Commercial Water Research Articles

Enhancing the efficiency of solar-powered water distillation units by utilization of waste heat

ABSTRACT Thermal water desalination is based on the evaporation and condensation of water, and such a process consumes a lot of energy, which lowers the economy of the process for commercial water desalination. The objective of this research is to improve the desalination energy efficiency of a novel domestic water desalination unit, which is based on thermal desalination, and this is done via utilization of the waste heat in the generated steam and reducing the operating costs. The distillation process begins with solar-powered evaporation of the salty water in the evaporator, followed by condensation of the generated water vapor coming from the evaporator over the cross-flow heat exchangers located in the condenser, which preheats the incoming saline water from the saltwater tank before it enters the evaporator. To assess the system's performance, comprehensive measurements are taken, including the electrical energy output from the PV panels and the volume of the output distilled water. Notably, the energy efficiency of the distillation is defined as the ratio of the heat energy gained by the distilled water, i.e. collected at the end of the day, to the electrical energy input to the electric heater, and it is found to be, on average, 82%.

An All-Passive and Macropatterned Architecture Design for Water Harvesting.

Solar evaporation designs show great promise in water harvesting without electricity inputs. Unfortunately, they have been heavily limited by a low water yield. To overcome this challenge, we introduced a new architecture featuring both system-level and materials-level designs. At the system level, we implemented a macropatterned architecture with a decoupled design for water evaporation and condensation to enhance water yield efficiency. This design also ensures that condensed water droplets do not block the solar evaporation process. At the materials level, solar selective heating and radiative cooling were applied to improve passive water yield performance. As a proof of concept, our design showed an indoor water collection rate of 2.06 kg m-2 h-1 under one sun and an average outdoor water collection rate of 1.85 kg m-2 h-1 over five consecutive days. The decoupled, all-passive, and macropatterned architecture offers substantial potential for commercial water collection applications toward mitigating global water scarcity.

Corrosion-resistant NiFe anode towards kilowatt-scale alkaline seawater electrolysis

Development of large-scale alkaline seawater electrolysis requires robust and corrosion-resistant anodes. Here we propose engineering NiFe layered double hydroxide (LDH)-based anodes by incorporating a series of anions into the LDH interlayers. The most optimal NiFe LDH anode with intercalated phosphates demonstrates stable operation at a high current density of 1.0 A cm−2 for over 1000 hours in a 2 W-scale alkaline seawater electrolyzer (ASWE). Fundamental studies indicate that the basicity, indicated by pKa values, of the intercalated anions in NiFe LDH governs its oxygen evolution reaction activity and corrosion resistance. Highly basic anions (i.e., phosphates) securely anchor Fe sites and facilitate proton transfer to boost both durability and activity. Notably, we demonstrate the proof-of-concept for the NiFe anode in an industrial 1 kW-scale ASWE stack (1,081.2 cm2 anode area in total). This unit achieves a stable operating current density of 0.5 A cm−2 at about 2.0 V, twice that of the commercial alkaline pure water electrolyzer, contributing to an economically competitive hydrogen production cost of US$ 1.96 kgH2−1.

In Situ Synthesis of Nano PtRuW/WC Hydrogen Evolution Reaction Catalyst for Acid Hydrogen Evolution by a Microwave Method

Abstract One of the primary challenges in electrocatalysis for the hydrogen evolution reaction (HER) lies in the development of highly efficient catalysts suitable in acidic environments. Tungsten carbide-based materials have long been proposed as potential substitutes for Pt due to their “Pt-like” electronic properties in the HER process. However, tungsten carbide still falls short of the performance exhibited by commercial precious-metal catalysts. Herein, PtRuW/WC was prepared by a microwave heating method and acted as a HER electrocatalyst. The microwave method not only enhances the diffraction peaks of the substrate tungsten carbide but also facilitates the growth of metal ions at specific sites. The PtRuW/WC catalyst demonstrates outstanding performance in acidic HER, characterized by a minimal overpotential of 40.7 mV at 10 mA/cm2 (ɳ10). Furthermore, it exhibits exceptional stability in acidic solutions, showing no substantial degradation during 20 h at 1000 mA/cm2. The catalyst-assembled polymer electrolyte membrane (PEM) electrolytic water electrode further proves that PtRuW/WC has excellent electrolytic water performance and makes some efforts for the development of commercial PEM electrolytic water.

