Water For Human Consumption Research Articles

Bioadsorption potency of Albizia ferruginea in the removal of fluoride from contaminated water

Due to the high toxicity of fluoride to humanity, it is imperative to treat fluoride-contaminatked water for human consumption. The most commonly used method for the defluoridation of water is bio-adsorption. The present study has investigated the ability of Albizia ferruginea to remove fluoride from water through adsorption. This experiment was undertaken in batch mode. The adsorption process was systematically studied regarding the influence of pH, interaction time, temperature, adsorbent loading, fluoride ion concentration and the effect of coexisting anions to understand the ideal conditions for the adsorption. The effect of different parameters viz. contact time (30-150 min), initial concentration (4-20 mg/L), adsorbent dose (50-250 g/L), mixing speed (30-150 rpm), temperature (25-450 C) has been investigated to determine the adsorption capacity of Albizia ferruginea. The data were analyzed by applying the Langmuir isotherm model. The adsorption kinetics was studied from the data obtained through pseudo-first and pseudo-second-order equations. Various adsorption isotherms, such as the Langmuir isotherm model, were studied to determine adsorption capacity. The adsorption data best fitted for Langmuir isotherm and the process obeyed both pseudo-first and second order. The effectiveness of the best adsorbent was evaluated by removing fluoride contamination rapidly from wastewater. So, from the above study, it was revealed that Albizia ferruginea could be used as an efficient adsorbent for removing fluoride ions.

Modeling transport and fate of metals for risk assessment in the Parauapebas river

Excessive concentrations of metals in surface waters may impose risks to both human health and biota. Several processes, such as advection, dispersion, and sorption, determine the transport and fate of these elements in rivers. This study models the transport and fate of 19 metals across 107 km of the Parauapebas river, in the state of Pará, Brazil. The main goal is to evaluate the risk associated with threshold exceedances in the river until the city of Parauapebas, where the river is a source of drinking water. The Hec-Ras software is used to simulate river flow during dry and rainy seasons, and the results are integrated into the SihQual model. This tool incorporates a module for metal changes, considering the dissolved/particulate dynamics, and other relevant processes. The model's accuracy is evaluated using simulated and observed data at 10 monitoring points. The modeled results fall within a 20% range of the observed data variation, particularly for concentration intervals that pose concern for human health and ecological safety. The results indicate iron, manganese, and aluminum as the main substances of concern for surface water quality. Although the risks for the adult health indicated by sampling measurements from 2017 are low, simulated scenarios of increased metal levels indicate higher risks of threshold exceedances. The study implies that reducing metal contents in water for human consumption near Parauapebas city is necessary. Point sources have a larger impact on water quality during the dry season, while diffuse contributions have a larger impact on metal concentrations during the rainy season, especially in deforested areas. The modeling framework can guide pollution control and remediation efforts for stakeholders in the public or industrial sectors.

Molecular Characterization of Antibiotic Resistance Determinants in Klebsiella pneumoniae Isolates Recovered from Hospital Effluents in the Eastern Cape Province, South Africa.

