Sources Of Water Pollution Research Articles

Bio-green synthesis of bismuth oxide nanoparticles using almond gum for enhanced photocatalytic degradation of water pollutants and biocompatibility.

The discharge of dye-contaminated industrial wastewater is a significant source of water and soil pollution. The eco-friendly synthesis of multifunctional bismuth oxide nanoparticles (BiO-NPs) offers a promising approach for the removal of toxic contaminants. The incorporation of natural polymers in nanoparticle production has gained significant scientific attention due to their environmentally friendly and efficient properties. This study emphasizes the use of almond gum (ALG) as a potent bio-reductant for the green synthesis of BiO-NPs. The synthesized BiO NPs exhibited a surface area of 24.5774 m2/g, demonstrating their potential for enhanced catalytic activity. The photocatalytic activity of the BiO NPs was evaluated by degrading Congo Red and Brilliant Green dyes under visible light irradiation, achieving degradation efficiencies of 90.21 % ± 0.32 and 90.52 % ± 0.29, respectively. Radical trapping experiments confirmed the primary roles of photo-generated electrons and hydroxyl radicals in the degradation process. The reusability analysis demonstrated that the BiO-NPs could be effectively recycled for 4 cycles, maintaining good stability. Degradation intermediates were identified using LCMS. Additionally, the catalytic reduction conversion of 4-nitrophenol to 4-aminophenol using NaBH₄ achieved a degradation efficiency of 92 % ± 0.41 within 32 min. Biocompatibility assessments using NIH/3T3 cell lines indicated that ALG-BiO NPs are safe for environmental applications.

Evaluation of water quality status and pollution source apportionment of Kulfo River adjacent to Arba Minch town

Evaluation of water quality status and pollution source apportionment of Kulfo River adjacent to Arba Minch town

Tracing the Surface Water Pollution in a Chemical Park Based on the Fusion of Spectral and Chromatographic Characteristic Data

Identification of the pollution source of surface water in a chemical park was difficult because many industrial enterprises with complex wastewater components and similar characteristics are located there. Therefore, a national-level chemical park in Jiaxing City was studied, and wastewater samples from ten batches of seven key enterprises in the park were collected and analyzed using 3D excitation emission matrix spectrometry （EEMS） and gas chromatography-mass spectrometry （GC-MS）. Parallel factor analysis was used to extract common components of EEMS spectra from different batches of drainage in the same enterprise to construct an EEMS characteristic data matrix. Furthermore, specific substances with high detection rates or that could effectively distinguish other enterprise drainage were screened out from the GC-MS data to construct a GC-MS characteristic data matrix. Pollution source identification was attempted with different models based on different data matrices. The results showed that regardless of whether being based on the EEMS original data matrix, the EEMS characteristic data matrix, or the GC-MS characteristic data matrix, the identification accuracy of the BP neural network model was not high, only 71.43%, 76.19%, and 71.43%, respectively, which was slightly higher than that of the support vector machine model （76.19%, 76.19%, and 57.14%）. However, when the EEMS and GC-MS characteristic data fusion matrix were used, the pollution source identification performance was significantly improved. The identification accuracy, macro precision, macro recall, and macro harmonic mean of the support vector machine model for the wastewater of the seven enterprises were 95.24%, 96.43%, 95.24%, and 95.10%, respectively, while the performance of the BP neural network model was better, with all four indicators close to 100%. The study provides an effective method for identifying surface water pollution sources in chemical parks.

