Dynamics of meteorological and hydrological drought: The impact of groundwater and El Niño events on forest fires in the Amazon.

Over recent decades, anthropogenic forest fires have significantly altered vegetation dynamics in the Amazon region. While human activities primarily initiate these fires, their escalation is intricately linked to climatic conditions, particularly droughts induced by the warm El Niño phase. This study investigates the impact of meteorological and hydrological drought on forest fires in the Amazon, focusing on the role of groundwater and El Niño events.

Characterization of groundwater storage changes in the Amazon River Basin based on downscaling of GRACE/GRACE-FO data with machine learning models.

Groundwater storage changes in the Amazon River Basin (ARB) play an important role in the hydrological behavior of the region, with significant influence on climate variability and rainforest ecosystems. The GRACE and GRACE-FO satellite missions provide gravity anomalies from which it is possible to monitor changes in terrestrial water storage, albeit at low spatial resolution. This study downscaled GRACE and GRACE-FO data from machine learning models from 1° (110 km approx) to 0.

Hydrogeochemical and isotopic evaluation of VOC commingled plumes in a weathered fractured bedrock aquifer treated with thermal and bioremediation.

Chlorinated ethanes and ethenes isotopic analyses in groundwater and hydrogeochemical results from a former industrial area in Sao Paulo (Brazil) were used to confirm the existence and allow further characterization of source areas and their commingled plumes, both before and after thermal and bioremediation treatments. Prior to full scale remediation, a recently identified off-site source area with unknown history and limited access for further intrusive works presented lower δC values (-6.5‰ to -1.

Physicochemical and isotopic properties of ambient aerosols and precipitation particles during winter in Seoul, South Korea.

The aim of this study was to characterize the physicochemical properties and microbial communities of particulate matter (PM) in Seoul, Korea. We collected long-term (2017-2019) precipitation samples and PM and PM monitoring data to determine the impact of soluble and insoluble chemical species on the soil surface. Ambient PM concentrations were higher than PM concentrations during the monitoring period, but both decreased during rainfall due to the washing effect of precipitation.

Characterizing land use effect on shallow groundwater contamination by using self-organizing map and buffer zone.

Nitrate-nitrogen (NO-N) contamination in groundwater is a major problem of drinking and domestic waters in rural areas. This study revealed the influence of land use type on shallow alluvial groundwaters in a typical rural area in South Korea by applying a self-organizing map (SOM), principal component analysis (PCA), and hierarchical cluster analysis (HCA). The uncertainty of spatial information on land use was improved by using a buffer zone of the average influence radius of 32.

Spatiotemporal change in coastal waters caused by land-based fish farm wastewater-borne nutrients: Results from Jeju Island, Korea.

We investigated spatiotemporal distributions of dissolved inorganic nutrients and organic carbon (DOC) and nitrogen (DON) in coastal waters and land-based fish farm wastewater to determine effects of wastewater on seawater of Jeju Island, Korea. The nutrient concentrations in seawater were lower than in wastewater with negative correlations against salinity, indicating a terrestrial source. Wastewater-derived DOC and DON were transported offshore while wastewater-derived inorganic nutrients were effectively removed, likely via biological production, and this was closely linked to decline in N:P ratios.

Contribution of nitrate-nitrogen concentration in groundwater to stream water in an agricultural head watershed.

This study characterized nitrate-nitrogen (NO-N) concentrations in groundwater and stream water in an agricultural head watershed in South Korea and identified the pollution load of NO-N as a result of the groundwater entering streams using field surveys, analyses of chemical constituents, and numerical modeling. The mean NO-N concentration in groundwater was 7.373 mg/L, which is approximately 1.

Effects of water level and vegetation on nitrate dynamics at varying sediment depths in laboratory-scale wetland mesocosms.

Recent increases in the frequency of extreme floods and droughts associated with climate change can affect fluctuating groundwater or wetland water levels and wetland plant growth, and consequently cause redox condition changes in nitrogen dynamics in wetland sediments. Here, we studied the fate of nitrate (NO), dissolved organic carbon (DOC), and the microbial characteristics at different sediment depths in response to water levels (i.e.

Oxidation and reduction of redox-sensitive elements in the presence of humic substances in subsurface environments: A review.

The oxidation and reduction (redox) processes of redox-sensitive elements (RSE) in the presence of humic substances (HS) have become a significantly important issue in the terms of biogeochemical cycles. Redox processes are crucial for determining the speciation, mobility, toxicity, and bioavailability of RSE in natural environments. It is known that HS act as an effective redox mediator for accepting and donating electrons, and thereby transfers them to RSE.

Transmissivity of Aquifer by Capture Zone Method: An Application in the Sete Lagoas Karst Aquifer, MG, Brazil.

