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Different effects of extreme hydrological events are evident in the physical and chemical water characteristics. Such events can cause water supply interruptions in rural areas, as is the case in Vlasotince, south-eastern Serbia. Therefore, this paper examines the values of selected parameters such as ammonia, nitrates, nitrites, turbidity, chemical oxygen demand calculated from the amount of potassium permanganate, iron, manganese, temperature, pH value, colour, and aluminium at the measuring point of Vlasotince to identify changes in raw water quality parameters during extreme hydrological events. Over a five-year period, fluctuations in water flow in the Vlasina River basin are considered. The interdependence between water flow and raw water quality parameters is assessed using a one-way analysis of variance and a post hoc Tukey Honestly Significant Difference test. Results reveal substantial differences in turbidity, chemical oxygen demand, nitrates, temperature, iron, colour, and manganese. Ammonia, nitrites, pH value, and aluminium exhibit no significant differences based on water flow intensity. The identification and quantification of risk factors affecting water supply during extreme hydrological events allow for a more appropriate response to given challenges and the organization of work in rural water supply systems.

This study in Rwanda offers a comprehensive analysis of water quality, reliability, and cost-effectiveness, departing from previous research by utilizing panel data analysis for a nuanced understanding of spatiotemporal dynamics. Unlike earlier studies focusing on specific aspects, this research adopts a holistic approach, examining factors crucial for water supply, quality, and cost, thus providing an integrated view of Rwanda's water sector. By analyzing data from various sources, including the Water and Sanitation Corporation (WASAC), the study evaluates the reliability, quality, and cost-effectiveness of drinking water. It identifies cost-effective water treatment plants and studies determinants such as production cost, raw water quality, and supply between 2017 and 2022, introducing novel metrics such as performance scores and a drinking water quality index. Despite an increase in lost water, WASAC notably improves water supply, resulting in a higher water access rate by 2022. The study highlights the influence of factors such as performance scores and raw water quality on water supply and quality. It emphasizes continuous monitoring, targeted interventions, and community engagement for sustainable water service delivery. The findings provide actionable insights for policymakers, stakeholders, and practitioners, aiming to enhance water management strategies and improve water access in Rwanda. HIGHLIGHTS Panel data analysis offers nuanced spatiotemporal insights departing from cross-sectional methods.; Holistic approach examines water supply, quality, and cost, unlike prior single-focus studies.; Innovative metrics introduced include performance score and water quality index.; Practical insights help identify cost-effective water treatment plants and key determinants.; Sustainability focus emphasizes continuous monitoring and community engagement.;

The physical and chemical water characteristics show different effects of extreme hydrological events. Such events can cause water supply interruptions in rural areas, such as Vlasotince, south-eastern Serbia. Therefore, this paper examines the values of selected parameters such as ammonia, nitrates, nitrites, turbidity, and chemical oxygen demand calculated from the amount of potassium permanganate, iron, manganese, temperature, pH value, colour, and aluminium at the measuring point of Vlasotince to identify changes in raw water quality parameters during extreme hydrological events. Over five years, fluctuations in water flow in the Vlasina River basin are considered. The interdependence between water flow and raw water quality parameters is assessed using a one-way analysis of variance and a post hoc Tukey Honestly Significant Difference test. Results reveal substantial differences in turbidity, chemical oxygen demand, nitrates, temperature, iron, colour, and manganese. Ammonia, nitrites, pH value, and aluminium exhibit no significant differences based on water flow intensity. Identifying and quantifying risk factors affecting water supply during extreme hydrological events allow for a more appropriate response to given challenges and the organisation of work in rural water supply systems. [ABSTRACT FROM AUTHOR]

