Official Standards Research Articles

Comparisons and contradictions

Jatin Dua also argues for expanding the scope of the concept but in a scalar modality suggested by his own deep ethnographic experience of international piracy (see Dua 2019). He asks how we might see subversive archaism at work in entities both larger and smaller than the nation-state. The archaists themselves provide some answers by way of exemplary illustration. The Zoniani, for example, regard the encompassing administrative control of the European Union with an ambivalence concentric with their attitude to the nation-state. Rozakou (2018) has also suggested that voluntarism in Greece today represents a surrender to supposedly European and colonial models of civility, thereby hinting once again, this time in her own person, that the subversive archaist may be the anthropologist. Against such views, culturally conservative elites will have every interest in contesting the idea that adherence to European civilizational norms constitutes subservience to a colonial order (see, e.g., Kindi 2019). The ambivalence of civility, as I suggest in the book and as Riccardi-Swartz observes for the Reactive Orthodox, allows for shifting orientations to official norms and standards. Such shiftiness does not sit well with any political or cultural establishment.

Assessment of Microbial Contamination in the Infulene River Basin, Mozambique

Water microbial contamination is one of the major threats to human health. The study focus is on Infulene River Basin, a urban catchment with mainly informal settlements, with limited water supply and sanitation. In the catchment there are two wastewater treatment plants, one hospital and beer factory located on the banks of the main stream; water from this stream is used for urban agriculture and domestic uses by some dwellers. These factors present a significant health risk from water-borne diseases. At the moment there is limited knowledge about the level of microbial contamination of the different sources of water at the disposal of the communities. Thus, a preliminary study on fecal microbial contamination was conducted targeting the Infulene River and the drainage system from the nearby Maputo city draining into the system, with additional investigation on the drinking water provided by the city water supply company. The quantification of Total Coliforms (TC) and Escherichia coli (EC) was conducted at several sampling locations. Results were compared with official drinking water standards. Eighty two percent (82%) and 61% of Infulene river water and drainage water samples were positive for TC (105 to 109 NPN/100 mL) and EC (105 to 107 NPN/100 mL), respectively. For drinking water samples, 63% and 23% were positive for TC (up to 6000 NPN/100 mL) and EC (up to 1000 NPN/100 mL), respectively. Higher microbial contamination was found in neighborhoods with the poorest sanitation and shallow groundwater, i.e., Chamanculo, Xipamanine, Mafalala, Aeroporto and Maxaquene, a situation that was more expressive during the rainy season. Overall, the study confirmed the high vulnerability to microbial contamination of all sources investigated due to poor sanitation and lack of drainage infrastructure. The risks to human health might be even higher considering that contaminated water is used for gardening of vegetable watering and domestic use.

Perspectives of Saudi Occupational Therapists Regarding Telerehabilitation: A Qualitative Study.

Telerehabilitation is emerging in Saudi Arabia. This study investigated occupational therapy professionals' perspectives on using telerehabilitation in their practice. Data were collected through semi-structured phone interviews conducted with nine Saudi occupational therapists. A pragmatic qualitative evaluation approach was used. Experience and perceptions of participants regarding telerehabilitation were represented as follows: awareness and knowledge of telerehabilitation; how telerehabilitation increases occupational therapy availability and access in Saudi Arabia; telerehabilitation in the pandemic; telerehabilitation is preferred; suitability of telerehabilitation in Saudi Arabia; telerehabilitation care pathways; telerehabilitation readiness in Saudi Arabia; and telerehabilitation willingness by Saudi occupational therapists. Saudi occupational therapists have good knowledge and awareness of telerehabilitation, and some had used it during the pandemic. They showed positive attitudes and a willingness to use telerehabilitation if appropriate technology infrastructure, official policy standards and guidelines, training, data security, and financial resources could be provided to support implementation.

The impact of subjective and objective inconsistencies in scientific and technological innovation attributes on the listing of enterprises on the Science and Technology Innovation Board

The attribute of high-tech innovation is the most essential characteristic that distinguishes enterprises on the Science and Technology Innovation Board (STAR) Market from other stock markets. In this paper, we aim to examine the impact of consistency in information disclosure of subjective and objective tech-attributes of enterprises on their success of the application on this board. We construct a science and technology innovation dictionary by Word2vec, and calculate the subjective tech-attributes degree of the enterprise registration statements; Based on the official listing standards document for tech-attributes, we select 7 objective scientific and technological innovation indicators and calculate the enterprises' objective tech-attributes degree via the principal component analysis, and construct the consistency indicator for the two tech-attributes. In the empirical analysis, we collected the registration statement of 708 companies that applied for listing from 2019 to 2022 and studied the inconsistencies between the subjective tech-attributes of the text of the enterprise registration statements and their objective tech-attributes innovation evaluation indicators, and found the factors that affected the successful listing. The results show that both subjective and objective scientific innovation are positively correlated with the successful listing, and the consistency indicator is significantly negatively correlated with the successful listing. When the degree of inconsistency between the subjective and objective tech-attributes is greater, the lower the probability of passing the review and listing of the STAR Market is.

