Water Sources Research Articles

Natural History of the Genus Elasmoderus Saussure, 1888 (Orthoptera: Tristiridae), an Endemic and Eremic Element of the Transitional Coastal Desert of Chile.

The genus Elasmoderus belongs to the family Tristiridae, an orthopteran group that is distributed across the transitional region of South America and represented in the Andean areas of Peru, Argentina, and Chile. The species of Elasmoderus have morphological adaptations that make them especially suited for surviving in extreme arid environments and are an endemic and eremic group of the north-central region of Chile. On the basis of field samplings, direct observations, and a comprehensive literature review, we collected information about the genus Elasmoderus. The objectives of this research were: (i) to provide updated information on the geographical distribution range of the species of the genus Elasmoderus, and (ii) to collect and synthesize the most relevant information on the natural history and ecology of this orthopteran group as a basis for future long-term studies of its populations. Although this genus is underrepresented compared to other orthopteran families, it has developed interesting adaptations to extreme arid environments that remain unstudied to this date. E. lutescens is known to be one of the species with a wider latitudinal distribution, mostly on the coast and longitudinal valley of Atacama. E. minutus has a more restricted distribution, whereas E. wagenknechti is concentrated in coastal and interior environments of the Coquimbo region, an area where it reaches high population densities, thus affecting crops and natural vegetation and polluting water sources. Our findings underscore the importance of conducting comprehensive research on native insect groups that are poorly known but crucial for arid and semiarid ecosystems. These data will serve as a starting point for conducting long-term studies on this orthopteran group to gain a better understanding of the importance and role of these species in the semiarid ecosystems of northern Chile.

Organic petrography, biomarkers, and stable isotope (δ13C, δD, δ15N, δ18O) compositions of liptinite-rich coals

Liptinite-rich coals were evaluated using organic petrography, biomarkers, and stable isotopes to investigate their origin and paleoenvironmental significance, particularly, to explore fractionation characteristics of stable isotopes (δ13C, δD, δ15N, and δ18O) between bulk coal, extractable organic matter (EOM), and extracted coal residue (ER). The samples were collected from Cenozoic coal seams from the Yunnan and Liaoning Provinces in China. The samples are characterized by the enrichment of different types of liptinite. The late Pliocene sample YNP (liptinite = 73.5%) is dominated by sporinite and bituminite, whereas the late Pliocene sample YND (liptinite = 65.5%) is characterized by isolated resinite particles and amorphous resinite. The liptinite in the Eocene sample SB (46.0%) is represented by blocky resinite with homogeneous morphology. The differences in distribution and morphology of liptinite are due to the different coal-forming plants and depositional environments, as indicated by the biomarker compositions. Biomarker results indicated that the sample YNP was formed mainly by Pinaceae and angiosperms under oxidizing conditions with bacterial/fungal degradation, whereas the sample YND was derived from the woody parts of gymnosperms with lower contributions of angiosperms under reducing conditions with low microbial activity. The sample SB predominantly originated from Cupressaceae/Pinaceae under reducing conditions with a lack of bacterial/fungal degradation.The fractionations of δ13C, δD, δ15N, and δ18O between bulk coal, EOM, and ER in the liptinite-rich coals are different. The δ13C values of bulk coal, EOM, and ER are mostly controlled by precursor paleovegetation and isotopic composition of CO2. The lower δ13C values of samples YNP and YND from the late Pliocene compared to that of the Eocene sample SB resulted from the change of palaeoconditions (e.g., δ13C of atmospheric CO2, cooling, and decrease of CO2 concentration). The δ13C values of EOM in the samples YNP and YND are about 3‰ lower than δ13C values of bulk coal/ER, whereas δ13C fractionation between EOM and bulk coal/ER is small (< 0.8‰) in the sample SB, probably due to the very limited microbial/fungal degradation. The δD values of EOM are 50 to 90‰ lower than that of bulk coal/ER within the same sample, reflecting different isotopic compositions of monomeric compounds compared to the macromolecular matrix of kerogen most probably due to differences in H-isotope fractionation during biosynthesis. The δ15N of bulk coal and ER show limited fractionation (< 0.5‰) and are mainly controlled by precursor paleovegetation and microbial induced degradation processes. The studied liptinite-rich coals yield higher δ18O values than those detected in humic coals. The differences of δ18O values (bulk coal, EOM, ER) between the samples YNP/YND and the corresponding δ18O values of the sample SB indicate that this isotope parameter is mostly controlled by the δ18O value of source water. The weaker fractionation of oxygen isotope between EOM and bulk coal/ER compared to δ13C and δD may be attributed to the fact that oxygen-containing compounds within EOM did not experience a cleavage or any change of the O-containing bonds. The calculated δ18O and δD values of source rain waters fall in the range of modern rain waters at different sites.