Membrane-Free Water Electrolysis for Hydrogen Generation with Low Cost.

Conventional water electrolysis relies on expensive membrane-electrode assemblies and sluggish oxygen evolution reaction (OER) at the anode, which makes the cost of green hydrogen (H2) generation much higher than that of grey H2. Here, we develop an innovative and efficient membrane-free water electrolysis system to overcome these two obstacles simultaneously. This system utilizes the thermodynamically more favorable urea oxidation reaction (UOR) to generate clean N2 over a new class of Cu-based catalyst (CuXO) for replacing OER, fundamentally eliminating the explosion risk of H2 and O2 mixing while removing the need for membranes. Notably, this membrane-free electrolysis system exhibits the highest H2 Faradaic efficiency among reported membrane-free electrolysis work. In situ spectroscopic studies reveal that the new N2Hy intermediate-mediated UOR mechanism on the CuXO catalyst ensures its unique N2 selectivity and OER inertness. More importantly, an industrial-type membrane-free water electrolyser (MFE) based on this system successfully reduces electricity consumption to only 3.78 kWh Nm-3, significantly lower than the 5.17 kWh Nm-3 of commercial alkaline water electrolyzers (AWE). Comprehensive techno-economic analysis (TEA) suggests that the membrane-free design and reduced electricity input of the MFE plants reduce the green H2 production cost to US$1.81 kg-1, which is lower than those of grey H2 while meeting the technical target (US$2.00-2.50 kg-1) set by European Commission and United States Department of Energy.

Membrane‐Free Water Electrolysis for Hydrogen Generation with Low Cost

AbstractConventional water electrolysis relies on expensive membrane‐electrode assemblies and sluggish oxygen evolution reaction (OER) at the anode, which makes the cost of green hydrogen (H2) generation much higher than that of grey H2. Here, we develop an innovative and efficient membrane‐free water electrolysis system to overcome these two obstacles simultaneously. This system utilizes the thermodynamically more favorable urea oxidation reaction (UOR) to generate clean N2 over a new class of Cu‐based catalyst (CuXO) for replacing OER, fundamentally eliminating the explosion risk of H2 and O2 mixing while removing the need for membranes. Notably, this membrane‐free electrolysis system exhibits the highest H2 Faradaic efficiency among reported membrane‐free electrolysis work. In situ spectroscopic studies reveal that the new N2Hy intermediate‐mediated UOR mechanism on the CuXO catalyst ensures its unique N2 selectivity and OER inertness. More importantly, an industrial‐type membrane‐free water electrolyser (MFE) based on this system successfully reduces electricity consumption to only 3.78 kWh Nm−3, significantly lower than the 5.17 kWh Nm−3 of commercial alkaline water electrolyzers (AWE). Comprehensive techno‐economic analysis (TEA) suggests that the membrane‐free design and reduced electricity input of the MFE plants reduce the green H2 production cost to US$1.81 kg−1, which is lower than those of grey H2 while meeting the technical target (US$2.00–2.50 kg−1) set by European Commission and United States Department of Energy.

Innovative electrochemical sensor based on platinum group metal complexes for determination of nitrite: Application for simultaneous detection of nitrite and tartrazine

