Natural Water Research Articles

Applying Bourdieu’s Theory to Public Perceptions of Water Scarcity during El Niño: A Case Study of Santa Marta, Colombia

This study investigated the sociological dimensions informing public perceptions of water scarcity during the El Niño drought period in Colombia. We conducted this study in Santa Marta, Colombia, and surveyed 405 urban and rural residents to understand their perceptions of water scarcity, management, and the impacts of the El Niño phenomenon. The survey used a Likert scale to measure responses and employed a multivariate analysis of variance to analyze the data while considering factors such as location (urban versus rural) and gender. The study results indicated that urban residents often experience an irregular water supply all year, whereas most rural respondents noted a more consistent availability of water. The perception of water scarcity also differed notably between urban and rural areas due to their different historical and cultural experiences (habitus). Urban respondents mostly recognized the presence of water, while rural perspectives were less conclusive, likely influenced by their direct access to natural water sources. Participants across various demographics consistently reported that poor management by local, regional, and national governments contributes to the water scarcity crisis, highlighting the importance of improving communication about climate events like El Niño and water management to increase community engagement in public policies. Our research suggests that better understanding the social foundations of such perceptions using Bourdieu’s concepts of social fields, habitus, and capital forms can significantly enhance water management strategies.

Harnessing the Power of Natural Mineral Waters in Bread Formulations: Effects on Chemical, Physical, and Physicochemical Properties

Harnessing the Power of Natural Mineral Waters in Bread Formulations: Effects on Chemical, Physical, and Physicochemical Properties

Spatially Explicit Impact of Land Use Changes in the Bay Area on Anthropogenic Phosphorus Emissions and Freshwater Eutrophication Potential.

Land use changes significantly impact anthropogenic phosphorus (P) emissions, their migration to a water environment, and the formation of freshwater eutrophication potential (FEP), yet the spatiotemporally heterogeneous relationships at the regional scale have been less explored. This study combines land use classification, P-flow modeling, spatial analysis, and cause-effect chain modeling to assess P emissions and P-induced FEP at a fine spatial resolution in Guangdong-Hong Kong-Macao Greater Bay Area and reveals their dynamic responses to land use changes. We find that land conversion from cultivated land to impervious land corresponded to an increase in P emissions of 4.1, 1.8, and 0.5 Gg during 2000-2005, 2005-2010, and 2010-2015 periods, respectively, revealing its dominant but weakening role in the intensification of P emissions especially in less-developed cities. Expansion of aquacultural land gradually became the primary contributor to the increase in both the amount and intensity of P emissions. Land conversions from cultivated land to impervious land and from natural water bodies to aquacultural land led to 35.9% and 25.3% of the increase in FEP, respectively. Our study identifies hotspots for mitigating the environmental pressure from P emissions and provides tailored land management strategies at specific regional development stages and within sensitive areas.

Ultraviolet/dielectric barrier discharge enhanced ultrafiltration for treating natural water: Performance, mechanism and iodinated disinfection by-product fate

This study employed ultraviolet (UV)/ dielectric barrier discharge (DBD) pre-treatment to mitigate ultrafiltration membrane fouling and enhance the purification efficiency of natural surface water. Moreover, as an emerging contaminant, the iodinated disinfection by-products’ fate and degradation performance were discussed. The investigation revealed that the generation of numerous active species (⋅OH, ⋅O2−, 1O2, etc) under high input voltage and low pH conditions were advantageous for augmenting membrane flux, with sodium sulfate electrolyte playing a role in promoting the formation of selective sulfate radicals. Fluorescence excitation-emission matrix spectroscopy indicated that the UV/DBD system at 5.5 kV can effectively degrade proteins and humic substances in surface water, leading to an enhancement in water quality. With the assistance of UV radiation, macromolecular organic matter underwent extensive decomposition into smaller molecules, thus creating an ideal environment for controlling membrane fouling in the UV/DBD system. Additionally, it was identified the intermediate products and degradation pathways during iopamidol degradation by UV/DBD. It also affirmed the minimal risk of disinfection by-product generation with this strategy. The study provides a viable and efficient pre-treatment approach for mitigating membrane fouling and purifying water.