Use of EDS/EDX to evaluate heavy metals pollution in water sources

The objective of the study was to evaluate the role of brick kilns in contaminating water bodies with heavy metals in Punjab, India. The energy-dispersive x-ray spectroscopy (EDS/EDX) machine effectively tested heavy metals in water samples. The research revealed that the surface water near the brick kilns was extensively polluted with heavy metals. Their Pollution Load Index (PLI) values varied between 2.83 and 52.98, and their degree of contamination was “Progressive deterioration”. The PLI values for groundwater ranged between 0.089 and 3.68, and the degree of contamination varied from “Baseline levels of pollutants” to “Progressive deterioration”. In general, the groundwater of the studied area had a PLI value of 0.477 (Baseline levels of pollutants), whereas the surface water had a PLI value of 11.453 (Progressive deterioration). The Water Quality Index (WQI) of groundwater was highly influenced by heavy metals, notably Arsenic (As) from lithologic origins, and Lead (Pb) from the burning of fuels in the brick kilns. In descending order, Pb>Zn>As>Cr>Ni metals were influencing the PLI, and the correlation matrixes demonstrated that the presence of heavy metals was associated with the PLI and WQI values. Therefore, there is evidence that brick kilns are polluting water bodies with heavy metals. EDS proved to be one of the instruments to evaluate the chemical elements in water. It was recommended to enforce the law governing the use of biomass to reduce vast quantities of coal used in baking bricks.

Remote sensing research on plastics in marine and inland water: Development, opportunities and challenge.

The accumulation of plastic waste from various sources into marine and inland water is considered a global problem due to its serious impacts on aquatic ecosystems and human health. In the past decade, remote sensing has played an important role in monitoring of plastic pollution in marine and inland water sources and has achieved a series of research results in this field. In this study, a comprehensive review was conducted on the development, opportunities, and challenges of datasets and methods in Marine and Inland Water Plastics Remote Sensing (MIWPRS) monitoring over the past decade, based on the Web of Science (WOS) core database. The results indicated that compared with traditional methods, remote sensing has attracted the attention of scholars due to its advantages. Since 2014, the number of related publications has been increasing year by year, especially in China and the United States, which have achieved tremendous development. The MIWPRS research focus mostly on the use of different satellite remote sensing data and related algorithms to obtain the distribution of plastics in marine and inland water. However, it faces the challenge of lacking subsequent systematic impact assessment models and key pollution prevention measures. In terms of data acquisition, there is a lack of continuous observation models due to the fluidity of marine and inland water. Therefore, MIWPRS has great development opportunities in developing specialized sensors and combining multi-source data with interdisciplinary knowledge such as artificial intelligence (AI) and GIS. It is necessary for us to improve the seasonal migration model of plastics in water and promote the development of MIWPRS towards broader and deeper fields.

Институциональный подход к реализации инновационного проекта «Чистая вода» в регионах России

The article examines the activities of state and municipal authorities in the implementation of the project «Clean Water». The set of organizational, managerial and economic relations for providing the population with clean drinking water is analyzed. The main reasons for bad-th position in providing the population with clean water technology from water sector and insufficient investment, required in the new water treatment technology, water treatment and sanitation, the result of which is that the poor quality of water services, widespread pollution of water sources in industrial and domestic sewage. It is proved that if in the coming years it is not possible to lay the foundations and create mechanisms for the transition of the water supply sector to an innovative development model, then we can expect a further deterioration in the situation in the field of providing clean water to the population. Innovative approaches to the implementation of the «Clean Water» project (institutional support of the project implementation process; development and application of new technologies for water treatment and water supply; use of new organizational and managerial approaches to improving the economic and social efficiency of water supply to the population) are justified. The elements of the institutional support of the Clean Water project are shown. Based on the analysis of the process of water supply and water supply in the Vologda region, the possibility of implementing the project «Clean Water» is justified. The theoretical and methodological analysis of the formation and development of program approaches to providing clean drinking water to the population is carried out, the need for an innovative approach to the implementation of the strategic directions of the State Program «Clean Water» is justified. Justified budgetary efficiency index, which is defined as the ratio of the volume of investments from the Federal budget allocated for this object to the planned target of increasing the share of the population with quality drinking water from centralized water supply systems. It is shown that the achievement of goal-setting in the field of water supply and water supply, including in the implementation of the Clean Water project, should take into account social factors, organizational, managerial and institutional influences, and factors that counteract the achievement of a synergistic effect

Extraction of heavy metal ions from aqueous solutions by frame sorbents based on benzene-1,3,5-tricarboxylate (MBTC) and benzene-1,4-dicarboxylates (MB DC) of various metals

