River Water Research Articles

Dispersive solid phase extraction of 18 PFAS from environmental water samples using a novel MOF-polymeric monolith composite followed by High-Resolution mass spectrometry analysis

Metal-organic frameworks (MOFs) have been broadly coupled with many pretreatment techniques due to their remarkable attributes including high porosity, significantly increased specific surface area, and chemical stability, but their nanoscale dimensions make their handling challenging. To overcome this, a novel MOF-polymeric monolith composite was synthesized and studied as a novel sorbent material in an analytical technique. A rapid and efficient method for the extraction of a mixture of 18 per- and poly-fluoroalkyl (PFAS) compounds from environmental water samples was established based on MOF-polymeric monolith composite assisted dispersive solid phase extraction (d-SPE). The analytical methodology was carried out with the aid of liquid chromatography tandem high-resolution mass spectrometry. Several parameters influencing the extraction efficiency were comprehensively evaluated and optimized. The optimization was based on two processes: the one-variable-at-a-time approach (OVAT) and the central composite design (CCD). Preliminary studies were conducted and the extraction and elution time, as well as the sample volume were evaluated by adopting OVAT approach. The optimal parameters were found to be 15 min for extraction time, 5 min for the elution time and 10 mL as sample volume. Under the optimum conditions, the sample pH, sorbent amount and eluent volume were all evaluated under the design of experiments (DoE). ANOVA demonstrated the suitability of the suggested model with a p-value of less than 0.05 and various diagnostic tests validate the well-fitting results. The software extracted the optimal conditions which were pH = 7, sorbent amount = 10 mg and eluent volume = 750 μL. The method was subsequently validated with respect to accuracy, linearity detection limits and reproducibility. The proposed method presented recoveries over 70 %, method detection limits 1–46 ng/L and relative standard deviations <20 %. Before the implementation of the method in real samples, the “green” character was evaluated using the ComplexGAPI index, indicating the satisfactorily “green” character of the new MOF-based dSPE-LC-HRMS method. Finally, the efficacy of the method for determining PFASs in four environmental water matrices was tested using several matrices of varying complexity, including wastewater effluent, river water, marine water, and runoff.

A newly NH2-UiO-66 composite functionalized by molecularly imprinted polymer for selective and rapid removal of sulfamethoxazole

Metal–organic frameworks (MOFs) are used as novel adsorption materials owing to their large surface area and tunable pore size. However, the lack of selectivity considerably limits their application. Consequently, designing functionalized MOFs with specific recognition abilities is essential for enhancing their adsorption performance. Herein, we synthesized a functionalized NH2-UiO-66 composite modified by molecularly imprinted polymers (MIP@NH2-UiO-66) via a one-step polymerization process in which NH2-UiO-66 and MIP were formed simultaneously. Results demonstrate that MIP@NH2-UiO-66 effectively recognized sulfamethoxazole (SMX) in complex matrices. The adsorption equilibrium was reached in only 30 min, and this fast SMX adsorption on MIP@NH2-UiO-66 was described by the Avrami kinetic model, which indicates a spontaneous and exothermic adsorption process. Within the pH range of 3.0–10.0, MIP@NH2-UiO-66 exhibited an optimal binding capacity for SMX, and the maximum adsorption of SMX was 68.36 mg g−1 at 25°C, which exceeded those of existing adsorption materials (< 60.10 mg g−1). Additionally, MIP@NH2-UiO-66 was regenerated for ∼17 cycles compared to less than eight cycles for the other adsorbents. MIP@NH2-UiO-66 effectively removed 90.58%–99.60% of SMX from river water, rainwater, soil, sediment, chicken, pork, and milk samples, with a relative standard deviation of less than 4.43%. The superior adsorption of SMX on MIP@NH2-UiO-66 was primarily driven by the synergistic effects of the imprinting sites, hydrogen bonding, and electrostatic forces. The one-step polymerization method substantially simplified the synthesis process and reduced the costs, which are promising factors for the synthesis of MOFs with high selectivity.

