Water Samples Research Articles

Eco-friendly spectrophotometric methods for concurrent analysis of phenol, 2-aminophenol, and 4-aminophenol in ternary mixtures and water samples: assessment of environmental sustainability.

Recently, there has been a high demand for green procedures in analytical chemistry, particularly those utilizing eco-friendly solvents. In this context, three feasible derivative UV spectrophotometric methods namely, derivative ratio-zero crossing spectra (DRZCS), double divisor ratio spectra (DDRS), and successive derivative subtraction coupled with constant multiplication (SDS-CM) were developed to quantify a ternary mixture of phenol (P), 2-aminophenol (2-AP), and 4-aminophenol (4-AP) in real water samples simultaneously, using ethanol as a solvent. The established methods demonstrated a good linear range, covering 2-60 μg mL-1 for P and 2-50 μg mL-1 for 2-AP and 4-AP, in all approaches with a high correlation coefficient (R2 ≥ 0.9995). In compliance with ICH guidelines, the methods exhibited acceptable precision and accuracy, as indicated by good spike recovery with low relative standard deviations. The eco-friendliness of the UV spectrophotometric approach was assessed using analytical eco-scale (AES), analytical greenness (AGREE), and analytical greenness metrics for sample preparation (AGREEprep). These evaluations confirmed the eco-friendliness of the proposed methods in terms of solvents, energy consumption, and waste generation. The proposed procedure proved to be efficient in quantifying each component in laboratory-synthesized mixtures and real water samples, thanks to its simplicity, accuracy, sensitivity, and cost-effectiveness.

The first investigation on the radiotoxicity risks associated with ingesting radium in drinking water from the Oujda Region-Morocco and some bottled mineral waters

Drinking water is essential to human life. However, it can be polluted by various factors, including radioactive substances such as radon 222Rn and radium 226Ra. Therefore, the determination of their concentrations is important for public health. The aim of this work is to measure the concentration of 226Ra in samples of tap, natural spring and well water taken from different sources in the eastern region of Morocco, as well as in a few samples of bottled mineral water. We used an AlphaGUARD detector with an AlphaKit accessory and an RTM1688-2 to carry out measurements of radon in secular equilibrium with radium. The got results show that the 226Ra activity is less than 0.104 ± 0.023 Bq/L, the Annual Effective Dose (AED)) for adults and children is less than 29.1 ± 4.7 μSv.y−1and 123.8 ± 4.7 μSv.y−1 for infants. The chemical toxicity risk evaluated using the Lifetime Average Daily Dose (LADD) was found less than 0.23 ± 0.05 μgkg−1day−1.The obtained results are reasonable in relation to international guidelines, and do not present any radiological hazard to consumers that could be attributed to the radium and radon in the analyzed water samples.

Swift and quantitative naked-eye detection of cyanide: A dual-mode approach using an ICT-based colorimetric and ratiometric fluorescent chemodosimeter

A chemodosimeter (1) based on dicyanovinyl with a strong intramolecular charge transfer (ICT) mechanism has been devised for the selective and sensitive detection of cyanide (CN−) in a tetrahydrofuran aqueous solution. In polar solvents, chemodosimeter 1 exhibits robust ICT-induced emission; however, in the solid state, its fluorescence weakens owing to the formation of molecular aggregates prompted by intermolecular π–π interactions. The colorimetric and ratiometric fluorescent changes observed in the chemodosimeter upon exposure to CN− result from the incorporation of CN− at the β-conjugated site of the dicyanovinyl moiety of chemodosimeter 1, effectively hindering the ICT process. This alteration is supported by 1H NMR titration experiments and density functional theory calculations, which corroborate the cyanide-induced ICT on–off switching mechanism. The detection limit of chemodosimeter 1 (5.8 × 10−7 M) for CN− falls below the maximum allowable level of cyanide in drinking water (1.9 × 10−6 M), as established by the World Health Organization. Test strips utilizing chemodosimeter 1 offer a potential solution for swift and quantitative naked-eye detection of CN− in real-time scenarios. Moreover, chemodosimeter 1 was effectively employed for detecting cyanide in actual environmental water samples.