Pollution of soils and water sources with heavy metals leads to negative consequences for the environment associated with disruption of ecosystem balance, harm to the health of living organisms and humans. To solve this problem, organometallic frame sorbents capable of efficiently extracting heavy metal ions from aqueous solutions have been synthesized. During the conducted research, the regularities of the adsorption of cadmium, lead, copper, cobalt and nickel ions were studied using synthesized frame sorbents based on benzene-1,3,5-tricarboxylates (MBTC) and benzene-1,4-dicarboxylates (MBDC). The identification analysis performed on diffractograms of CoBTC and NiBTC powders showed the presence of structures [Co3(BTC)2·12H2O] and [Ni3(BTC)2·12H2O]. Unlike NiBTC, NiBDC dicarboxylate crystallizes in triclinic syngony (spatial group P1¯, Z = 1) and corresponds to the crystal structure [Ni3(OH)2(BDC)2··4H2O], the sample of the CuBTC compound crystallizes in cubic symmetry with the space group Fm3¯m (Z = 16) and corresponds to the crystal structure [Cu3(BTC)2·3H2O], and the CuBDC compound has a structure belonging to the monoclinic symmetry. The results of the analysis of isotherms of low-temperature nitrogen adsorption using synthesized MOFs made it possible to determine important textural characteristics of sorbents. It was noted that a strong adsorbate-adsorbent interaction is realized for CoBTC in the micropore region. It is shown that the specific surface area of synthesized sorbents, calculated by the Brunnauer-Emmett-Teller (BET) method, varies widely. Thus, for CoBTC and NiBTC compounds, it was 276.0 and 9.0 m2/g, respectively. The noted differences are due to the presence of a large number of micropores in the sorbent CoBTC. In most cases, the kinetic patterns of the adsorption of heavy metal ions can be described by a pseudo-second-order equation. The only example of the process proceeding according to the kinetic equation of the pseudo-first order is the adsorption of copper ions on the NiBDC sorbent. It is noted that cobalt, nickel and copper ions are better absorbed by sorbents containing the corresponding ions of the same name according to the Paneta-Faience rule. The linear relationship found between the sorption capacity and the logarithm of the ratio of the radius of ions to their electronegativity implies that the mechanism of adsorption of metal ions on MOFs is determined by the physicochemical properties of the ions themselves. The developed organometallic frame compounds can be effectively used in technologies for purification of water resources from toxic heavy metal ions.

Black Plum (Syzygium Cumini) Seeds Adsorbent for Underground Water Nitrate Attenuation and Statgraphics Optimization

Nitrate (NO3–) pollution of water sources are a global issue, and gets transformed into nitrite (NO2–) when in contact with the saliva, resulting in a significant health implication. Groundwater from Tandari Budum, Maiduguri, Nigeria, was denitrified in this study by varying the black plum seed (BPS) adsorbent dosage, contact time, temperature and pH in the range of 0.1-1.0g, 20-140 min, 30-90℃ and 5-11, respectively. From the Draper-Lin small composite design (DSCD) 18 runs optimization studies on NO3– concentration and adsorption capacity () responses carried out, it was found that time and temperature have the most impact on the process. For NO3– reduction to 45 mg/L maximum value, optimal factors were 60℃, 80-85 min, pH = 8 and 0.4g dose; whereas for (13.7 mg/g), it is pH = 8, dose = 0.4g, 20 min time and 39℃. There was an observed slight similarity (in the optimal outputs), differences (in the optimal factors) and discrepancies in results obtained from non-standardized experimental runs conducted initially when compared with the DSCD design of experiment (DOE). But then, the Statgraphic Centurion 19-X64 v. 19.6.04 software analysis gave a more reasonable findings, which fits a quadratic model at R2 = 0.9295 (predicted NO3– reduction) and 0.9068 (estimated ). Since an alkaline pH, shorter time, moderate temperature and little resources are needed to attenuate NO3– (initially at 123 mg/L) from Tandari Budum groundwater, BPS is a novel adsorbent discovered in this study, corresponding to 63.41% removal efficiency.

