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Dissolved Oxygen (DO) in water enables marine life. Measuring the prevalence of DO in a body of water is an important part of sustainability efforts because low oxygen levels are a primary indicator of contamination and distress in bodies of water. Therefore, aquariums and aquaculture of all types are in need of near real-time dissolved oxygen monitoring and spend a lot of money on purchasing and maintaining DO meters that are either expensive, inefficient, or manually operated—in which case they also need to ensure that manual readings are taken frequently which is time consuming. Hence a cost-effective and sustainable automated Internet of Things (IoT) system for this task is necessary and long overdue. DOxy, is such an IoT system under research and development at Santa Clara University's Ethical, Pragmatic, and Intelligent Computing (EPIC) Laboratory which utilizes cost-effective, accessible, and sustainable Sensing Units (SUs) for measuring the dissolved oxygen levels present in bodies of water which send their readings to a web based cloud infrastructure for storage, analysis, and visualization. DOxy's SUs are equipped with a High-sensitivity Pulse Oximeter meant for measuring dissolved oxygen levels in human blood, not water. Hence a number of parallel readings of water samples were gathered by both the High-sensitivity Pulse Oximeter and a standard dissolved oxygen meter. Then, two approaches for relating the readings were investigated. In the first, various machine learning models were trained and tested to produce a dynamic mapping of sensor readings to actual DO values. In the second, curve-fitting models were used to produce a successful conversion formula usable in the DOxy SUs offline. Both proved successful in producing accurate results. [ABSTRACT FROM AUTHOR]

ABSTRACTGroundwater is a significant source of drinking water in Kathmandu Valley of Nepal. The study aims to evaluate the groundwater quality in terms of water quality index. We compared the physicochemical and microbial parameters of 159 groundwater samples. The study showed that conductivity, hardness, chloride, and nitrate were found to be significantly higher in well water and ammonia was found to have significantly higher concentrations in boring water. The Spearman’s rank correlation coefficient demonstrated a positive correlation between conductivity and hardness, turbidity and iron, total hardness and chloride, and ammonia and arsenic. The drinking water quality parameters including pH, conductivity, turbidity, chloride, hardness, iron, ammonia, total coliform, and Escherichia coli count exceeded National Drinking Water Quality Standards, 2022 by 7.55%, 22.01%, 50.94%, 1.26%, 3.77%, 69.81%, 41.51%, 93.71%, and 47.17% samples, respectively. The water quality index showed that 38.36% of groundwater samples fall under grade-E which requires proper treatment before use. Linear regression revealed that with the increase in turbidity and iron, the water quality index also increases. The principal component analysis identified hardness, iron, conductivity, and nitrate as the major variables governing groundwater quality with no significant difference between well and boring water. Results suggest an urgent need for appropriate treatment of groundwater to mitigate pollutants.

Cyanuric acid is a widely used fine chemical intermediate that acts as a free chlorine buffer in swimming pool water, wherein it is often used as a stabilizer to maintain the germicidal efficacy of chlorinated disinfectants. However, it has also been associated with health risks. Herein, we introduced the sources and functions of cyanuric acid in swimming pool water, focusing on potential health risks associated with excessive concentration of the component and the current control standards worldwide. Also, the prevention and control measures were summarized in terms of physical chemistry, biodegradation, and ultraviolet radiation to provide a basis for the development of public health policies for swimming pool management.