Atmospheric water generator: design for rural zones with low and medium humidity level

Water shortage is one of the major issues in the world. The consequences can impact negatively on the develop of a location. Puno is an arid region located in Peru. There have been different problems related to water shortage in recent years. Some communities use a waterhole filled by precipitation as a source of water. This is usually far from their communities, then they have to transport manually buckets of water by waking. In this paper, we establish a design procedure of an atmospheric water generator (AWG) located at Puno with a capacity of 40L per day in order to deal with the water shortage. Current AWGs are designed for locations with favorable climatic conditions as high relative humidity (RH). However, they wouldn't be able to operate in dried seasons as at Puno with RH under 25%. An adsorption process is implemented as an additional module in order to compensate the low ambient temperature and RH during the worst climatic conditions from June to August. An analytic model of dehumidification by a heat exchanger was developed in order to quantify influence of parameters as climatic conditions and mass fluxes. Results showed that the design is capable to produce water during all the variable climactic conditions over the year. Numerical simulations of the analytic model indicated that the system can produce water by direct cooling in most months without the support of adsorption process.

A Fuzzy-Based Approach for Flexible Modeling and Management of Freshwater Fish Farming

Most populated developing countries having water resources, like Egypt, are interested in aquaculture since it supplies around 30% of the cheap protein consumed by customers. Increasing the production of aquaculture, specifically fish farming, in such countries represents an essential need. One candidate water resource for freshwater fish farming in Egypt is the Nile River (1530 km long). Yet, this represents a challenging task due to the existing variations in its water quality (WQ) parameters, such as dissolved oxygen, acidity, and temperature, at different sites. Climate change and pollution negatively affect many water quality parameters. This work provides a fuzzy-based approach for modeling WQ requirements for a set of fish types and evaluates the suitability of a water site for farming them. Thus, it greatly helps managing and planning fish farming in a set of water sites. It benefits from the flexibility of fuzzy logic to model the farming requirements of each fish type. Consequently, it evaluates and clusters the water sites with respect to their degrees of suitability for farming various fish types. The illustrative case study considers 27 freshwater sites spread along the Nile River and 17 freshwater fish types. The result incorporates a set of suitable clusters and a set of unsuitable ones for farming each fish type. It greatly helps managing and planning fish farming, to maximize the overall productivity and prevent probable catastrophic damage. In addition, it shows how to enhance each unsuitable site. We believe that eliminating the causes of pollution in the polluted freshwater sites along a water source could cause a significant boom in the cultivation of multiple freshwater fish types.

Composite coatings of poly(methyl methacrylate) with silicon dioxide nanoparticles for capacitive sensors of nickel content control in water

Pollution of the environment, in particular water sources, with heavy metals is a serious environmental problem. In this regard, it is relevant to develop new sensor systems that allow rapid tests and are not inferior in analytical parameters to classical methods for detecting heavy metals. Promising materials for creating such sensor systems are composite coatings based on polymer compounds with inorganic nanoparticles. The article presents the results of using poly(methyl methacrylate) (PMMA) coatings and PMMA nanocomposites with silicon dioxide nanoparticles (SiO2 NPs) to develop capacitive sensors for analyzing the content of Ni2+ ions in water. The structural and morphological characteristics of a conductive nickel layer and nanostructured films based on poly(methyl methacrylate) were studied using atomic force microscopy. Based on the experimental data on the dependence of the capacitance characteristics of sensors on the concentration of Ni2+ in solutions, the operating characteristics of sensors were established: response time is 5 min; working range of concentrations of Ni2+ ions: 1 ‧ 10–3 – 50 mM; lower detection limit ≈ 0.06 mg/l (maximum nickel concentration limit in water is 0.1 mg/l). It has been shown that the formation of a coating of the composition PMMA + NPs-SiO2 (1 : 41.7 mol) on a conductive nickel layer using the spin-coating method leads to increasing the sensitivity of a sensor and its service life (up to seven cycles).