Klebsiella pneumoniae (K. pneumoniae) is an opportunistic bacteria responsible for many nosocomial and community-acquired infections. The emergence and spread of antibiotic resistances have resulted in widespread epidemics and endemic dissemination of multidrug-resistant pathogens. A total of 145 K. pneumoniae isolates were recovered from hospital wastewater effluents and subjected to antibiogram profiling. Furthermore, the antibiotic resistance determinants were assessed among phenotypic resistant isolates using polymerase chain reaction (PCR). The isolates showed a wide range of antibiotic resistance against 21 selected antibiotics under 11 classes, with the most susceptible shown against imipenem (94.5%) and the most resistant shown against ampicillin (86.2%). The isolates also showed susceptibility to piperacillin/tazobactam (89.0%), ertapenem (87.6%), norfloxacin (86.2%), cefoxitin (86.2%), meropenem (76.6%), doripenem (76.6%), gentamicin (76.6%), chloramphenicol (73.1%), nitrofurantoin (71.7%), ciprofloxacin (79.3%), amikacin (60.7%), and amoxicillin/clavulanic acid (70.4%). Conversely, resistance was also recorded against tetracycline (69%), doxycycline (56.6%), cefuroxime (46.2%), cefotaxime (48.3%), ceftazidime (41.4%). Out of the 32 resistance genes tested, 28 were confirmed, with [tetA (58.8%), tetD (47.89%), tetM (25.2%), tetB (5.9%)], [sul1 (68.4%), sul1I (66.6%)], and [aadA (62.3%), strA (26%), aac(3)-IIa(aacC2)a (14.4%)] genes having the highest occurrence. Strong significant associations exist among the resistance determinants screened. About 82.7% of the K. pneumoniae isolates were multidrug-resistant (MDR) with a multiple antibiotics resistance index (MARI) range of 0.24 to 1.0. A dual presence of the resistant genes among K. pneumoniae was also observed to occur more frequently than multiple presences. This study reveals a worrisome presence of multidrug-resistant K. pneumoniae isolates and resistance genes in hospital waste effluent, resulting in higher public health risks using untreated surface water for human consumption. As a result, adequate water treatment and monitoring initiatives designed to monitor antimicrobial resistance patterns in the aquatic ecosystem are required.

Surveillance spilled Chironomidae (Diptera) larvae from drinking water treatment plants in South Korea using morphogenetic species analysis and eDNA metabarcoding

Chironomid larvae (Diptera: Chironomidae) are tremendous indicator species that can tolerate a broad range of environmental conditions, from polluted to unimpaired water ecosystems. These species are ubiquitously observed in all bioregions and can even be found in drinking water treatment plants (DWTPs). Detection of chironomid larvae in DWTPs is a critical issue because their presence may be indicative of the water quality in the supply of tap water for human consumption. Therefore, the aim of the present study was to identify the chironomid communities that reflect the water quality of DWTPs and develop a biomonitoring tool to detect biological contamination of the chironomids in DWTPs. To do so, we investigated the identity and distribution of chironomid larvae in seven DWTP areas using morphological identification, DNA barcoding, and sediment environmental DNA (eDNA) analysis. A total of 7924 chironomid individuals encompassing three subfamilies and 25 species of 19 genera were identified in 33 sites within the DWTPs. The Gongchon and Bupyeong DWTPs were dominated by Chironomus spp. larvae, which were correlated with low levels of dissolved oxygen in the water. In the Samgye DWTP and Hwajeong DWTP, Chironomus spp. were almost absent, and instead, Tanytarsus spp. were abundant. Additionally, the Gangjeong DWTP was dominated by a Microtendipes sp., and two species of Orthocladiinae (a Parametriocnemus sp. and a Paratrichocladius sp.) were found only in the Jeju DWTP. We also identified the eight most abundant Chironomidae larvae found in the DWTPs. Furthermore, eDNA metabarcoding of DWTP sediment indicated the presence of different eukaryotic fauna and confirmed the presence of chironomids in DWTPs. These data provide useful morphological and genetic information regarding chironomid larvae that can be used for the water quality biomonitoring of DWTPs to support the supply of clean drinking water.

Hydrological and Precipitation Extremes and Trends over the Paraiba do Sul River Basin, Brazil

The Paraiba do Sul River Basin (PSRB) is a vital source of water resources in Brazil, providing water for human consumption, industry, agriculture, and hydroelectric energy generation. As part of one of the most developed areas of the country, in the Southeast of Brazil, the region is vulnerable to the impacts of climate change, with evidence of extreme events such as droughts and floods affecting the availability and quality of water. Hence, this study analyzes precipitation and streamflow rates data from the PSRB between 1939–2020 to investigate the spatial variability of average patterns and extreme events, trends, and their relationship with urban growth and socioeconomic development. The analysis reveals significant spatial variations in precipitation and runoff rates, with higher altitude areas, such as the Serra da Mantiqueira, exhibiting higher average values. Moreover, the Mann–Kendall trend results showed in most of the sites no significant trend regarding precipitation data; however, about 50% of the sites in the PSRB presented a decreasing trend of runoff rates. Since the precipitation does not explain identified changes in the hydrological patterns, the evaluation of the area’s urban growth and socioeconomic development throughout the decades suggested that human activities, such as those associated with urbanization, have played a significant role in altering the runoff patterns in the basin. These findings highlight the importance of sustainable land-use planning and water resource-management practices in the PSRB to mitigate the negative impacts of urbanization on the hydrological cycle and to enhance the resilience of the region’s water resources.