This study in Rwanda offers a comprehensive analysis of water quality, reliability, and cost-effectiveness, departing from previous research by utilizing panel data analysis for a nuanced understanding of spatiotemporal dynamics. Unlike earlier studies focusing on specific aspects, this research adopts a holistic approach, examining factors crucial for water supply, quality, and cost, thus providing an integrated view of Rwanda's water sector. By analyzing data from various sources, including the Water and Sanitation Corporation (WASAC), the study evaluates the reliability, quality, and cost-effectiveness of drinking water. It identifies cost-effective water treatment plants and studies determinants such as production cost, raw water quality, and supply between 2017 and 2022, introducing novel metrics such as performance scores and a drinking water quality index. Despite an increase in lost water, WASAC notably improves water supply, resulting in a higher water access rate by 2022. The study highlights the influence of factors such as performance scores and raw water quality on water supply and quality. It emphasizes continuous monitoring, targeted interventions, and community engagement for sustainable water service delivery. The findings provide actionable insights for policymakers, stakeholders, and practitioners, aiming to enhance water management strategies and improve water access in Rwanda. [ABSTRACT FROM AUTHOR]

In this paper, a comparative analysis of the parameters of water steam condensation was performed in the calculations of the built-in bundle of the condenser of a cogeneration steam turbine using the Metro-Vickers method and the refined method of the All-Russian Thermal Engineering Institute. A computational analysis of the operating modes of the condenser was also performed using various calculation methods with the joint cooling of the main bundles of the condenser with circulating water, as well as that of the built-in bundles with raw water with a wide variation of the main parameters. The results established that the values of the heat transfer coefficients for the built-in bundle, determined using various methods, differed significantly from each other, especially at low values of the specific heat load of the condenser, limiting the use of the Metro-Vickers method under these conditions. In the calculation analysis of the condenser operating modes, several dependencies obtained using the Metro-Vickers method demonstrated significantly greater differences from the experimental data than when using the refined method of the All-Russian Thermal Engineering Institute, especially at reduced condenser steam loads. The study also identified several features of the joint operation of the main and built-in condenser bundles in the cogeneration modes of the turbine unit. [ABSTRACT FROM AUTHOR]

This research was conducted at Bandung City with the aim of building a model using machine learning methods so that it can estimated clean water demands in Bandung City, as well as knowing the external factors that are considered to affect the model. Machine learning is a part of Artificial Intelligence (AI) discipline. The modeling is carried out using independent variables in the form of climate parameters which are rainfall, rainy days, and humidity, as well as the dependent variable in the form of drinking water needs which are represented by raw water. Data collection is done through secondary data. The model was built by using the TPOT module, and produces the AdaBoost.R2 algorithm as the most optimal model, by using the model algorithm, the best sub-model is produced with the most influential external factors, namely rainy days and humidity which has an MAE of 326,077.70 and a MAPE of 4.75%. This model is compared with the ARIMA model which has an MAE of 330,672.088 and an MAPE of 5.07%.

As an emerging contaminant, the presence of microplastics is widespread in the environment. However, current research regarding the removal of microplastics by drinking water treatment plants (DWTPs) remains insufficient. This study aims to investigate microplastics in water and sludge in four DWTPs in Zhengzhou; these DWTPs have different water sources. The results revealed that the abundance of microplastics in raw water ranged from 12.80 ± 0.80 to 25.07 ± 1.67 n/L. Overall, fibers and fragments ranging from 10 to 100 μm constituted the primary components. The proportion of white and transparent microplastics was the highest. Among the ten polymer types detected, polyvinyl chloride, polyphenylene oxide, and polyethylene terephthalate were the predominant ones in raw water; polyethylene terephthalate emerged as the prevalent polymer type in treated drinking water, with both polyethylene terephthalate and polyvinyl chloride being primarily present in sludge. The removal rate of microplastics ranged from 45.8% to 74.5%. Furthermore, the removal rates at the sedimentation tank outlet accounted for more than 50.0% of the total removal rate. The abundance of microplastics in sludge was significantly higher than that in water, indicating a concentrated environment for the persistence of microplastics. The proper disposal of sludge has emerged as one of the challenges requiring our attention. [ABSTRACT FROM AUTHOR]