In the context of this experimental study, new palladium and ruthenium complexes based on a symmetric ligand, named 2E-Peaemp ((3E,3’E)-3,3’-(((piperazine-1,4-diyl bis (ethane-2,1-diyl)) bis (azanediyl)) bis (ethan1-yl-1-ylidene)) bis (6-methyl-2H-pyran-2,4(3 H)-dione), and their hybrid compounds with carbon nanotubes were prepared and characterized. The sensors prepared using a cavity microelectrode (MEC) modified with a mixture of graphite (CG), carbon nanotubes (MWCNT) and the synthesized complexes (Pd-2E-Peaemp and Ru-2E-Peaemp) were applied to detect the pollutants such as Nitrites and Tartrazine separately and simultaneously in aqueous solutions and real samples (Tap water, wastewater and bottled commercial spring water). The detection limits (LODs) determined for nitrites and tartrazine are obtained using MEC/CG-MWCNT-Pd-2E-Peaemp electrode, and the electrochemical measurements demonstrated a sensitive and rapid response in the analysis of these species. LODs are 0.39 µM and 0.11 µM, respectively, within the concentration range of 0–909 µM for nitrites and 0–97 µM for tartrazine. This electrode modified by the palladium complex is also used to simultaneously detect nitrite and tartrazine analytes using the differential pulse voltammetry (DPV) technique, indicating that the proposed sensor can be an interesting alternative tool to measure these species in real samples. The application of this electrode in these natural environments reveals that the developed sensor can detect low concentrations of nitrite (NO2-; trace) without any interference from other ions substances as acetate (CH3COO-), borate (BO3−3), phosphate (PO4−3), dihydrogen ( 2 H+), sulfate (SO4−2), sodium (Na+), hydroxide (OH-), potasium (K+), chloride (Cl-), magnesium (I) ( Mg+), nitrate (NO3-), calcium (Ca2+), carbonate (CO3−2).

Developing Practical Catalysts for High‐Current‐Density Water Electrolysis

AbstractHigh‐current‐density water electrolysis is considered a promising technology for industrial‐scale green hydrogen production, which is of significant value to energy decarbonization and numerous sustainable industrial applications. To date, substantial research advancements are achieved in catalyst design for laboratory‐based water electrolysis. While the designed catalysts demonstrate remarkable performance at laboratory‐based low current densities, they suffer from marked deteriorations in both activity and long‐term stability under industrial‐level high‐current‐density operations. To provide a timely assessment that helps bridge the gap between laboratory‐scale fundamental research and industrial‐scale practical water electrolysis technology, here the current advancements in various commercial water electrolyzers are first systematically analyzed, then the key parameters including work temperature, current density, lifetime of stacks, cell efficiency, and capital cost of stacks are critically evaluated. In addition, the impact of high current density on the electrocatalytic behavior of catalysts, including intrinsic activity, long‐term stability, and mass transfer, is discussed to advance the catalyst design. Therefore, by covering a range of critical issues from fundamental material design principles to industrial‐scale performance parameters, here the future research directions in the development of highly efficient and low‐cost catalysts are presented and a procedure for screening laboratory‐designed catalysts for industrial‐scale water electrolysis is outlined.

Development of over 30-years of high spatiotemporal resolution air pollution models and surfaces for California

California’s diverse geography and meteorological conditions necessitate models capturing fine-grained patterns of air pollution distribution. This study presents the development of high-resolution (100 m) daily land use regression (LUR) models spanning 1989–2021 for nitrogen dioxide (NO2), fine particulate matter (PM2.5), and ozone (O3) across California. These machine learning LUR algorithms integrated comprehensive data sources, including traffic, land use, land cover, meteorological conditions, vegetation dynamics, and satellite data. The modeling process incorporated historical air quality observations utilizing continuous regulatory, fixed site saturation, and Google Streetcar mobile monitoring data. The model performance (adjusted R2) for NO2, PM2.5, and O3 was 84 %, 65 %, and 92 %, respectively.Over the years, NO2 concentrations showed a consistent decline, attributed to regulatory efforts and reduced human activities on weekends. Traffic density and weather conditions significantly influenced NO2 levels. PM2.5 concentrations also decreased over time, influenced by aerosol optical depth (AOD), traffic density, weather, and land use patterns, such as developed open spaces and vegetation. Industrial activities and residential areas contributed to higher PM2.5 concentrations. O3 concentrations exhibited no significant annual trend, with higher levels observed on weekends and lower levels associated with traffic density due to the scavenger effect. Weather conditions and land use, such as commercial areas and water bodies, influenced O3 concentrations.To extend the prediction of daily NO2, PM2.5, and O3 to 1989, models were developed for predictors such as daily road traffic, normalized difference vegetation index (NDVI), Ozone Monitoring Instrument (OMI)–NO2, monthly AOD, and OMI-O3. These models enabled effective estimation for any period with known daily weather conditions.Longitudinal analysis revealed a consistent NO2 decline, regulatory-driven PM2.5 decreases countered by wildfire impacts, and spatially variable O3 concentrations with no long-term trend. This study enhances understanding of air pollution trends, aiding in identifying lifetime exposure for statewide populations and supporting informed policy decisions and environmental justice advocacy.