Evaluation of Groundwater Quality for Drinking and Irrigation Purposes Using GIS-Based IWQI, EWQI and HHR Model

Groundwater pollution has emerged as a significant water crisis in various regions around the globe. Groundwater serves as a crucial source of water for human consumption and agricultural activities in the Sichuan Basin where groundwater quality has yet to be concentrated. A total of 41 groundwater samples were collected from domestic wells in Suining city of the Sichuan Basin, which were used for analyzing the hydrogeochemical processes and suitability for irrigation and drinking purposes. In the study area, groundwater samples belonged to the HCO3-Ca type. Hydrochemical compositions were dominated by carbonate and silicate mineral dissolution with positive cation exchange. Agricultural activities and urban sewage were the primary sources of NO3− pollution. The irrigation water quality index (IWQI) was calculated using electronic conductivity (EC), Na+, Cl−, HCO3−, and sodium adsorption ratio (SAR). The IWQI values showed that the suitability of groundwater irrigation was generally good and presented the decreasing trend southeastwardly. According to the entropy-weighted water quality index (EWQI), the groundwater quality for drinking purposes was generally good. However, there were some local areas with poor water quality concentrated in the southeast part. According to the human health risk (HHR) model, the groundwater was deemed safe for adults and children. However, for infants, the nitrate level in the groundwater remained high and posed potential health risks. The combined IWQI and EWQI evaluation served as a valuable reference for the utilization of the groundwater resource in the Sichuan Basin, as well as other comparable regions worldwide.

Earth System at Risk: Challenging Environmental (In)Justice

Earth System at Risk: Challenging Environmental (In)Justice

Efficient removal of Mn2+ ions from aqueous solutions using apple pomace biochar

The increasing contamination of water resources is a severe environmental problem. Manganese is highly soluble in water, has adverse effects on the environment and human health during excessive exposure, and is difficult to remove. Biosorbents have been suggested to remove metals from aqueous solutions, therefore, apple pomace was utilized to prepare activated biochar (activated charcoal from apple pomace, ACAP). The biochar sample was characterized by X-ray fluorescence spectrometry, scanning electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, and Brunauer–Emmett–Teller analysis. The aim of this study was to use ACAP as an adsorbent to remove Mn2+ ions from aqueous solutions. Adsorption experiments were performed in the pH range 3.2–6.5, with various masses of ACAP biochar and Mn2+ ion concentrations. The results were evaluated using the pseudo-first order, pseudo-second order, general order, Elovich, and Webber and Morris kinetics models. All the models fitted the experimental results, the equilibrium time was 15 min, and the pseudo-second order model presented the highest constant (k2), indicating that chemosorption is an important mechanism in adsorption. The adsorption isotherm results were adjusted using different models, wherein the Langmuir and Temkin models exhibited the best fit to the experimental results. Adsorption experiments yielded a 97.5% removal rate of Mn2+ ions at pH 6.5 and <5% at pH 3.2, and the desorption of manganese in nitric acid (0.1 M) was 97.5%. Overall, apple pomace biochar is an efficient adsorbent for removing Mn2+ ions in aqueous media, and is applicable for treating water for human consumption.

Insights into Anthropogenic Micro- and Nanoplastic Accumulation in Drinking Water Sources and Their Potential Effects on Human Health.

