Water Sources Research Articles

Introduction of broadleaf tree species can promote the resource use efficiency and gross primary productivity of pure forests.

Long-term pure forest (PF) management and successive planting has result resulted in "low-efficiency artificial forests" in large areas. However, controversy persists over the promoting effect of introduction of broadleaf tree species on production efficiency of PF. This study hypothesised that introduced broadleaf tree species can significantly promote both water-nutrient use efficiency and gross primary productivity (GPP)of PF. Tree ring chronologies, water source, water use efficiency and GPP were analysed in coniferous Cunninghamia lanceolata and broadleaved Phoebe zhennan growing over the past three decades. The introduction of P. zhennan into C. lanceolata plantations resulted in inter-specific competition for water, probably because of the similarity of the main water source of these two tree species. However, C. lanceolata absorbed more water with a higher nutrient level from the 40-60-cm soil layer in mixed forests (MF). Although the co-existing tree species limited the basal area increment and growth rates of C. lanceolata in MF plots, the acquisition of dissolved nutrients from the fertile topsoil layer were enhanced; this increased the water use efficiency and GPP of MF plots. To achieve better ecological benefits and GPP, MFs should be constructed in southern China.

Emerging eco-friendly technologies for remediation of Per- and poly-fluoroalkyl substances (PFAS) in water and wastewater: A pathway to environmental sustainability

Per- and polyfluoroalkyl substances (PFAS) are rampant, toxic contaminants from anthropogenic sources, called forever chemicals for their recalcitrance. Although banned in several parts of the world for public health implications, including liver, kidney, and testicular diseases, PFAS are abundant in water sources due to easy dispersion. With chemical properties resulting from strong hydrophobic bonds, they defile many physicochemical removal methods. Though adsorption processes such as granular activated carbon (GAC) are widely used, they are marred by several limitations, including cost and secondary contamination. Thus, eco-friendly methods involving a synergy of the removal principles have been preferred for ease of use, cost-effectiveness, and near-zero effect on the environment. We present novel eco-friendly methods as the solution to PFAS remediation towards environmental sustainability. Current eco-friendly methods of PFAS removal from water sources, including electrocoagulation, membrane/filtration, adsorption, and phytoremediation methods, were highlighted, although with limitations. Novel eco-friendly methods such as microbial fuel cells, photoelectrical cells, and plasma treatment offer solutions to PFAS remediation and are quite efficient in terms of cost, result, and environmental sustainability. Overall, the successful integration of eco-friendly techniques in a seamless manner ensures the desired result. We also present a balanced position on the ecosystem impact of these ecofriendly methods, noting the successes towards environmental sustainability while exposing the gaps for further research.

Reduction of Water Consumption for Heating Plant Cooling with an Indirect Cooling System

In order to combat drought, many industrial companies are taking austerity measures in their water management. They are driven not only by economic reasons but also by tightening legislation, directly prohibiting the extraction of water from the environment when a drought is declared. The article deals with the case of a company that operates a heating plant for an industrial zone and the adjacent town. The water source is a river 2.5 km away. In the event of a drought, the company is affected by a ban on river-water extraction, which has a direct impact on the operation of the heating plant and the entire industrial zone, with the current heating-plant cooling system consuming up to 60% of the industrial water. Previous studies have shown the impossibility of installing a dry or hybrid cooling system in the area. A possible economical option is closed-loop cooling. Most of the cooling water is lost by evaporation, the rest by surface blowdown, neither of which occurs in a closed circuit. This paper deals with an alternative closed cooling system using a river and its design parameter calculation, including a comparison of the different options for pipe location and routing.

