3% after the 3-day incubation as a result of high soil pH. The available phosphorus in soil improved significantly (p ≤ 0.01) with adding unpyrolyzed calotropis residues and its biochar produced at different pyrolysis temperatures compared to the unamended soil. The values of available phosphorus in the soil under study influenced significantly by pyrolysis temperatures of produced biochar; this is due to the pyrolysis of feedstocks increases labile phosphorus. Thenceforth, using biochar is an important strategy for enhancing carbon sequestration, decreasing ammonia volatilization and improving soil quality parameters in arid regions. This study investigated whether low-level blood and urinary lead, cadmium and mercury exposures were associated with blood pressure (BP) in children and adolescents. Data from National Health and Nutrition Examination Survey (NHANES) between 2007 and 2016 for children and adolescents aged 8-17 years (n = 7076) were analyzed. Outcome variables were systolic BP, diastolic BP and high BP status. High BP was defined as self-reported antihypertensive medication usage or a diagnosis of hypertension; classified as having elevated BP/hypertension according to 2017 AAP guidelines. Multivariable linear and logistic regressions models were performed and stratified by race/ethnicity and gender. Blood lead was negatively associated with diastolic BP among blacks, and positively associated with diastolic BP among whites. For a two-fold increase of blood lead concentration, the change in diastolic BP was -1.59 mm Hg (95% CI -3.04 to -0.16 mm Hg) among blacks and 1.38 mm Hg (95% CI 0.40 to 2.36 mm Hg) among whites. No significant associations between either systolic BP or diastolic BP with urinary lead were observed. The inverse associations between blood lead and high BP were found in females, Mexican Americans and other Hispanics. No associations between blood cadmium and BP were observed, except in other Hispanics. Urinary cadmium levels were inversely correlated with systolic BP, diastolic BP and high BP in all participants and in men. When compared to the lowest quartile of urinary cadmium levels, participants with a urinary cadmium level ≥ 0.12 μg/L had 0.48 (95% CI 0.29-0.78) times and 0.53 (95% CI 0.30-0.94) times reduced odds of having high BP in all participants and in men, respectively. LDK378 No associations between either blood mercury or urinary mercury with systolic BP were observed. Significant inverse associations were found between blood total mercury and methyl mercury with diastolic BP in all participants and in men. Future prospective studies are warranted to confirm these findings. A detailed study of groundwater and surface water nitrate over four seasons across an area of varied landuse provided insights into the mechanisms that underlie accumulation and transport of nitrate. High nitrate concentrations found in a significant percentage of surface water and shallow groundwater samples are due to anthropogenic contamination. Statistics (PCA, ANOVA, parsimonious model and general linear regression) were used to explore the relationship between NO3- and land use, and confirmed that areas of high NO3- concentration are associated with dairy pasture and horticulture. Seasonally, NO3- levels are greater during winter, the wettest part of the year. Values of δ15N showed that most nitrate is sourced from livestock waste, with a smaller contribution from synthetic fertilizer. Direct wash-off of animal waste from dairy farms results in higher NO3- concentrations in surface water than in groundwater. Denitrification is an important NO3- attenuation mechanism which reduces NO3- to NH4, as demonstynthetic fertilizer. Crown V. All rights reserved.Vegetation cover has implications for seasonally frozen soil dynamics and greenhouse gas emissions. We examined the frozen soil dynamics and N2O and CO2 efflux in a forest plantation (Populus ssp.) and farmland. The experiments were carried out at a forest reclamation site in Zhangbei county, Hebei province, China, from November 2017 to May 2018. Compared to the farmland, the forest plantation prolonged the retention of frozen soil because the shallower snow and the longer duration of snow cover in the forest contributed to a deeper frost depth and delayed soil thawing. The canopy also sheltered the frozen soil from the extreme fluctuations in freeze-thaw cycles (FTCs) during the snow-free period. Contrasting snow regimes and FTC dynamics contributed to variations in CO2 and N2O between the forest plantation and the farmland. Path analysis showed that the soil water content and soil temperature were the main regulators of N2O and CO2 emissions, respectively, in both land-use types. By contrast, soil substrate and microorganism biomass minimally influenced N2O and CO2 efflux. In conclusion, forest cover influences frozen soil dynamics and greenhouse gas emissions by buffering temperature fluctuations in both snow-covered and snow-free periods. This study further highlights the potential importance of anthropogenic land-use changes in influencing the cold season energy balance and gas efflux in future milder winter climates. 