Integrating portable X-ray fluorescence site survey and ArcGIS models for rapid risk assessment and mitigation strategies at an abandoned arsenic mine site: a case study

ABSTRACT Australia’s metalliferous abandoned mine sites (MAMSs), pose tangible threats to the environment and human health. To address these concerns, our study utilised state-of-the-art handheld XRF technology to conduct a real-time assessment of the Mole River arsenic mine site. The data revealed notably elevated levels of arsenic and manganese, with the southeast corner of the site identified as a contaminant hotspot. We used a tiered risk assessment approach to compare the detected contaminant concentrations to the Australian health investigation levels (tier 1). This led us to a broader examination of erosion vulnerabilities and the potential migration of contaminants (tier 2). Further, a hydrological assessment (tier 3) identified significant erosion in southern regions, indicating the potential for contaminants to be transported off-site through surface water runoff to Sam’s Creek and Mole River. The proximity of a reservoir to these runoff pathways brought forth additional challenges, especially during heavy rainfall events. Subsequent laboratory analysis of water samples reinforced our findings, as they confirmed heightened arsenic concentrations in Mole River downstream, accentuating the potential risks to ecosystems and human health. By integrating the XRF contour map and erosion assessment with the RUSLE model, valuable insights are gained into critical hotspots with high contamination and erosion potential. By directing rehabilitation efforts towards critical hotspots, resources can be allocated more efficiently and cost-effectively.

Study of the Bunsen–Roscoe Reciprocity Law in Solar Water Disinfection (Optical Effect) for E. coli, E. faecalis and C. perfringens

Water stress and water quality represent major environmental challenges in the 21st century. In response, wastewater management and its potential reuse emerge as strategies to mitigate these problems. This research aims to verify the law of reciprocity in the solar disinfection process of real secondary wastewater effluents for different faecal microorganisms. Flat disinfection reactors, subjected only to natural and continuous UV radiation, were used. The study focused on the optical effect of UV radiation, eliminating the significant influence of the thermal effect and its synergy in solar disinfection at temperatures above 45 °C, by controlling the temperatures of the water samples to levels below 20 °C. Three experimental tests were carried out on sunny days. Each test comprised two trials, under the following conditions: (a) low solar irradiance over a prolonged time (duration approximately: 2.6 h) and (b) high solar irradiance and a shorter period of time (approximately 2 h), with each receiving the same UV dose. Inactivation kinetics was analysed for E. coli, E. faecalis, and C. perfringens (including spores). The results validated the reciprocity law for E. coli in all tests for UV doses > 20 Wh/m2, showing no significant deviations, with inactivation rates of 0.44 to 0.51 m2/Wh for initial concentrations of 106–107 CFU/100 mL. In contrast, for E. faecalis, the reciprocity was only valid at intensities < 700 W/m2, with rates of 0.04 and 0.035 m2/Wh for 105–106 CFU/100 mL; above this irradiance value, the law varied significantly and was not valid. C. perfringens did not show significant disinfection results during the experiments to verify this law, mainly due to the resistance of its spores. Additional experimentation with C. perfringens is necessary, by extending the length of the experiments and/or conducting them at higher irradiance values, in order to reach bacterial inactivation to enable the analysis of the reciprocity law. In general, the main conclusion from these results is that the reciprocity law in solar disinfection would be difficult to use for the estimation of water solar disinfection based on the irradiance and exposure times, as there are deviations from it at least in one specie (E. faecalis). Mores studies should be carried out to fully understand and determine the validity of this law and its potential application for forecasting solar water disinfection.