Combining statistical analyses and GIS-based approach for modeling the sanitary boundary of drinking water wells in Yaoundé, Cameroon

In slums and urban areas with unplanned housing such as in the city of Yaounde, Cameroon, poor water quality and inadequate sanitation pose significant health risks. The absence of locally-defined sanitary boundaries, tailored to hydrogeological conditions, hinders effective zoning and land use planning, exacerbating environmental degradation and health hazards. In this study, the sanitary boundary between drinking water wells and sources of pollution in the city of Yaoundé was defined using statistical analysis techniques and Geographic Information Systems (GIS). The Groundwater Quality Index (GWQI) and certain significant parameters affecting water quality notably the transmissivity of the aquifer and well depth were used to establish the sanitary boundary equation which was then interpolated in a GIS environment to obtain the sanitary boundary map of the study area. The linear equation deduced from the significant factors was defined to map the health boundaries between wells and pollution sources for a nominal value of the GWQI (GWQI = 25). Of the 112 wells analysed, 37 % had an excellent GWQI, 16 % were good while the remaining 47 % were poor. Statistical analysis showed a strong correlation between the GWQI and significant factors of groundwater pollution, such as the distance between well and pit latrines (r = −0.753), the aquifer transmissivity of the formation (r = 0.671) and the depth of the wells (r = - 0.855) but no correlation with elevation (r = 0.017) and well age (r = 0.090). Linear regression analysis confirmed the association of the GWQI with the main factors of pollution (p ≤ 0.05). A coefficient of determination of R2 = 0.85 was obtained when validating the linear regression plot based on independent data between measured and predicted GWQI. The sanitary boundary map shows that the wells in our study area should be located between 39 m and 370 m, with an average value of 215 m. New regulations on the distance between well and pit latrines are essential to prevent groundwater pollution.

Application Research of an Automatic Control Seawater Reverse Osmosis (SWRO) System Based on the Siemens PLC

To solve the global environmental problem of a shortage of freshwater resources, seawater desalination is considered one of the most promising solutions. In this research, the main novelty of the seawater desalination system lies in its utilization of a reverse osmosis unit as the core process for producing drinking water. By optimizing the pretreatment section in the process flow, a seawater reverse osmosis (SWRO) control system based on Siemens PLC with a high degree of automation was developed, which has the advantages of convenient maintenance and monitoring. In addition, through research on reverse osmosis systems, the results showed that within two years of operation, the total desalination rates of the primary and secondary reverse osmosis systems were not less than 99% and 97.5%, respectively. Furthermore, the water quality after desalination was tested. When the doses of CaCl2, MgCl2 and NaHCO3 were 20 mg/L, 15 mg/L, and 50 mg/L, respectively, high-quality drinking water was obtained. Finally, a reasonable process plan and corresponding estimates were given for the complex water source conditions. Compared with traditional seawater desalination systems, our system has the advantages of easy operation, efficient water production and lower price. Accordingly, this study will help to solve drinking-water problems in some freshwater-scarce regions.

The global disease burden attributable to unsafe water, sanitation, and handwashing with unqualified facilities from 1990 to 2019.

Water, sanitation, and hygiene (WaSH) are crucial determinants of human health. However, the spatio-temporal trends in the global burden of disease attributable to unsafe WaSH remain poorly understood. This study aimed to estimate the disease burden attributable to unsafe WaSH from 1990 to 2019 using data from the Global Burden of Disease (GBD) Study 2019, providing new insights into the associated health conditions. We extracted data on deaths and disability-adjusted life years (DALYs) attributable to unsafe WaSH from 1990 to 2019 from the GBD 2019. The disease burden was evaluated by region, sociodemographic index (SDI), sex, age, risk factor, and specific disease. Globally, unsafe WaSH was responsible for 1 656 887.37 (95% uncertainty interval (UI) = 1 198 864.94, 2 312 688.33) deaths in 2019, a 49% decrease from 1990. The global age-standardised DALY rate due to unsafe WaSH was 1244.29 (95% UI = 993.20, 1544.13) per 100 000 in 2019, a 66% reduction since 1990. Western sub-Saharan Africa had the highest age-standardised death rate (ASDR) and age-standardised DALY rate in both 1990 and 2019. Among the 21 regions studied, only high-income North America witnessed an increasing ASDR from 1990 to 2019. Countries and territories in low SDI regions had higher ASDRs and age-standardised DALY rates. U-shaped associations were observed between the estimated annual percentage change (EAPC) of ASDR, EAPC of age-standardised DALY rate, and SDI. Both rates were slightly lower in females, with the burden concentrated in those under five and over 80 years old. In 2019, unsafe water source and diarrhoeal diseases remained the leading risk factor and cause of unsafe WaSH-related disease burden, respectively. Despite substantial improvements in hygiene awareness and health education, unsafe WaSH persists as a significant global health risk and a major contributor to the burden of diarrhoeal diseases. Disparities across regions and age groups remain evident. Increased efforts are needed to raise awareness and strengthen water and sanitation infrastructure, particularly in low SDI settings, to mitigate the health risks associated with unsafe WaSH.