Assessment and Empirical Treatment of Chronic Abdominal Pain from Suspected Helicobacter Pylori Infection In a Remote Setting

The prevalence of Helicobacter Pylori (H. Pylori) remains globally high, with an estimated 50% of the words population believed to be infected. Despite the continually high incident rates of infection 90% of those infected remain asymptomatic. H.Pylori is a gram-negative, microaerophilic bacteria, mostly found in stomach of affected individuals that causes inflammation and ulceration. Definitive routes of transmission and subsequent infection are still debated. The most likely mechanism of transmission is thought to be intrafamilliar, this encapsulates fecal-oral, gastric-oral, oral-oral and sexual vectors. Contaminated foods and water sources are also highly likely mechanisms of transmission. Therefore in developing countries with poor sanitation, potentially contaminated water sources and regions with social-economic hardship experience increased symptomatic cases of H.Pylori.

Assessing the environmental impacts of reclaimed and conventional water in hydroponics based on a life cycle assessment approach

ABSTRACT As the global population is approaching toward 9 billion by 2050, challenges of food and water scarcity intensify. Hydroponics, an innovative and eco-friendly technology, has gained prominence in addressing these challenges. This study employs life cycle assessment (LCA) to comprehensively evaluate the environmental and economic impacts of utilizing reclaimed water in a hydroponic system. Results from midpoint, endpoint, and normalized analyses reveal key contributors to the hydroponic system's environmental burden, including water, substrates, fertilizers, and energy sources. Significant impacts have been observed in marine and terrestrial ecotoxicity as well as photochemical ozone formation. Reclaimed water consistently demonstrates lower environmental impacts compared to conventional water across various indicators, such as climate change (131 kg CO2 eq.), fine particulate matter formation (0.108 kg PM2.5 eq.), and freshwater consumption (0.291 m3). The study emphasizes the potential of hydroponics with reclaimed water to offer sustainable and environmentally friendly agricultural practices. The detailed LCA results provide valuable insights for policymakers and stakeholders, promoting the adoption of hydroponics to address food and water scarcity challenges. From the findings, reclaimed water in hydroponics lowers the environmental impacts as compared to conventional water and PVC along with electricity is the major contributor in environmental burden.

Occurrence and Risk Assessment of N-nitrosamines and Their Precursors in Qingjiang River Basin

N-nitrosamines are a type of nitrogen-containing organic pollutant with high carcinogenicity and mutagenicity. In the main drinking water sources of small and medium-sized towns in China, the contamination levels of N-nitrosamines remain unclear. In addition, there is still lack of research on the concentration of N-nitrosamines and their precursors in tributary rivers. In this study, eight N-nitrosamines and their formation potentials （FPs） were investigated in the Qingjiang River, which is a primary tributary of the Yangtze River. The sewage discharge sites were also monitored, and the environmental influencing factors, carcinogenic and ecological risks caused by N-nitrosamines, and their precursors were evaluated. The results showed that six N-nitrosamines were detected in water samples of the Qingjiang River, among which NDMA [（10 ±15） ng·L-1], NDEA [（9.3 ±9.3） ng·L-1], and NDBA [（14 ±7.8） ng·L-1] were the dominant N-nitrosamines, whereas seven N-nitrosamines were detected in chloraminated water samples, among which NDMA-FP [（46 ±21） ng·L-1], NDEA-FP [（26 ±8.3） ng·L-1], and NDBA-FP [（22 ±13） ng·L-1] were the dominant N-nitrosamine FPs. The concentrations of N-nitrosamines in the middle reaches of the Qingjiang River were higher than those in the upper and lower reaches. Furthermore, the concentrations of N-nitrosamines in the sample sites of sewage discharge and tributaries were significantly higher than those in other sampling sites. The monitoring results at the direct sewage discharge points indicated that the main source of N-nitrosamines in river water was the sewage carrying N-nitrosamines and their precursors. In addition, the concentrations of the three dominant N-nitrosamines including NDMA, NDBA, and NDEA were positively correlated with each other, mainly because of their similar sewage sources. The average carcinogenic risk to residents due to N-nitrosamine in drinking water sources was 2.4×10-5, indicating a potential carcinogenic risk. Moreover, due to the high concentrations of N-nitrosamine formation potentials in the Qingjiang River, the carcinogenic risk of drinking water may be even higher. The ecological risk assessment showed that the ecological risk quotient values of N-nitrosamines in the Qingjiang River watershed were lower than 0.002, which was negligible.

