Damriddle7716

LMB is a widely utilized material for the management of sediment-derived phosphorus (P) in eutrophic lakes. However, the properties of organic P at the sediment-water interface and the effect of LMB on organic P fractions in sediments are still unclear. The batch studies reported here indicate that LMB has good adsorption properties toward organic P (Glucose-6-phosphate), and the tentative adsorption mechanism relies on chemisorption. Laboratory microcosmic experiments were conducted to study the immobilization effect of LMB on the organic P in water and sediments. #link# The results indicated that the concentration of total P, labile P and organic P in overlying water and pore water could be effectively reduced by LMB capping of sediments. After treatment, the optimal immobilization effects appeared on the 7th day and until the 60th day. However, the fractions of organic P change during the capping time. Active organic P eluted with NaHCO3 transforms into moderately labile or non-labile P through the physical and chemical processes, as well as microbial action. Microbial community analysis showed that the addition of LMB had inhibitory effect on the phosphorus-solubilizing bacteria, which also affected the transformation between various forms of organic P. This study provided new insights of LMB in situ capping of organic P and the mechanisms of the migration and cycling of internal organic P, which is beneficial for the management of eutrophic lakes.The present study aimed to determine the spatial and temporal variations in trophic state and identify potential causes for these variations in 60 Korean reservoirs. Empirical models were developed using the relations of nutrients (total phosphorus, TP, and total nitrogen, TN) with chlorophyll-a (CHL-a) for efficient lake managements. link2 The empirical models indicated that TP was the key regulating factor for algal growth in agricultural (R2 = 0.69) and power generation (R2 = 0.50) reservoirs. The CHL-aTP and TNTP ratios, indicators of phosphorus limitation, were used to validate the phosphorus reduction approach. The mean CHL-aTP ratio of agricultural reservoirs was 0.60, indicating that algal chlorophyll is potentially limited by TP than any other factors. Agricultural, multipurpose, and power generation reservoirs, based on the NP ratios, were more P- limited systems than natural lakes and estuarine reservoirs. The trophic state index (TSI) of Korean reservoirs varied between mesotrophy to hypereutrophy based on values of TSI (TP), TSI (CHL-a), and TSI (SD). Agricultural reservoirs were hypereutrophic using the criteria of TSI (CHL-a) and blue-green algae dominated the algal community. Analysis of trophic state index deviation (TSID) indicated that agricultural reservoirs were primarily P limited and other factors had minor effect. In contrast, the trophic status of estuarine and power generation reservoirs and natural lakes was largely modified by non-algal turbidity. Our outcomes may be effectively used for Korean lakes and reservoirs management.The European Arctic is a region of high interest for climate change. Water vapor plays a fundamental role in global warming; therefore, high-quality water vapor monitoring is essential for assimilation in forecast simulations. link3 The seven analyzed instruments on-board satellite platforms are Atmospheric Infrared Sounder (AIRS), Global Ozone Monitoring Instrument 2 (GOME-2), Moderate-Resolution Imaging Spectroradiometer (MODIS), Ozone Monitoring Instrument (OMI), SCanning Imaging Absorption Spectrometer for Atmospheric Carthography (SCIAMACHY) and Polarization and Directionality of the Earth's Reflectances (POLDER). The GNSS data from Ny-Ålesund are matched to satellite observations of IWV in a 30-min temporal window, and 100-km radius. Then, statistics and the distribution of satellite-ground differences under different conditions are studied. The correlation coefficient (R2) with ground-based measurements is about 0.7 for all products except OMI (R2=0.5), and MODIS NIR and POLDER (R2=0.3). OMI shows high bias y.Nitrate (NO3-) is one of the most widespread contaminants in groundwater primarily due to agricultural activities utilizing N-containing fertilizers and the presence of animal wastes. Hydrochemical and nitrate isotope data (δ15N-NO3- and δ18O-NO3-) from the unconfined aquifer in the urban area of Del Campillo city and its surrounding rural area with different land-use types, i.e. individual sanitation systems, agricultural areas and livestock breeding facilities, were generated to investigate the impact of nitrogen pollution sources and to assess N-biogeochemical processes. The Principal Component Analysis of hydrochemical and isotopic data were used to compare the factors that control the groundwater quality and particularly the nitrate concentrations in the urban and the rural area. The results showed that nitrate pollution in the urban area of Del Campillo city originated mainly from the on-site sanitation systems and/or animal domestic wastes, whereas in the rural area nitrate pollution was mostly attributed to a combination of urea-based fertilizers and manure from livestock breeding activities. The aquifer is under oxic to suboxic conditions in the rural area and becomes suboxic in the urban area where the higher supply of organic matter consumes oxygen. As a result, denitrification was more significant in the urban area compared to the rural area, as evidenced by the higher N and O isotope enrichment factor (ε). AP20187 nmr will be used to benchmark the current nitrate contamination status in the region and evaluate effective planning of environmental measures and remediation strategies.The aim of this study was to quantify carbon stocks and the emission of the greenhouse gases (N2O and CH4) in mangrove forests with different vegetation assemblies in coastal lagoons of Veracruz Mexico. The vegetation included black mangrove BM, dominated by Avicennia germinans, white mangrove WM, dominated by Laguncularia. racemose, red mangrove RM, dominated by Rhizophora mangle and mixed mangrove MM, dominated