Food Safety Analysis Based on Halal Food with The Use of Water as a Food Need in Indonesia

Halal food security in Indonesia is a complex issue viewed from a religious perspective, especially in water processing. This article examines the public's understanding of the water treatment process, whether halal or non-halal. This research also examines the risks from the views of people with this understanding. The method used uses a literature study consisting of several pieces of literature that are reviewed and analyzed descriptively to understand the existing problems properly. The results of this research answered this understanding with an analysis of environmental, technical, social, financial, security, and institutional risks, as well as a comparison with regulations and hadith. The water treatment process carried out by water management institutions follows the rules and is considered to duplicate natural processes, namely the water cycle. This perspective is also supported by several regulations in Indonesia, which indicate that food safety, especially water, can be adequately implemented. This study shows that there is always involvement between officeholders, service providers, and the community in maintaining the safety of water sources.

Identification of feasible regions for managed aquifer recharge in the Republic of Cyprus using a co-participative multi-criteria decision analysis

This study proposes an integrated approach that aims at finding locations which are eligible for Managed Aquifer Recharge (MAR) installation in Cyprus via the active involvement of key stakeholders of MAR-related sectors during all stages of the decision process to ensure the validity of the outcomes. The MAR problem is jointly formulated with the key stakeholders according to the site needs by introducing the so-called "MAR typology" concept, consisting of the recharge objective, the recharge method, and the available water sources. Tertiary-treated wastewater is adapted as the water source, which is recharged in aquifers via recharge ponds for irrigation. Various sources of information have been considered for assessing the degree of feasibility, aggregated in three thematic clusters (feasibility components), namely intrinsic site-suitability, the availability of water resources for MAR purposes, and water demand. Twelve criteria have been selected jointly with key stakeholders to evaluate the feasibility components via a GIS-MCDA process. Seven of these criteria are associated with the intrinsic suitability of a region (aquifer, land-use, and topographical properties), and five criteria are associated with the amount of water available for MAR (characteristics of the water source and evapotranspiration) and the crop irrigation needs. Stakeholder meetings were conducted to determine weights for each criterion and thematic cluster, leading to thematic and feasibility maps. The results demonstrate large discrepancies among the feasibility components in terms of their spatial variation and the location where the most favourable regions are present. Smoother profiles are observed for intrinsic suitability compared to the other thematic layers, partly attributed to the use of a larger number of criteria. Sensitivity analysis demonstrates that the MAR-favourable regions are weakly influenced by the variation of the relevant importance among the thematic layers, being mostly present in the vicinity of the southern and south-eastern coastlines.

Antibiotic resistance of E. coli isolates from different water sources in Mbarara, Uganda

Antibiotic resistance of <i>E. coli</i> isolates from different water sources in Mbarara, Uganda

CuMn2O4 anchored on mesoporous yttrium orthovanadate for the visible-light removal of hexavalent chromium ions in water