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The objective of this study is to assess the quality of the Cenrana River water as a potential drinking water source for a community in the Cenrana watershed Wajo, as well as to evaluate the effectiveness of a basic water purification system in improving its condition. Cenrana River is located in the Maros Regency and Bone Regency, South Sulawesi Province, Indonesia. The study was conducted at the Laboratory of Material Testing, Faculty of Engineering Universitas Negeri Makassar, and the Makassar Health Laboratory Center. Water samples are taken in the Walanae River located in Bone Regency and tested in the abovementioned laboratory. This type of research is experimental, which involves assembling a simple clarification tool in the material testing laboratory, and then raw water is purified with the device. Water samples, both raw water and purified water, are tested at the Makassar Health Laboratory Center. The data analysis used is qualitative descriptive, which compares the results of laboratory tests of raw water that have not been clarified and the results of laboratory tests of water that have been purified with the parameters of clean water standard criteria based on the regulation by the Ministry of Health of the Republic of Indonesia. The results showed that although the water had been cleaned through two filters, several parameters tended to increase from the previous year's test results with one filter, such as the No2 content from 0.017 to 0.034, No3 from 0.01 to 0.39, dissolved solids from 152 to 156, Fe from 0.01 to 0.17, Mn from 0.01 to 0.15, SO4 from 14.39 to 15, 54, and Ammonia from 0.05 to 0.29 even though it still meets the standards of the Ministry of Health of the Republic of Indonesia. In addition, the raw water coliform content also increased from an average of 6,600/100 ml in 2016 to 20,050/100 ml in 2019. This means that there is a tendency for Cenrana River water pollution may increase every year. [ABSTRACT FROM AUTHOR]

One source of raw water for drinking water is river water. The raw water source for drinking water must meet the requirements for quantity, continuity, and quality. Raw water for drinking water must meet class I water quality requirements. This study aims to assess of the potential for water availability and water quality in the Serang River. Analysis of water availability used statistical methods and simulated rainfall-runoff with the HEC-HMS model. Calibration of the hydrological model was carried out in sub-watersheds where there were observational discharge data. Water availability is reviewed in the second-order river. Water quality status was analyzed using the Pollutant Index and Storet methods. The results of the analysis of water availability for reliable discharge with a probability of 80%, 90%, and 95% in several sections of the Serang River to order 2 rivers can be presented in the form of a flow duration curve. The results of the analysis of the status of water quality in several sections of the upstream Serang river based on the Storet method and the Polluter Index method show that in general, it is in a slightly polluted condition.

Of recent concern is the degradation of plastics from macro- to micro- and even nanosized. This study investigates the content of microplastics and nanoplastics (MNPs) particles in raw water sources for the local population and in tap and drinking water as treated water. A total of 189 samples were selected and analysed for the quality and quantity of microplastics and nanoplastics (MNPs). The results found MNPs in all water samples, with an average abundance ranging from 204 ± 54 to 336 ± 87 particles/L in raw water, from 22 ± 7 to 33 ± 12 particles/L in tap water, and from 25 ± 15 to 73 ± 30 particles/L in drinking water. MNPs were divided into three categories according to their shape. Fragments and fibres clearly dominated in all samples. The majority of particles with sizes greater than 125 μm are found in raw water, while those with ranging sizes from 20 nm to 125 μm are mostly found in treated water. The MNPs were domains of fibres and fragments. The majority of the MNPs were composed of polyethylene terephthalate, polypropylene, and polyethylene (PE). This study contributes to filling the knowledge gap in the field of emerging MNPs pollution of raw and treated water, which is of concern due to the potential human exposure to MNPs. HIGHLIGHTS MNPs counts might be related to water source, processing and production, packaging, and transport.; MNPs concentrations were detected in the treated water, especially for particles smaller than 20 nm in size.; The smallest MNPs were least removed at the treatment plants.;

The CDF method sedimentation tank is a new method that makes a continuous and controlled exhaust flow a new force acting on the particles to be removed, increasing the efficiency of turbidity removal. The exhaust flow, due to continuous and controlled leaks, causes the production capacity of the sedimentation tank to decrease. To maintain the production capacity of the sedimentation tank and to increase the efficiency of the turbidity removal, the effluent due to leakage is recirculated to the inlet of the flocculation tank. The research reactor consisted of a coagulation tank in the form of a waterfall, a flocculationtank in the form of a baffle channel, and a sedimentation tank using the CDF method. The research reactor was designed with a production capacity of 240 L/hour. To test the capability of increasing the production capacity of the sedimentation tank using the CDF method without increasing the number of sedimentation tank units which is referred to as the uprating process, an experiment was carried out in this study by increasing the production capacity to 360 L/hour or 1.5 times the capacity of the original reactor design. The variations in the recirculation of the effluent due to leaking at the bottom of the settling zone to the inlet of the flocculation bath were 0% (no recirculation), 25%, 50%, 75%, and 100% (all effluent recirculated). The results showed that the higher the CDF flow recirculation value, the higher the turbidity removal efficiency. The highest turbidity removal efficiency was achieved at a 100% CDF flow recirculation value which was 87.21% with a treated water turbidity of 3.267 NTU at a design discharge of 240 L/hour, while at a discharge of 360 L/hour, it was 82.50% with a treated water turbidity of 4.528 NTU.