Dissolved Oxygen (DO) in water enables marine life. Measuring the prevalence of DO in a body of water is an important part of sustainability efforts because low oxygen levels are a primary indicator of contamination and distress in bodies of water. Therefore, aquariums and aquaculture of all types are in need of near real-time dissolved oxygen monitoring and spend a lot of money on purchasing and maintaining DO meters that are either expensive, inefficient, or manually operated—in which case they also need to ensure that manual readings are taken frequently which is time consuming. Hence a cost-effective and sustainable automated Internet of Things (IoT) system for this task is necessary and long overdue. DOxy, is such an IoT system under research and development at Santa Clara University’s Ethical, Pragmatic, and Intelligent Computing (EPIC) Laboratory which utilizes cost-effective, accessible, and sustainable Sensing Units (SUs) for measuring the dissolved oxygen levels present in bodies of water which send their readings to a web based cloud infrastructure for storage, analysis, and visualization. DOxy’s SUs are equipped with a High-sensitivity Pulse Oximeter meant for measuring dissolved oxygen levels in human blood, not water. Hence a number of parallel readings of water samples were gathered by both the High-sensitivity Pulse Oximeter and a standard dissolved oxygen meter. Then, two approaches for relating the readings were investigated. In the first, various machine learning models were trained and tested to produce a dynamic mapping of sensor readings to actual DO values. In the second, curve-fitting models were used to produce a successful conversion formula usable in the DOxy SUs offline. Both proved successful in producing accurate results.

Combined with photoelectric detection technology and UV-Vis absorption spectroscopy in spectral analysis technology, a multi-parameter portable surface water quality detection system is developed, which can quickly detect phosphate, nitrite, and chemical oxygen demand (COD) and ammonia nitrogen water quality parameters on site. For the substances in the water body that absorb the characteristic wavelengths in the visible part, a camera is used to collect the visible spectrum, and the grayscale image of the visible spectrum image is modeled by a convolutional neural network. The concentration value of substances whose absorption characteristic wavelength is in the ultraviolet band is measured by photoelectric detection technology. The established convolutional neural network model is transplanted into ZYNQ, combined with ultraviolet photoelectric sensor, the concentration value of the detected substance is displayed on the LCD, so as to realize the economy, portability, real-time and rapidity of the water quality detector. Research indicates: The prediction value of convolutional neural network is obtained as the tendency value of sample solution in 8 output types of concentration value, the highest accuracy is 100%, and the lowest is 40%. The highest error of COD concentration value is 10%, which proves that the detection system has practical value with low noise and high precision. [ABSTRACT FROM AUTHOR]

Many rural communities in Andean countries of South America rely on springs as their primary drinking water source. A variety of spring capture methods are employed resulting in varying water quality. Water from these spring-fed sources, delivered to the community via a distribution network, is often not chlorinated, increasing the risk of water-borne pathogens. A simple, improved technique has been developed in Ecuador's Chimborazo Province by a local Christian organization, Corporación de Desarrollo Integral Socio Económico (CODEINSE), to protect spring water sources for community water supply. This new technique, ‘the CODEINSE method’, builds on the strengths of traditional subterranean spring captures while employing several design improvements, like a concrete cap and sufficient gravel pack, to prevent surface water contamination. According to water quality data collected in Ecuador, the CODEINSE method consistently provides high-quality water with substantially reduced levels of water-borne pathogens compared to traditional spring capture methods. On average, the CODEINSE method yields water with less than 1.0 CFU/100 mL, water that is deemed no risk by the World Health Organization. The CODEINSE method has the potential to improve water quality not only in the rural Andean communities in Ecuador but also in developing countries across the world. HIGHLIGHTS The CODEINSE method yields water with reduced coliform bacteria amounts.; The CODEINSE method yields water with a WHO (World Health Organization) classification of ‘no risk’ over 50% of the time.; The CODEINSE method is simple to construct and requires low maintenance.; The CODEINSE method reduces opportunities for contamination compared to traditional capture methods.;