Recently, there has been significant interest in using one-dimensional nanomaterials for environmental cleanup in water sources, particularly for breaking down and eliminating harmful pollutants. Creating a reusable and effective photocatalyst poses a challenge in addressing semiconductor flaws such as instability and rapid recombination. This work discusses developing a highly responding photocatalyst by introducing varying quantities of CuMn2O4 (CMO) onto the surface of yttrium vanadate (YVO4) nanoparticles using the surfactant sol-gel method. The structures and morphology of these developed nanocomposites were verified using many characterization methods. The findings reveal that CMO is an electron trap within the dual system, which impedes charge carrier recombination and ameliorates photocatalytic performance. Their photocatalytic efficacy was evaluated through the photoreduction of Cr(VI) ions under visible illumination, revealing that adding CMO nanoparticles significantly boosts YVO4's photocatalytic activity. The Cr(VI) photoreduction follows a first-order reaction model. Among the tested photocatalysts, the 2.0 g/L dose of 9.0 % CMO-YVO4 demonstrated the most effective and reusable performance within 45 min. This sustained photocatalytic performance is credited to improved capture of light and effective transfer of charges resulting from the combination of CMO and YVO4.

Simultaneous Removal of As(iii) and As(v) from Aqueous Solution by Using Iron-Functionalized Polythiophene: A Novel Approach toward Water Treatment.

Arsenic contamination in groundwater poses a significant threat to human health, affecting millions worldwide. This study presents a novel approach for simultaneous remediation of both As(III) and As(V) by using iron-functionalized polythiophene (PTh@Fe) composites. The PTh@Fe composite was synthesized by a reduction process involving FeCl2/FeCl3 byproducts of polymerization, resulting in a highly efficient adsorbent for both As(III) and As(V) species. The investigation systematically examined key parameters influencing arsenic removal, including adsorbent dosage, pH, initial arsenic concentration, and contact time. The composite exhibited exceptional adsorption capacities, with maximum removal percentages of 98.7% for As(III) and 98.8% for As(V) under the optimized conditions. Thermodynamic and kinetic analyses suggested endothermic and spontaneous adsorption processes following a pseudo 2nd-order mechanism. Furthermore, the Langmuir isotherm model provided an excellent fit to the experimental data, with maximum adsorption capacities of 8.62 mg/g for As(V) and 7.57 mg/g for As(III). Density functional theory (DFT) calculations confirmed the feasibility of arsenic adsorption onto iron species in various oxidation states, offering valuable theoretical insights into the process. Furthermore, the composite demonstrated good reusability over multiple adsorption-desorption cycles and tolerance to coexisting anions, highlighting its practical applicability for water purification. This research demonstrates the potential of iron-functionalized polythiophene composites as a promising solution for addressing arsenic contamination in water sources, bridging the gap between innovative materials and theoretical understanding in environmental science and water treatment technologies.

Weaving different forms of knowledge of managed aquifer recharge in a Saharan oasis (Algeria)

This paper demonstrates the reciprocal benefits of a socio-hydrology approach that fosters fruitful exchanges between different ‘knowers’ of complex water dynamics in weaving different types of knowledge. For centuries, the managed aquifer recharge and use system in the Beni Isguen oasis in Algeria was diligently monitored by communal water stewards and the data meticulously recorded and stored. Throughout our research project on the origin of groundwater and its replenishment, intense dialogue between scientists and communal water stewards greatly enhanced the research protocol based on isotope tracers, while simultaneously contributing to the active knowledge base of the community. The dialogue was based on mutual respect, trust and a reciprocal desire to share knowledge. Our findings revealed increased mineralization of shallow groundwater during drought periods, which was attributed to geological processes, and emphasized the crucial role of floods. Also, contrary to the initial assumption that deep Continental Intercalaire groundwater was only used for drinking, it was identified as a vital external resource, responsible for substantial recharge of the phreatic aquifer of the oasis. This source of water explains the continued use of the phreatic aquifer for irrigation more than 10 years after the last major flood. This collaborative socio-hydrology approach between differently situated ‘knowers’ contributes to the grounding of socio-hydrology. While respecting the strong water conservation culture, weaving different forms of knowledge may help develop a virtuous and original development model in the Algerian Sahara and beyond.