The health risks linked to the consumption of microcystin-accumulating crops have been increasing worldwide in toxic cyanobloom-occurring regions. The bioaccumulation of microcystins (MCs) in agricultural produce at environmentally realistic concentrations is poorly investigated. In this field study, we assessed the health risks of MCs in raw water used for irrigating fruit crops (bioaccumulation) and watering farm animals in the Lalla Takerkoust agricultural region (Marrakesh, Morocco). Thus, MCs were extracted from water and fruit samples and quantified by enzyme-linked immunosorbent assay in order to calculate the health risk indicators. MCs posed a high health-risk level to poultry and horses, with estimated daily intakes (EDI) being 14- and 19-fold higher than the recommended limits (3.1 and 2.3 μg MC-LR L−1), respectively. Furthermore, pomegranate posed the same level of risk, with EDI being 22- and 53-fold higher than the limit dose (0.04 μg MC-LR kg−1) for adults and children, respectively. There was an urgent need for guidelines regarding water use and management in MC-polluted areas, besides the setup of nature-based tools for toxin removal from raw water used in farming practices. Moreover, MCs could contaminate the human food chain, which implies further investigations of their potential accumulation in livestock- and poultry-based food. [ABSTRACT FROM AUTHOR]

Several authors have carried out physic-chemical analyses of the raw water from the Beni Haroun dam since it was exploited, and others continue to do so. The aim of this work is to present a temporal synthesis (2003-2018) of the variation in their quality. It depends on several parameters, such as climate, socio-economic development and population growth around its tributaries. The parameters studied are : Temperature, pH, EC, TDS, and in (mg/l) Ca2+, Mg2+, Na+, K+, Cl-, SO42-, HCO3-, NO3-, NO2-, NH4+ and PO43-, as well as organic parameters such as: COD, BOD5, dissolved O2 and certain heavy metals (μg/l): Pb, Cd, Zn, Fe, Cr, Cu and Mn. The results of this collection of publications show that the quality of the raw water from the Beni Haroun dam varies over time, depending on the season and mainly on the water supply resulting from rainfall, which leads to dilution of the various chemical elements. The air temperature modifies the water temperature, which affects the organic composition. The conclusion shared by all the authors is that raw water must undergo prior treatment before being used for drinking or irrigation. [ABSTRACT FROM AUTHOR]

The presence of algae in the water treatment process is problematic. The best way to control algae is to remove the algae cell intact without rupturing the cell, as most common methods cause disinfection by-products, which are often very dangerous. The aim of this study was to evaluate the efficiency of microstrainer and ozonation systems in combined removal of algae from raw water. For this purpose, Box-Behnken Design was used in the Response Surface Methodology by Design Expert software. Experimental variables included input turbidity (50-150 NTU), microstrainer surface load (10.8-18 m/h) and injectable ozone dose (1-3 mg/L). Based on the experimental conditions, the algae removal efficiency in the integrated microstrainer and ozonation system was 39.64-88.76%. The parameters of inlet water turbidity, injected ozone dose and micro-strainer surface load with effect coefficients of 15.37, 8.98 and 4.01, respectively, had the greatest effect on system efficiency in algae removal. Increasing the turbidity and surface load of the microstrainer decreased the algal removal efficiency and increased the injection ozone dose increased the efficiency. The final model based on the desired parameters was obtained as a quadratic equation with correlation coefficient, modified correlation coefficient and predicted correlation coefficient equal to 0.948, 0.928 and 0.868, respectively.

