While numerous studies have examined pollution sources and seasonal effects on surface water quality independently, the complex interactions between these factors remain understudied. This research aimed to fractionate and quantify pollution sources and examine their interactive effects with seasonal variations on surface water quality in Khanh Hoa, Vietnam. The current study was based on 1080 surface water samples taken from three common water bodies - lakes, rivers, and canals across dry and rainy seasons and analyzed for 13 physiochemical properties. Findings revealed that surface water quality was influenced by four primary pollution sources: agricultural activities, residential areas, onsite erosion, and climatic factors. Agricultural sources dominated canal water quality (93.0-94.7%) but had less impact on lakes and rivers (12.8-23.8%). Residential sources significantly affected lakes and rivers (30.23-32.66%) but minimally influenced canals (2.6-5.6%). Onsite erosion sources had greater impacts on lakes and rivers typically during the rainy season and exhibited minimal impacts on canals. Lakes and rivers maintained consistent and higher water quality across seasons (water quality index (WQI) 9.1 to 9.3 out of 1.0 - excellent), while canals exhibited substantially lower quality in the dry season (WQI 0.75) compared to the rainy season (WQI 0.78). These interactive impacts were mitigated by self-purification, water residence time in lakes and rivers, dilution effects, and fast pollutant transport in canals. Our findings highlight the importance of effective management of these key pollution sources in interaction with seasonal variation for maintaining water quality and ensuring environmental sustainability.
The impact of four distinct calcium sources on the microbial solidification of sand in the Kashi Desert, Xinjiang, was investigated. A wind tunnel test over a 60-day period revealed the cracking behavior of four different complex calcium nutrient solutions. By comparing the bearing capacity and the results from dry-wet cycling and freeze-thaw cycle tests, it was concluded that the sample treated with calcium gluconate exhibited superior sand fixation performance, whereas the sample treated with calcium acetate showed weaker sand fixation effects. The microstructure of the treated sand samples was analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Elemental analysis was conducted via energy dispersive spectroscopy (EDS), and functional groups were identified through Fourier transform infrared spectroscopy (FTIR). These experimental findings hold significant implications for soil remediation, pollutant removal in soil, enhancement of soil fertility, and desert soil stabilization.
In the mountainous headwaters of the Colorado River episodic dust deposition from adjacent arid and disturbed landscapes darkens snow and accelerates snowmelt, impacting basin hydrology. Patterns and impacts across the heterogenous landscape cannot be inferred from current in situ observations. To fill this gap daily remotely sensed retrievals of radiative forcing and contribution to melt were analyzed over the MODIS period of record (2001-2023) to quantify spatiotemporal impacts of snow darkening. Each season radiative forcing magnitudes were lowest in early spring and intensified as snowmelt progressed, with interannual variability in timing and magnitude of peak impact. Over the full record, radiative forcing was elevated in the first decade relative to the last decade. Snowmelt was accelerated in all years and impacts were most intense in the central to southern headwaters. The spatiotemporal patterns motivate further study to understand controls on variability and related perturbations to snow water resources.
Targets for ecosystem restoration have been made at global, regional, and national scales, but monitoring of progress remains challenging. Differences in definitions, goals, and practices among restoration initiatives, linked to policy drivers and funding sources, add complexity. We evaluate the current state of ecological restoration activity in Colombia, where, since 2012, legal requirements to compensate for environmental damage may be driving widespread restoration efforts, alongside a long history of government and private restoration initiatives. We systematically searched several public databases, and circulated an online survey, to collect records of 675 terrestrial and coastal restoration projects initiated between 1963 and 2021, capturing data on: location, funding, monitoring, ecosystem type and actors. Location was reported for 613 projects at municipality level, and 261 projects at point level. Restoration aims included recovery of ecological processes, hydrological processes, soil erosion, and natural resources. Only 24 % reported any monitoring, with just 2 % monitoring effectiveness. Forty-one percent of projects were enacted under environmental compensation laws. Funding was mostly from within Colombia, with minimal international funding. This work highlights major gaps in the monitoring needed to achieve effective implementation of restoration targets. Enhancing coordination among institutions, and enhancing monitoring, will now be crucial to achieving restoration goals.