Efficient simultaneous removal of phosphate and microcystin-LR in water using a novel g-C3N4/calcite composite under dark-visible light cycles

Harmful algal blooms (HABs) associated with the abundant presence of phosphorus and microcystin in natural waters have raised a growing global concern. In this study, an adsorption-photocatalysis strategy was developed using a novel g-C3N4/calcite composite for efficient simultaneous removal of phosphate and microcystin-LR in water under dark-visible light cycles for the first time. The appropriate introduction of calcite into g-C3N4 (i.e., g-C3N4/calcite-1) was efficient in both phosphate adsorption (>78.5 %) and microcystin-LR degradation (>84.3 %) under a dark-visible light cycle of 3:3h at an optimal dosage of 100 mg/L in waters (pH 5–9 and temperature 10–40 °C). The simultaneous removal mechanisms proposed that g-C3N4/calcite-1 adsorbed phosphate via adsorption and precipitation with surface Ca2+, and degraded microcystin-LR via oxidation by photogenerated reactive species (mainly h+ and •OH). The material characterizations and density functional theory (DFT) calculations revealed that the combination of g-C3N4 and calcite could not only change the electric field distributions of calcite and optimize the charge transfer during adsorption to improve its adsorption capacity towards phosphate, but also narrow the band gaps of g-C3N4, promote the electron-hole separation and lower the first-step reaction barrier in oxygen reduction pathway during photocatalysis to enhance its visible-light photocatalytic activity towards microcystin-LR. Collectively, these findings are believed to offer valuable insights on the green material design for water environmental remediation and the underlying mechanism elucidation for simultaneous removal of phosphorus and microcystin in water to achieve effective comprehensive management of HABs.

Water insecurity may exacerbate food insecurity even in water-rich environments: Evidence from the Bolivian Amazon

Globally, challenges with water and food are two of the most pressing problems people face. Yet hydrologically water-rich environments and rural environments are often overlooked in these discussions due to abundance of natural water resources. Here we test the relationship between water and food insecurity among 270 Tsimane' households in the Bolivian Amazon. Water challenges were evaluated with the Household Water Insecurity Experiences Scale (HWISE), water quality perception, objective water quality analyses, and water access via the JMP drinking water ladder. Food insecurity was measured with the Household Food Insecurity Access Scale (HFIAS), and quantitative measures of food frequency recall were used to further test the water and food insecurity relationship. Using multilevel mixed-effects linear regression, each point increase in HWISE score was associated with 0.47 point (95 % CI: 0.30, 0.62, p < 0.001) higher food insecurity, and households with access to improved water sources had between 1.25 and 1.36 points (95 % CI: −2.61, −0.01, p < 0.05) lower food insecurity compared to households reliant on surface water. These relationships held true independent of quantitative measures of both fish and meat consumption. Using mixed-effects logistic regression analyses, each point increase in HWISE score was associated with 43 % (95 % CI: 1.25–1.66, p < 0.001) increased odds of experiencing severe food insecurity. Households changing what was eaten due to experienced water problems was associated with 2.33 points (95 % CI: 0.41, 4.25, p < 0.05) higher food insecurity. This relationship held true independent of perceived water quality, indicating other structural water problems may be important here in the household water and food insecurity relationship. These results demonstrate that even in water-rich environments, like the Amazon, water and food insecurity are interconnected. Further, despite the challenging conditions, equitable structural interventions, like the development of improved water infrastructure, are critical for the provision of clean drinking water and may simultaneously help alleviate food insecurity.

Layered bismuthene forming the interfacial pathway for rapid charge transfer in CuNb13O33/g-C3N5 photocatalyst for enhancing ciprofloxacin degradation

The objective of the present research was to examine the usefulness of the photocatalytic degradation process in removing the ciprofloxacin drug from wastewater, which is difficult to remove from waterbodies. To tackle this difficulty, a ternary copper niobium oxide/carbon nitride/layered bismuthene heterostructure (CuNb13O33/g-C3N5-L-Bi) composite was developed by an intuitive solvothermal process. layered bismuthene (L-Bi) was prepared using a unique ball milling approach. According to the results of the characterization, adding L-Bi and g-C3N5 with a low band gap to the original band structure of CuNb13O33 makes it more efficient. After 120 min of irradiation, the modified CuNb13O33/g-C3N5-L-Bi sample significantly improved ciprofloxacin degradation, resulting in a degradation rate of 98 %. In addition, the impact of the catalyst that has been created on the removal of ciprofloxacin at various pH, catalyst dosages, and scavengers was also examined, demonstrating the catalyst’s suitability for purifying natural water environments. A detailed study of the steps used to break down ciprofloxacin has shown that many active species are involved, with a focus on the important roles played by reactive oxidative species (ROS). Thus, this study introduces a novel combination of layered bismuthene photocatalysts for environmentally friendly degradation of antibiotics.