Multi-Objective Optimization Strategy for Commercial Vehicle Permanent Magnet Water Pump Motor Based on Improved Sparrow Algorithm

In order to achieve multi-objective optimization for a permanent magnet water pump motor in heavy commercial vehicles, we propose a strategy based on response-surface methodology and the improved sparrow algorithm (CGE-SSA). Firstly, the output capacity of the pump during actual operation was tested with an experimental bench to determine the design parameters of the motor, and then its modeling was completed using Ansys Maxwell 2022r2 software. Secondly, the response-surface model was established by taking the parameters of permanent magnet width, rib width, and slot width as optimization parameters and the output torque (Ta), torque ripple (Tr), and back electromotive force (EMF) amplitude as optimization objectives. Meanwhile, three methods—namely, circular sinusoidal chaotic mapping, improved golden sinusoidal strategy, and adaptive weight coefficients—were used to improve the convergence speed and accuracy of the sparrow search algorithm (SSA). Finally, the multi-objective optimization of the permanent magnet synchronous motor was completed using the improved sparrow algorithm. A comparative analysis of the motor’s output before and after optimization showed that the torque pulsation and reverse electromotive force of the motor were significantly improved after optimization.

Cooling Effectiveness of the Sustainable Cooling Solution for Cattle: Case Study in Poland

Recently, the dairy sector has been ever more affected by global warming. This study aimed to test a novel conductive cooling system for cattle that was successfully implemented and evaluated under summer thermally challenging weather conditions in Poland. The system consists mainly of the chiller, tank, and chilled water-driven mattress, designed to prioritize animal well-being. The experimental evaluation was carried out on three Friesian dry cows, housed on different types of bedding—commercial water mattress, straw, and cooling water mattress—and supplied with water at 10 °C (day) and 16 °C (night). The cooling water mattress’ surface temperature was twice as low as that of the commercial water mattress. The animal’s thermal comfort was assessed with physiological and behavioral reactions. The cooling effect on animals’ bodies was demonstrated with a lower reticulorumen temperature of the cooled cow (p < 0.05) than the reference ones. The local effect of cooling was proved with an 8 °C-lower skin temperature after the cow’s resting period. The presented study opens a new research direction toward dairy cattle’s welfare, sustainability, and the food–energy–water nexus, based on potential energy and water savings.

Novel optimal high pressure determination method for CO2 air source heat pump water heater: Experimental study and methodology development

As an efficient and environment-friendly solution to replace traditional fuel-fired boiler, CO2 air source heat pump water heater (HPWH) is widely used in the commercial and residential water heating. In order to achieve the optimal performance of CO2 air source HPWH systems, the effects of electronic expansion valve (EEV) opening and inlet water flow rate on system performance are experimentally studied and the optimal matching of the two parameters are obtained in this study. Then, the relationship between the optimal high pressure and the optimal matching of EEV opening and water flow rate is discussed. Finally, a new parameter, the endpoint temperature difference (ΔTep), is defined and a novel control strategy of ΔTep = 0 is proposed to determine the optimal high pressure. The results indicate that the optimal matching of EEV opening and water flow rate corresponds to the optimal high pressure and the best COPheat of system. A smaller ΔTep corresponding to a better matching degree and a larger system COPheat. The maximum deviation between the high pressure determined by the proposed new control strategy and the optimal high pressure is less than 1.8 %, and the system COPheat under the proposed new control strategy can achieve more than 97.6 % of the maximum COPheat. Therefore, the proposed control strategy in the paper is better than that of the commonly used off-line optimal high pressure correlation and can provide guidance for the efficient operation of the CO2 air source HPWH system.