Stable Isotopes of Landfast Sea Ice as a Record of La Grande River Under-Ice Plume Dispersal

Vertical profiles of salinity, and isotopic abundance ratios of hydrogen (δ2H ) and oxygen (@delta;18O) of 18 landfast ice cores, collected along the northeast coast of James Bay in March 2019, and one ice core collected in Belcher Islands, were used to obtain the winter timeseries of the spatiotemporal evolution of the under-ice plume of La Grande River (LGR), the dominant river in the area. Variability in the isotopic composition and salinity of the ice cores indicated changes to the water source composition at the ice-water interface when the ice layers formed. The increased presence of river water beneath the ice during January-March was marked by more negative isotopic ratios in the lower portion of the ice as river discharge was increased for hydroelectric production. River water was the source of ~43% of the ice in our ice core samples (n=320) with the interquartile range from 16% to 71%. The river water fractions incorporated into the ice indicate that LGR under-ice plume extended more than 75 km north and at least 30 km south of the river mouth for ~3 months. These findings correspond well with more challenging to obtain hydrographic observations. End-of-winter ice core sampling and analysis for isotopic abundance has potential as a tool to monitor dispersal of LGR discharge into the ice-covered coastal environment.

Adsorptive and oxidative removal of phenolphthalein by sono-assisted synthesized FeAcC in advanced oxidation-integrated fluidized bed reactor

ABSTRACT Environmental water sources are under increasing threat due to the addition of harmful chemicals not addressed by conventional water treatment processes. To work on this concern, the current study aimed to synthesize sono-assisted Fe-modified activated carbon-chitosan (FeAcC) composite and construct a laboratory-scale ozone-integrated fluidized bed reactor (FBR) to eliminate phenolphthalein (php). Following 120 min of incubation, the adsorbent demonstrated a 27.28 mg g−1 of php adsorption capacity at pH 4 with 0.5 g L−1 of adsorbent dosage. The adsorption efficacy and mechanism were defined using isotherm and kinetic models. The study investigated the impact of different factors including, initial concentration, reuse of FeAcC, recirculation flow rate, and hydraulic retention time (HRT), on the efficiency of php removal. The optimum removal efficiency was observed at approximately 95% after 20 min of operation at 1.5 L min−1 recirculation flow rate (batch FBR) and 70 min of HRT (continuous FBR) under 400 mg h−1 ozonation rate. Experimental parameters were optimized using response surface methodology (RSM) with central composite design (CCD) to improve php removal. The large-scale implementation of the findings in the future can be a step for adding new technology for clean water treatment processes for emerging toxic pollutants.

Vertical Distribution Characteristics and Driving Factors of Bacterioplankton and Nitrogen Phosphorus Cycle Genes in Danjiangkou Reservoir