Greek Preschool Teachers’ Professional Features and Their Knowledge and Views of the Official Standards of Early Writing Teaching

Greek Preschool Teachers’ Professional Features and Their Knowledge and Views of the Official Standards of Early Writing Teaching

Functioning of Cinemas in the Cities of the Tobolsk Province at the Beginning of the XX Century .

The purpose of the article is to conduct an overview of the functioning of pre–revolutionary cinemas in one of the most remote provinces of Russia based on the analysis of archival materials, chronicle newspaper publications and the advertising component of regional periodicals. The object of the study is stationary cinematographic institutions of the cities of the Tobolsk province, the subject is the peculiarities of their functioning at the beginning of the XX century. In methodological terms, the work is based on descriptive-narrative, comparative-historical, logical and retrospective methods of scientific cognition, the method of historical reconstruction. It describes the formation of urban cinematographies of the province, their technical characteristics and infrastructure elements in accordance with official Russian standards, the conditions of acceptance of buildings, fire safety issues and problematic aspects of the existence of cinemas. Attention is paid to the repertoire content of film screenings, pricing policy, the phenomena of competition among film entrepreneurs, their work with the audience. The scientific novelty of the study is due to the lack of comprehensive regional works considering the specifics of the activities of pre-revolutionary cinematographic institutions in the territorial framework of the Tobolsk province. It is determined that cinema, having arisen at the end of the XIX century as a sporadic form of entertainment for citizens, during the first decades of the XX century it evolved into an important social phenomenon of everyday life and became one of the key factors of transformations that took place in the system of value attitudes and behavioral stereotypes of the population of the region. Stationary cinemas were not only a fundamentally new type of communication for representatives of the urban community, but over time they turned into significant objects of socio-cultural infrastructure and leisure centers for citizens of the Tobolsk province. A key trend in the progressive development of the cinema services industry in the studied region was constructive competition for the audience, during which the owners of institutions improved the infrastructure and regularly updated the repertoire of cinemas, resorted to intensification and forcing the advertising component in the development of their own business.

Evaluation of Three Low-Cost Particulate Matter (PM2.5) Sensors for Ambient and High Exposure Conditions in Arba Minch, Ethiopia

The burden of disease from ambient and indoor air pollution is highest in low-income countries, while their resources for monitoring air pollutants are the lowest. PM2.5 is the primary indicator of air pollution. Reference monitors of PM2.5 are expensive, but there is an increased use of low-cost sensors (LCS). Three LCS, the UCB-PATS+ (PATS), Airvisual Pro (IQAV) and Sensirion SPS30 (SPSA) are being used in Arba Minch, Ethiopia, but their quality has not yet been evaluated under circumstances common to low-income countries, and the variety of metrics used in evaluation studies make comparisons difficult. This study aims to evaluate the three LCS under circumstances encountered in Arba Minch, with metrics commonly used and officially prescribed. Measurements were conducted with the LCS at 2 ambient and 4 high exposure (kitchen) concentrations, and at four of those locations with the gravimetric reference method as well. The quality of the three LCS was evaluated within identical, with reference, and between different types, with commonly reported (regression slope and R2) and officially prescribed (Pearson correlation, bias, accuracy, expanded uncertainty) metrics. The SPSA has low within variation in both ambient and high-exposure situations, meets official requirements compared to the reference, and shows a stable bias across different time and concentration levels. The IQAV and PATS within variations are not up to official standards but show strong linear associations. The IQAVs as a group, and PATSs individually, meet official reference requirements at daily level. Between comparison reveals that all LCS show strong linear associations even at 10-minute average level. For SPSA the association is similar across all ranges, and for the others the association is strong when different ranges are taken into account. Generally, all LCS are a good alternative for expensive reference methods. The strong linear associations suggest the possibility of correcting LCS measurement data based on other studies’ results and based on other LCS, across different concentration ranges. Projects with a budget of $600 can already supply 10 measurement locations. Higher-budget projects can contribute to the quality of low-budget projects when they do not only use expensive monitors, but also LCS at the same location.