Anthropogenic microplastics (MPs) and nanoplastics (NPs) are ubiquitous pollutants found in aquatic, food, soil and air environments. Recently, drinking water for human consumption has been considered a significant pathway for ingestion of such plastic pollutants. Most of the analytical methods developed for detection and identification of MPs have been established for particles with sizes > 10 μm, but new analytical approaches are required to identify NPs below 1 μm. This review aims to evaluate the most recent information on the release of MPs and NPs in water sources intended for human consumption, specifically tap water and commercial bottled water. The potential effects on human health of dermal exposure, inhalation, and ingestion of these particles were examined. Emerging technologies used to remove MPs and/or NPs from drinking water sources and their advantages and limitations were also assessed. The main findings showed that the MPs with sizes > 10 μm were completely removed from drinking water treatment plants (DWTPs). The smallest NP identified using pyrolysis-gas chromatography-mass spectrometry (Pyr-GC/MS) had a diameter of 58 nm. Contamination with MPs/NPs can occur during the distribution of tap water to consumers, as well as when opening and closing screw caps of bottled water or when using recycled plastic or glass bottles for drinking water. In conclusion, this comprehensive study emphasizes the importance of a unified approach to detect MPs and NPs in drinking water, as well as raising the awareness of regulators, policymakers and the public about the impact of these pollutants, which pose a human health risk.

Development of a Point-of-Use Drinking Water Purifier Using Aluminum Oxide-Based Flocculent-Disinfectant Composite

One in every three people in the world still lacks access to clean drinking water. Aside from microbiological pollution, high fluoride content in drinking water is one of the most serious problems in African countries. This study aimed to contribute to the availability of clean water by developing a point-of-use drinking water purifier using an aluminum oxide-based flocculent-disinfectant composite. Batch experiments were conducted to determine factors affecting fluoride removal efficiency (FRE) and E. coli log reduction efficiency. AO of 75 mg/L, 800 mg/L alum, lime (35% alum dose), and 1.5 mg/L Ca(OCl)₂ doses achieved 95% FRE and 5 log10 reductions of E. coli using 15 mg/L as initial fluoride concentration ([F−]0), and 105 CFU/100 mL E. coli concentration. [F−]0 affected FRE but showed no effect on E. coli log reduction. The optimum pH of the solution for both FRE and E. coli log reduction was found to be in the range of 4–8. Three prototypes in powder form were developed. The prototypes were tested on real water samples from the Ethiopian Rift Valley, and the results were found to be within the drinking water standards, thus indicating the capability of the developed products to purify contaminated water for human consumption.

Effectiveness of household measures for the disinfection of water for human consumption in the context of Santarém, Pará, Amazônia, Brazil

Effectiveness of household measures for the disinfection of water for human consumption in the context of Santarém, Pará, Amazônia, Brazil

Relations between personal exposure to elevated concentrations of arsenic in water and soil and blood arsenic levels amongst people living in rural areas in Limpopo, South Africa

Exposure to arsenic even at low levels can lead to adverse health outcomes, however, there is a paucity of research from South Africa in relation to human exposure to arsenic. We investigated long-term exposure of residents in Limpopo province, South Africa, in a cross-sectional study by analysing water, soil and blood arsenic concentrations from two arsenic-exposed (high and medium–low exposure) villages and one non-exposed (control) village. There were statistically significant differences in the distribution of arsenic in water, soil and blood amongst the three sites. The median drinking water arsenic concentration in the high-exposure village was 1.75 µg/L (range = 0.02 to 81.30 µg/L), 0.45 µg/L (range = 0.100 to 6.00 µg/L) in the medium- / low-exposure village and 0.15 µg/L (range = < limit of detection (LOD) to 29.30 µg/L) in the control site. The median soil arsenic concentration in the high-exposure village was 23.91 mg/kg (range = < LOD to 92.10 mg/kg) whilst arsenic concentrations were below the limit of detection in all soil samples collected from the medium-/low-exposure and control villages. In the high-exposure village, the median blood arsenic concentration was 1.6 µg/L (range = 0.7 to 4.2 µg/L); 0.90 µg/L (range = < LOD to 2.5 µg/L) in the medium-/low-exposure village and 0.6 µg/L (range = < LOD to 3.3 µg/L) in the control village. Significant percentages of drinking water, soil and blood samples from the exposed sites were above the internationally recommended guidelines (namely, 10 µg/L, 20 mg/kg and 1 µg/L, respectively). Majority of participants (86%) relied on borehole water for drinking and there was a significant positive correlation between arsenic in blood and borehole water (p-value = 0.031). There was also a statistically significant correlation between arsenic concentrations in participants’ blood and soil samples collected from gardens (p-value = 0.051). Univariate quantile regression found that blood arsenic concentrations increased by 0.034 µg/L (95% CI = 0.02–0.05) for each one unit increase in water arsenic concentrations (p < 0.001). After adjusting for age, water source and homegrown vegetable consumption in multivariate quantile regression, participants from the high-exposure site had significantly higher blood concentrations than those in the control site (coefficient: 1.00; 95% CI = 0.25–1.74; p-value = 0.009) demonstrating that blood arsenic is a good biomarker of arsenic exposure. Our findings also provide new evidence for South Africa on the association between drinking water and arsenic exposure, emphasising the need for the provision of potable water for human consumption in areas with high environmental arsenic concentrations.