Danjiangkou Reservoir is a critical water source for the South-to-North Water Diversion Project, which harbors a diverse bacterioplankton community with varying depths, and the understanding of its nitrogen and phosphorus cycle and associated driving factors remains limited. In this study, we selected five ecological sites within Danjiangkou Reservoir and conducted metagenomics analysis to investigate the vertical distribution of bacterioplankton communities in the surface, middle, and bottom layers. Furthermore, we analyzed and predicted the function of nitrogen and phosphorus cycles, along with their driving factors. Our findings revealed the dominance of Proteobacteria, Actinobacteria, and Planctomycetes in the Danjiangkou Reservoir. Significant differences were observed in the structure of bacterioplankton communities across different depths, with temperature （T）, oxidation-reduction potential （ORP）, dissolved oxygen （DO）, and Chla identified as primary factors influencing the bacterioplankton composition. Analysis of nitrogen cycle functional genes identified 39 genes, including gltB, glnA, gltD, gdhA, NRT, etc., which were involved in seven main pathways, encompassing nitrogen fixation, nitrification, denitrification, and dissimilatory nitrate reduction. Phosphorus cycle function gene analysis identified 54 genes, including pstS, ppx-gppA, glpQ, ppk1, etc., primarily participating in six main pathways, including organic P mineralization, inorganic P solubilization, and regulatory. Cluster analysis indicated that different depths were significant factors influencing the composition and abundance of nitrogen and phosphorus cycle functional genes. The composition and abundance of nitrogen and phosphorus cycle functional genes in the surface and bottom layers differed and were generally higher than those in the middle layer. Deinococcus, Hydrogenophaga, Limnohabitans, Clavibacter, and others were identified as key species involved in the nitrogen and phosphorus cycle. Additionally, we found significant correlations between nitrogen and phosphorus cycle functional genes and environmental factors such as DO, pH, T, total dissolved solids （TDS）, electrical conductivity （EC）, and Chla. Furthermore, the content of these environmental factors exhibited depth-related changes in the Danjiangkou Reservoir, resulting in a distinct vertical distribution pattern of bacterioplankton nitrogen and phosphorus cycle functional genes. Overall, this study sheds light on the composition, function, and influencing factors of bacterioplankton communities across different layers of Danjiangkou Reservoir, offering valuable insights for the ecological function and diversity protection of bacterioplankton in this crucial reservoir ecosystem.

Using irregular ranger patrols to quantify elephant occupancy in non‐protected and community‐modified landscapes

AbstractWhile wildlife management efforts have primarily focused on protected areas, unprotected areas – including community‐owned lands – are becoming increasingly important as habitat linkages and dispersal areas between multiple protected areas for species and processes that sustain them. However, these unprotected areas and community lands often lack structured protection measures and face numerous threats to both species and habitats. Involvement of local communities in the management of these areas through community‐led strategies can enhance safety for both people and wildlife, thereby promoting coexistence. To examine the effectiveness of community‐led strategies for managing wildlife outside protected areas, we fit multi‐season occupancy models on African elephant (Loxodonta africana) sightings data collected by volunteer Village Game Scouts (VGS) while on irregular and demand‐driven patrols within Mwanga district in Northern Tanzania. Patrol data were processed using the Spatial Monitoring And Reporting Tool (SMART). We estimated elephant probability of occupancy, detection, colonization and extinction, identifying key elephant dispersal areas in the community‐modified areas within the district. Our results indicate that proximity to Tsavo West National Park and the availability of seasonal water sources positively influenced the probability of elephant colonization. In contrast, the proportion of built‐up and farmed areas, and distance to permanent water sources, negatively influenced the probability of colonization. The number of scout patrols did not significantly influence the probability of elephant colonization or extinction, and elephant occupancy remained relatively stable during the study period. Our study highlights the complementary role of non‐protected areas in maintaining populations of endangered species such as elephants. We demonstrate that structured, volunteer community‐led strategies coupled with effective communication with authorities, can be used to monitor wildlife spatial distribution and identify factors influencing their distribution in non‐protected areas. We recommend community‐led protection measures for corridors and dispersal areas, as well as transboundary collaboration to maintain landscape connectivity for endangered species such as elephants.

