental Kuznets curve hypothesis is validated at the panel and country-specific levels, the effect of renewable energy consumption and trade, are disparate across countries. The panel Granger causality shows a mono-directional causality flowing from energy prices, GDP, the quadratic term of GDP and trade to CO2 emissions. Renewable energy consumption, however, has no causal relationship with CO2 emissions but indirectly affects CO2 emissions through its direct effect on energy prices. Joint action on trade, energy prices, and country-specific renewable energy policies have implications for environmental sustainability and the attainment of the Sustainable Development Goals (SDGs). Pollution of the marine environment by litter composed of plastics is a growing concern. Chemical additives such as organophosphate flame retardants (OPFRs), which are added to plastics to improve their qualities, are in focus because they allegedly cause adverse effects on marine fauna. Here we analyse OPFR levels in the muscle of fin whales because, as a mysticete, this cetacean obtains its food by filter-feeding and is thus highly vulnerable to marine litter. Moreover, the fin whale performs long-range migrations from low-latitude areas in winter to high-latitude areas in summer, a trait that makes it a potentially good large-scale biomonitor of pollution. We also analyse OPFR levels in its main prey, the krill Meganyctiphanes norvegica, to assess transfer through diet. The samples analysed consisted of muscle tissue from 20 fin whales and whole-body homogenates of 10 krill samples, all collected off West Iceland. From the 19 OPFRs analysed, we detected 7 in the fin whale and 5 in the krill samples. Tri-n-butyl phosphate (TNBP), Isopropylated triphenyl phosphate (IPPP) and Triphenylphosphine oxide (TPPO) were the most abundant compounds found in both species. Mean ∑OPFR concentration, expressed on a lipid weight basis, was 985 (SD = 2239) ng g-1 in fin whale muscle, and 949 (SD = 1090) ng g-1 in krill homogenates. These results constitute the first evidence of the presence of OPFRs in the tissues of fin whales. Furthermore, they seem to support the non-significance of bioaccumulation of OPFRs through lifespan and of biomagnification trough the food web. SO2 concentration decreased rapidly in recent years in China due to the implementation of strict control policies by the government. Particulate sulfate (pSO42-) and gaseous H2SO4 (SA) are two major products of SO2 and they play important roles in the haze formation and new particle formation (NPF), respectively. We examined the change in pSO42- and SA concentrations in response to reduced SO2 concentration using long-term measurement data in Beijing. Simulations from the Community Multiscale Air Quality model with a 2-D Volatility Basis Set (CMAQ/2D-VBS) were used for comparison. From 2013 to 2018, SO2 concentration in Beijing decreased by ~81% (from 9.1 ppb to 1.7 ppb). pSO42- concentration in submicrometer particles decreased by ~60% from 2012-2013 (monthly average of ~10 μg·m-3) to 2018-2019 (monthly average of ~4 μg·m-3). Accordingly, the fraction of pSO42- in these particles decreased from 20-30% to less then 10%. Increased sulfur oxidation ratio was observed both in the measurements and the CMAQ/2D-VBS simulations. Despite the reduction in SO2 concentration, there was no obvious decrease in SA concentration based on data from several measuring periods from 2008 to 2019. This was supported by the increased SASO2 ratio with reduced SO2 concentration and condensation sink. NPF frequency in Beijing between 2004 and 2019 remains relatively constant. This constant NPF frequency is consistent with the relatively stable SA concentration in Beijing, while different from some other cities where NPF frequency was reported to decrease with decreased SO2 concentrations.