Cu (II)-based metal-organic framework functionalized with graphene oxide as a sorbent for the dispersive micro-solid-phase extraction of losartan potassium from water

AbstractIn this study, a new metal–organic framework (MOF) based on copper (II) functionalized with graphene oxide (MOF-Cu@GO) was successfully synthesized and applied as an efficient sorbent for dispersive micro-solid phase extraction (D-μSPE) of losartan potassium (LP) from water. The MOF-Cu@GO sorbent was characterized using DRX, FTIR, XPS, TGA, RAMAN, BET, SEM, EDX, and potential Z. The influence of different parameters in the D-μSPE method was studied and optimized using the fractional factorial design 25–1 and central composite design. The results indicated that the adsorption process was spontaneous and endothermic followed the pseudo-second order model kinetics and the Freundlich isotherm. The maximum adsorption capacity of MOF-Cu@GO sorbent was 415 mg g−1. The adsorption mechanism proposed of LP onto MOF-Cu@GO proceeded via electrostatic interaction, hydrogen bonds, unsaturated sites of the ligand, and π-π interactions. The microextraction procedure was followed by determination of LP with high performance liquid chromatography (HPLC–UV-Vis). Under optimized conditions, the limits of detection and quantitation were found to be 25 and 80 ng ml−1 respectively, the method exhibited a linear response (r = 0.998) in the concentration range of 0.1–50 µg ml−1 of LP, with a relative standard deviation less than 2% (n = 5). The D-μSPE method showed preconcentration factor of 684.9 and high percentage of LP extraction of 99.78% ± 2.62, the accuracy of the method was demonstrated by studying the recovery of LP from water samples of 100.3 ± 1.06. The material obtained can be used up to 3 cycles with time for the sorption and determination of 30 min indicating good stability and reusability. The MOF-Cu@GO proposed is an efficient and fast sorbent in the D-μSPE for determination of LP from aqueous solutions.

Hydrogeochemical and GIS Analysis of Groundwater Quality for Drinking and Irrigation Purposes in Kuzhithuraiyar Sub-Basin, Kanniyakumari District, Tamil Nadu, India

A hydrogeochemical analysis was conducted to find the suitability of the groundwater for drinking and irrigation purposes in the Kuzhithuraiyar sub-basin, Kanniyakumari district, Tamil Nadu, India. 48 groundwater samples were collected from the different locations of the study area during both the pre- and postmonsoon periods. This study assesses the groundwater quality for drinking and irrigation purposes based on the analytical results, water quality index, Wilcox plot, and irrigation parameters such as electrical conductance, Kelly’s ratio, sodium absorption ratio values, magnesium hazards, bicarbonate, and the residual sodium carbonate index. The pH values ranged from 8.5 to 6.5, suggesting generally acceptable conditions. TDS concentrations range from 24 to 1277 mg/L, whereas EC values range from 37.50 to 1996 μS/cm. It is observed from the collected samples that the pre-monsoon water samples TDS’ values were exceeded the recommended TDS limits than postmonsoon samples. Water quality indices indicate that 50% of premonsoon samples and 48% of postmonsoon samples are suitable for drinking. In total, 10% of samples are admissible to a doubtful category before and after the monsoon, 6% are good to permissible during the monsoon, and 84% are good to permissible. Kelly’s ratio shows that 56% and 48% of samples collected during the post- and premonsoon are suitable for irrigation, respectively, whereas the remaining samples are not. Due to magnesium hazards, 40% and 44% of pre- and postmonsoon samples are not suitable for irrigation. Overall, the postmonsoon samples exceeded the permissible TDS limit (1000 mg/L) by 10% and the premonsoon samples by 6. 13% of samples obtained after the monsoon and 19% collected before the monsoon have a potential salinity greater than three, indicating that these samples are unacceptable. The sustaining water quality and mitigating possible hazards in the Kuzhithuraiyar sub-basin require continuous monitoring and focused measures.