Bottleneck Problems and Countermeasures in Operation and Maintenance of Non-Point Source Pollution Ecological Treatment Projects in China

At present, non-point source pollution (NPSP) has overtaken point source as the most important source of water pollution in China. Ecological treatment projects (ETP) suitable for non-point source pollution have been widely recommended. However, China’s NPSP prevention system has not yet taken shape, the implementation and management levels are disorganized, and the long-term management and protection of NPSP-ETP remains an urgent problem. This paper focuses on the practical problems encountered in the promotion of ETP in China, and ways to solve these problems in the operation and maintenance process. First, problems encountered in the practice of NPSP-ETP in China are summarized as being caused by a lack of systematic regulation on operation and maintenance. Following this, promising countermeasures to solve these problems are proposed, including establishing an ecological treatment technology system, improving the technology selection assessment system, improving the assessment method in project operation, and establishing a systematic operation and maintenance process. Finally, a novel theory of Monitoring-Assessment-Repair (MAR) for ETP is proposed to solve the systematic bottlenecks in engineering operation and maintenance. Furthermore, the problem of clogging in infrastructure is discussed in detail, to illustrate the concrete operation of MAR theory. Overall, this study clarifies the issues in favor of a long-term mechanism of NPSP prevention in and beyond China.

Characteristics of urban drainage water and its impacts on neighboring rivers

ABSTRACT Drainage systems in urban areas are designed to collect and transport stormwater from citizen areas. However, the water in drainage systems might contain untreated, misconnected, or low-treated sewage and polluted runoff and potentially pollute neighboring urban rivers. In this study, the drainage waters in Taipei city, Taiwan, were investigated, and the impacts on water quality in the receiving Keelung River were assessed by the Water Quality Analysis Simulation Program (WASP) and five scenarios. If the drainage outlets were not intercepted but discharged to the river, the BOD and NH3-N in the Keelung River would increase by 5.7% and 2.9%, respectively. Moreover, the BOD concentration under low-flow conditions (Q75) increased by 30%, and the NH3-N increased by 37.6%. If all domestic wastewater is treated and zero point pollution sources in the drainage water in the future, the BOD could decrease by 55.4%, and the NH3-N could decrease by 44.8%.

A Study of innovative Approaches to Water pollution Control: Emerging Strategies and Technologies

Abstract The study explores the innovative ways of controlling sustainable water pollution, which has become a necessity as water bodies become contaminated by the day, with the influence of industrialization, urbanization, and agricultural practice. It includes detailed explanations about the types and sources of water pollutants, while criticizing the traditional treatment for not taking into consideration sustainability. It has also brought emerging strategies that have potential alternatives to conventional techniques with the aim of higher efficiency and reduced impact on the environment, including green chemistry, bioremediation, nanotechnology, and advanced oxidation processes. Case studies demonstrated successful implementations of innovations in different regions as great emphasis is placed on specific solutions and collaboration among stakeholders. These technological changes are further developed regarding issues of scalability, costs, and regulatory matters inhibiting the use of the same. Finally, recommendations have been made toward stronger research and development of said technologies, appropriate policies toward management of water, and civic activism that would help make responsible, healthy, and friendly environments for both health care systems and the environment.

A Comparative Assessment of Water Quality in the Pavana River: Urban vs. Suburban Locations in Pune, India

Water pollution continues to be a serious environmental issue that threatens human health and ecological sustainability. In this study, a comparative analysis of water pollution was conducted between urban and suburban/rural areas by identifying locations as “City” and “Outskirts,” and reviewing data for the years 2017-2018 respectively. Water samples werecollected from each location and analysed for various tests like Biochemical Oxygen Demand (BOD), PH, Dissolved Oxygen (DO) and chlorine content. The analysis showed a significant difference in water pollution sources between the city and the outskirts. The city had the worst water quality in all tested parameters due to high industrial activities, urban runoffand sewage discharge. Water in the outskirts was the least polluted with water since there were few impervious surfaces and low human activities compared to the city. On the other hand, agricultural runoff or diffuse pollution was still a notable issue in suburban/rural areas. This demonstrates the complicated relationships between land use, human activitiesand environmental factors that shape the water quality situation. Such results indicate the necessity of fast pollution control initiatives and sustainable land treatment steps to reduce water pollution in urban and suburban areas. By doing so, it is possible to secure water resources for the present and the next generation.