Removal of acetaminophen from wastewater using a novel bimetallic La/Th metal-organic framework: Kinetics, thermodynamics, isotherms, and optimization through Box-Behnken design

Acetaminophen (ACT), a common drug pollutant, has been effectively removed from wastewater by a novel adsorbent called La/Th-MOF. This adsorbent is made of stacked nanorods of 2-methyl imidazole with lanthanum and thorium. La/Th-MOF, which is characterized by sophisticated techniques including SEM, XRD, and BET analysis, has a mesoporous assembly with a 1.23 nm pore size and a capacious surface area of 2226.93 m2/g, which facilitates effectual adsorption. The adsorption tests, which were impacted by factors such as pH levels, ACT concentration, and contact time, fit into a pseudo-second-order chemisorption kinetic model and with the Langmuir isotherm, suggesting homogenous monolayer adsorption. The material in question demonstrated a noteworthy maximum adsorption capability of 339.75 mg/g for ACT, indicating its probable as a feasible and economical adsorbent for the mitigation of pharmaceutical contamination in wastewater. Our results designate that pH levels have an important influence on the efficacy of ACT absorption by La/Th-MOF, with an acidic pH 5 environment being most favorable for maximal adsorption at a material dosage of 0.02 g. It was discovered that the adsorption procedure was endothermic. Using pseudo-second-order kinetic models and the Langmuir isotherm, which both fit the experimental data very well, to explain the adsorption kinetics. A chemisorption mechanism was found to be predominant throughout the process, as specified by the predicted adsorption energy of 22.62 kJ/mol. In addition, optimized the influencing parameters by using the Box-Behnken design (BBD) and response surface methodology (RSM), which improved process efficiency. La/Th-MOF, has a remarkable half-life, as demonstrated by six rounds of adsorption and desorption without a discernible decline in performance. Research endeavors aimed at elucidating the interplay between La/Th-MOF and ACT hint to several plausible points of contact that could contribute to the adsorption procedure, such as hydrogen bonding, π-π interactions, pore filling or electrostatic forces. This study, which is innovative in its use, reveals the exceptional efficacy of La/Th-MOF in wastewater purification using ACT extraction. An astounding 339.75 mg/g of optimal adsorption capability was attained at an acidic pH of 5. This highlights how the La/Th-MOF can be used in practice to treat pharmaceutical pollutants found in water sources.

An Integrated Process of Struvite Precipitation/Membrane Filtration Using Flat Ceramic Membranes Is an Effective Method for the Treatment of Liquid Fraction Digestate from a Municipal Biogas Plant

One method of processing municipal waste biogas plant digestate is to separate it into solid and liquid fractions. Since the digestate can be a potential source of water, it must undergo the appropriate treatment. Pressurised membrane processes preceded by struvite precipitation can be particularly useful in this regard. Experiments were conducted to determine the effectiveness of treating the digestate liquid fraction from a municipal waste biogas plant using an integrated process that combines struvite precipitation with membrane filtration, employing flat ceramic membranes with different cut-off values. The results confirm that this integrated process is effective for digestate treatment. A significantly increased improvement in the final quality of the test solution and a reduction in membrane fouling intensity were observed compared to those of these processes conducted separately. It is noteworthy that the purest solution was obtained when struvite precipitation and filtration through a flat ceramic membrane with a cut-off of 1 kDa were combined. This approach enabled the precipitation of struvite, a valuable fertiliser; the protection of the membranes from fouling; and a high degree of organic compound removal. The recovered water from the digestate (after dilution or removal of excess salts) can be used in agriculture or horticulture.

Groundwater Chemistry in Jind District: Physiochemical Appraisal and Drinking Water Quality Assessment

It is essential to have access to safe drinking water, particularly in rural regions where groundwater is the primary water source. The physicochemical quality of the groundwater in Jind District, Haryana, India, has been evaluated in this research. Six hundred samples were collected from thirty different places, and the following physiochemical characteristics were measured: pH, total dissolved solids, total hardness, alkalinity, electrical conductivity, calcium, magnesium, sodium, potassium, nitrate, fluoride, and sulfate. The World Health Organization, the Bureau of Indian Standards, the Indian Council of Medical Research, and other regulatory bodies' standards were compared to these results. Most of the necessary criteria were found to be within acceptable levels; however, total hardness, calcium, and magnesium were found to be greater than recommended in certain areas. The Water Quality Index states that the declining quality of the groundwater in certain areas makes it unfit for human consumption. In addition to providing critical information to assist mitigation measures and ensure the provision of sustainable and clean water resources for the population of the Jind district in the state of Haryana, this research highlights the need of regular monitoring