Safe and genotyped. A non-invasive method for extraction of amphibian DNA from water baths and its application on Northern spectacled salamanders, Salamandrina perspicillata (Savi 1821)

AbstractThe global decline of amphibian populations, with 40.7% of species classified as threatened, calls for innovative and ethical approaches in conservation genetics. Molecular biology advancements have introduced environmental DNA (eDNA) analysis, primarily focusing on aquatic environments. However, the present study explores a novel non-invasive protocol using water samples to extract DNA from terrestrial and semi-terrestrial amphibians, specifically the endangered Italian endemic salamander, Salamandrina perspicillata (Savi, 1821). Unlike traditional invasive methods involving tissue sampling, this protocol immerses animals briefly, eliminating the need for digit or tail amputations or manipulation for buccal swabs. The study validated the protocol through DNA extraction, amplification, and sequencing, yielding results comparable to traditional methods. The non-invasive nature of the protocol aligns with the 3Rs principles (Replace, Reduce, Refine) and offers a streamlined, stress-minimizing alternative for studying protected and endangered species. Future experiments should also explore further refinements, including reduced soaking times and additional applications, such as skin microbiota analysis. This protocol represents a significant step towards ethical and effective research practices in amphibian conservation genetics, encouraging a paradigm shift in wildlife research ethics. Continued innovation in non-invasive methodologies is essential for comprehensive understanding and robust conservation strategies amid the ongoing biodiversity crisis.

Molecular composition of clouds: a comparison between samples collected at tropical (Réunion Island, France) and mid-north (Puy de Dôme, France) latitudes

Abstract. The composition of dissolved organic matter of cloud water has been investigated through non-targeted high-resolution mass spectrometry on only a few samples that were mostly collected in the Northern Hemisphere in the USA, Europe and China. There remains, therefore, a lack of measurements for clouds located in the Southern Hemisphere, under tropical conditions and influenced by forest emissions. As a matter of fact, the comparison of the composition of clouds collected in different locations is challenging since the methodology for the analysis and data treatment is not standardized. In this work, the chemical composition of three samples collected at Réunion Island (REU) during the BIO-MAÏDO field campaign, in the Indian Ocean, with influences from marine, anthropogenic and biogenic (tropical) emissions, is investigated and compared to the chemical composition of samples collected at the Puy de Dôme (PUY) observatory in France. The same methodology of analysis and data treatment was employed, producing a unique dataset for the investigation of the molecular composition of organic matter in cloud water. Besides the analysis of elemental composition, we investigated the carbon oxidation state (OSC) of dissolved organic matter, finding that overall samples collected at PUY are more oxidized than those collected at REU. Molecular formulas were also classified based on stoichiometric elemental ratios, showing the high frequency and abundance of reduced organic compounds, classified as lipids (LipidC), in this matrix, which led to a search for terpene oxidation products in cloud water samples. To better discriminate between samples collected at PUY and REU, statistical analysis (principal component analysis and agglomerative hierarchical clustering) was performed on the ensemble of molecular formulas and their intensities. Samples collected at REU have a different composition from samples collected at PUY, which is mainly linked to different primary sources, the processing of organic matter in cloud water and the influence of different primary emissions at the two locations.

Endotoxin, a novel biomarker for the rapid risk assessment of faecal contamination of coastal and transitional waters

ABSTRACT Contaminated water has been responsible for the spread of disease for centuries. Current methods for testing water for faecal contamination rely on the culture of faecal indicator bacteria (FIB; Escherichia coli and Enterococci) that take 24–48 h, which leads to delays in taking proactive measures and poses a risk to public health. More rapid methods are therefore required. Here, we have tested a rapid, portable assay (Bacterisk) that detects the bacterial biomarker endotoxin in 30 min to quantify the bacterial biomass present, to evaluate 159 coastal water samples and to compare the results with the traditional culture of FIB. There was a significant correlation between the Bacterisk data given in endotoxin risk (ER) units and FIB culture that could accurately distinguish between poor and sufficient or good quality bathing water using the EU bathing directive values. Receiver operating characteristic analysis was used to determine the optimal ER threshold for coastal water samples, and the area under the curve was 0.9176 with a p-value of <0.0001. The optimal threshold was 7,300 ER units with a sensitivity of 95.45% and a specificity of 83.48%. In conclusion, we have shown that the Bacterisk assay provides a rapid and easy-to-use in situ method to assess bathing water quality.