Different studies identified the presence of several altered genes in familial and sporadic amyotrophic lateral sclerosis (ALS) forms. The experimental data, together with the epidemiological data, would seem to suggest the existence of molecular mechanisms (e.g., axonal transport) related to these genes, together with a susceptibility of the same genes to certain environmental factors that would therefore suggest an impact of the environment on the etiopathogenesis of ALS. In our review, we considered the most relevant environmental clusters around the world, collecting different hypotheses and underlining common environmental factors among the different clusters. Moreover, further epidemiological data identified a higher risk of ALS in professional athletes and, in particular, in soccer and football players. Despite this increased risk of ALS highlighted by the epidemiological evidence in aforementioned sports, the mechanisms remain unclear. At last, the use of raw water has been associated with ALS risk. The aim of the present review is to characterize a possible relationship between these clusters, to be explored in the context of the interaction between genetic and environmental factors on the etiopathogenesis of ALS. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the origin, quantity, and composition of chromophoric dissolved organic matter (CDOM) from two urbanized watersheds (Cikapundung and Cimahi River), examine how CDOM compounds and absorbances change along the process of two different conventional WTPs (WTP Dago and Cimahi) using PARAFAC, and identify absorbance as potential surrogate parameters for CDOM compounds. Samples were collected from intake, secondary treatment, and filter outlets. PARAFAC was conducted based on two data scenarios: (1) from rainy and dry seasons in Cikapundung river and WTP Dago and (2) from the two rivers and two WTPs during rainy season. Tryptophan-like (C1A) and humic-like (C2A) compounds were identified based on scenario-1 analysis. For scenario-2, humic-like (C1B), peak-M (C2B), and tryptophan-like (C3B) were the main compounds. CDOM compound quantity is consistent with the fluorescence index (FI) and biological index (BIX) which confirmed sewage and animal manure pollution in both watersheds. The best overall removal of CDOM compound occurred in WTP Dago in rainy season. The high concentration of tryptophan-like in Cikapundung River in dry season and in Cimahi River in rainy season has worsen the WTP capability to reduce CDOM. Scenario-1 has shown that in WTP Dago, the potential surrogate parameter for C1A was A240 in rainy season (r = 0.60; p < 0.01) and A410 in dry season (r = − 0.43, p < 0.05). Based on scenario-2, for the WTP Dago in rainy season, C1B strongly correlated with A254 (r = 0.86; p < 0.01), C2B has the strongest correlation with A298 (r = 0.93; p < 0.01), and C3B correlated well with A240 (r = 0.59; p < 0.01). In WTP Cimahi, during rainy season, all compounds correlated well with all measured absorbances, with the strongest correlation with A298. [ABSTRACT FROM AUTHOR]

High nitrate concentration in water endangers health to both humans and livestock. The aim of this research was to investigate the efficacy of a roughing filter enhanced by an external carbon source in removing nitrate in raw water. Two upward vertical roughing filters in series were used—a vertical roughing filter with ethanol as a carbon source (VRFwt) and a vertical roughing filter without a carbon source (VRFwo). The average nitrate removal efficiency in a VRFwt was 88%, 70% and 83%, at carbon:nitrogen ratios (C/N ratio) of 1.05, 1.08 and 1.1, respectively. The average chemical oxygen demand (COD) removal efficiency in the VRFwt was 75%, 43% and 46% at C/N ratios of 1.05, 1.08 and 1.1, respectively. The total average reduction of dissolved oxygen (DO) in the VRFwt at C/N ratios of 1.05, 1.08 and 1.1 was 42%, 54% and 51%, respectively, while the drop in the VRFwo was 17%, 18% and 17%. The VRFwt showed a high potential for removing nitrate in raw water. Therefore, when the VRFwt is applied at large scale, it would improve access to water sources that were previously declared unacceptable by many water utilities due to excessive nitrate concentrations. [ABSTRACT FROM AUTHOR]