In-situ electrogenerated persulfate activated by co-existing Cu(II) for sustainable removal of sulfonamides from environmental waters

In this study, in-situ electrogenerated persulfate (E-PS) was proposed as an alternative to the conventional addition of persulfate for advanced oxidation processes (AOPs) with facilitating conversion of co-existing Cu(II) to Cu(I) to degrade antibiotics without requiring any external supply of chemical additives. The degradation rate of sulfamethoxazole (SMX) by E/Cu(Ⅱ)/Na2SO4 system (C0(Cu(Ⅱ))=1mM, C0(Na2SO4)=1mM, E=25V) was 93.3% at t=90min. Quenching combined with electron paramagnetic resonance (EPR) tests revealed that SO4•-, •OH and Cu(Ⅲ) were the primary contributors to SMX degradation. Solution pH, co-existing anions and organic matter affected the degradation performance of SMX. Four degradation pathways were proposed based on transformed products (TPs) determination, with pathways I and II being the dominant ones involving the cleavage of S-N bond in SMX. Ecological structure activity relationships (ECOSAR) program analysis implied that the TPs exhibited lower toxicity levels toward aquatic organisms compared to that of SMX. Additionally, the E/Cu(II)/Na2SO4 system achieved decomposition rates over 80% for various sulfonamides (SAs) and also demonstrated remarkable efficacy for SMX removal in different real waters, including tap water, lake water, river water and aquaculture wastewater, with all exceeding 80% at t=90min. E/Cu(Ⅱ)/Na2SO4 system developed in this study had the potential to be a prospective technique for SAs purification due to its outstanding performance in degrading and detoxifying SAs.

Village-level Processing of Pangi (Pangium edule Reinw.) Seeds by the Obu Manuvu Improves the Edibility and Level of Some Nutritional Factors [RESEARCH NOTE

Pangi (Pangium edule Reinw) seed is known to be a poisonous material. However, it becomes safe for consumption after processing. This study determined the effect of village-level processing by the Obu Manuvu community of Marilog District, Davao City, Philippines on the antinutrient and nutritional composition of Pangi seeds. Processing methods involved washing with running water for about 15 s, boiling in water for 30 min, and soaking in flowing water in a nearby river overnight. Results showed that after processing, the levels of antinutrients such as cyanogenic glycosides and oxalates were reduced significantly (p &lt; 0.05) by 99.15% and 78.23%, respectively. Further, the tannin content was also significantly reduced by 96.15%. The crude fat content significantly increased (p &lt; 0.05) by about 54%. Crude ash and fiber decreased, while protein did not change significantly (p &lt; 0.05). Minerals such as calcium and zinc increased (p &lt; 0.05) by 221.43% and 64.39%, respectively while the iron and manganese levels remained unaffected. Findings of the study suggested that the processing method by the Obu Manuvu effectively reduces the level of antinutrients, thereby improving the edibility and safety of Pangi seeds. Further, the processing method improves the level of some nutrients, specifically crude fat, calcium, and zinc.

Mof-derived carbon aerogel for rapid on-site extraction of chlorophenols based on drone-liquid circulation system

The rapid on-site extraction of chlorophenols (CPs) from environmental water sample is crucial for the scientific assessment of environmental risks and the implementation of control measures. However, this process presents significant technical challenges. In this study, a solid phase microextraction (SPME) device of drone-liquid circulation system was designed. The device utilized a ZIF-8/agarose derived carbon aerogel coated fiber (ZIF-8/AG-CA-F) for on-site extraction of CPs. Compared to commercial fiber, the ZIF-8/AG-CA-F demonstrated rapid and efficient capacity towards the four selected analytes due to its interconnected hollow porous structure and rich functional groups. The fiber carried by the designed on-site device was used for extracting CPs in actual river water sample. With the help of the micro-pump, the diffusion of the analytes towards the sorptive phase was promoted by accelerating the flow rate of the water sample. The combined effect of SPME fiber and the device accelerates the extraction rate, providing a new approach for rapid and efficient on-site determination of organic pollutants.