Microbiological assessment of ready-to-eat foods and drinking water sources as a potential vehicle of bacterial pathogens in northern India.

Foodborne illnesses caused by the consumption of contaminated foods have frequent occurrences in developing countries. The incorporation of contaminated water in food processes, preparation, and serving is directly linked to several gastrointestinal infections. Keeping in view, this study was conducted to assess the microbial quality of both drinking water sources and commonly consumed fresh ready-to-eat (RTE) foods in the region. The drinking water samples from water sources and consumer points, as well as food samples from canteens, cafes, hotels, and restaurants, were collected for the microbiological analysis. Fifty-five percent (n = 286) of water samples were found to be positive for total coliforms with MPN counts ranging from 3 to 2600 (100 ml) -1. E. coli was detected in nearly 30% of the total water samples. Overall, 65% tap water samples were found unsatisfactory, followed by submersible (53%), filter (40%), and WTP (30%) sources. Furthermore, the examination of RTE foods (n = 80) found that 60% were of unsatisfactory microbial quality with high aerobic plate counts. The salads were the most contaminated category with highest mean APC 8.3 log CFU/g followed by pani puri, chats, and chutneys. Presence of coliforms and common enteropathogens was observed in both water and food samples. The detected isolates from the samples were identified as Enterobacter spp., Klebsiella spp., Pseudomonas aeruginosa, Salmonella spp., Shigella spp., and Staphylococcus spp. Based on these findings, microbiological quality was found compromised and this may pose hazard to public health. This exploratory study in the Punjab region also suggests that poor microbiological quality of water sources can be an important source of contamination for fresh uncooked RTE foods, thus transferring pathogens to the food chain. Therefore, only safe potable drinking water post-treatment should be used at all stages.

Phthalic acid esters: Are they a big concern for rivers flowing into reservoir with ecological facilities?

The city-river-reservoir system is an important system for safeguarding drinking water. Phthalic acid esters (PAEs) are emerging contaminants in drinking water sources that are gaining attention, and they could pose risks to human health and aquatic organisms. In this study, field studies that lasted four years were conducted to analyze the concentrations, spatial-temporal distribution, and removal effects of six PAEs. The total concentrations of the Σ6PAEs in the water and sediment samples were 0.2–7.4 μg L−1 (mean: 1.3 μg L−1) and 9.2–9594.1 ng g−1 (mean: 847.5 ng g−1), respectively. Di-n-butyl phthalate (DBP) and, bis(2-ethylhexyl) phthalate (DEHP) were the predominant congeners, accounting for 57.2 % in the water samples and 94.1 % in the sediment samples. The urban area contributed 72 % of the PAEs in the system. A significant removal effect of PAEs was observed in the wetland, with a removal rate of 40.2 %. The partitioning of PAEs between the water and sediment was attributed to the removal of dimethyl phthalate and diethyl phthalate that occurred during the water phase, while the removal of DBP and DEHP primarily occurred during the sediment phase. The ecological risk calculation based on the sensitivity distribution model indicated that DBP (HQwater = 0.19, HQsediment = 0.46) and DEHP (HQwater = 0.20, HQsediment = 0.13) possessed moderate risks according to some water and sediment samples. The ecological projects were verified to be effective engineering strategies to reduce ecological risk in the drinking water source.

Higher diversity of sulfur-oxidizing bacteria based on soxB gene sequencing in surface water than in spring in Wudalianchi volcanic group, NE China.