Exploring Multiscale Variability in Groundwater Quality: A Comparative Analysis of Spatial and Temporal Patterns via Clustering

Defining homogeneous units to optimize the monitoring and management of groundwater is a key challenge for organizations responsible for the protection of water for human consumption. However, the number of groundwater bodies (GWBs) is too large for targeted monitoring and recommendations. This study, carried out in the Provence-Alpes-Côte d’Azur region of France, is based on the intersection of two databases, one grouping together the physicochemical and bacteriological analyses of water and the other delimiting the boundaries of groundwater bodies. The extracted dataset contains 8627 measurements from 1143 observation points distributed over 63 GWB. Data conditioning through logarithmic transformation, dimensional reduction through principal component analysis, and hierarchical classification allows the grouping of GWBs into 11 homogeneous clusters. The fractions of unexplained variance (FUV) and ANOVA R2 were calculated to assess the performance of the method at each scale. For example, for the total dissolved load (TDS) parameter, the temporal variance was quantified at 0.36 and the clustering causes a loss of information with an R2 going from 0.63 to 0.4 from the scale of the sampling point to that of the GWB cluster. The results show that the logarithmic transformation reduces the effect of outliers and improves the quality of the GWB clustering. The groups of GWBs are homogeneous and clearly distinguishable from each other. The results can be used to define specific management and protection strategies for each group. The study also highlights the need to take into account the temporal variability of groundwater quality when implementing monitoring and management programs.

A Review of the Current State of Microplastic Pollution in South Asian Countries

Microplastic contamination has become a concerning topic of study in recent decades. This review discusses the development of microplastic pollution based on a selection of South Asian countries consisting of Bangladesh, Iran, Philippines, Thailand, India, Indonesia, and Vietnam. The condition of microplastic pollution related to the abundance of microplastic found in various environments as well as the presence of microplastics in food and the air, is covered in this review. Several reports found that drinking water sourced from taps was found to have about 83% of microplastic particles in the year 2017 based on results from 14 nations, and in the year 2018, 260 bodies of water for human consumption in 11 countries were found to have about 93% of microplastic particles. Micro debris pollution in seas and oceans worldwide is predicted to be at an amount of 236,000 metric tons based on a statistical report. A mean value of 30 micro debris per liter of glacier water was recovered from the top of Mount Everest, whereas about 2200 small particles per liter were discovered in the deep waters of the Mariana Trench. The main environments that are severely microplastic-contaminated are water-based places such as rivers, estuaries, and beaches. The presence of microplastics in food items, such as tea bags, sugar, shrimp paste, and salt packets, has been reported. In terms of impacts on the environment, microplastic contamination includes the ingestion of microplastics by aquatic creatures in water environments. The impacts on terrestrial environments relate to microplastics sinking into the soil, leading to the alteration of the physicochemical parameters of soil. Meanwhile, the impacts on the atmospheric environment include the settling of microplastics on the external bodies of animals and humans.

Exogenous Auxin and Gibberellin on Fluoride Phytoremediation by Eichhornia crassipes.