Influence mechanisms of dissolved organic matter and iron minerals on naphthalene attenuation during river infiltration

Natural attenuation of naphthalene (NAP) in riverbank filtration zones is vital for maintaining water quality and is affected by dissolved organic matter (DOM) and iron minerals. However, the effects of DOM and iron minerals on the attenuation of NAP remain unclear. In this study, the attenuation mechanisms of NAP under the influence of DOM and iron minerals were explored in a riverside source area. Field dynamic monitoring data revealed that the NAP concentration in groundwater is mainly influenced by DOM, effective bound‑iron, and the intensity of river water infiltration recharge. Column experiments indicated that DOM with α-Fe2O3 or α-FeO(OH) reduced medium permeability by 8.16 % or 6.85 %, respectively, increasing water retention time. However, they had different effects on the attenuation of NAP. The coexistence of α-Fe2O3 and DOM enhanced NAP attenuation capacity by 9.13 %–45.91 %, while α-FeO(OH) and DOM reduced it by −13.25 % to −24.13 %. These effects were attributed to changes in the medium permeability, particle size, secondary mineral formation, and microbial community structure. Specifically, α-Fe2O3 and DOM reduced medium permeability, increasing the adsorption and biodegradation reaction time of NAP, and promoted secondary mineral (FeCO3) formation, increasing the adsorption capacity of medium for NAP, while α-FeO(OH) and DOM underwent cementation, resulting in larger particles and reduced adsorption capacity for NAP. Additionally, α-FeO(OH) and DOM promoted Shewanlla growth, inhibiting NAP attenuation by competing with NAP-degrading bacteria. These findings improve the understanding of the natural attenuation of polycyclic aromatic hydrocarbons (PAHs) in riverbank filtration, offering a basis for evaluating and controlling PAH pollution risks.

Magnetic recyclable g-C3N4/CuFe2O4/MnO2 activated peroxymonosulfate process via dual Z-scheme heterojunction for photodegradation of ciprofloxacin

Composite heterojunctions effectively enhance the separation efficiency of photoelectrons and holes, thereby activating the peroxymonosulfate (PMS) process to degrade recalcitrant pollutants. Consequently, a g-C3N4/CuFe2O4/MnO2 (CN/CFO/MN) composite with a dual Z-scheme heterojunction was developed for the first time and coupled with PMS for the degradation of ciprofloxacin. CN/CFO/MN exhibited strong binding ability to ciprofloxacin with an adsorption capacity of 38mg/g, reaching adsorption equilibrium within 60min with high efficiency, which is crucial for effective degradation. Additionally, isolated CN/CFO/MN and bare PMS (0.3g/L) demonstrated limited degradation capabilities with ciprofloxacin removal rate of 51% and 41% under illumination, respectively. Notably, the elimination efficiency of ciprofloxacin was enhanced to nearly 100% by integrating CN/CFO/MN photodegradation with PMS activation. Furthermore, compared to pure CN, CFO, MN, and the binary CN/CFO, CN/CFO/MN provided superior photocatalytic degradation, improving the removal efficiency from 45% to 63%. The dual Z-scheme heterojunction in CN/CFO/MN furnishes ample photoelectrons to activate the PMS process for the generation of free radicals. Active species exploration experiments suggest that the CN/CFO/MN-PMS-light method primarily degrades ciprofloxacin by catalyzing the generation of holes, superoxide, hydroxyl and sulfate radicals. The CN/CFO/MN-PMS-light method achieved complete removal of 0.02–0.1g/L ciprofloxacin within 5min in tap, pond and river water systems. Ultra-performance liquid chromatography-mass spectrometry analysis-determined the degradation pathways of ciprofloxacin to involve the piperazine ring, defluorination reaction, and oxidation reaction of quinolone. Assessment via toxicity estimation software indicated that the toxicity of the degradation products was significantly reduced reaching harmless level. This work demonstrates that the CN/CFO/MN-PMS-light method with a dual Z-scheme heterojunction holds considerable potential for environmental purification.