Sulfur-oxidizing bacteria (SOB) play a key role in the biogeochemical cycling of sulfur. To explore SOB diversity, distribution, and physicochemical drivers in five volcanic lakes and twosprings in the Wudalianchi volcanic field, China. This study analyzed microbial communities in samples via high-throughput sequencing of the soxB gene. Physical-chemical parameters were measured, and QIIME 2 (v2019.4), R, Vsearch, MEGA7, and Mothur processed the data. Alpha diversity indices and UPGMA clustering assessed community differences, while heat maps visualized intra-sample variations. Canoco 5.0 analyzed community-environment correlations, and NMDS, Adonis, and PcoA explored sample dissimilarities and environmental factor correlations. SPSS v.18.0 tested for statistical significance. The diversity of SOB in surface water was higher than in springs (more than 7.27 times). We detectedSOB affiliated to β-proteobacteria (72.3 %), α-proteobacteria (22.8 %), and γ-proteobacteria (4.2 %) distributedwidely in these lakes and springs. Rhodoferax and Cupriavidus were most frequent in all water samples, whileRhodoferax and Bradyrhizobium are dominant in surface waters but rare in springs. SOB genera in both habitatswere positively correlated. Co-occurrence analysis identified Bradyrhizobium, Blastochloris, Methylibium, andMetyhlobacterium as potential keystone taxa. Redundancy analysis (RDA) revealed positive correlations betweenSOB diversity and total carbon (TC), Fe2+, and total nitrogen (TN) in all water samples. The diversity and community structure of SOB in volcanic lakes and springs in the Wudalianchivolcanic group were clarified. Moreover, the diversity and abundance of SOB decreased with the variation of wateropenness, from open lakes to semi-enclosed lakes and enclosed lakes.

Detection of <I>Giardia</I> cyst and <I>Taenia</I> eggs in river water samples collected from Aleto River in Eleme Local Government Area, Rivers State, Nigeria

This study aimed at detecting Giardia cyst and Taenia eggs in river water samples collected from Aleto River in Eleme Local Government Area, River State, Nigeria, to check for potability and purity of water.Water samples of river water were collected from two points (downstream and midstream) of Aleto river. Labelled clean sample bottles with tightly-fitted lids were used to collect water samples from the river and stored in coolers with ice packs to maintain their temperature and transportation to the laboratory. Collected water samples were transferred into sterile vial tubes and centrifuged at 2000 rpm for five minutes, after which the supernatant fluids were discarded, while the sediments smeared using spatula on labelled slides stained with specific dyes, using the wet mounts, trichome stain technique, and modified Ziehl–Neelsen techniques, and viewed under the light microscope to identify the presence of parasites.This study showed the presence of ten trophozoites of Giardia lamblia and ten eggs of Taenia species isolated from the river water samples collected. These findings highlight the potential health risks associated with waterborne parasites and emphasizes the importance of effective water quality management to safeguard public health. Furthermore, the observation of parasites underscores the need for comprehensive water quality assessment and monitoring. This study highlights the contamination of the river with parasitic organisms and urgently needs effective water management strategies to mitigate the risks to public health. Vital interventions encompass enhancing sanitation practices, curbing fecal contamination, and augmenting water quality surveillance mechanisms.

Enhancing photodegradation of thiamethoxam insecticide using SnS2/NCL as a photocatalyst: Mechanistic insights and environmental implications