Enhanced adsorption of Cr(VI) pollutants using CaFe2O4@rGO modified-biochar derived from mixture of black soldier flier exuviae and durian peel

To solve the problem of hexavalent chromium (Cr(VI))-polluted water sources, mixed black soldier flier exuviae (BSFE) and durian peel (DP)-derived biochar modified with CaFe2O4@rGO (BC-CFr) was synthesized to remove Cr(VI) from wastewater. Our findings indicated that the adsorption of Cr(VI) on BC-CFr reached a maximum at a pH of 2.0, biochar dosage of 0.3 g/100 mL, and initial Cr(VI) concentration of 50 mg/L, with a Cr(VI) adsorption capacity of 30.8 mg/g, which was approximately two times greater than that on pristine biochar (PBC). The characterization results showed that the as-prepared modified biochar was rich in surface functional groups, including amine groups (−NH2) and active sites. Cr(VI) adsorption followed the Elovich kinetic and Freundlich isotherm models, illustrating the adsorption process involved multilayer on the heterogeneous surface. The thermodynamic study confirmed the adsorption process was endothermic. The proposed adsorption mechanisms included adsorption-coupled reduction, electrostatic attraction, and pore filling. This study provided a simple method to prepare compositing biochar using abundantly available agricultural by-products that dealt with the dual problems of Cr(VI)-contaminated water and agricultural solid waste. Besides, the BC-CFr exhibited high desorption performance and recyclability over five consecutive adsorption-desorption cycles, suggesting the BC-CFr is a feasible nanocomposite biochar for effectively removing Cr(VI) from wastewater in practice.

Using Repeated Lysis Steps Fractionates Between Heterotrophic and Cyanobacterial DNA Extracted from Xenic Cyanobacterial Cultures.

Extracting DNA from cyanobacteria can be a challenge because of their diverse morphologies, challenging cellular structure, and the heterotrophic microbiome often present within cyanobacterial cultures. As such, even when our DNA yields are sufficient for sequencing, the percentage of reads coming from the cyanobacterial host can be low, leading to incomplete genomes spread across several scaffolds. In this research, we optimized a DNA isolation protocol using three iterative cell lysis steps to enrich the portion of DNA isolated coming from the cyanobacterial host rather than the heterotrophic microbiome. In order to utilize in-house nanopore sequencing, we faced a challenge in that our lysis protocol led to DNA shearing and a lower molecular weight DNA extract than is suitable for this sequencing technology. As such we used two bead-based size selection steps to remove shorter molecules of DNA before nanopore sequencing. EPI2ME analysis of the processed reads from the iterative lysis steps showed that in the first lysis the heterotrophic microbiome could make up more than half of all reads, but with each lysis the proportion of reads coming from these other species decreased. Using our iterative lysis protocol, we were able to sequence the genomes of two cyanobacteria isolated from fresh water sources around northern Mississippi, namely Leptolyngbya sp. BL-A-14 and Limnothrix sp. BL-A-16. The genomes of these isolates were assembled as closed chromosomes of 7.2 and 4.5 Mb for Leptolyngbya sp. BL-A-14 and Limnothrix sp. BL-A-16, respectively. Because some cyanobacteria have symbioses with their heterotrophic microbiome it is not always possible to prepare axenic cultures of these organisms, we hope our approach will be useful for sequencing xenic cultures of cyanobacteria, but we can also imagine applications in studying this microbiome specifically by focusing sequencing efforts on the first fraction.

Real-time chlorophyll-a forecasting using machine learning framework with dimension reduction and hyperspectral data