Prevalence of stunting and its correlates among children under 5 in Afghanistan: the potential impact of basic and full vaccination

BackgroundChild stunting is prevalent in low and middle-income countries (LMICs), but an information gap remains regarding its current prevalence, correlates, and the impact of vaccination against this condition in Afghanistan. This study aimed to determine the prevalence and correlates of moderate and severe stunting and the potential impact of basic and full vaccination among children under five in Afghanistan.MethodsThis is a secondary analysis of the 2022-23 Afghanistan Multiple Indicators Cluster Survey (MICS) including 32,989 children under 5. Descriptive statistics were employed to describe the distribution of independent variables and the prevalence of stunting across them. Chi-square analysis was used to examine the association between each independent variable with stunting. Multinomial logistic regression was used to examine the risk of stunting across different independent variables.ResultsA total of 32,989 children under 5 years old were included in this study. Of those 44.7% were stunted with 21.74% being severely stunted. Children aged 24–35 and 36–47 months faced the highest risk as compared to those aged 1–5 months. The prevalence was lower in female children and they were less likely to experience severe stunting. Stunting was more prevalent in rural areas, with children there 1.16 to 1.23 times more likely to be affected than urban counterparts. Lower wealth correlated with higher stunting. Younger maternal age at birth (≤ 18) correlated with increased stunting risks, particularly in severe cases. Parental education was inversely related to stunting; higher education levels in parents, especially fathers, were associated with lower stunting rates. Households with more than seven children showed a 25% and 44% higher risk of moderate and severe stunting, respectively, compared to families with 1–4 children. Improved sanitation, but not drinking water sources, was linked to reduced stunting in the adjusted model. Vaccination had a protective effect; in the adjusted analysis, basic and full vaccinations significantly lowered the risk of severe stunting by 46% and 41%, respectively.ConclusionIn this nationally representative study, the prevalence of stunting was substantial (44.7%) in Afghan children. Additionally, the findings emphasize the critical factors associated with child stunting and underscore the protective role of vaccination against this condition, which provides policymakers with directions for policy efforts and intervention strategies to reduce child stunting in Afghanistan.

A proposed methodology to evaluate the influence of climate change on drinking water treatments and costs

Drinking water (DW) production treatments can be affected by climate change, in particular intense rainfall events, having an impact on the availability and quality of the water source. The current study proposes a methodology for the evaluation of the costs of the different treatment steps for surface water (SW) and groundwater (GW), through the analysis and quantification of the main cost items. It provides the details to count for strong variations in the key quality parameters of inlet water following severe rainfalls (namely turbidity, iron, manganese, and E. coli). This methodology is then applied to a large drinking water treatment plant (DWTP) in Italy, which treats both SW, around 70 %, and GW, around 30%. It discusses the overall DW production costs (from 7.60 c€/m3 to 10.43 c€/m3) during the period 2019–2021 and analyzes the contributions of the different treatment steps in water and sludge trains. Then it focuses on the effects on the treatments of significant variations in SW turbidity (up to 1863 NTU) due to intense rainfalls, and on the daily costs of DW with respect to the average (baseline) costs evaluated on the annual basis. It emerges that, when SW has low turbidity levels, the energy-based steps have the biggest contribution on the costs (final pumping 22 % for SW and 10 % for GW, withdrawal 15 % and 14 %, respectively), whereas at very high turbidity levels, sludge greatly increases, and its treatment and disposal costs become significant (up to 14 % and 50 %). Efforts are being made to adopt the best strategies for the management of DWTPs in these adverse conditions, with the aim to guarantee potable water and optimize water production costs. A mitigation measure consists of increasing GW withdrawal up to the authorized flow rate, thus reducing SW withdrawal. In this context, the study is completed by discussing the potential upgrading of the DWTP by only treating GW withdrawn from riverbank filtration. The DW production cost would be 7.76 c€/m3, which is lower than that seen for the same year (2021) with the current plant configuration (8.32 c€/m3).