In this paper, we take a water quality testing Unmanned Surface Vessel (USV) as the research object. We propose a heading keeping strategy based on Human Simulated Intelligent Control (HSIC) algorithm and a trajectory tracking strategy under line-of-sight (LOS) algorithm. The practicality of the proposed control strategies was verified by combining simulations and experiments. The main contents were constructed with three parts: Firstly, we designed a complete control system of a water quality inspection unmanned boat with Arduino microcontroller as the core processor. Secondly, we derived the mathematical model of motion after reasonable simplification. Combined with the cycle experiment, the mapping relation between virtual rudder angle and motor speed was established. Then, the USV heading direction control strategy of HSIC was presented and the reliability of the proposed strategy was verified by the course control experiment of USV. Finally, aiming at the defects and shortcomings of the upper-level trajectory tracking LOS algorithm in practical application, we propose the trajectory correction and precise steering control strategies, and the practicality of the improved algorithm was verified by multi-point trajectory tracking experiments. The autonomous fixed-point water quality testing experiment was designed and verified the effectiveness of the proposed strategies. [ABSTRACT FROM AUTHOR]

ABSTRAK Pengujian kualitas air berdasarkan Standar Nasional Indonesia (SNI) menggunakan alat-alat khusus yang hanya ada di laboratorium dan harus dioperasikan oleh seorang laboran menyebabkan keterbatasan data yang diperlukan karena memerlukan biaya yang tinggi. Oleh karena itu diperlukan metode alternatif yang lebih terjangkau dan mudah digunakan dalam uji kualitas air. Dengan menggunakan Test Strip sebagai alat untuk menguji kontaminasi bakteri Escherichia coli (E.Coli) dan total coliform pada sampel air bersih. Penelitian ini bertujuan untuk mengetahui bagaimana kemampuan penggunaan alat Test Strip diterapkan dalam metode alternatif untuk uji kualitas air yang tidak berdasarkan standar SNI. Metode penelitian menggunakan metode deskriptif eksploratif, dimana hasil penelitian berdasarkan pengamatan yang dialami oleh penulis selama menggunakan Test Strip. Hasil menunjukkan bahwa Test Strip merupakan alat yang mudah digunakan, terjangkau dan dapat digunakan sebagai alat edukasi mandiri dalam menghasilkan informasi kualitas air bersih dalam uji mikroba pada sampel air, tetapi untuk mendapatkan hasil yang akurat tidak dianjurkan untuk menggunakan alat Test Strip. Penggunaan Test Strip lebih sesuai digunakan untuk kondisi yang cepat atau mendesak sehingga para pengguna dapat melakukan tindakan preventif awal yang lebih cepat terhadap adanya kontaminan bakteri pada air bersih yang biasa dikonsumsi. Kata kunci: metode alternatif, mudah digunakan, terjangkau, Test Strip, uji kualitas air ABSTRACT Indonesian National Standard (SNI) to testing water quality using special equipment that is only available in the laboratory and must be operated by a laboratory assistant can be causing limited result because required high cost. Therefore we need an alternative method that is more affordable and easy to use in testing water quality. Test Strip used as a tool to test for contamination of Escherichia coli (E.Coli) and total coliform in clean water samples. This study aims to determine how the capability of Test Strip as an alternative method that is not based on SNI standards in clean water quality testing. The research used descriptive exploratory as the research method, where the results of the study are based on the observations experienced by the author along with using the Test Strip. The results show Test Strip is a tool that easy to use, affordable, and can be used as an independent educational tool in producing clean water quality information. But, Test Strip is not recommended to be used to get accurate results. Test Strip is more suitable to obtain water quality information in rapid or urgent conditions so that users can take faster preventive action against the presence of bacterial contaminants in clean water. Keywords: affordable, alternative, easy to use, Test Strip, water quality testing