Conditions for the Development and Certification of Industry 4.0 Technical Competencies

The development of industry 4.0 requires the existence of a workforce with technical skills associated with the new technologies on which it is based, as well as with personal skills that allow them to adapt to the changing work environment. Those competencies can be developed on young people, as a new workforce that joins this market, or with veteran workers who need to be updated to continue current. Several actors are involved, from educational institutions to industry and government. The various international models of skills development in workers focus on tripartite collaboration schemes and the establishment of official standards. Therefore, the purpose of this study is to analyze and describe the existing contextual conditions in Mexico for the development and certification of competencies in Industry 4.0. This study is qualitative and uses document analysis techniques to collect information that is relevant to identify the main elements currently existing. As a result, it is observed the need to strengthen collaboration schemes, as well as to provide the existing national certification system of greater relevance in the worker placement processes. Correspondingly, apprenticeship programs are presented as a field that has not been explored sufficiently within the country context.

MICROBIOLOGICAL QUALITY OF LEAFY GREEN VEGETABLES GROWN IN THE TOLUCA VALLEY

The intake of fresh fruits and vegetables has increased in recent years, as have outbreaks of foodborne illnesses associated with these products. The risk of microbiological hazards in vegetables can occur from the field to the table. The main sources of contamination are agricultural soil and irrigation water, which can affect product quality and be a reservoir of foodborne pathogenic bacteria. This research analysed the microbiological quality of green leafy vegetable crops: spinach (Spinacia oleracea L.), lettuce (Lactuca sativa L.) and coriander (Coriandrum sativum L.), grown in the valley of Toluca. The presence of microorganisms indicating microbiological contamination (mesophilic bacteria, total coliforms, faecal coliforms and Escherichia coli, Salmonella and Listeria) was evaluated in plants, water and soil. Sampling, processing, isolation and bacterial identification were performed in accordance with Mexican Official Standards and the FDA Bacteriological Analytical Manual. The recovered bacteria were subjected to biochemical tests, serotyping and PCR. Microbial counts were present in 100 % of the samples tested. The spinach culture had higher recovery of mesophilic bacteria and total coliforms, while the lettuce culture presented higher values for the faecal coliform group. The results indicated higher microbiological contamination in water and soil > 250 CFU for mesophilic bacteria, total coliforms and faecal coliforms, respectively. The microbiological counts of the three cultures were found within the maximum limits established by Mexican regulations. However, the presence of faecal coliforms, which included E. coli bacteria of serotype O105 ab flagellar, compromises the quality of the product and poses a risk to the health of the consumer.

Quality assessment and geographical origin classification of extra-virgin olive oils imported into China

Extra-virgin olive oil (EVOO) is an important imported commercial product in China. This study comprehensively evaluated the quality of EVOOs imported from different countries into China based on chemical parameters and sensory attributes. Multivariate statistics were used to authenticate their geographical origins. 71.8% of the oils failed to meet the current official standards at inland and abroad established for commercial EVOO category. Pyropheophytin, defect attributes, peroxide value, and K270 were above the limits in 32%, 24%, 23%, and 5% of the failed samples respectively, while free acidity, K232 and delta K were above the limits in 4%. Fatty acids and delta ECN42 were beyond the limits in 2% of the failed samples. Linear discriminant analysis (LDA) and orthogonal partial least squares discriminant analysis (OPLS-DA) based on fatty acids and triacyglycerols succeeded in identifying the origin of olive oils. 3.5% of the total might be mislabelled the geographical origin. The main quality problems of the analyzed oils include oxidation, counterfeiting with refined oils and origin fraud. Considering the results and the fact that most EVOOs in China are imported from other countries, chemometrics combined with critical quality attributes should be an ideal way of EVOO quality control, protecting consumers from frauds.