13C CP-MAS nuclear magnetic resonance (NMR) and diffuse reflectance infrared Fourier transform (DRIFT) spectroscopies were compared for evaluating their potential to characterise the influence of land use change on organic carbon (OC) chemistry of particulate organic matter (POM) and mineral associated OM (MOM) fractions of different soil types. link2 Surface soil samples of Ferralsol, Luvisol, Vertisol and Solonetz were collected from native and crop lands and isolated into different density fractions. NMR and DRIFT showed distinct OC composition for all the soil fractions of two land uses. In NMR spectra, greater proportion of carbohydrate and aromatic C was observed in POM, while MOM fractions were rich in carbohydrate, amino groups and aliphatic C. DRIFT spectra showed greater carboxylic, aromatic C and amide N in MOM than corresponding POM. NMR spectroscopy detected charred aromatic C in both fractions, which was not feasible with DRIFT. The overall effect of land use in both techniques appeared similar on the composition of POM- OC, i.e., increased aromaticity and decreased alkyl CO-alkyl C ratio. However, differences of land use impact were observed in MOM-OC, e.g., overall decreased aromaticity and increased alkyl CO-alkyl C for all soils in NMR, and in DRIFT, it varied with soil type (aromaticity Ferralsol, Vertisol > Luvisol, Solonetz). However, these trends were inconsistent and indistinct among fractions of four soils. Discrepancy in NMR and DRIFT results was ascribed to the sensitivity limitations of the two techniques in characterising soil OM in mineral rich fractions, and sample pre-treatment effect in NMR. We conclude that combination of NMR and DRIFT spectroscopy, preferably supplemented by other techniques e.g., mass spectroscopy and XPS, would improve the proficiency in elucidating small changes in soil OM composition with land use conversion. The spatial distribution of isotopic signatures in the form of isoscape is a valuable tool to map their spatial heterogeneity in various environmental settings. However, only limited information about δ18O and δ2H in water across South Korea is available and to our knowledge no study so far has tried to examine the isotopic heterogeneity of tap water and human scalp hair in South Korea. Here, we present the first national scale analyses of stream water, groundwater, tap water, and human scalp hair isoscapes for South Korea. link3 Stream water, groundwater, tap water, and human scalp hair samples were collected from across South Korea. These samples were analyzed for δ18O and δ2H, and the isotopic data were then used to generate interpolated δ18O and δ2H isoscapes for South Korea. The results of linear regression analyses showed strong and significant relationships between δ18Ohair and δ18Owater (R2 = 0.83, P  less then  0.002) and between δ2Hhair and δ2Hwater (R2 = 0.74, P  less then  0.006), primarily reflecting a close co-relationship between water and hair. The slopes of linear regressions for δ18O (Δδ18Ohair/Δδ18Owater) and δ2H (Δδ2Hhair/Δδ2Hwater) suggested that approximately 27% of hydrogen and 36% of oxygen in hair keratin were derived from the local drinking water. Interpolated δ18O and δ2H isotope maps of stream water, groundwater, and tap water samples collected from across South Korea showed similar spatial patterns of isotope variability. These samples showed a clear latitudinal gradient with high isotopic values in the south which progressively decrease toward the north. The same trends were observed in hair isoscapes as well, and had gradients matching the isotopic pattern of water samples. The strong relationship between water and human hair, and the consistent spatial pattern between them suggest that hair isotope signatures in South Korea can be used in provenance- and forensic-related activities. Struvite precipitation may become ineffective in removing phosphorus due to the low concentration of phosphate in the liquid. In this study, electrolysis with a magnesium anode was applied to recovering phosphorus and ammonia as struvite from wastewater. A novel electrodialysis process (ED) with a magnesium anode was developed, and its feasibility to treat synthetic wastewater with low phosphate concentration was demonstrated in a pilot-scale experimental system. To achieve high phosphate removal efficiency in the product stream, the optimal initial pH and flow rate were found to be 8.8 and 200 L h-1, respectively, for the ED system at a constant current of 0.1 A. The pilot-scale ED system under the consecutive batch mode removed 65% phosphate from the synthetic wastewater containning 10 mg L-1P, and the phosphate concentration in the product stream was kept at 30 mg L-1 after 280 min. The running cost of the ED system was estimated to be $31.27 kg-1 P for synthetic wastewater with 10 mg L-1 P, mainly resulting from the cost of the loss of the magnesium anode. The precipitates generated from the product stream were confirmed as struvite by XRD analysis. Understanding soil moisture spatiotemporal variability at regional scales is of great importance for studying various ecohydrological and land surface processes. In this study, long-term soil moisture data (5 years) were obtained from three regional monitoring networks across the continental United States with contrasting climatic conditions, including the Enviro-weather Automated Weather Station Network in Michigan, the Nebraska Mesonet, and the Soil Climate Analysis Network in Utah. Both soil moisture spatial variance and temporal variance were decomposed into time-invariant and time-variant components. To evaluate the impacts of different environmental factors on soil moisture spatiotemporal variability and its contribution components, static (e.g., soil properties) and non-static (e.g., climatic variables) environmental factors were also compiled for the stations of each network. The results showed that the time-invariant component was the leading factor for controlling the soil moisture spatial variance in all study regions with marked seasonal variations due to changes in soil moisture wetness conditions.