Cellulose acetate fibers were modified with a gelatin cryogel adsorbent incorporating an iron–carboxylate metal–organic framework and hypercrosslinked polymer composite. The hybrid adsorption materials facilitated the adsorption ability toward polycyclic aromatic hydrocarbons and were entrapped into gelatin cryogel to be hierarchically coated on cellulose acetate fibers which helped to reduce the clogging problem of packed adsorbent. The composite adsorbent was employed as the solid phase of an in-syringe miniaturized solid-phase extraction system. The adsorbent was packed into the needle hub of a disposable syringe and used to extract and preconcentrate polycyclic aromatic hydrocarbons in water sample. The fabricated porous composite adsorbent was characterized and extraction conditions were optimized to achieve the best extraction performance. High-performance liquid chromatography was employed to separate and quantify extracted PAHs. The developed analysis method provided a linear range of 0.020–50 µg L−1 for phenanthrene and benzo(b)fluoranthene, 0.010–50 µg L−1 for pyrene, 0.0020–50 µg L−1 for benzo(a)anthracene, and 0.0050–50 µg L−1 for benzo(a)pyrene and dibenzo(a,h)anthracene. The limits of detection ranged from 0.5 to 5.0 ng L−1. Recoveries ranged from 89 to 98% with RSDs below 7%. The good stability of the adsorbent allowed up to 21 cycles of efficient extraction and desorption. [ABSTRACT FROM AUTHOR]

Approximately 23 million U.S. households rely on private wells for drinking water. This study first summarizes drinking water behaviors and perceptions from a large-scale survey of households that rely on private wells in Iowa. Few households test as frequently as recommended by public health experts. Around 40% of households do not regularly test, treat, or avoid their drinking water, suggesting pollution exposure may be widespread among this population. Next, we utilize a randomized control trial to study how nitrate test strips and information about a free, comprehensive water quality testing program influence households' behaviors and perceptions. The intervention significantly increased testing, including high-quality follow-up testing, but had limited statistically detectable impacts on other behaviors and perceptions. Households' willingness to pay for nitrate test kits and testing information exceeds program costs, suggesting that the intervention was welfare-enhancing.

Rural water systems in Africa have room to improve water quality monitoring. However, the most cost-effective approach for microbial water testing remains uncertain. This study compared the cost per E. coli test (membrane filtration) of four approaches representing different levels of centralization: (i) one centralized laboratory serving all water systems, (ii) a mobile laboratory serving all systems, (iii) multiple semi-centralized laboratories serving clusters of systems, and (iv) decentralized analysis at each system. We employed Monte Carlo analyses to model the costs of these approaches in three real-world contexts in Ghana and Uganda and in hypothetical simulations capturing various conditions across rural Africa. Centralized testing was the lowest cost in two real-world settings and the widest variety of simulations, especially those with water systems close to a central laboratory (<36 km). Semi-centralized testing was the lowest cost in one real-world setting and in simulations with clustered water systems and intermediate sampling frequencies (1-2 monthly samples per system). The mobile lab was the lowest cost in the fewest simulations, requiring few systems and infrequent sampling. Decentralized testing was cost-effective for remote systems and frequent sampling, but only if sampling did not require a dedicated vehicle. Alternative low-cost testing methods could make decentralized testing more competitive.

In this paper, we take a water quality testing Unmanned Surface Vessel (USV) as the research object. We propose a heading keeping strategy based on Human Simulated Intelligent Control (HSIC) algorithm and a trajectory tracking strategy under line-of-sight (LOS) algorithm. The practicality of the proposed control strategies was verified by combining simulations and experiments. The main contents were constructed with three parts: Firstly, we designed a complete control system of a water quality inspection unmanned boat with Arduino microcontroller as the core processor. Secondly, we derived the mathematical model of motion after reasonable simplification. Combined with the cycle experiment, the mapping relation between virtual rudder angle and motor speed was established. Then, the USV heading direction control strategy of HSIC was presented and the reliability of the proposed strategy was verified by the course control experiment of USV. Finally, aiming at the defects and shortcomings of the upper-level trajectory tracking LOS algorithm in practical application, we propose the trajectory correction and precise steering control strategies, and the practicality of the improved algorithm was verified by multi-point trajectory tracking experiments. The autonomous fixed-point water quality testing experiment was designed and verified the effectiveness of the proposed strategies.