Transmissivity is an important hydraulic parameter to determine the amount of water passed horizontally across a given saturated thickness of an aquifer. The techniques to quantify this parameter, such as grain size analyses or pumping tests, can have limitations of time/spatial scale, viability, or economically. One technique that can be used, but little adopted, is the capture zone analysis.

Process Recovery after CaO Addition Due to Granule Formation in a CSTR Co-Digester-A Tool to Influence the Composition of the Microbial Community and Stabilize the Process?

The composition, structure and function of granules formed during process recovery with calcium oxide in a laboratory-scale fermenter fed with sewage sludge and rapeseed oil were studied. In the course of over-acidification and successful process recovery, only minor changes were observed in the bacterial community of the digestate, while granules appeared during recovery. Fluorescence microscopic analysis of the granules showed a close spatial relationship between calcium and oil and/or long chain fatty acids.

Glacial recharge, salinisation and anthropogenic contamination in the coastal aquifers of Recife (Brazil).

Implying large residence times and complex water origins deep coastal aquifers are of particular interest as they are remarkable markers of climate, water use and land use changes. Over the last decades, the Metropolitan Region of Recife (Brazil) went through extensive environmental changes increasing the pressure on water resources and giving rise to numerous environmental consequences on the coastal groundwater systems. We analysed the groundwater of the deep aquifers Cabo and Beberibe that are increasingly exploited.

Trace element concentrations in leachates and mustard plant tissue (Sinapis alba L.) after biochar application to temperate soils.

Biochar application to agricultural soils has been increasingly promoted worldwide. However, this may be accompanied by unexpected side effects in terms of trace element (TE) behavior. We used a greenhouse pot experiment to study the influence of woodchip-derived biochar (wcBC) on leaching and plant concentration of various TEs (Al, Cd, Cu, Pb, Mn, As, B, Mo, Se).

Groundwater resources in Brazil: a review of possible impacts caused by climate change.

Groundwater has a strategic role in times of climate change mainly because aquifers can provide water for long periods, even during very long and severe drought. The reduction and/or changes on the precipitation pattern can diminish the recharge mainly in unconfined aquifer, causing available groundwater restriction. The expected impact of long-term climate changes on the Brazilian aquifers for 2050 will lead to a severe reduction in 70% of recharge in the Northeast region aquifers (comparing to 2010 values), varying from 30% to 70% in the North region.

Bioattenuation in groundwater impacted by landfill leachate traced with δ13C.

The impact on groundwater imparted by the infiltration of high dissolved organic carbon (DOC) leachate from capped, unlined landfills can be attenuated by biogeochemical reactions beyond the waste source, although such reactive loss in the aquifer is difficult to distinguish from conservative advective dispersion. Compound-specific measurement of δ(13)C in carbon species, including CH(4), dissolved inorganic carbon (DIC), and the major DOC compounds (acetate, humic acid, and fulvic acid) provides a constraint in this assessment that can assist in exercises of modeling and prediction of leachate transport. The Trail Road municipal landfill near Ottawa, Ontario, Canada, hosts an unlined sector which produces a highly enriched leachate (DOC >4500 mg/L) that provides a good site to examine reactive attenuation within the receptor aquifer.

Role of organic matter and clay fraction on migration of Escherichia coli cells through pyroclastic soils, southern Italy.

A comparative study on the adsorption of Escherichia coli cells to two different pyroclastic soils collected in southern Italy (carbonate Apennines) was performed in laboratory using surfactant-free solutions and solutions with the surfactants sodium dodecyl sulphate (SDS, anionic) and octylphenoxypolyethoxyethanol (Triton X-100, non-ionic). Both soils are rich in organic matter (up to 35%), but only one contains a clay fraction (2-5%). The experiments demonstrated that E.

Filtration of Bacillus subtilis and Bacillus cereus spores in a pyroclastic topsoil, carbonate Apennines, southern Italy.

A comparative study on the filtration of Bacillus subtilis and Bacillus cereus spores in a pyroclastic topsoil was performed in laboratory using surfactant-free solutions and solutions with the surfactant sodium dodecyl sulphate (SDS) (anionic). The results of the column experiments demonstrate that the SDS does not significantly influence the retention of both B. subtilis and B.

Fate of the herbicides 2,4,5-T, atrazine, and DNOC in a shallow, anaerobic aquifer investigated by in situ passive diffusive emitters and laboratory batch experiments.

The fate of the three herbicides 2,4,5-T (2,4,5-trichlorophenoxyacetic acid), atrazine (6-chloro-N-ethyl-N'-[1-methyl-ethyl]-1,3,5-triazine-2,4-diamine), and DNOC (4,6-dinitro-2-methylphenol) in an anaerobic sandy aquifer was investigated. In the field, each of the herbicides was released simultaneously with tritiated water (HTO) as tracer in the depth interval 3 to 4 mbs (meters below surface) by use of passive diffusive emitters. Atrazine and 2,4,5-T were persistent during the approximately 18 days residence time in the aquifer.