The current research highlights the fabrication of a novel SnS2/CO32−@Ni–Co LDH (SnS2/NCL) by precipitating Ni–Co LDH over hydrothermally synthesized SnS2 nanoparticles for the enhanced degradation of thiamethoxam (THM) insecticide through the advanced oxidation process. The effect of several reaction parameters was optimized, and a maximum degradation of 98.1 ± 1.2 % with a rate constant of 0.0541 min−1 of 10 ppm THM was reached at a catalyst loading of 0.16 gL-1 using 0.3 mM of H2O2 within 70 min of visible light irradiation. The effect of metal cations, inorganic anions, dissolved organic matter, organic compounds and water samples on the photodegradation performance of SnS2/NCL nanocomposite was also examined to evaluate the prepared photocatalyst's suitability for use in actual wastewater conditions. The metal cations blocked the active sites of the photocatalyst and reduced the degradation efficiency except for Fe2+ ions, since it is a Fenton reagent and increased the production of hydroxyl radicals. Inorganic anions are the scavengers of hydroxyl radicals and hinder photocatalytic activity. Meanwhile, lake water containing varying degrees of co-existing ions shows the lowest degradation efficiency among other water samples. The SnS2/NCL nanocomposite could be reused for five cycles while maintaining a photocatalytic efficiency of 83.6 ± 0.3 % in the fifth run. The prepared SnS2/NCL nanocomposite also showed excellent photodegradation of several other emerging organic pollutants with an efficiency of over 80 % under optimum conditions. Incorporating Ni–Co LDH with SnS2 helped to delocalize photoinduced charges, leading to increased photocatalytic activity and a slower electron-hole recombination rate. The present research highlights the photocatalytic activity of SnS2/NCL photocatalysts for the photocatalytic degradation of emerging contaminants from wastewater.

Effect of "ColdArc" WAAM Regime and Arc Torch Weaving on Microstructure and Properties of As-Built and Subtransus Quenched Ti-6Al-4V.

Defect-free thin-walled samples were built using wire arc additive manufacturing (WAAM) combined with the "coldArc" deposition technique by feeding a Ti-6Al-4V welding wire and using two deposition strategies, namely with and without the welding torch weaving. The microstructures formed in these samples were examined in relation to mechanical characteristics. The arc torch weaving at 1 Hz allowed us to interfere with the epitaxial growth of the β-Ti columnar grains and, thus, obtain them a lower aspect ratio. Upon cooling, the α/α'+β structure was formed inside the former β-Ti grains, and this structure proved to be more uniform as compared to that of the samples built without the weaving. The subtransus quenching of the samples in water did not have any effect on the structure and properties of samples built with the arc torch weaving, whereas a more uniform grain structure was formed in the sample built without weaving. Quenching resulted also in a reduction in the relative elongation by 30% in both cases.

Design of a pebbles-like erbium stannate integrated with graphene nanoribbons for the anti-cancer drug nilutamide detection in water and biological samples

The invention of antibiotics revolutionized modern medicine, yet their unchecked usage poses risks to the environment and human health. Nilutamide (NLT), an anti-androgen drug for prostate cancer, undergoes hepatic metabolism, producing harmful by-products. Recent studies have detected elevated NLT levels in ecosystems, demanding comprehensive monitoring. Electrochemical sensors have evolved, offering compact, sensitive, and selective detection. Integration of nanotechnology has further enhanced these sensors, particularly graphene nanoribbons (GNRs) and pyrochlore oxides like erbium stannate (Er2Sn2O7). This study focuses on fabricating a GNR/Er2Sn2O7 nanocomposite-modified electrode and proposing its application for NLT detection in water and human samples. The nanocomposite's hierarchical arrangement, facilitated by synergistic effects and quantum confinement within the hybrid heterojunction, enhances the electrode modifier's activation, enabling the detection of NLT with an outstanding limit of detection (LOD) as well as a wide linear range and appreciable recoveries in real samples.

Thiol-based chemically modified carbon screen-printed electrode for simultaneous quantification of trace level Pb(II) and Cd(II).