Prioritising preventive measures for unintentional sport and recreation-related deaths in Québec, Canada, based on a 14-year review

ObjectivesThis study analysed sport and recreation-related fatalities in Québec, Canada, from January 2006 to December 2019, focusing on the six activities with the highest mortality frequencies. It aimed to identify...

Enhanced removal of recalcitrant naphthenic acids through electro-cocatalytic activation of peracetic acid: Synergistic effects of multiple factors

Herein, a peracetic acid (PAA)-based electro-cocatalytic system (EC/PAA/Fe(III)) has been established for efficient degradation of 1-adamantanecarboxylic acid (ACA), which is a typical model chemical for naphthenic acids (NAs) that are abundantly present in petroleum industrial wastewater. The electric field greatly boosted the regeneration of Fe(II) to activate PAA in the system, resulting in 99.8 % removal for ACA within 20-min reaction time, with kobs of 0.3451 min−1. Results of quenching and chemical probe experiments verified the production of •CH3, CH3C(O)O•, •OH and FeIVO2+, in the EC/PAA/Fe(III) system with the FeIVO2+ identified as the primary contributor to ACA removal. The H2O2 present in the PAA solution enhanced the activation of PAA by promoting Fe(II) generation, thereby significantly improving ACA degradation efficiency. The ACA degradation byproducts and pathways were identified using the results of high resolution mass spectrometry analysis and density functional theory (DFT) calculations. Decarboxylation, hydroxy substitution, and carbonyl substitution reactions were predominant oxidation pathways of ACA decontamination. The EC/PAA/Fe(III) system demonstrated resilient degradation performance under the influence of anions and the natural water matrix for effective degradation of the commercial NAs mixture. Overall, the EC/PAA/Fe(III) system has been established with effectiveness and reliability for future remediation of NAs in petroleum industrial wastewater.

How Well Does the F-10 Australian Curriculum Prepare Students to be Water Literate Citizens?

Abstract Global water availability and management are persistent challenges to sustainable futures, yet people may have limited understandings of water systems and may hold negative attitudes towards sustainable solutions. With education a mechanism for realising a water literate citizenry, this study asks: How well does the Australian curriculum prepare students to be water literate citizens? McCarroll and Hamann’s (2020) Dimensions of Water Literacy guided a document analysis of Version 9.0 of the F-10 Australian Science and Humanities and Social Sciences (HASS) curricula. Findings revealed that concepts related to water literacy were largely confined to the Year 4 Science and Year 7 Geography curricula. In Science, the dimensions of Science and Systems Knowledge and Local Knowledge were through concepts related to the natural and urban water cycle. In HASS, the Hydrosocial Knowledge dimension was privileged, owing to people’s interactions with water. While there were occurrences of Functional Knowledge in both curricula, the organisation of the curriculum according to knowledge and skills does not explicitly focus on the development of students’ positive attitudes and values towards water conservation, nor engage them in individual or collective decision-making and action. Implications for the Australian curriculum and what it means to be a water literate citizen are discussed.

Integration of Local Wisdom of Natural Color Sasirangan in Project-based Learning with STEAM Approach to train Science Literacy

&lt;span lang="EN-US"&gt;Science learning should provide meaningful experiences for students to understand various scientific phenomena in life. Integrating local wisdom in learning can improve scientific literacy because the various concepts learned are witnessed directly by students in life. This research uses theoretical studies to describe the integration of local wisdom of natural color sasirangan in project-based learning with the STEAM approach to improve science literacy.&lt;/span&gt;&lt;span lang="EN-US"&gt; The STEAM approach is in the form of a) science in the form of the phenomenon of abundant dye water from the pot due to expansion; b) technology in the form of sasirangan fabric dyeing machines; c) engineering in the form of manipulation of the use of natural dyes and fixation; d) art in the form of making sasirangan cloth motifs; e) Mathematics in the form of temperature measurement using a thermometer and heat to increase the temperature of the dye liquid. The stage of making sasirangan cloth consists of making patterns, jalujur, sisit, dye, dedel, washing and ironing. The concept of temperature and heat found in the process of making natural color sasirangan includes; a) the concept of temperature when cooked water slowly becomes hot; b) the concept of expansion on the phenomenon of natural dye water spilling from the pot when cooked; c) the concept of heat is seen in water that has a large mass requires more heat to achieve a certain temperature increase; d) The concept of radiant heat transfer can be proven when the sasirangan cloth is dried in the sun&lt;/span&gt;