Fluorine fluid experimental determination of the refractive index, spectral and thermal variation, and transparency quantification of the MezzoCielo telescope

The MezzoCielo (or "half of the sky") is a telescope that aims to revolutionize the way astronomical observations are carried out: once operational, it will be able to continuously patrol the whole sky due to its extremely large field of view estimated to be around 104 square degrees, showing, at the same time, the spatial resolution required for scientific purposes. It is a monocentric optical device designed on the concept of an optical sphere; the latter requires the filling of its inner volume with special fluid in order to be actually convergent with a reasonable focal ratio (for spherical aberration reduction). This fluid must exhibit two main properties, namely, a low refractive index and an extremely high transparency in the visible range. In addition, many other characteristics are also required: thermal and chemical stability over time, no toxicity or flammability, and compatibility with glass and metals are some examples. On the basis of these considerations, two fluorine liquids have been selected: the fluids commercially known as FC-72, perfluorohexane with n d = 1.251 at T = 25°C, and Novec7200, ethoxy-nonafluorobutane with n d = 1.282 at T = 25°C. In this work, the experimental evaluation of their optical properties (refractive index and transparency) in the visible range and in the thermal interval [-10,+25]°C has been carried out in order to verify the data supplied by the manufacturer and to fully characterize their optical behaviour both spectrally and thermally. All the employed techniques have been firstly applied to commercial pure water, for which extensive literature could be used as reference for the procedures validation.

Fabricated of Photovoltaic Thermal System with Phase Change Material

At present, solar energy is widely recognized as one of the primary sources of renewable energy. Nonetheless, conventional solar photovoltaic (PV) panels suffer a significant decrease in efficiency when exposed to extreme temperatures, making them unsuitable for long-term operation. To address these limitations, hybrid photovoltaic thermal (PVT) systems with phase change materials (PCM) have emerged as sophisticated solutions, leveraging thermal energy for water heating and PCM for thermal energy storage. This work aims to evaluate key economic parameters of fabricated PVT system (with and without PCM) against commercial solar water heaters and electric heaters, using metrics such as payback period and annual worth. The calculations are carried out using Microsoft Excel spreadsheets. The results reveal that the payback period for PVT systems, both with and without PCM, exceeds 25 years, primarily due to the high initial costs associated with PVT technology. In contrast, solar water heaters and electric water heaters offer shorter payback periods. Specifically, after 25 years, the annual worth for the fabricated PVT system is MYR 923.12. Essentially, the economic analysis suggests that the PVT system has a longer operational lifetime than solar water heaters and electric heaters, despite the extended payback period. This economic analysis has the potential to encourage the large-scale fabrication and installation of efficient PVT-PCM systems. It provides consumers with a viable alternative to consider installing PVT and PVT-PCM systems instead of PV and solar thermal systems separately. Additionally, this study contributes to reducing carbon emissions and advancing the Sustainable Development Goals (SDGs).

Natural High Strontium Mineral Water Might Reduce Liver Protein Synthesis: A Non-Targeted Metabolomics Study in Rats.

Strontium-rich mineral water (strontium > 0.20mg/L) is the second largest type of mineral water on commercial drinking water market. Exposure to high levels of strontium through drinking water or soil may interfere with calcium metabolism and increase the risk of cardiovascular and skeletal diseases, but no in-depth mechanism has been disclosed to date. Data on liver metabolic alterations in rats resulted from drinking natural high strontium mineral water (strontium 26.06mg/L, SrHW) or tap water (filtered by activated carbon, strontium 0.49mg/L, TW) for 3months were obtained and analyzed with non-targeted metabolomics strategy. Compared with rats drinking TW, those drinking SrHW showed a significant change in 36 liver metabolites. Among them, 33 liver metabolites (including 14 amino acids, 6 carbohydrates, 4 short-chain fatty acids, 4 organic acids, 2 phenylpropanoic acids, 1 fatty acid, 1 peptide, and 1 bile acid) were down-regulated, and 3 (hydroxyphenyllactic acid, propionylcarnitine and S-adenosine homocysteine) were up-regulated. Metabolic pathway analysis showed that aminoacyl-tRNA biosynthesis, valine, leucine and isoleucine biosynthesis, and alanine, aspartate and glutamate metabolism are most impacted. Furthermore, the serum prealbumin content also significantly decreased in rats drinking SrHW. Therefore, changes in liver metabolites and serum protein levels suggested that high concentration of strontium in water was associated with decreased liver protein synthesis; changes in liver metabolites suggested that high strontium was associated with decreased lipid levels. In conclusion, high strontium in water may exert a negative effect on protein synthesis, and further study on the dose-response relationship is necessary.