Since water is an essential resource in various fields, it requires constant monitoring. Chlorophyll-a concentration is a crucial indicator of water quality and can be used to monitor water quality. In this study, we developed methods to forecast chlorophyll-a concentrations in real-time using hyperspectral data on IoT platform and various machine learning algorithms. Compared to regular cameras that record information only in the three broad color bands of red, green, and blue, the hyperspectral images of drinking water sources record the data in dozens or even hundreds of distinct small wavelength bands, providing each pixel in an image with a full spectrum. Different machine learning algorithms have been developed using hyperspectral data and field observations of water quality and weather conditions. Previous studies have predicted chlorophyll concentrations using either partial least squares (PLS), which is a dimensionality reduction method, or machine learning. In contrast, our study employed the PLS technique as a preprocessing step to diminish the dimensionality of the hyperspectral data, followed by the application of the machine learning techniques with optimized hyperparameters to improve the precision of the predictions, thereby introducing a real-time mechanism for chlorophyll-a prediction. Consequently, a machine learning algorithm with R2 values of 0.9 or above and sufficiently small RMSE was developed for real-time chlorophyll-a forecasting. Real-time chlorophyll-a forecasting using LightGBM has the best performance, with a mean R2 of 0.963 and a mean RMSE of 2.679. This paper is expected to have applications in algal bloom early detection on monitoring systems.

Natural vs. anthropogenic sources of N-Nitrosodimethylamine precursors in surface water

N-nitrosodimethylamine (NDMA) is a carcinogenic disinfection byproduct formed from reactions between dichloramine and organic nitrogen-containing precursors. It is unclear if NDMA precursors in surface water intakes originate in anthropogenic (i.e., wastewater) or natural sources. The Truckee River has a single point source release of treated wastewater effluent, making it an ideal system to study the relative importance of precursor sources. Three Lagrangian sampling events were conducted. NDMA formation potential (FP, a measurement of precursors) above the wastewater outfall indicated that the natural background of NDMA precursors was 2-28 ng/L. NDMA FP increased to 18-31 ng/L immediately downstream of the wastewater outfall, but decreased rapidly in a first order manner, and were not statistically different from the upstream samples in only ∼6 km. This suggests that the dominant source of NDMA precursors may be wastewater derived only near wastewater outfalls and deviates from the previous belief that wastewater-derived precursors are responsible for NDMA formation in drinking water sources located further downstream. Additionally, given the rapid loss of the wastewater precursors in this study, precursors which are slow to biodegrade/photolyze/adsorb to sediment are likely to be poor surrogates for the overall wastewater NDMA precursor pool. To understand temporal changes in the wastewater impact on environmental NDMA precursor loading, two 24-hour sampling events were conducted near (<3 km) the wastewater outfall and demonstrated that temporal changes in the NDMA precursors directly downstream of the wastewater outfall are directly linked to the wastewater flow contribution.

Metal-polymer-clay nanocomposites based electrochemical sensor for detecting hydrazine in water sources

AgNPs embedded polymer-clay (AgNPs@PEI-HNT) nanocomposites were successfully employed to sensitively detect hydrazine in water samples using differential pulse voltammetry (DPV) and amperometry methods. In-situ polymerization was utilized for assembling the polymer-clay composites, which were subsequently coated with AgNPs. PEI improves conductivity and absorbs AgNPs on the surface of HNTs, as evidenced with the help of UV-Visible, IR spectroscopy, XRD, XPS and morphological studies (FE-SEM and TEM). Nanocomposites were coated with GCE, which improved their electrocatalytic performance during hydrazine oxidation. The Tafel plot, Galus and Cottrell equations were used to compute the electron transfer coefficient (0.64), catalytic reaction rate constant (4.81 × 104 M−1s−1) and diffusion coefficient (2.56 × 10−5 cm2/s) of hydrazine at AgNPs@PEI-HNT/GCE. Amperometry technique was used to determine the LOD along with sensitivity of hydrazine, which were 0.22 nm and 116.76 µA µM−1 cm−2. Modified electrode offers enhanced properties for example strong anti-interference capability, good reproducibility, long-term stability, sensitivity, and so on. The designed sensor successfully detects hydrazine in water samples with high recovery rates (R.S.D. < 5 %).