Copper slag based catalytic material was prepared using a one-pot method to efficiently activate of peroxymonosulfate for degradation of carbamazepine

Smelt slag-based environmental catalytic materials offer a sustainable and valuable approach to solid waste management. In this study, a novel peroxymonosulfate (PMS) catalyst (MCT-2) was prepared from copper slag (MCT-1) by a non-calcined method. Subsequently, the MCT/PMS-AOP catalytic system was established. The copper slag, mainly composed of Si, Ca, Mg, Fe and O, was converted into MCT-2 by hydrothermal treatment, NaOH etching and edta-2na-induced crystallization, and finally, the molecular self-loading of MCT was achieved by the "one-pot method" under hydrothermal conditions. MCT-2 exhibits a layered surface morphology and CaFeO3 phase. In the MCT-2/PMS system, the dominant reactive oxygen species (ROSs) generated were SO4•− and HO•. The performance of the system was evaluated using CBZ as a simulated pollutant and actual river water as a carrier, and it was found that MCT-2/PMS degraded CBZ, BPA, DCF and ATZ up to 99%. Further mechanistic studies showed that MCT-2 has relatively high catalytic activity and the lowest reaction energy barrier compared with similar materials. The easy availability of raw materials, environmentally friendly preparation method, and high degradation efficiency make MCT/PMS-AOP have a broad application prospect.

Research on intelligent river water quality management system using blockchain-internet of things

Research on intelligent river water quality management system using blockchain-internet of things

Rubber additives and relevant oxidation products in groundwater in a central China region: Levels, influencing factors and exposure

This study investigated the presence of rubber additives and relevant oxidation products (RAROPs) in groundwater in central China's aboveground river region. Seven RAROPs were detected, and their levels in shallow groundwater showed a mild decreasing trend from the area near the Yellow River (Avg: 8.49 ng·L-1) to the area on the far bank of the Yellow River (Avg: 5.01 ng·L-1). In contrast, deep groundwater's RAROPs contents showed a dramatic decrease to only 0.26 ng·L-1. The dominant contaminant was found to be N-(1, 3-dimethylbutyl) -N′-phenyl -p-phenylenediamine (6PPD). The vicinity of the garages and car parks was often characterized as contamination hotspots. Correlation analyses further indicated that aquaculture was likely to be a potential pathway for shallow groundwater contaminant inputs. The amount of RAROPs intake by humans through groundwater is nearly 30 times different due to the imbalanced development between urban and rural areas. Children were the most vulnerable to RAROPs. Therefore, human activities (transportation, waste tire storage, water resource allocation and utilization patterns, diversion of Yellow River water to aquaculture ponds) may exacerbate RAROPs pollution in groundwater by leaching contaminants through the surface soil. These results are important for developing appropriate utilization and protection strategies for groundwater resources in developing countries.

Electrochemical immunosensor based on phages/CdSe nanoparticles as tracers to quantify clomazone in water

Clomazone, an herbicide used worldwide, contaminates river and lakes, as well as surface and ground water. Therefore, there is great interest in developing new analytical tools for detecting environmental pollutants that are simple, highly sensitive and provide an extended analytical range. This work describes a disposable, highly sensitive and reproducible electrochemical immunosensor based on a non-competitive and enzyme-free immunoassay to quantify clomazone in water samples. A specific clone of recombinant phage particles labelled with CdSe nanoparticles, which form a trivalent complex with the clomazone/monoclonal antibody anti clomazone immuno-complex, was used as tracer. Clomazone was determined indirectly by square wave anodic stripping voltammetry through the anodic oxidation of Cd previously deposited in an accumulation step from the reduction of Cd2+ ions released from CdSe nanoparticles. An excellent analytical performance, with a limit of detection and a midpoint sensitivity of 0.038 ng mL−1 and 1.34 ng mL−1, respectively, were found. The limit of detection was 60-fold lower than the limit of detection obtained using the same antibody and un-label phage in an optimized non-competitive ELISA. The developed electrochemical immunosensor was successively used to assay undiluted river water samples, where very good recoveries percentages were reached. The very low limit of detection achieved with the electrochemical immunosensor allows it to be used as an important environmental tool for the determination of clomazone.