Rationale. Glaciers in the Tibetan Plateau (TP), especially in the Himalayas, are retreating rapidly due to rising air temperature and increasing anthropogenic emissions from nearby regions. Traditionally, pollutants deposited on the glaciers have been assumed to originate from long-range transport from its outside. Methodology. This study investigated the concentrations of black carbon (BC) and major ions in snowpit samples collected from two glaciers in the south-eastern TP (Demula and Palongzangbu) and one glacier in the west Himalayas (Jiemayangzong). The radiative forcing of BC was calculated based on BC concentration and glacier characteristics. Results. The results revealed that the BC/Ca2+ concentration ratio in snowpit samples from Palongzangbu, located near residential villages, is similar to 2.05 times higher than that of Demula, which is mainly influenced by long-range transported pollutants. Furthermore, on Jiemayangzong glacier, snowpit samples collected with 100-m vertical resolution exhibited that BC-induced radiative forcings at low altitude are similar to 2.37 +/- 0.16 times greater than those at high altitude. Discussion. These findings demonstrated that in addition to long-range transport, emissions from local residents also make substantial contributions to BC and certain major ions (e.g. SO42-). To accurately assess the sources and radiative forcing of BC and other light-absorbing impurities on glaciers of the TP, it is necessary to consider the impact of local populations and altitude-dependent variations.
Colonizing other planets, like Mars, marks a significant milestone in the pursuit of a multi-planetary existence. Millions of people would settle on Mars in self-sufficient bases. Colonizing Mars is a long-term mission that demands self-sufficient, secure habitats and comprehensive planning. Importing structures, such as inflatable structures, from Earth is cost-prohibitive, making the utilization of in-situ resources and onsite construction the most viable approach for preparing the required buildings. Studies have shown that it is possible to produce and craft several kinds of binders and concretes with appropriate mechanical behavior using Martian soil composition; however, determining the optimal option for onsite construction remains a challenge. This study investigates available cement/concrete options for onsite construction on Mars from a structural engineering perspective, taking into account the available resources and technologies. In this regard, the observations and data provided by Martian landers, rovers, orbiters and methods such as Viking-1 & 2, Pathfinder, Spirit, Opportunity, Curiosity, Mars Express, Ultraviolet-visible/Near-infrared reflectivity spectra and Alpha particle X-ray spectrometer were used to obtain a comprehensive and detailed investigation. Eleven types of Martian cement/ concrete based on the in-situ resources, soil composition, and available technologies were compared based on the criteria and indices defined in accordance with the structural engineering point of view to select the best practical option for onsite construction. These criteria encompass factors such as mechanical behavior, Martian structural loads, raw material accessibility, available sources, energy required for production, water requirement, curing and hardening time, possibility of using 3D printers, byproduct usefulness, conditions required for hardening and curing, importation requirements from Earth, production complexity, long-term durability and behavior under galactic cosmic rays (GCRs) and solar energetic particles (SEPs). The pros and cons of each cement/concrete option are thoroughly assessed, considering the harsh conditions on Mars. Additionally, the study highlights extra considerations that are crucial for onsite construction on Mars. To determine the best practical option for onsite construction and sustainable colonization, the proposed cements/concretes were compared using multi-scale spider/radar diagrams and a quantitative point of view. This perspective was enabled by assigning weights to each criterion through expert consultation, experimental data, and literature review, ensuring that the diagrams accurately reflect the features of each concrete mix. This comprehensive investigation aims to provide valuable insights into selecting the most suitable cement/concrete for onsite construction on Mars, considering the structural engineering perspective and the long-term goal of sustainable colonization.