NuTag: a proof-of-concept study for a long-baseline neutrino beam

The study of neutrino oscillation at accelerators is limited by systematic uncertainties, in particular on the neutrino flux, cross section, and energy estimates. These systematic uncertainties could be eliminated by a novel experimental technique: neutrino tagging. This technique relies on a new type of neutrino beamline and its associated instrumentation which would enable the kinematic reconstruction of the neutrinos produced in and decays. This article presents a proof-of-concept study for such a tagged beamline, aiming to serve a long-baseline neutrino experiment exploiting a megaton scale natural water Cherenkov detector. After optimising the target and the beamline optics to first order, a complete Monte Carlo simulation of the beamline has been performed. The results show that the beamline provides a meson beam compatible with the operation of the spectrometer, and delivers a neutrino flux sufficient to collect neutrino samples with a size comparable with similar experiments and with other un-tagged long-baseline neutrino experimental proposals.

Fluorescence Visualization Quantitative Detection of Tetracycline and Nitrofurantoin in Food and Natural Water by Zn2+@Eu-bpdc Composite.

Quantitative detection of tetracycline (TC) and nitrofurantoin (NFT) in food and water is of importance for food safety and environmental protection. Herein, Zn2+ was introduced into a europium metal-organic framework Eu-bpdc (H2bpdc = 2,2'-bipyridyl-5,5'-dicarboxylic acid) to prepare a composite of Zn2+@Eu-bpdc, which was developed as a fluorescence sensor for TC and NFT. The fluorescence mechanism concerns with bpdc2- ligand-to-Eu(III) charge transfer, and the detection mechanism is the inner filter effect. Zn2+@Eu-bpdc is a ratiometric fluorescence sensor for TC with the linear fitting equation of I520/I618 = 1.94 × 104 M-1CTC, whose limit of detection (LOD) is 0.148 μmol·L-1 (μM); it is also a fluorescence "turn-off" sensor for NFT with the fitting equation of (I0-I)/I = 3.62 × 104 M-1CNFT and LOD = 0.0792 μM. Zn2+@Eu-bpdc can detect TC or NFT in lake water, honey, and milk with high accuracy. The emission color changes of paper-based Zn2+@Eu-bpdc depending on CTC or CNFT reveal the visualization detections of TC and NFT. With the red and green values as input signals, smartphone-assisted on-site detection is utilized to recognize the antibiotic residuals of TC and NFT by a self-programmed APP. Zn2+@Eu-bpdc is promising in a smartphone-assisted intelligent platform for on-site detection of TC and NFT.

Transformation of Engineered Copper Oxide Nanoparticles in Surface Waters.

Copper oxide nanoparticles (CuO-NPs) are widely used for their catalytic properties, conductive capacity, and innovations in the fields of superconductors, alloys, and solar energy sensors. To better understand the impact of water chemistry on the stability of CuO nanoparticles, a series of measurements were carried out on nanoparticles suspended in pure water, natural water, and water enriched with natural organic matter fulvic acid (FA). ICP-MS characterization in single-particle mode (SP-ICP-MS) was performed to determine the stability or transformation of nanoparticles in contrasting water conditions. We first observed that particle sedimentation was very fast in pure Milli-Q water. The addition of FA favored the dissolution of CuO-NPs with an increase in the dissolved copper concentration, for both Milli-Q water and natural water. The presence of FA also reduced the size of CuO-NPs (i.e., less aggregation) measured in natural water. By comparing signals of single particles, FA decreased nanoparticle numbers as well, confirming the increase in dissolution of CuO-NPs over time. The transformation products of CuO-NPs are important in the ecological context since the uptake and toxicity of parent nanoparticles differ from those of the chemical species in solution. Further considerations are needed on the fate of released NPs to better assess their exposure pathways to aquatic organisms and potential environmental risks.