Sea urchin inspired ultrafast response low humidity sensor based on ionic liquid modified UiO-66 with advanced applications

Numerous applications require low humidity sensors that not only sensitive but also stable, small hysteresis, high resolution and fast response. However, most reported low humidity sensors cannot possess these properties at the same time. In this work, inspired by sea urchin, we developed an ionic liquid (IL) modified metal organic framework (UiO-66) based low humidity sensor. Owing to the synergistic effect of the hydrophilicity and ionic conductivity of IL and the steric hindrance effects of UiO-66, the optimized low humidity sensor simultaneously exhibits high response (47.5), small hysteresis (0.3 % RH), ultrafast response speed (0.2 s), high resolution (1 % RH), and excellent long-term stability (>120 days). In particular, the sensor has been proved to have potential applications in visual humidity detection and water source location. This work provides a preliminary design principle that will contribute to the preparation of high-performance low humidity sensing materials.

Microbial stratification and DOM removal in drinking water biofilters: Implications for enhanced performance

Biofiltration is a low-cost, low-energy technology that employs a biologically activated bed of porous medium to reduce the biodegradable fraction of the dissolved organic matter (DOM) pool in source water, resulting in the production of drinking water. Microbial communities at different bed depths within the biofilter play crucial roles in the degradation and removal of dissolved organic carbon (DOC), ultimately impacting its performance. However, the relationships between the composition of microbial communities inhabiting different biofilter depths and their utilisation of various DOC fractions remain poorly understood. To address this knowledge gap, we conducted an experimental study where microbial communities from the upper (i.e., top 10 cm) and lower (i.e., bottom 10 cm) sections of a 30-cm long laboratory-scale biofilter were recovered. These communities were then individually incubated for 10 days using the same source water as the biofilter influent. Our study revealed that the bottom microbial community exhibited lower diversity yet had a co-occurrence network with a higher degree of interconnections among its members compared to the top microbial community. Moreover, we established a direct correlation between the composition and network structure of the microbial communities and their ability to utilise various DOM compounds within a DOM pool. Interestingly, although the bottom microbial community had only 20 % of the total cell abundance compared to the top community at the beginning of the incubation, it utilised and hence removed approximately 60 % more total DOC from the DOM pool than the top community. While both communities rapidly utilised labile carbon fractions, such as low-molecular-weight neutrals, the utilisation of more refractory carbon fractions, like high-molecular-weight humic substances with an average molecular weight of more than ca. 1451 g/mol, was exclusive to the bottom microbial community. By employing techniques that capture microbial diversity (i.e., flow cytometry and 16S rRNA amplicon sequencing) and considering the complexities of DOM (i.e., LCOCD), our study provides novel insights into how microbial community structure could influence the microbial-mediated processes of engineering significance in drinking water production. Finally, our findings could offer the opportunity to improve biofilter performances via engineering interventions that shape the compositions of biofilter microbial communities and enhance their utilisation and removal of DOM, most notably the more classically humified and refractory DOM compound groups.

Sunflower (Helianthus annuus) seeds as a natural coagulant for water turbidity treatment: assessment of efficacy and dosage

The quality of river and borehole water fluctuates because of both agricultural and industrial pollutants. Surface runoff during the rainy seasons is high which promote increased turbidity levels in water sources, and this exerts pressure on the quality and usability of the water for domestic use. Unfortunately, most municipalities in developing countries are poor to afford conventional water treatment methods. This study assessed the use of natural coagulants extracted from sunflower seeds for turbidity treatment. Water samples were collected during summer, winter, and autumn from 10 randomly selected groundwater sources and three segments of the Mwerahari River in Buhera District, Zimbabwe. Results captured seasonal turbidity variations across the river segments and the boreholes. Summer season recorded the maximum average levels of turbidity (76 NTU) while autumn and winter recorded 38.7 NTU 36.7 NTU, respectively. Water turbidity levels were above the acceptable 5 NTU Standard Association of Zimbabwe and WHO. The maximum removal efficiency of turbidity was achieved at 80 min at the dose of 4 g/l. These results revealed that the removal efficiency of 95% with 4.6 NTU turbidity is a function of dose; removal efficiency increases as dose of coagulant increases. These results demonstrated that sunflower seed is an effective low-cost natural coagulant for turbidity water treatment.