Greenhouse gas, water, and economic implications of permeable pavements: Quantification for pilot sponge cities in China

Climate change has exacerbated the occurrence of extreme storms, resulting in urban flooding. However, rainwater is a potential source of water for various end uses of municipal water. In this context, permeable pavements are promising for mitigating floods and alleviating water stress in cities. Herein, a process-based life-cycle inventory modeling approach was used to quantify the life-cycle greenhouse gas (GHG) and water footprints of different road pavements in 28 pilot sponge cities in China. Three asphalt pavements were considered in this study: permeable-surface, permeable-base, and conventional nonpermeable pavements. Moreover, life-cycle cost analyses were performed to reveal the cost-effectiveness of these pavements. Results showed that permeable-base pavements exhibited the highest levelized GHG emissions (5.9 kg CO2e/m2/yr), followed by nonpermeable (5.5 kg CO2e/m2/yr) and permeable-surface pavements (3.8 kg CO2e/m2/yr). In terms of levelized water footprint, permeable-base and permeable-surface pavements enabled water savings (433.8 and 304.1 kg/m2/yr, respectively), while nonpermeable pavements consumed 30.6 kg/m2/yr of water. The levelized life-cycle costs of permeable-surface, permeable-base, and nonpermeable pavements were 32.8, 35.4, and 40.5 yuan/m2/yr, respectively. With regard to transitioning from nonpermeable to permeable pavements in urban road construction, Chongqing and Shenzhen presented favorable potential for GHG mitigation (22 and 26 kt CO2e/yr, respectively) and water savings (196 and 187 Mt/yr, respectively). Contrarily, Hebi, Yuxi, Sanya, Qianan, Chizhou, and Xining were not cost-effective in terms of GHG emission reduction. Moreover, in this study, GHG–water–cost tradeoffs were identified among different pavements, highlighting directions for unlocking the green benefits of installing permeable asphalt pavements in China.

Rational design double S-scheme heterosystem based Photo-Electrocatalytic membrane device for continuous phytotoxin remediation

Today, the escalating contamination of water sources with phytotoxins poses a significant danger to both ecosystems and human health. Consequently, the implementation of advanced and sustainable remediation technologies becomes imperative for the effective removal of toxins. This study introduces a pioneering method for continuous phytotoxin remediation by integrating a photoelectrocatalytic membrane reactor, which utilizes a ZnCdFeSe heterojunction photocatalyst with a double S-scheme, is derived from the ZnCd prussian blue analog. This design capitalizes on the unique electronic structure and synergistic effects of the catalyst enabling efficient photo-electrocatalysis in the device. The proposed system attains an impressive phytotoxin rejection efficiency of 98.39%, accompanied by enhanced membrane permeation and anti-fouling performance. The obtained results are noteworthy for an emerging process that combines the simultaneous degradation and separation of toxic species, enabling prolonged and uninterrupted remediation processes. Experimental and density function theory (DFT) results demonstrate that, under optimal conditions, the well-stabilized double S-scheme ZnCdFeSe heterojunction achieves a mineralization rate of 85.67%. Even after six cycles of the photocatalytic membrane, the removal rate of ricin remains high at 78.96%, indicating the membrane’s commendable reusability and stability. This research not only contributes to the advancement of innovative environmental remediation strategies but also provides valuable insights for designing and optimizing photoelectrocatalytic systems for the persistent removal of toxins in water treatment applications.

Impact of temperature and water source on drinking water microbiome during distribution in a pilot-scale study

This study utilized a pilot-scale distribution network to examine the impact of temperature increases (16 °C, 20 °C, 24 °C) and source variations (treated ground- and surface water) on bulk and biofilm communities over 137 days. Microbial characterization employed flow cytometry and 16 S rRNA gene-based amplicon sequencing to elucidate bulk-biofilm interactions. Bacterial bulk cell densities increased with higher temperatures, while water source variations significantly influenced bulk cell densities as well as the community composition. Additionally, growth curves were fitted on the flow cytometry results, and growth rates and carrying capacities were higher with treated groundwater at elevated temperatures. Conversely, biofilm cell densities remained unaffected by temperature. A mature biofilm was observed from day 70 onwards and a core biofilm microbiome, resilient to temperature and water source changes, was identified. These findings emphasize the importance of water source quality for maintaining biological stability in drinking water systems, particularly in the face of changing environmental conditions.