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Cyanuric acid is a widely used fine chemical intermediate that acts as a free chlorine buffer in swimming pool water, wherein it is often used as a stabilizer to maintain the germicidal efficacy of chlorinated disinfectants. However, it has also been associated with health risks. Herein, we introduced the sources and functions of cyanuric acid in swimming pool water, focusing on potential health risks associated with excessive concentration of the component and the current control standards worldwide. Also, the prevention and control measures were summarized in terms of physical chemistry, biodegradation, and ultraviolet radiation to provide a basis for the development of public health policies for swimming pool management., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Chen, Su, Chen, Li and Wang.)

In this paper, the two-dimensional hydrodynamic mathematical model of Delft 3D was used to evaluate the hydrodynamic behaviour of Beidaihe Bay, and also to simulate the diffusion of pollutants in the Beidaihe bay. The chemical oxygen demand, nitrite nitrogen, total phosphorus content and heavy metal content in Bohai bay was analyzed, and the present situation of shallow water quality was also analyzed. Coupled simulation of coastal water quality with flow module and WAQ module in Delft 3D, the diffusion characteristics of pollutant emission were obtained. The study of impact from land-source pollution in Beidaihe Bay helps in further understanding the existing pollution status and provides a better view of land-source pollution to the general public. [ABSTRACT FROM AUTHOR]

In this study, a two-dimensional hydrodynamic modeling and pollutant transport model were firstly established. The experiments verify the feasibility of the models. Through the hydrodynamic and the pollutant diffusion model, the numerical simulation of the pollutant diffusion in Bohai Bay is simulated. The diffusion characteristics of pollutant emission were obtained. At the same time, we analyzed the present situation of shallow water quality from chemical oxygen demand, nitrite nitrogen, total phosphorus content, and heavy metal content [ABSTRACT FROM AUTHOR]

A compact absorptiometer for water quality testing that does not need a special technique to take measurements was studied where the absorbance of a sample solution could be stably measured without decreasing the sensitivity over time. Three types of devices were developed, namely, horizontal straight-line type, vertical straight-line type, and multiple reflection type, that consisted of a light emitting diode (LED), a photodiode (PD), and a glass capillary used as a sample cell. The results from our experiments conducted to detect the nitrite nitrogen in water, which is a factor in water pollution, were used to evaluate how these three devices perform. The shapes of the liquid surfaces at the end of the capillaries in the horizontal and vertical straight-line types, which had the LED, PD, and the glass capillary in line horizontally and vertically, respectively, significantly influenced the output voltage of the PD and this output significantly changed over time, so it was difficult to precisely measure the absorbance. The change in the shape of the liquid surface at the end of the capillary was particularly considerable in the horizontal straight-line type. On the other hand, in the multiple reflection type, which had reflective plates surrounding the glass capillary, the absorbance was measured quite stably because the light emitted by the LED did not transmit through the liquid surface at the end of the capillary and the output voltage of the PD was uninfluenced by the change in the shape of the liquid surface. Additionally, controlling the sensitivity of the absorbance was possible by adjusting the length of the reflective plates, i.e., adjusting the light path. The sample solution in this device did not come into direct contact with the reflective plate, so the device can suppress the decrease in the sensitivity caused by materials becoming directly attached to the reflection plate. The compact multiple reflection type device that was developed could be used in a manually operated portable absorptiometer and also in an automated water quality analysis system that incorporates mixing and flow devices.