Sugars and °Brix in honey from Apis mellifera, Melipona beecheii, and commercial honey from a local market in Mexico

Fructose and glucose are the main sugars in honey, and their concentration is expected to correspond to the specifications of official standards. The study compared the composition of sugars and ºBrix in honey from Apis mellifera and Melipona beecheii bees, and a product marketed as bee honey in a local market. The sugar content was determined by highperformance liquid chromatography (HPLC) with a refractive index detector, and °Brix was determined using a refractometer. None of the honey analyzed had detectable levels of sucrose. The average concentration of fructose and glucose in honey was 36.4 and 28.9 g 100 g-1 for Apis mellifera, and 38.5 and 28.2 g 100 g-1 for honey from Melipona beecheii. For honey from the local market, the respective concentrations of these sugars were 7.5 and 17.0 g 100 g-1. The fructose:glucose ratio (F:G) was higher than one in Apis mellifera and Melipona beecheii honey, and 0.4 for honey from the local market. The three types of honey compared had similar values for °Brix. It is concluded that the honey under study by Apis mellifera and Melipona beecheii have similar qualities within international standards. In contrast, the product marketed as bee honey in the local market did not meet official regulations specifications and could not be considered authentic.

English

Dietary supplements, particularly nutraceuticals, are an expanding sector on the South African market, especially since the beginning of the COVID-19 pandemic. However, regulatory authorities do not regulate nutraceuticals and concern arose regarding safety, quality and efficacy of the product reaching the end-user. The aim of the study was to evaluate the pharmaceutical quality, specifically the physical and the in-vitro release properties of two commonly marketed L-lysine products in South Africa. An experimental design was used. Two L-lysine products, a tablet and a capsule, available on the South African market were evaluated for pharmaceutical quality. Tests performed were: Weight variation test, dimensions test, friability test, hardness test, assay, and drug release studies. The quality of products was compared to official USP standards. Tablets were of consistent diameter, length and thickness. Not more than 2 tablets had weights outside the 5% deviation range for each sample. Tablets had an average friability of 17.56%, although their hardness was greater than the acceptable range. All tablets disintegrated within the 15 min. Two out of three samples had amount of lysine below the acceptable range. Tablets sampled released just about 70% of the contained L-lysine by 45 min. Capsules had inconsistent powder weight and contained an amount of L-lysine less than the label claim. Capsules disintegrated within 4 min and released just over 75% of drug by 45 min. There seems to be inconsistences in the characteristics of L-lysine products and their quality cannot be guaranteed. More investigations on other marketed L-lysine products are suggested, to further advice on the necessity of a relook of their quality assurance procedures and labelling. Key words: Nutraceuticals, pharmaceutical quality, L-lysine.

Proximate and Physicochemical Characterization of Moringa stenopetala Seed Oil Through Soxhlet Extractor in Dawro Zone, Ethiopia

Background: Moringa stenopetala is a fast-growing deciduous cabbage plant for human food and animal feeding in the dry season in Ethiopia’s Dawro zone. However, little is known about the proximate and physicochemical parameters of seed oil of M. Stenopetala grown in the study area. Methods: In this study, the proximate composition and physicochemical parameters of oil extracted from M. stenopetala seeds were conducted through the Soxhlet extractor as the extracting medium. This study analyzed five selected varieties of M. stenopetala seed oils. Result: The proximate analysis of M. stenopetala seed oils revealed that the moisture content ranged from (7.23±0.61%-10.52±0.52%), Oil yield (29.41±1.05%-40.18±0.89%), Ash content (4.91±0.22%-5.77±0.04%), whereas the average crude fiber content was (6.88±0.24% -8.55±0.22%) and crude protein content (26.07±0.62%-30.01±1.31%). The physicochemical parameters of seed oil obtained confirmed that the oils were of good quality to those in the Association of Official Analytical Chemists standards.

중국어 사전의 동형동음어 처리에 대한 연구 — 『네이버 중국어 사전』을 중심으로

Homonym is the universal linguistic phenomenon found not only in Chinese language, but in other languages. Homonym are words that have the same phonetic form but different meanings. The study subjects were the homonyms that have the same writing form and phonetic form, but different meanings.BR Since a homonym has the same writing form and phonetic form but different meanings, it is easily confused with a polysemant that has multiple senses of a dictionary entry. Generally, a homonym is distinguished from a polysemant on the following grounds: ‘whether to be associated with a meaning’. Words in the homonym relationship are different from each other, are irrelevant with each other historically, and have far different meanings in the linguistic life at present. No matter how many a polysemant has senses of a dictionary entry, these senses always have association of meanings.BR 『Modern Chinese Dictionary』(the 7th Edition) defines homonyms on the basis of ‘whether it is necessary to distinguish and process words in terms of meanings’, and handles words in the homonym relationship as individual headwords. It processes 368 polysyllabic words as homonyms. 『Naver Chinese Dictionary』, the Chinese-Korean Dictionary most used in Korea, processes most of these homonyms as polysemants. The words in the homonym relationship are different, and the dictionary needs to set one word as one headword. Even though the dictionary should process homonyms on the basis of 『Modern Chinese Dictionary』, it needs to reflect the cognitive characteristics of Korean learners of Chinese language and to apply the official meaning standards of Chinese words when processing homonyms.BR By suggesting the necessity to distinguish between homonym and polysemant of Chinese words and conducting relevant theory research, it will be possible to develop one step further the domestic Chinese language lexicology as ontology research. In addition, by correcting errors of a Korean-Chinese dictionary on the basis of Chinese language lexicology theory, it will be possible to improve the quality of the dictionary and deliver accurate information to dictionary users.