Present work reports, the development of a novel electrochemical sensor based on a diazonium-coupling reaction and covalent attachment of the -NH2 group of cysteamine (Cyst) on screen-printed carbon electrode (SPCE), for simultaneous determination of Pb(II) and Cd(II). Initially, the in-situ generated 4-carboxyphenyl (4-CP) diazonium salt was electro-grafted to generate 4-CP/SPCE, followed by covalent bonding of terminal carboxylic group of 4-CP with -NH2 group of Cyst to give Cyst/4-CP/SPCE. The modified electrode showed an enhanced selectivity and sensitivity toward the quantification of Pb(II) and Cd(II) using square wave anodic stripping voltammetry (SWASV) without mutual interference. Under optimal experimental conditions, the newly designed sensor showed a wide linear range of 0.01µM to 0.7µM. The limit of detection (LOD) obtained was 0.882nM (0.09 ppb) and 0.65nM (0.134ppb) for Cd(II) and Pb(II), respectively. The modified SPCE exhibited good stability, selectivity, and reproducibility. Furthermore, the sensor was successfully applied for the determination of Pb(II) and Cd(II) ions in water samples which illustrated excellent recoveries in different spiked samples and the results were in line with the standard ICP-AES analysis.

Groundwater assessment for sustainable development in the Wadi Al-Hamd Basin, Al-Madinah Al-Munawarah, KSA

This study relied on well monitoring many drilled wells data in the Wadi Al-Hamd Basin to determine water level and chemical properties from field measurements. The characteristics of groundwater must be assessed in terms of present and future eases and stresses to ensure sustainable development. Hydrogeological, hydrochemical, groundwater quality indices and Geographic Information Systems (GIS) data sets have been integrated to assess the groundwater aquifer in the study area. To implement this work, we measured the depth to the water table from eighty-eight drilled wells. Also, the major ions were determined from 82 water samples to evaluate the physicochemical properties, groundwater facies, and controlling mechanisms using diagrams such as the modified Piper proposed by Chadha, Total Ionic Salinity (TIS), and Gibbs. In this study, five irrigation water quality indicators (IWQI), including total dissolved solids (TDS), sodium adsorption ratio (SAR), potential salinity (PS), magnesium hazard (MH), and residual sodium carbonate (RSC) have been determined to assess the suitability of groundwater for irrigation. Based on the findings of this study, groundwater flows from the southeast and northwest to the west and south, respectively. In this basin, 56% of water samples have TDS greater than 2000 mg/L, while 62% of water points are categorised as Na–Cl water type, which indicates that evaporation and rock–groundwater interaction influenced groundwater quality evolution. Almost 87% of samples were rated good to excellent for irrigation use with respect to SAR. On the other hand, all water points are suitable for irrigation based on RSC. Likewise, groundwater is suitable for irrigation purposes despite the relatively high PS levels (>5 meq/L in about 49% of samples) and some small spots with high levels of MH (>50% in about 12% of samples), especially in the southern and central portions of the studied basin.

Integrated geophysical and geochemical characterization of hydrocarbon contaminated site in Erhoike-Kokori, Southern Nigeria

The effectiveness of geophysical and geochemical methods in delineating hydrocarbon contamination in a spill site is carried out around theErhoike flow station in Kokori, Ethiope East LGA, Delta State. Wenner array was used for the transverse in acquiring the data which spanned a transverse of 200m and 3D model resistivity images were obtained from the inversion and presented in horizontal depth slices. Well water samples were also taken for Total Petroleum Hydrocarbon (TPH) content while soil samples from the location were also taken for Porosity and coefficient of permeability. The result of the 3D horizontal depth slices in the location reveals that Erhoike is impacted with hydrocarbon plume to a depth of 31.7m. The concentration of TPHCs from the water analysis shows that the wells around the suspected zones are affected by hydrocarbon. The laboratory tests for porosity (Փ ) and coefficient of permeability (k) for the soil samples are indicative of sand/silty sand which thus allows the flow of PHCs plume to the soil and groundwater in the study area. The results of the study have shown that the soil is permeable and porous which would allow the passage of the leaked and spilled PHCs through the soil to groundwater where the PHCs could mix, float and sink into groundwater. The 3D analysis revealed the presence of PHCs up to a depth of 33.7m but prominent at a depth of 10m which indicates the presence of PHCs in the wells. The hydrochemical analysis also proved the same results as that of the 3D which authenticated the reliability of the method used in the study.