Adoption of molecular-based water quality tests has been limited despite their advantage over traditional culture-based tests. A better understanding of the factors affecting adoption of these tests is needed for effective implementation. The Consolidated Framework for Implementation Research (CFIR) was used to analyze interviews with policy makers, watershed managers and laboratory managers in British Columbia (BC), Canada about their perceptions of molecular water tests currently under development in order to assess readiness for adoption and identify factors that may impact implementation. Many of the CFIR constructs were addressed by study participants, thus confirming their validity in the water-testing context. Other constructs were not mentioned, which suggests that awareness about these constructs need to be increased to ensure that they are incorporated into implementation strategies. In general, there was much enthusiasm for the new tests, which were seen to provide valuable information that could enable improved management of watersheds and treatment of source water. However, prior to adopting the tests, stakeholders would require evidence supporting the tests' validity and reliability, would need to assess the complexity of introducing the tests into laboratories and water sampling processes, and would require support interpreting the test results. Even if all the aforementioned issues are satisfactorily addressed, the tests may not be adopted unless regulations and policies were changed to allow the use of these test results to inform decision making. The results support that implementation of new technologies, such as these water quality tests, need to address potential barriers that could hinder uptake despite the advantages of the new product. [ABSTRACT FROM AUTHOR]

A social cognition model of health behavior, the health belief model, was applied to the pro-environmental behavior of private well water testing. Conceptualizing environmental behaviors as health behaviors may provide new insight into pro-environmental behavior change. A groundwater education program was provided to K-12 children throughout New England. Both child participants and their parents completed surveys pertaining to private well water behavior. Results indicate that perceived barriers and socioeconomic status significantly influenced past well water testing of parent participants. Perceived barriers included: participants' concern related to the cost of treating their water, and how a well water problem would influence their property value. Parent participants also indicated that they would perform future well water testing if they received a reminder cue to action that might include: getting a discount or reminder in the mail, if a well testing program was available, and state or local requirement. Our findings reinforce the need for continued private well water research and parallels to additional environmental behaviors. [ABSTRACT FROM AUTHOR]

The aim of this research is to study the effectiveness of using videoconferencing as a tool for collaborative learning on water pollution among students from two secondary schools located in different districts. The poor water quality of the nullahs in urban areas aroused the interest of students from two secondary schools in Tin Shui Wai and Wong Tai Sin who had experienced the nasty smell of the water from Tin Shui Wai Nullah and Kai Tak River respectively. Students of both schools were quickly aware of the need to improve the environment around their schools. Through the use of internet-based videoconferencing, the students shared and learned from each other's experiences in analysing pollutants in their own water channel. With the help of governmental and non-governmental organisations involved in environmental protection, the students also exchanged ideas on how water quality can be improved. They conducted three video conferences thus far. These involved lectures, data exchanges and information sharing. After these conferences, the data taken from the school-based curriculum design, the students' worksheets, their reflections and the video-clips of lesson observation were analysed. This paper discusses the data collected, and the results show that students' interest was aroused and their learning outcomes in knowledge, skills and attitude were recognised. Teachers involved also considered the project to be an opportunity for teacher development and to enhance their own learning. [ABSTRACT FROM AUTHOR]

[Display omitted] • A simple, efficient and sensitive fluorescent biosensor for Ag+ detection. • The specificity is based on the strong, particular binding interaction of C-Ag+-C. • Excellent performance of sensitivity using HCR as amplification method. • The limited of detection of Ag+ is down to 0.69 pM. Ag is widely distributed in nature and it is used in almost all areas of human life. However, due to the widespread use of Ag materials, Ag+ pollution seriously threatens the human health and environment. The traditional detection methods for Ag+ suffer from disadvantages including high operational cost, complicated operating unit and instrument, and high requirements for professionals. Thus, in this study, a new type of Ag+ detection biosensor based on the hybridization signal amplification was designed to overcome these problems. Combining cytosine-Ag+-cytosine mismatch structure with the hybridization chain reaction, this biosensor converted the conventional detection signal into the nucleic acid amplification signal, which realized efficient, rapid, sensitive, and specific detection of Ag+. The limit-of-detection of this sensor reached 0.69 pM, which is much less than the maximum concentration (0.1 mg L−1, 927 nM) suggested for drinking water by the World Health Organization, and the maximum concentration (0.05 mg L−1, 464 nM) suggested by the United States Environmental Protection Agency. This method provides a promising new platform for detecting Ag+ concentrations at ultralow levels. [ABSTRACT FROM AUTHOR]