High rates of fluorosis were reported worldwide as a result of human consumption of water with fluoride contents. Adjusting fluoride concentration in water as recommended by the World Health Organization (<1.5 mg L-1) is a concern and it needs to be conducted through inexpensive, but efficient techniques, such as phytoremediation. The application of phytohormones was investigated as a strategy to improve this process. Thus, the main goal of this research was to evaluate the effect of exogenous auxin and gibberellin on the tropical duckweed Eichhornia crassipes performance for fluoride phytoremediation. Definitive screening and central composite rotatable designs were used for experiments where fluoride concentration (5~15 mg L-1), phosphorus concentration (1~10 mg L-1), and pH (5~9) were assessed as well throughout 10 days. Fluoride contents were determined in solution and plant tissues by potentiometry. Higher concentrations of fluoride reflected on greater absorptions by plants, though in relative terms removal efficiencies were quite similar for all treatments (~60%). Auxin and acidic conditions favored fluoride removals per mass of plant. Fluoride accumulated mostly in leaves and auxin probably alleviated toxic effects on E. crassipes while gibberellin showed no effect. Therefore, E. crassipes could be employed as a fluoride accumulator plant for water treatment and exogenous auxin may be used to improve the process.

Comparison between Different Technologies (Zerovalent Iron, Coagulation-Flocculation, Adsorption) for Arsenic Treatment at High Concentrations

The presence of arsenic in water for human consumption is of concern, especially in developing countries, and the design of simple and economic treatments for arsenic removal is imperative. In this paper, three low-cost technologies were evaluated for As(V) or As(III) (5 mg L−1) removal: (1) zerovalent iron (Fe(0)), as powdered (μFe(0)) and iron wool (wFe(0)); (2) coagulation-flocculation with Al2(SO4)3 or FeCl3; and (3) adsorption on a natural clay. μFe(0) was more efficient than wFe(0), requiring a minimal dose of 0.25 g L−1 to achieve [As(V)] &lt; 0.01 mg L−1 after 288 h; the reaction time was reduced to 168 h under stirring. When starting from As(III), partial oxidation to As(V) was observed, and removal was not complete even after 648 h with 1 g L−1 μFe(0). As(V) removal using FeCl3 and Al2(SO4)3 was very fast and completed in 15 min with 0.25 g L−1 of both reagents. However, Al2(SO4)3 was not efficient to remove As(III). With the clay, doses higher than 50 g L−1 and times longer than 648 h were needed to remove both As species. Arsenic leached from μFe(0) used to treat As(III) was almost negligible. Thus, Fe(0) may be the best alternative for low-cost, small-scale applications.

Search for a Relevant Scale to Optimize the Quality Monitoring of Groundwater Bodies in the Occitanie Region (France)

In France, and more generally in Europe, the high number of groundwater bodies (GWB) per administrative region is an obstacle for the management and monitoring of water for human consumption by regional health agencies. Moreover, GWBs show a high spatial, temporal, physico-chemical, and bacteriological variability. The objective is to establish homogeneous groupings of GWB from the point of view of water quality and the processes responsible for this quality. In the Occitanie region in southwestern France, the cross-referencing of two databases, namely the French reference system for groundwater bodies and SISE-EAUX, provided a dataset of 8110 observations and 15 parameters distributed over 106 GWB. The 8-step approach, including data conditioning, dimensional reduction by Principal Component Analysis, and hierarchical clustering, resulted in 20 homogeneous groups of GWB over the whole region. The loss of information caused by this grouping is quantified by the evolution of the explained variance. Splitting the region into two large basins (Adour-Garonne and Rhône Méditerranée) according to the recommendations of the European community does not result in a significant additional loss of information contained in the data. A quick study of a few groups allows to highlight the specificities of each one, thus enabling targeted guidelines or recommendations for water quality management and monitoring. In the future, the method will have to be tested on the scale of large European watersheds, as well as in the context of an increase in the number of parameters.