Public Transportation System using Swarm Technology

Pedestrians, ridden or herded animals, vehicles, streetcars, and buses are all instances of road users who travel alone or in groups on public roadways. Both informal and official standards are included in the phrase "road regulations." standards and legislation that have emerged over time to help keep traffic flowing smoothly and efficiently. The informal rules and legislation that have developed over time to facilitate the orderly and timely flow of traffic are known as rules of the road. In structured traffic, terms like priorities, lanes, right-of-way, and traffic management have specific definitions. Heavy motor vehicles (cars, trucks), other vehicles (mopeds, bicycles), and pedestrians are the three types of traffic. Some countries have complicated and detailed traffic laws, while others rely on common sense and driver cooperation. In terms of travel, the organization t gives a better mix of safety and efficiency. Road work, garbage, and street collisions can all obstruct traffic flow and transform it into a chaotic mess. On heavily packed freeways, a minor disruption will persist, a phenomenon known as traffic waves. A complete breakdown of organization can result in gridlock and traffic congestion. In simulations of organized traffic, stochastic processes, queuing theory, and mathematical physics equations are widely used.

Quantifying on-road vehicle emissions during traffic congestion using updated emission factors of light-duty gasoline vehicles and real-world traffic monitoring big data

Light-duty gasoline vehicles (LDGVs) have made up >90 % of vehicle fleets in China since 2019, moreover, with a high annual growth rate (> 10 %) since 2017. Hence, accurate estimates of air pollutant emissions of these fast-changing LDGVs are vital for air quality management, human healthcare, and ecological protection. However, this issue is poorly quantified due to insufficient reserves of timely updated LDGV emission factors, which are dependent on real-world activity levels. Here we constructed a big dataset of explicit emission profiles (e.g., emission factors and accumulated mileages) for 159,051 LDGVs based on an official I/M database by matching real-time traffic dynamics via real-world traffic monitoring (e.g., traffic volumes and speeds). Consequently, we provide robust evidence that the emission factors of these LDGVs follow a clear heavy-tailed distribution. The top 10 % emitters contributed >60 % to the total fleet emissions, while the bottom 50 % contributed <10 %. Such emission factors were effectively reduced by 75.7–86.2 % as official emission standards upgraded gradually (i.e., from China 2 to China 5) within 13 years from 2004 to 2017. Nevertheless, such achievements would be offset once traffic congestion occurred. In the real world, the typical traffic congestions (i.e., vehicle speed <5 km/h) can lead to emissions 5– 9 times higher than those on non-congested roads (i.e., vehicle speed >50 km/h). These empirical analyses enabled us to propose future traffic scenarios that could harmonize emission standards and traffic congestion. Practical approaches on vehicle emission controls under realistic conditions are proposed, which would provide new insights for future urban vehicle emission management.

Development and In-Vitro Evaluation of Plantago ovata Based Rapid Disintegrating Tablets of Labetalol Hydrochloride

Objectives: To avoid swallowing problems of conventional tablets and improved patient compliance Plantago Ovata based Labetalol HCl Rapid disintegrating tablets have been prepared. Methods: Six different (F1 to F6) batches of Labetalol HCl Rapid disintegrating tablets were developed by ‘direct compression method’ using Plantago ovata as a natural super-disintegrating agent. The formulated RDT were tested for angle of repose’, densities like tapped and bulk density, Hausner’s ratio, Carr’s index like pre-compression parameters and for thickness, weight variation or weight uniformity, tablet hardness, % drug content or content uniformity, water absorption ratio’, time require for wetting of tablets’ means wetting time, in-vitro drug disintegration time and in-vitro drug dissolution studies under post-compression parameters of evaluation. Results: It was found that the all the results of these pre-compression and post-compression parameters comply with official standards. The drug release was determined using dissolution media of pH 6.8 phosphate buffer through in-vitro dissolution of drug. This study showed that a rapid drug release by prepared tablets. The optimized formulation F6 showed higher water absorption ratio`, lower wetting time, minimum in-vitro disintegration time’ and higher drug release amongst all the formulations. The F6 formulation was considered the best among all formulations. Conclusion: The prepared rapid disintegrating tablets shows rapid onset of action by quick drug release, minimize side effects and enhanced patient compliance. These prepared tablets containing selective alpha-1 and non-selective beta adrenergic antagonist’ drug candidate Labetalol HCl, will be very useful in the treatment of high blood pressure with enhanced bioavailability.&#x0D; Keywords: Rapid disintegrating tablets, Labetalol Hydrochloride, Bioavailability Enhancement, Natural Superdisintegrant, Plantago Ovata, High Blood Pressure, RDT, Patient Compliance