Heavy metal contamination in water and soil presents a growing global issue that poses significant risks to environmental integrity and human well-being. Various heavy metals, including arsenic (As), lead (Pb), mercury (Hg), cadmium (Cd), and chromium (Cr), contaminate ecosystems. These metals enter the environment through both natural processes and human activities such as coal mining, leather production, metal processing, agriculture, and industrial waste disposal. With their high toxicity and tendency to accumulate in organisms, heavy metals induce oxidative stress in cells, resulting in organelle damage. This toxicity can lead to genetic mutations and histone alterations. Given the severe effects of heavy metals, urgent actions are required to eliminate them from polluted soil and water. While physicochemical techniques like membrane filtration, precipitation, oxidation, and reduction exist, they have limitations. Hence, there is a pressing need to devise environmentally friendly and cost-efficient approaches for heavy metal removal. This article examines heavy metal contamination in water and soil, its adverse impacts, and the cleanup of heavy metals using eco-friendly methods. [GRAPHICAL ABSTRACT]
Heavy metal compounds are used in a variety of industrial processes, including tanning, chrome plating, anti-corrosion treatments, and wood preservation. Heavy metal ion pollution in water and wastewater is often caused by industrial effluent discharge into open water sources. Toxic heavy metal ions such as As (III), Cr (VI), Cd (II), and Pb (II) are well-known and enter the body through a variety of pathways, including the food chain, respiration, skin absorption, and drinking water. These heavy metal ions produce oxidative stress in cells, resulting in cell organelle destruction. Heavy metals produce toxicity and may cause genetic material mutation or change, histone modification, and epigenetic alteration at various stages. Furthermore, heavy metals are linked to heart failure, renal damage, liver failure, and a variety of skin problems. For heavy metals cleanup, several standard approaches are utilized. Nonetheless, these technologies are costly and result in toxic sludge after treatment. As a result, there is an urgent need for an appropriate, environmentally safe, and efficient heavy metal removal technology. For heavy metal removal, microbial-based approaches are regarded as both environmentally benign and cost-effective. This review focuses on heavy metal pollution in water, its harmful consequences, and heavy metal cleanup by microbiological means.
Mining can greatly affect water quality in nearby areas, especially when mines are abandoned and lead to contamination from tailings and drainage. This study examines the impact of the abandoned Ze & iuml;da lead mine on water sources in the Upper Moulouya region of northwestern Morocco. We aimed to evaluate water quality, understand geochemical processes, and determine the suitability of water for drinking and irrigation. In summer 2021, 21 water samples were collected from rivers, dams, groundwater, and quarry lakes. We analyzed 18 physicochemical and metallic parameters, finding significant variations in ion concentrations. The main ions were ranked as Na+ > Mg2+ > Ca2+ > K+ and HCO3- > Cl- > SO42- > NO3-. Metal concentrations followed the order Zn > Cu > Pb > As > Cd. The Drinking Water Quality Index (DWQI) showed that 95% of the samples were not suitable for drinking. Similarly, the Irrigation Water Quality Indexes (IWQIs) indicated that quarry lakes were unsuitable for irrigation, while groundwater met acceptable criteria. Over 70% of the samples showed no significant metal contamination based on the Heavy Metal Evaluation Index (HEI) and Heavy Metal Pollution Index (HPI). The data suggest that water-rock interactions are the main drivers of hydrochemical changes, with processes like calcite, dolomite, otavite, and cerussite precipitation, as well as the weathering of minerals like halite, starkeyite, and sylvite. To protect water quality and prevent environmental damage, ongoing monitoring and appropriate measures are recommended for the Ze & iuml;da mining area.
Hydraulic conductivity (K) is a crucial parameter in hydrogeology but is highly heterogeneous and anisotropic due to variations in sediment texture, making its large-scale estimation challenging. Traditional laboratory and empirical methods based on grain-size distribution (GSD) analysis from limited data provide local K measurements, resulting in a poor representation of aquifer heterogeneity. In contrast, pumping tests estimate an integrated K value over a of the aquifer within the cone of depression but still lack the spatial resolution needed to reveal detailed variations in K across larger aquifer extents. In this study, the Di models method was used to simulate local GSD in three-dimensional (3-D) detrital systems. The focus was to explore the potential to estimate K through simulated particle-size fractions derived from a 3-D geological model of the City of Munich. By employing log-cubic interpolation, a complete and accurate representation of the fictive GSD enabled the application of multiple empirical relationships for K estimation. The resulting 3-D K fields preserved the variability in K within each aquifer system. When averaged for each separate aquifer system across different lateral extents, i.e., 50-150 and 550 m, the predicted K values showed success rates of 44-47% with deviations of at least one order of magnitude in 15-19% of cases when compared to 364 K values derived from pumping-test data. The results highlight the ability of the approach to successfully estimate K while accounting for spatial heterogeneity, suggesting its potential for groundwater modeling, aquifer yield assessments and groundwater heat pump system design.