Comprehensive assessment of surface water quality and pollution sources in Al-Muzaynah dam lake, Syria: insights from multivariate statistical analysis

Comprehensive assessment of surface water quality and pollution sources in Al-Muzaynah dam lake, Syria: insights from multivariate statistical analysis

A review on pharmaceutical pollutants removal in water solution by catalytic ozonation using zeolite

AbstractThe presence of pharmaceutical pollutants in water sources constitute a serious risk to human health and the environment. Catalytic ozonation has emerged as a promising strategy for reducing these pollutants. This procedure uses ozone with the help of catalysts to improve the oxidation of organic molecules. Recently, there has been a lot of interest in using zeolite as an ozonation catalyst in the elimination of pharmaceutical contaminants from water solutions. Zeolites have unique properties such as their high surface area, porosity, and ion‐exchange capabilities, that make them effective catalysts for the decomposition of ozone and the oxidation of organic pollutants into harmless byproducts. This study aims to investigate the efficiency of zeolite catalytic ozonation in the elimination of pharmaceutical pollutants from aqueous solutions encompassing the working mechanisms, the determinants affecting the process's efficiency, potential obstacles, and perspective avenues for advancement within this field.

A high-resolution multi-scale industrial water use dataset in China

Water is crucial for achieving the UN Sustainable Development Goals, particularly SDG 6. As a major source of water use and pollution, industrial sector requires improved water management based on more systematic and refined analysis. Such analysis, however, is compromised by the accuracy, granularity, and coverage of industrial water data. Here we present an open dataset of China’s industrial water use, compiled from 1,480,265 plant-level reports. This high-resolution multi-scale dataset offers unparalleled details, supporting multi-scale analysis at the province, city, and county levels, and across 2-digit, 3-digit, and 4-digit industrial classifications. It provides comprehensive information on water use, recycling, pollution, and wastewater processing. Such data enables further macro- and micro-level analysis, including multi-regional input-output analysis, structural decomposition analysis, statistical analysis, machine learning, as well as many other advanced analytical methods. This dataset can equip researchers and policymakers with a valuable tool to advance sustainable water management, fostering alignment with global sustainability goals.

The evolution patterns and driving factors of urban domestic water pollution utilizing China’s two national pollution source surveys

Characteristics of domestic water pollution are of significant practical importance for implementing targeted urban wastewater treatment strategies. The pollutant source census in China serves as a fundamental undertaking in the study of pollution sources, providing crucial data for the analysis of pollution from domestic sources. This study employs pollution coefficients derived from China's two national pollution source surveys, integrating spatial autocorrelation and center-of-gravity shift analysis methods to investigate the national-scale spatial evolution characteristics of major urban domestic water pollutants, including BOD, TN, TP, and Oils. Furthermore, the impact of urbanization processes in population, economic, social, and spatial dimensions on urban domestic water pollution sources is explored using the multi-scale geographically weighted regression (MGWR) method. The results show that: (1) Urban domestic water pollution exhibits an east-high and west-low distribution pattern, with EHL being the primary region of pollution generation. Compared to 2007, the western region experienced a faster increase in BOD (30% increase), while the eastern region showed a sharper decline in TN (45% decrease) by 2017. (2) The results of spatial autocorrelation show that high-value clusters of urban domestic water pollution are located in the eastern China and around Chongqing, while low-value clusters are extensively distributed in the western region, indicating significant spatial heterogeneity in water pollution. (2) Based on center-of-gravity analysis, pollution displays a discernible migration trend from the northeast to the southwest, with the center located near the border of Henan and Hubei provinces, within the latitudinal and longitudinal range of 32°N–32.79°N and 113.09°E–113.85°E. The migration distances, ranked in descending order, are as follows: Oils (72.23 km) > BOD (65.59 km) > TN (63.9 km) > TP (22.73 km). (3) Significant differences are observed in the effects and spatial regions influenced by urbanization factors across different dimensions. Population and social urbanization exhibit pollution-increasing effects, whereas economic and spatial urbanization demonstrate pollution-reducing effects. These results will deepen our understanding of the spatial differentiation patterns of urban domestic source pollution, providing theoretical guidance for alleviating the pressure of urban pollution management. In addition, this article is an in-depth study of the first two pollution source surveys, which can lay a research foundation for future investigation work.