Health Risk Assessment of Heavy Metals: Cu, Cd, Pb, Ni and Hg, in Catfish Ariopsis felis in Southern Mexico

Background: Metal pollution is a problem in many parts of the world. These metals can be harmful when they exceed the recommended limits. By analyzing metal concentrations in living organisms, it is possible to deduce the bioavailability and the level of environmental contamination for specific metals in an ecosystem. The aim of this study was to determine the heavy metals copper, cadmium, lead, nickel and mercury in edible tissues of fish, to establish the risk analysis for human health. There are currently no studies in this area indicating these factors. Methods: The edible tissue samples were treated under the techniques of the official mexican standards (NOM-117-SSA1) and analyzed using atomic absorption spectroscopy (flame and graphite). The heavy metal concentrations were used to calculate the estimated daily intakes, target hazard quotients, hazard indices, and target cancer risks for children and adults. Results: The highest concentrations of copper (138.82 μg/g), cadmium (1.28 μg/g) and lead (3.20 μg/g) in the edible tissue samples exceeded the permissible limits considered in this study while nickel and mercury levels did not. The target hazard quotient indices for copper, cadmium and nickel in specific sites were higher than the United States Environmental Protection Agency (US-EPA) criteria (&gt;1), while the values ​​for mercury and lead were below one. The hazard indices were higher than the US-EPA criteria (&gt;1) in more than 50% of the sites analyzed. Conclusion: This study is an alert, indicating that inhabitants who consume the fish, particularly children, are at risk of cadmium, lead and nickel toxicity.

Heavy metals in macroinvertebrates (Penaeus) in the Mexican coasts of the Gulf of Mexico: status, sources, and regulations

The present work analyzes the current situation of scientific research on heavy metals and current regulations in macroinvertebrates (Penaeus) from the coastal region of the Gulf of Mexico. Its association with public health was identified based on national and international permissible limits for this fishery resource. The research analysis identified a high percentage of studies that report concentrations within the permissible limits established by the Mexican Official Standards and European regulations, reflecting a high percentage of consumption of this fishery resource that does not represent a risk to public health. However, specific cases exceeded national and international concentration limits, which justifies the importance of monitoring this fishery resource with emphasis on compliance with current regulations, supporting the need to redefine regulatory policies to address the current situation. Likewise, it is important to quantify these metals in a homogeneous, systematic, and continuous way to contrast the different studies on macroinvertebrates as environmental health bioindicator organisms and to know the distribution of these pollutants in the ecosystems inhabited by this important fishery resource.

Development of a Community-scale Autonomous Water Purifier (AWP) Prototype to Remove Heavy Metals

In this paper, we present the design and evaluation of a prototype Autonomous Water Purifier (AWP) for removing heavy metals from contaminated water. The AWP prototype uses solar energy for its operation; the autonomous photovoltaic system is designed to operate up to 8 hours per day and to generate a water flow of 112 liters per day. The prototype was designed to remove biological and chemical agents. It was achieved the elimination of total coliforms, fecal coliforms, total alkalinity, total hardness, total solids, chloride and sulfate from 50 to 100%, as well as the removal of heavy metals. The Pb2+, Hg2+, Cd2+ and Cu2+ were eliminated from 80 to 99%. This wide range of contaminant removal shows a unique way to treat contaminated water in comparison to existing purification systems. The prototype was evaluated with river and spring water from different rural communities of Chiapas, Mexico. The results indicate that the prototype is able to completely remove contaminants in natural waters and get water that meets the guidelines that mark the Mexican official standards. This work helps to solve problems in marginalized communities and natural disaster areas where they have no access to clean water, electricity and suffer from waterborne diseases