Pollution Monitoring via Potentiometric Membrane Sensors for the Determination of Chlorpromazine Hydrochloride in the Presence of Its Main Photo-Degradation Products in River Water

The utilization of membrane sensors for the monitoring and determination of pharmaceutical environmental pollutants has emerged as a crucial objective in recent years. Given the extensive use of chlorpromazine hydrochloride (CPZ) in medicine, its presence in the environment, particularly in surface water such as rivers, is highly probable. Prolonged exposure of river water to sunlight and the photo-degradability of CPZ may enhance its photo-degradation. For the purpose of measuring CPZ in the presence of its primary photo-degradants, two sensitive and selective membrane electrodes were developed. These were synthesized utilizing two ion-pairing agents: sodium tetraphenylborate (TPB) and phosphotungstic acid (PTA). The electrodes exhibited a linear range that extended from 1 × 10−6 M to 1 × 10−2 M. The membrane electrodes of CPZ-TPB and CPZ-PTA exhibited slopes of 59.90 ± 0.60 mV/decade and 58.90 ± 0.80 mV/decade, respectively. The sensors mentioned above showed acceptable performance in a pH range of 2.0 to 6.0. All test parameters were optimized to provide superior electrochemical performance. The fabricated membranes were effectively employed to sensitively quantify CPZ in the presence of its principal photodegradants. The developed sensors were successfully employed to quantify CPZ in river water samples without necessitating pre-treatment procedures.

Plant and soil responses to sediment deposition and nutrient‐enrichment in healthy, deteriorating, and newly created coastal marshes of the Mississippi River Delta

Coastal marshes vulnerable to sea‐level rise may benefit from sediment amendments to increase elevation. However, nutrient‐loading to estuaries may counter elevation gain through reduced root production and/or increased decomposition. Here, we test if belowground plant productivity, root decomposition, and marsh accretion response to nutrient‐loading differs with sediment addition in three marsh types: a healthy intermediate salinity marsh, a deteriorating brackish marsh, and a created marsh in Barataria Basin, Louisiana, United States. In this region, wetland loss is rapid, and a major restoration project is underway to introduce Mississippi River water, sediment, and nutrients to offset marsh loss. Porewater nutrient concentrations, vegetation structure, belowground productivity and decomposition, and accretion rates were measured over 450 days. Experimental nitrate additions yielded high porewater ammonium‐N concentrations in the Deteriorating marsh but had a smaller effect in Healthy and Created marshes. Belowground productivity in the Deteriorating marsh was neutral to negatively affected by nutrient and sediment treatments, whereas positive effects occurred in Healthy and Created marshes. Despite elevation increase from sediment treatments, and substantial effects of nutrient treatments on porewater nutrient concentrations, belowground decomposition and surface accretion rates were not affected by treatments. Sediment deposition increased species richness in the Healthy marsh and added sediment and added nutrients with sediment increased plant height in the Created and Deteriorating marshes, respectively. Over the timescale measured, experimental sedimentation and pulsed nutrient input had few consistent effects on belowground ingrowth, decomposition, or surface accretion. Our findings highlight that response to nutrient pulses are complex and depend on baseline marsh conditions.

Origin of Intercrystalline Brine Formation in the Balun Mahai Basin, Qaidam: Constraints from Geochemistry and H-O-Sr Isotopes

The Balun Mahai Basin (BLMH), located in the northern Qaidam Basin (QB), is endowed with substantial brine resources; however, the genetic mechanisms and potential of these brine resources remain inadequately understood. This study investigated the intercrystalline brine (inter-brine) in BLMH, performing a comprehensive geochemical analysis of elemental compositions and H-O-Sr isotopes. It evaluated the water source, solute origin, evolutionary process, and genetic model associated with this brine. Moreover, a mass balance equation based on the 87Sr/86Sr isotopic ratio was developed to quantitatively evaluate the contributions of Ca-Cl water and river water to the inter-brine in the study area. The results suggest that the hydrochemical type of inter-brine in the north part of BLMH is Cl-SO4-type and in the south part is Ca-Cl-type. The solutes in brine are mainly derived from the dissolution of minerals such as halite, sylvite, and gypsum. The hydrochemical process of brine is controlled by evaporation concentration, water–rock interaction, and ion exchange interaction. Hydrogen and oxygen isotopes suggest that the inter-brine originates from atmospheric precipitation or ice melt water and has experienced intense evaporation concentration and water–rock interaction. The strontium isotopes suggest that the inter-brine was affected by the recharge and mixing of Ca-Cl water and river water, which controlled the spatial distribution and formation of brine hydrochemical types. The analysis of ionic ratios suggest that the inter-brine is derived from salt dissolution and filtration, characterized by poor sealing and short sealing time in the salt-bearing formation. The differences in hydrochemical types and spatial distribution between the north and the south are fundamentally related to the replenishment and mixing of these two sources, which can be summarized as mixed origin model of “dissolution and filtration replenishment + deep replenishment” in BLMH.