CH4 and CO2 Reductions from Methanol Production Using Municipal Solid Waste Gasification with Hydrogen Enhancement

This study evaluates the greenhouse gas (GHG) impacts of converting municipal solid waste (MSW) into methanol, focusing on both landfill methane (CH4) emission avoidance and the provision of cleaner liquid fuels with lower carbon intensity. We conduct a life cycle assessment (LCA) to assess potential GHG reductions from MSW gasification to methanol, enhanced with hydrogen produced via natural gas pyrolysis or water electrolysis. Hydrogen enhancement effectively doubles the methanol yield from a given amount of MSW. Special attention is given to hydrogen production through natural gas pyrolysis due to its potential for lower-cost hydrogen and reduced reliance on renewable electricity compared to electrolytic hydrogen. Our analysis uses a case study of methanol production from an oxygen-fired entrained flow gasifier fed with refuse-derived fuel (RDF) simulated in Aspen HYSYS. The LCA incorporates the significant impact of landfill methane avoidance, particularly when considering the 20-year global warming potential (GWP). Based on the LCA, the process has illustrative net GHG emissions of 183 and 709 kgCO2e/t MeOH using renewable electricity for electrolytic hydrogen and pyrolytic hydrogen, respectively, for the 100-year GWP. The net GHG emissions using 20-year GWP are −1222 and −434 kgCO2e/t MeOH, respectively. Additionally, we analyze the sensitivity of net GHG emissions to varying levels of fugitive methane emissions.

One-pot fabrication of open-spherical shapes based on the decoration of copper sulfide/poly-O-amino benzenethiol on copper oxide as a promising photocathode for hydrogen generation from the natural source of Red Sea water

Abstract Harnessing green hydrogen production from natural Red Sea water offers an innovative solution to address energy challenges. A one-pot fabrication method is used to create novel nanocomposite thin films with open-spherical shapes, utilizing copper sulfide/poly-O-amino benzenethiol decorated on copper oxide as a promising photocathode. After thorough analysis, a unique morphology characterized by open spherical shapes is projected, which contributes to improved optical absorption. The bandgap of the nanocomposite is 1.17 eV, enabling efficient absorption of light across the entire optical spectrum, extending up to 950 nm. Utilizing Red Sea water as an electrolyte, the generated J ph serves as an indicator of H2 gas production. The substantial J ph value of −0.82 mA cm−2 is achieved at −0.85 V under light illumination. Furthermore, J ph values exhibit variability, starting at −0.58 mA cm−2 (at 730 nm) and increasing to −0.75 mA cm−2 at a wavelength of 340 nm. The estimated hydrogen gas production rate reaches 1.5 µmole h−1 cm−2, translating to an impressive 15 µmole h−1 for every 10 cm². This remarkable rate underscores the effectiveness of the photocathode, especially given its fabrication through a single-step process that is suitable for mass production. In addition, its cost-effectiveness further enhances its appeal as a viable solution for renewable energy production for hydrogen gas generation from seawater.

Antifouling activity of PEGylated chitosan coatings: Impacts of the side chain length and encapsulated ZnO/Ag nanoparticles

PEGylation is regarded as a common antifouling strategy and the effect is normally linked with surface hydrophilicity of the coatings. Herein, the biopolymer chitosan (CS) was grafted by polyethylene glycol (PEG) of different chain lengths (molecular weight 200, 4 k and 100 k Da) to verify if the hydrophilicity of CS-PEG coatings is crucial in determining antifouling activities and if PEG chain length influences biofouling in marine environment. Properties of copolymers such as melting points and crystallinity are affected by grafting PEG. The water contact angle (WCA) of CS-PEG coatings increases with the chain length of grafted PEG, from 27° to 58°. Photocatalyst of zinc oxide-silver (ZnO/Ag) was also studied and its embedment (2 % to CS-PEG) renders the surface of CS-PEG coatings more hydrophobic with WCA increased from 52° to 86°. Antibacterial, anti-diatom, and anti-biofilm activities of the coatings were evaluated in natural sea water. The bacterial density on CS-PEG coatings was dramatically reduced to 4 × 104 compared to the control of 7 × 104 ind/mm2, and further to 2 × 104 for CS-PEG-ZnO/Ag coatings. CS-PEG coatings also strongly inhibit diatoms (120–200 ind/mm2), but the inclusion of ZnO/Ag did not obviously enhance such effect (50–150 ind/mm2). The findings provide useful insights for designing polymer-based antifouling coatings.