by the three species. Soil C stocks ranged 187-671 Mg C ha 1 without significant (p = 0.149) differences among the mangroves with different vegetation. Significantly (p = 0.049) higher tree biomass C stock was observed in RM (127 Mg ha-1) than in MM (24.23 Mg ha-1). Methane emissions in RM (0.58-6.03 mg m-2 min-1) were significantly higher (p  less then  0.05) than in MM. (0.0035-0.07 mg m-2 min-1), in WM (-0.0026-0.029 mg m-2 min-1) and in BM (0.0054-0.0097 mg m-2 min-1),during rainy, windy and dry season.RM had the longest period of inundation, the highest soil carbon concentration, and the lowest salinity. CH4 emissions showed a significantly positive correlation with soils carbon concentration, water level and water pH and, negative correlation with water salinity and Cl-1 concentration in soil and water. Emissions of N2O (0.04-3.25 μg m-2 min-1) were not significantly different among the mangroves with different vegetation, but they showed seasonal variations, with higher emissions during windy and dry seasons. N2O emissions showed significantly positive correlations with soil nitrate concentration and soil temperature. Results of this research are useful for mangrove conservation and restoration strategies to maximize carbon storage and mitigate greenhouse gas emissions.The co-treatment of two synthetic faecal sludges (FS-1 and FS-2) with municipal synthetic wastewater (WW) was evaluated in an aerobic granular sludge (AGS) reactor. After characterisation, FS-1 showed the following concentrations, representative for medium-strength FS 12,180 mg TSS L-1, 24,300 mg total COD L-1, 93.8 mg PO3-P L-1, and 325 mg NH4-N L-1. The NO3-N concentration was relatively high (300 mg L-1). For FS-2, the main difference with FS-1 was a lower nitrate concentration (18 mg L-1). The recipes were added consecutively, together with the WW, to an AGS reactor. In the case of FS-1, the system was fed with 7.2 kg total COD m-3d-1 and 0.5 kg Nitrogen m-3d-1. Undesired denitrification occurred during feeding and settling resulting in floating sludge and wash-out. In the case of FS-2, the system was fed with 8.0 kg total COD m-3d-1 and 0.3 kg Nitrogen m-3d-1. The lower NO3-N concentration in FS-2 resulted in less floating sludge, a more stabilised granular bed and better effluent concentrations. To enhance the hydrolysis of the slowly biodegradable particulates from the synthetic FS, an anaerobic stand-by period was added and the aeration period was increased. Overall, when compared to a control AGS reactor, a lower COD consumption (from 87 to 35 mg g-1 VSS h-1), P-uptake rates (from 6.0 to 2.0 mg P g VSS-1 h-1) and NH4-N removal (from 2.5 to 1.4 mg NH4-N g VSS-1 h-1) were registered after introducing the synthetic FS. Approximately 40% of the granular bed became flocculent at the end of the study, and a reduction of the granular size accompanied by higher solids accumulation in the reactor was observed. A considerable protozoa Vorticella spp. bloom attached to the granules and the accumulated particles occurred; potentially contributing to the removal of the suspended solids which were part of the FS recipe.Childhood diarrhea has been one of the major public health concerns in countries that have limited resources like Ethiopia. Understanding the association between childhood diarrhea and meteorological factors would contribute to safeguard children from adverse health effects through early warning mechanisms. Thus, this study aimed at exploring the association between childhood diarrhea and meteorological factors to enable reducing health risks. A retrospective study design was used to explore the association between meteorological factors and childhood diarrhea in southwestern Ethiopia from 2010 to 2017. Mann Kendall trend test and Spearman's correlation were computed to test the association of childhood diarrhea and meteorological factors. The space-time permutation model was used to identify the risky periods, seasons with most likely clusters, and high childhood diarrhea. Similarly, a negative binomial regression model was fitted to determine the predictability of meteorological factors for childhood diarrhea. The highest childhood diarrhea morbidity was 92.60 per 1000 per under five children. The risk of childhood diarrhea increased by 16.66% (RR 1.1666; 95% CI 1.164-1.168) per increase in 1 °C temperature. Furthermore, rainfall was found to be a significant risk factor of childhood diarrhea, with 0.16% (RR 1.00167; 95% CI 1.001306-1.001928) per 1 mm increase in rainfall. The temperature was positively correlated with the occurrence of childhood diarrhea. But the association with rainfall showed spatial variability. The space-time permutation model revealed that dry season was found to be a high-risk period with excess childhood diarrhea. The results showed that the observed association between meteorological factors and childhood diarrhea could be used as evidence for early warning systems for the prevention of childhood diarrhea.Chemical compositions of non-refractory submicron aerosol (NR-PM1) were measured via an Aerodyne Aerosol Chemical Speciation Monitor at the coastal city Xiamen during the 2017 BRICS summit from August 10 to September 10. Mean hourly concentration of NR-PM1 was 13.55 ± 8.83 μg m-3 during the study period, decreasing from 18.83 μg m-3 before-BRICS to 13.02 μg m-3 in BRCIS I and 8.42 μg m-3 in BRICS II. Positive matrix factor analyses resolved four organic aerosols (OA) a hydrocarbon-like OA (HOA, 14.78%), a cooking-related OA (COA, 28.21%), a biomass burning OA (BBOA, 18.00%), and an oxygenated OA (OOA, 39.22%). The contributions of local pollutants like nitrate and HOA reduced, while the proportions of sulfate and OOA increased during the control episodes. The diurnal patterns of NR-PM1 species and OA components in each episode were characterized. The results showed that BC, nitrate, COA, and HOA had peaks in the morning and evening, which became less obvious under the emission control. Moreover, the diurnal variations of all species in Ep 3 with emission control were much flatter due to the effect of transport.