AVALIAÇÃO DA QUALIDADE MICROBIOLÓGICA DA ÁGUA DE FONTES NATURAIS DO DISTRITO DE ARAJARA

Ordinance GM/MS n⁰ 888, of May 4, 2021 defines as a microbiological criterion the absence of Escherichia coli in water for human consumption. Aiming at public health, analyzes are important to ensure good water quality in the microbiological aspect, given that the presence of these microorganisms indicates contamination and can cause pathologies. The esteemed work aims to evaluate the microbiological quality in springs used for human consumption in the district of Arajara in Barbalha, Ceará. The qualitative method of the chromogenic-fluorogenic substrate was used, and in triplicate. The water was collected from three springs located specifically on the Macaúba site, in the city of Barbalha. Nine collection bottles, gelox and a styrofoam box were used for sample conservation. For the procedure, the samples were taken to the laboratory hood using the Bunsen burner. A chromogenic-fluorogenic substrate was added to each flask containing 100 mL of the sample, which were then incubated in an oven at 37⁰ C for 24 hours. During the analysis, the presence of total coliforms and Escherichia coli was detected in all samples. In this context, Escherichia coli is indicative of fecal contamination because it lives mainly in the intestinal tract of humans and warm-blooded animals. It is concluded that the water from the three evaluated sources is unfit for consumption, since according to current legislation, water suitable for human consumption must be free of Escherichia coli. &nbsp; Keyword: Total coliforms; Escherichia coli; Springs.

Water Quality Assessment and Monitoring in Pakistan: A Comprehensive Review

Water quality has been a major problem in Pakistan owing to a mix of factors such as population expansion, industrial units in urban areas, and agricultural activities. The purpose of this research is to conduct a comprehensive evaluation of water quality monitoring and assessment in Pakistan. The article begins by examining the water sources of Pakistan (i.e., surface water, groundwater, and rainwater). The paper then discusses the methods used by researchers in Pakistan for water quality monitoring and assessment, including chemical, physical, and biological methods. It has been determined that in certain regions in Pakistan, the concentration of arsenic present in the groundwater exceeds the national and international prescribed maximum limits. The range of arsenic concentrations in the Punjab province can vary from 10 to 200 μg/L, while higher concentrations of up to 1400 μg/L have been recorded in Sindh. In the Punjab province, fluoride concentrations vary from 0.5 to 30 mg/L, while in Sindh, the levels can reach up to 18 mg/L. In addition, some of the research has talked about bacteria. A 2017 study found that the fecal coliform concentrations in certain water in different cities of Pakistan surpassed limits and were as high as 1100 CFU/100 mL. Additionally, natural factors such as geological formations and high salinity in some areas contribute to the contamination of water. The effect of water pollution on public health has the potential to cause harm. It is critical to investigate creative strategies for improving water quality, and it is necessary to make investments in research and development, which could include the implementation of sophisticated technologies and the conception of new treatment processes. The review performed in this paper facilitates an understanding of the current water quality in Pakistan, including the types and magnitudes of contaminants present in the water sources. Subsequently, the assessment emphasizes deficiencies and challenges in the existing water quality monitoring frameworks and provides suggestions for improving them. This review is also of significant benefit to all the stakeholders involved in ensuring clean and safe water for human consumption and other purposes in Pakistan, such as policymakers, water managers, researchers, and other stakeholders.

Microbiological analysis of water distributed in the urban area of the Municipality of Guajará, upstate of Amazonas, Brazil

The study aimed to analyze the microbiological characteristics of water from artisanal wells in the municipality of Guajará in Amazonas, verifying the presence of Escherichia coli and total coliforms. The collections were carried out in residences in the center of the city in 10 points. COLItest Kits were used, which have substances, nutrients and MUG in their formulation that, properly balanced, inhibit the growth of Gram-positive bacteria, favoring the growth of bacteria from the coliform group and facilitating the identification of E. coli through fluorescence after incubation at 37 °C in 48 hours. In the qualitative analysis of the water, it was observed the presence of total coliforms in 80% of them and in 20% they presented absence of microorganisms. The samples that showed total coliforms, it was possible to observe that in 75% there was contamination by E. coli, representing a great risk to the health of those who consume water from these points without adequate treatment. However, measures for the preservation of water sources, the treatment of water for human consumption and the practice of using chlorine or boiling the water in the places where they were collected are necessary actions to reduce the occurrence of total coliforms and Escherichia coli.