Designing Bifunctional Electrocatalysts Based on Complex Cobalt-Sulfo-Boride Compound for High-Current-Density Alkaline Water Electrolysis.

In the quest to harness renewable energy sources for green hydrogen production, alkaline water electrolysis has emerged as a pivotal technology. Enhancing the reaction rates of overall water electrolysis and streamlining electrode manufacturing necessitate the development of bifunctional and cost-effective electrocatalysts. With this aim, a complex compound electrocatalyst in the form of cobalt-sulfo-boride (Co-S-B) was fabricated using a simple chemical reduction method and tested for overall alkaline water electrolysis. A nanocrystalline form of Co-S-B displayed a combination of porous and nanoflake-like morphology with a high surface area. In comparison to Co-B and Co-S, the Co-S-B electrocatalyst exhibits better bifunctional characteristics requiring lower overpotentials of 144 mV for hydrogen evolution reaction and 280 mV for oxygen evolution reaction to achieve 10 mA/cm2 in an alkaline electrolyte. The improved Co-S-B performance is attributed to the synergistic effect of sulfur and boron on cobalt, which was experimentally confirmed through various material characterization tools. Tafel slope, electrochemical surface area, turnover frequency, and charge transfer resistance further endorse the active nature of the Co-S-B electrocatalyst. The robustness of the developed electrocatalyst was validated through a 50 h chronoamperometric stability test, along with a recyclability test involving 10,000 cycles of linear sweep voltammetry. Furthermore, Co-S-B was tested in an alkaline zero-gap water electrolyzer, reaching 1 A/cm2 at 2.06 V and 60 °C. The significant activity and stability demonstrated by the cobalt-sulfo-boride compound render it as a promising and cost-effective electrode material for commercial alkaline water electrolyzers.

Time Series Analysis to Estimate the Volume of Drinking Water Consumption in the City of Meoqui, Chihuahua, Mexico

Water is a vital resource for sustaining life and for numerous processes within the transformation industry. It is a finite resource, albeit one that can be renewed, and thus sustainable management is imperative. To achieve this objective, it is necessary to have the appropriate tools to assist with the planning policies for its management. This paper presents a time series analysis approach to measure and predict the pattern of water consumption by humans throughout subsectors (domestic, commercial, public sector, education, industry, and raw water) and total water consumption in Meoqui, Chihuahua, Mexico with data from 2011 to 2023, applying calibration model techniques to measure uncertainty in the forecasting. The municipality of Meoqui encompasses an area of 342 km2. The climate is semi-arid, with an average annual rainfall of 272 mm and average temperatures of 26.4 °C in summer and 9.7 °C in winter. The municipal seat, which has a population of 23,140, is supplied with water from ten wells, with an average consumption of 20 ± 579 m3 per user. The consumption of the general population indicates the existence of a seasonal autoregressive integrated moving average (SARIMA) (0,1,2)(0,0,2)12 model. (Sen’s Slope = 682.7, p < 0.001). The domestic sector exhibited the highest overall consumption, with a total volume of 17,169,009 m3 (13 ± 93). A SARIMA (2,1,0)(2,0,0)12 model was estimated, with a Sen’s slope of 221.65 and a p-value of less than 0.001. The second-largest consumer of total water was the “raw water” sector, which consumed 5,124,795 (30,146 ± 35,841) m3 and exhibited an SARIMA (0,1,1)(2,0,0)12 model with no statistically significant trend. The resulting models will facilitate the company’s ability to define water resource management strategies in a sustainable manner, in alignment with projected consumption trends.