ENVIRONMENTAL EFFECTS OF PORT ACTIVITIES IN COTONOU, BENIN (WEST AFRICA)

The environmental effects of port activities on the biological environment are one of the growing concerns due to the importance of ports for maritime trade and the environmental consequences they generate. Activities related to maritime transport, waste management, and dredging can disrupt marine ecosystems, introduce invasive species, and pollute the waters. The objective of this research is to analyze the environmental effects of port activities in Cotonou, Benin. The data comes from several sources, including field studies, research reports, and marine pollution data. The information includes water quality measurements, observations on marine biodiversity, and data on waste management practices in ports. The methods of analysis include case studies, statistical analyses of pollution data, and ecological impact assessments. Comparisons are made between port areas and surrounding marine areas to evaluate the effects of port activities. Risk assessment models are also used to understand the implications of the bioaccumulation of toxic substances in the food chain. The results of the research show that maritime transport is a major vector for the introduction of exotic species, which can disrupt local ecosystems. The discharge of hydrocarbons and solid waste has harmful effects on the health of aquatic organisms and raises concerns about the bioaccumulation of toxins. Dredging operations disturb marine habitats, burying organisms and introducing pollutants into the environment. Plastic waste poses a serious threat to marine life, leading to health issues for species and affecting the integrity of coastal ecosystems. The main hazards associated with port activities include fire, workplace and traffic accidents, water pollution, explosions, drownings, and contamination of the natural environment by toxic substances and accidental discharges. Discharges from ships at sea constitute one of the major sources of water pollution caused by maritime transport. Several types are observed. Cargo losses frequently occur during loading or unloading due to handling errors or faulty equipment. This can involve any type of goods.

Cigarette butt littering as a potential source of water pollution and human health risk

Smoked cigarette butts (CBs) serve as reservoirs for harmful contaminants. The objective of the current study is to assess the CB littering in Aizawl city and estimate its potential contribution to water pollution in downstream surface water sources, along with the associated human health risks. The spatial-temporal distribution of CB littering density (CBD) across the city, spanning various land-use patterns, was analyzed through a visual-oriented littering survey. With an annual average CBD of 0.438 ± 0.669 CBs/m2, commercial areas were identified as the littering hotspots. Further, the water pollution potential index (WPPI) was formulated considering leached concentrations of different contaminants from CBs into the water and their standard permissible limits. WPPI was calculated as 5.22 × 10−02, which represented water pollution potential from a single CB/L of water. This corresponded to a cumulative WPPI of (59.97 ± 6.68) × 10−06 from CB littering to surface water pollution through municipal sewerage system. The health risk assessment associated with CB littering was analyzed through the potential chronic daily intake (CDI) of leached contaminants, non-cancer risk (NCR), and cancer risk (CR). Heavy metals (lifetime exposure of 1125.9 mg from 1 CB/L) were found to be the most significant contributor to the cumulative CR (3.847 × 10−06) and hazard index (HI) (1.785 × 10−02). Further, it was estimated that the potential CR associated with 242 CBs/L in water is equivalent to smoking 1 cigarette per day for a lifetime. The WPPI, CR, and HI suggested that littered CBs can significantly contribute to water pollution.