Multi-Criteria Analysis for Geospatialization of Potential Areas for Water Reuse in Irrigated Agriculture in Hydrographic Regions

As the climate crisis progresses, droughts and the seasonal availability of fresh water are becoming increasingly common in different regions of the world. One solution to tackle this problem is the reuse of treated wastewater in agriculture. This study was carried out in two significant hydrographic regions located in the southeast of Brazil (Mogi Guaçu River Water Management Unit—UGRHI-09 and Piracicaba River Basin—PRB) that have notable differences in terms of land use and land cover. The aim of this study was to carry out a multi-criteria analysis of a set of environmental attributes in order to classify the areas under study according to their levels of soil suitability and runoff potential. The integrated analysis made it possible to geospatialize prospective regions for reuse, under two specified conditions. In the UGRHI-09, condition 1 corresponds to 3373.24 km2, while condition 2 comprises 286.07 km2, located mainly in the north-western and central-eastern portions of the unit. In the PRB, condition 1 was also more expressive in occupational terms, corresponding to 1447.83 km2; and condition 2 was perceptible in 53.11 km2, predominantly in the central region of the basin. The physical characteristics of the areas studied were decisive in delimiting the areas suitable for the reuse of treated wastewater.

Trace Element Composition of Surface Water in Almaty City and Human Health Risk Assessment

This investigation meticulously examined the elemental composition of 64 water samples collected during the seasons of spring, summer, autumn, and winter of the year 2023. The average seasonal concentrations of arsenic (As), beryllium (Be), cobalt (Co), cadmium (Cd), copper (Cu), lithium (Li), molybdenum (Mo), nickel (Ni), lead (Pb), selenium (Se), uranium (U), mercury (Hg), aluminum (Al), barium (Ba), chromium (Cr), iron (Fe), manganese (Mn), strontium (Sr), vanadium (V), zinc (Zn), calcium (Ca), potassium (K), magnesium (Mg), sodium (Na), and chlorine (Cl) as well as SO4 and dry residue were computed at 16 strategically selected sites along the Bolshaya and Malaya Almatinka, Esentai, and Kargalinka rivers situated in Almaty. The sampling locations were categorized into three distinct sectors: upper (adjacent to mountainous regions), middle (urban zone), and lower (exceeding city limits), thereby facilitating the examination of discrepancies in water quality and elemental concentrations. The results reveal that surface water resources in Almaty, particularly concerning As, Ni, Cr, U, and Pb, may present a considerable carcinogenic risk if utilized for consumption purposes. This is especially alarming given that these rivers constitute a vital source of drinking water for the inhabitants of the city. Specifically, at two sampling locations along the Bolshaya and Malaya Almatinka rivers in proximity to significant urban thoroughfares, untreated river water displayed an elevated carcinogenic risk (CR ~ 10−2). These results highlight the urgent necessity for enhanced water treatment and ongoing monitoring to safeguard public health.