Quality Assessment of Drinking Water from Vending Machines for a Healthier Life

Commercial water vending machines in urban communities are important for consumers because of their convenience and affordability. Therefore, this study investigated the environmental conditions, maintenance, and quality of drinking water distributed through vending machines in an urban community in Thailand. The research sampled 101 drinking water machines in Buriram Municipality, Buriram Province. These machines were assessed for physical characteristics and the surrounding environment and were conducted according to an evaluation form provided by the Ministry of Public Health, Thailand. The findings revealed that 93.07% of the machines had auto coin failures; did not record the date, month, and year of filter changes; and did not display the business license on the cabinet. Additionally, 89.1% of the cabinets had thick dust, 57.43% had damaged or rusted handles on the water inlet door, and 56.44% had algae or rust stains on the water dispenser head. A physiochemical analysis revealed that 83.2% of the machines did not detect the pH levels. Total coliform bacteria and E. coli were not detected in 39.6% and 12.9% of samples, respectively. This study was conducted to develop an application for monitoring the quality of drinking water from vending machines to ensure that standards are met and up-to-date information is provided to help consumers make informed decisions about using clean and safe drinking water from vending machines.

A Study the Role of Water and the Sustainable Development

Water is a crucial natural resource that serves as a primary source of water for irrigation, drinking, and industrial use in India. Despite its importance, Water resources in India are rapidly depleting due to increasing demand, climate change, and unsustainable management practices. Sustainable development, which aims to harmonize economic growth, social inclusion, and environmental sustainability, is paramount in addressing these water challenges. In this context, it is crucial to revisit the Water laws in India to ensure sustainable resource management. The current legal framework for Water in India is fragmented, outdated, and ineffective. the significance of Water has grown. Currently, private-Water resources provide about 90% of the domestic and commercial water needs as well as around 65% of the irrigation needs. However, people frequently mistakenly believe that this valuable resource is boundless and unbounded. As a result, the general public frequently overlooks crucial Water issues such its scientific management, conservation, and augmentation.

Verification and application of qPCR and viability-qPCR for Legionella monitoring in evaporative cooling systems complementing the conventional culture method

To date, in many countries the only legally valid method for evaporative cooling system (ECS) monitoring is the culture method. However, a duration of up to 14 days and a risk of underestimation of Legionella concentrations are seen as limitations of cultivation methods. Rapid cultivation-independent methods are an important step towards a more practicable monitoring of ECS to quickly control interventions if elevated concentrations of Legionella are found.Two commercial kits for quantitative polymerase chain reaction (qPCR) and viability-qPCR (v-qPCR) were studied, comprising sample filtration and DNA extraction. Cryopreserved Legionella pneumophila were established as calibration standard with intact (ILC) and total Legionella count (TLC) determined by flow cytometry before conducting spiking experiments in commercial mineral water and artificial process water. Final assessment was carried out using real ECS samples.Recovery and robustness ranged from 86 to 108 % for qPCR with a drop to 40–60 % for v-qPCR when compared to direct extraction, possibly attributable to cell damage during sample concentration. All methods including culture did perform well regarding linearity with R2 ≥ 0.95 for most trials. Detected concentrations in comparison to spiked Legionella counts differed with culture averaging 25 ± 7 % of spiked ILC and v-qPCR being closest to spiked concentrations with 65–144 %. In comparison, qPCR was several fold above spiked TLC concentrations. For real ECS samples Legionella spp. were detected in concentrations above 103 GU/100 mL by v-qPCR in 70–92 % of samples, depending on the kit used. Most of these samples were either culture-negative or not evaluable on agar plates.This study showed that a cryopreserved bacterial standard based examination is applicable and can be used for future v-qPCR verification. For assessment of differences in results between culture and v-qPCR/qPCR in ECS samples expert knowledge about the operating mode and used analytical methods is required. Guidelines addressing this issue could be a solution.