Selective Electrochemical Nitrate Reduction to Ammonia on Co-Based Catalysts

About 150 million metric tons of ammonia (NH3) were produced in 2023 mainly for agricultural purposes as a fertilizer [1]. This compound is industrially produced by the conventional Haber-Bosch process under high temperatures (350 – 550 °C) and high pressure (150 – 350 atm), thus, its production accounts for 1.8 tons of CO2 emissions per ton and 2% of the energy consumed in the world [2]. These factors have led to an interest in developing green alternative methods that allow the production of large amounts of NH3. Therefore, it has been demonstrated that the electrocatalytic synthesis of NH3 is a viable route that can be developed via the reduction of nitrate (NO3 -) to simultaneously mitigate its pollution in water sources, which has become a major human health concern when it is consumed [3]. Since the electrochemical reduction of NO3 - involves a complex eight – electron process, it is vital to design a highly selective, active, and stable catalyst. In this work, the performance of Co-based catalysts in alkaline conditions was evaluated and our studies demonstrated that a three-dimensional (3D) Co substrate can achieve a faradaic efficiency (F.E.) of up to 86% at +0.023 V vs RHE (Reversible Hydrogen Electrode) with a partial current density of 23 mA cm-2. However, in the presence of an excess of NH3, Co corrosion is promoted while creating a Co-NH3 complex. In order to avoid this, the thermo-oxidation of Co foam at 400, 600, and 800 °C was performed, proving that a larger oxide layer improves the stability as well as increases the active surface area of the electrode. Furthermore, the samples could reach greater current densities when subjected to a pre-reduction treatment. The sample oxidized at 600 °C presented superior performance, achieving a F.E. of 66% at +0.023V vs RHE, a partial current density of 170 mA cm-2, and approximately 8 h of stability. This work has provided an opportunity to explore the influence of the oxide layer on NH3 synthesis, as well as the necessity of advancing novel strategies to enhance the selectivity and stability of the proposed catalyst.[1] Production of ammonia worldwide from 2010 to 2023. Statista (2024). Retrieved from: https://www.statista.com/statistics/1266378/global-ammonia-production/#:~:text=Ammonia%20production%20has%20remained%20fairly,approximately%2064.6%20million%20metric%20tons.[2] Wang, J., Cai, C., Wang, Y., Yang, X., Wu, D., Zhu, Y., Li, M., Gu, M., & Shao, M. (2021). Electrocatalytic Reduction of Nitrate to Ammonia on Low-Cost Ultrathin CoOx Nanosheets. ACS Catalysis, 11(24), 15135–15140. https://doi.org/10.1021/acscatal.1c03918[3] Xu, H., Ma, Y., Chen, J., Zhang, W., & Yang, J. (2022). Electrocatalytic reduction of nitrate: a step towards a sustainable nitrogen cycle. Chemical Society Reviews, Issue 7. https://pubs.rsc.org/en/content/articlelanding/2022/cs/d1cs00857a

Gemini surfactant-engineered di-Schiff bases: Tailoring hydrophobicity to enhance catalytic and biological activities

This study explores the enhancement of catalytic performance of silver nanoparticles (AgNPs) using a series of gemini surfactants based on di-azomethine with varying hydrophobic tail lengths: DSGO, DSGD, and DSGH. By fine-tuning the molecular structure of these surfactants, we aim to develop more effective catalysts for purifying polluted water sources. The high surface energy of AgNPs often results in their aggregation, reducing their catalytic efficacy. However, increasing the surfactant tail length from 8 (DSGO) to 16 (DSGH) carbon atoms improves the stability and dispersibility of AgNPs, as confirmed by DLS, TEM, and UV analyses. DSGH, with its longer carbon tail, facilitates AgNPs synthesis with superior stability and smaller particle size, indicated by a higher zeta potential of +55.6 mV and a reduced size of 15.1 nm. This is attributed to the increased surface activity and hydrophobicity of the surfactants. As the tail length increases from 8 to 16, the investigated surfactant’s tendency for micellization and adsorption rises. Notably, DSGH exhibits the lowest critical micelle concentration (CMC) of 406 μM and the highest adsorption Gibbs free energy (ΔG°ads) of −59.08 kJ·mol−1 at 20 °C, enabling strong adsorption onto AgNPs. By modulating surfactant hydrophobicity, we effectively regulated AgNP catalytic activity. The DSGH/AgNPs composite shows enhanced catalytic activity, efficiently converting p-nitrophenol (p-NP) and methylene blue (MB) into less toxic species with apparent rate constants (kapp) of 0.368 and 0.537 min−1, respectively. Additionally, the AgNP-incorporated gemini surfactants exhibit promising antimicrobial activity against tested bacteria and fungi. Remarkably, the DSGD/AgNPs hybrid system surpasses commonly used commercial antimicrobial agents in efficacy. This study underscores the potential of manipulating surfactant structure to control the catalytic and antimicrobial activity of AgNPs.