Assessing the spatial variability of cage movement and velocity attenuation of an off-bottom oyster farm and its influence on eastern oyster (Crassostrea virginica) growth performance

The global shellfish aquaculture industry has expanded over the last seven decades. Similarly, the size of individual shellfish farming operations has grown in some states. Circulation processes in natural water bodies are dynamic and vary across multiple temporal and spatial scales. How gear installation affects the circulation of currents and waves, and subsequent phytoplankton delivery to crops within farms, is largely unknown. Documenting and understanding variability in wave and current energy within an individual farm could help optimize production. Our study sought to understand the variability in oyster growth attributable to hydrodynamic and atmospheric forcing across an active commercial shellfish aquaculture lease in the Patuxent River, Maryland. We observed a 17 % reduction in water flow downstream of the farm (rho = −0.673, p = 0.002, Spearman rank test), suggesting the bottom cages attenuated downstream current velocity during flood tides. Differences in flow speed and the movement of cages and oysters throughout the farm correlated with variances in oyster shell morphology and oyster survival while in bottom cages. Our results demonstrate the occurrence of variability in production within an individual farm location. Further, our findings suggest that insight into the spatial growth patterns across a lease can be practical for forecasting growth and quality of cultured oysters and may enable growers to strategically place oysters within their farm to improve yield and product consistency.

Functionalization of activated carbon with melamine binder for adsorption of metallic species from aqueous environments

ABSTRACT In the face of the increasing exposure to heavy metals in the environmental scenario, there arose the need for further research by the scientific community. In this perspective, the present work reports the application of a material made from Typha sp. leaf, activated and functionalised with molecules of 1,3,5-Triazine-2,4,6-triamine (melamine), for the selective adsorption of metal ions Cu(II), Cd(II), and Pb(II) in aqueous solutions. Confirmation of material functionalization occurred through infrared vibrational spectroscopy, revealing bands at 3467, 3424, and 1338 cm−1 associated with the stretching vibration of -NH2. These results provide evidence of the possible anchoring of the ligand on the material surface. Elemental nitrogen analysis corroborated the results of infrared spectroscopy and showed 2.21% nitrogen in the functionalised material, while 1.30% in activated carbon. X-ray photoelectron spectroscopy showed the modification of the material surface composition after the functionalization reaction. The specific surface area was calculated as 193.876 m2/g. Adsorption studies revealed a rapid kinetics, best described by the pseudo-second-order model. The optimised pH for adsorption was 6.0 (pHPZC = 7.5), aligning with conditions found in natural waters. The maximum adsorption capacity was 0.4388, 0.4025, and 0.2792 mmol g−1 for Cu(II), Pb(II), and Cd(II), respectively, following the Langmuir model. Furthermore, to facilitate practical application, parameters such as mass and flow rate were optimised. The results suggest that the developed material exhibits promising adsorptive properties, emerging as a potential solution for remediating areas contaminated by metallic species.

Alkali metal cation adsorption–induced surface polarization in polymeric carbon nitride for enhanced photocatalytic hydrogen peroxide production

Photocatalytic hydrogen peroxide (H2O2) generation on the catalyst surface from oxygen is an electron-demanding process, making the construction of an electron-rich surface highly advantageous. In this study, a localized electric field was observed on the surface of polymeric carbon nitride (g-C3N4) when alkali metal cations were adsorbed onto it. These fields effectively inhibited surface carrier recombination and extended their lifespan, thereby enhancing H2O2 production. As a result, g-C3N4 achieved a superior H2O2 yield of 2.25 mM after 1 h in a 0.25 M K+ solution, which was 2.06 times greater than that (1.09 mM) achieved in a pure solvent. Notably, the increase in photocatalytic efficiency showed a remarkable dependence on ion species. At low concentrations, H2O2 generation efficiency was in the order of Li+ < Na+ < K+ < Rb+ < Cs+. However, after optimizing the ion concentration, the highest H2O2 production was achieved in a solution containing K+ instead of Cs+. Molecular dynamics simulations and temperature-dependent photocatalysis experiments revealed that the synergistic interaction between adsorption energy and adsorption distance was crucial in governing the extent to which alkali metal cation adsorption enhanced g-C3N4 photocatalytic H2O2 production. This study provides theoretical insights for the design of materials for electron-demanding photocatalysis and aids in understanding variations in photocatalytic behavior in natural waters.