Fluorescent “On‐Off‐On” Probe for Cascade Detection of Ag(I) and Ascorbic Acid Using Folic Acid Protected Copper Nanoclusters

AbstractFolic acid (FA) protected copper nanoclusters (FA‐CuNCs, λex=350 nm, λem=445 nm) were synthesized and used as a fluorescent “on‐off‐on” probe for the cascade detection of Ag+ and ascorbic acid (AA). The fluorescence emission of FA‐CuNCs at 445 nm was quenched significantly by Ag+ due to the analyte‐induced aggregation followed by the formation of larger nanoparticles. However, when AA was added to the in‐situ generated Ag@FA‐CuNCs, the fluorescence emission of FA‐CuNCs was recovered at 445 nm because of the AA‐directed reduction of Ag+ to Ag0. The experimental conditions, such as pH, incubation time, and quencher Ag+ concentrations, were optimized to achieve improved sensitivity. The detection limit for Ag+ and AA was estimated as 37.1 nM and 0.27 μM with a linearity range of 2.49–22 μM and 4.71–81.53 μM, respectively. In real sample analysis, the recoveries of Ag+ ions in river water and AA in orange juice samples were found between 99–93 % and 97–94 % using the probes FA‐CuNCs and Ag@FA‐CuNCs, respectively. Overall, this work offers a viable method for the sequential detection of Ag+ and AA using FA‐CuNCs via a fluorescence “on‐off‐on” switch mechanism.

Pyrene Based Schiff Base for Cascade Fluorescent "On-Off" Detection of Aluminium(III) and Fluoride Ions and its Applications in Live Cells Imaging.

An easy-to-prepare pyrene-based Schiff base PNZ was synthesized by condensing equimolar amount of 1-pyrenebutyric hydrazide with 2-hydroxy-naphthaldehyde, and employed as a fluorescent chemosensor for in-situ cascade detection of aluminium (Al3+) and fluoride (F-) ions. In DMSO:H2O (1 : 1, v/v), the weakly emissive PNZ showed a significant fluorescence enhancement at 455 nm selectively upon the addition of Al3+ due to the complexation-induced formation of a pyrene excimer. Schiff base PNZ and Al3+ formed a complex in 2 : 1 binding ratio with the estimated binding constants of K1:1=9826.01 M-1 and K2:1=3188.49 M-1. The sensing mechanism was explored by performing quantum mechanical calculations and 1H-NMR titration of PNZ with Al3+. The in-situ formed PNZ-Al3+ complex species enabled the fluorescent turn-off detection of F-. Using PNZ and PNZ-Al3+, the concentrations of Al3+ and F- ions can be detected down to 2.89×10-7 M and 1.88×10-7 M, respectively. The cytotoxicity of the PNZ and its ability to bioimage Al3+ and F- ions was examined in the human cervical cancer cell line. Finally, the receptor PNZ was applied for the quantification of Al3+ and F- ions in various real samples, such as tap water, river water, rainwater, mouthwash, and toothpaste.

Construction of Mo-Doped CuO Incorporated on Carbon Black Modified Disposable Sensor for the Voltammetric Detection of Metol in Environmental Samples

Abstract In this study, a molybdenum-doped copper oxide (Mo–CuO) composite was synthesized via a hydrothermal method and combined with carbon black (CB) to form Mo–CuO@CB. This composite was used to modify a screen-printed carbon electrode (SPCE) for the detection of Metol (MT), an industrial pollutant harmful to both human health and the environment. Structural and surface characterization was performed using high-resolution transmission electron microscopy, field-effect scanning electron microscopy, energy-dispersive spectroscopy, Raman spectroscopy, X-rssy photoelectron spectroscopy, and X-ray diffraction. Electrochemical techniques, including differential pulse voltammetry and cyclic voltammetry, were used to assess the sensor's performance. The Mo–CuO@CB@SPCE sensor exhibited a low detection limit of 2.7 nM, and limit of quantification is 82 nM, a broad linear range (5.0 × 10−9 – 170 mol L-1), and high sensitivity (4.148 μA μM⁻¹ cm⁻²), benefiting from the catalytic activity of Mo–CuO and the large surface area of CB. With recovery rates ranging from 96 % to 100.6% in pond, river, and tap water, the sensor effectively detects MT in environmental samples, ensuring reliable monitoring of this persistent pollutant.

Evaluation the ecological service value of the Yangtze River water systems

Evaluation the ecological service value of the Yangtze River water systems