As an emerging contaminant, the presence of microplastics is widespread in the environment. However, current research regarding the removal of microplastics by drinking water treatment plants (DWTPs) remains insufficient. This study aims to investigate microplastics in water and sludge in four DWTPs in Zhengzhou; these DWTPs have different water sources. The results revealed that the abundance of microplastics in raw water ranged from 12.80 ± 0.80 to 25.07 ± 1.67 n/L. Overall, fibers and fragments ranging from 10 to 100 μm constituted the primary components. The proportion of white and transparent microplastics was the highest. Among the ten polymer types detected, polyvinyl chloride, polyphenylene oxide, and polyethylene terephthalate were the predominant ones in raw water; polyethylene terephthalate emerged as the prevalent polymer type in treated drinking water, with both polyethylene terephthalate and polyvinyl chloride being primarily present in sludge. The removal rate of microplastics ranged from 45.8% to 74.5%. Furthermore, the removal rates at the sedimentation tank outlet accounted for more than 50.0% of the total removal rate. The abundance of microplastics in sludge was significantly higher than that in water, indicating a concentrated environment for the persistence of microplastics. The proper disposal of sludge has emerged as one of the challenges requiring our attention.

Water production and distribution for the people in Bangkok, Nonthaburi, and Samut Prakan areas, have faced the problem of using salty tap water. Problem has been specially found in the water supply services in the eastern part of the Chao Phraya River basins that mainly use the Chao Phraya River as a raw water source for producing the water supply. The problematic issue of high salinity in the produced water supply can be caused by the seawater from the gulf of Thailand intruding into the Chao Phraya River. Therefore, this research aimed to study and find out proper solutions to the problem by reusing the treated wastewater from the Bangkok wastewater treatment plants as raw water to produce water supply during the seawater intrusion period. Based on the study results, it was found that the reuse of the treated wastewater as a raw water source for tap water production could not be practically suitable because BMA has reused some of the treated wastewater for their activities as well as discharged some of it to maintain the environmental and ecological conditions of the river and canals. Hence, two approaches have been suggested as possible solutions to the faced salt tap water problem including 1) relocation of the water intake station (the raw water pumping station) to prevent the high salinity polluting the raw water resource during the seawater intrusion period, and 2) provision of new water reservoirs for especially reserving raw water for producing water supply during the seawater intrusion period.

In order to reduce the influence of algae on the conventional treatment process of the water plant, the electro-flotation process was used to test the raw water of a lake-type reservoir. After raw water with cyanobacteria as the dominant algae is treated by the best electro-flotation process, the average removal rate of algal density can reach 99.1%. The effects of current density, residence time, and electrode spacing on the algal removal efficiency of the electro-floating process were investigated by orthogonal experiments. The order of influence was current density > residence time > electrode spacing. Considering economics, the optimal process conditions were as follows: the current density was 5 mA/cm2, the dwell time was 6 min, and electrode spacing was 10 mm.

The Badaksinga Drinking Water Processing Installation is an installation owned by Perumda Tirtawening Drinking Water, Bandung City, has 2 of these installations, the first of which is a design from Degremont - France, built around 1954 with a capacity of 1000 liters/second. The second installation is an IWACO-Dutch design with a flow rate of 800 liters/second. The raw water for the two installations comes from the Cisangkuy River and the Cikapundung River. To purify the raw water, PAC (Poly Aluminum Chloride) is used as a coagulant which is a complex inorganic compound with a clear to yellowish color. The coagulant addition process must be carried out efficiently because this coagulation process is a chemical process that requires a large amount of money for the water treatment process apart from chlorination. Excessive addition of coagulant doses will cause the cost of using coagulant chemicals to swell so that it will have an impact on overall operational costs. The purpose of this study was to determine the effectiveness of using PAC in reducing turbidity, in the form of the optimum dose of coagulant, turbidity and pH. The method used is the Jar Test which is a tool to test the ability of coagulants to determine the optimum dose in a water treatment process. From the samples, the raw water turbidity varied from 17.1 to 281 NTU, fluctuating due to geographical location and environmental conditions around each and the degree of acidity or an average pH of 7.13. After the Jar Test was carried out, the optimum dose was produced at a coagulant concentration of 30 mg/l resulting in turbidity in the range of 1.1 to 5.0 NTU and an average turbidity reduction efficiency of 94.5%, the pH of raw water, after coagulation and flocculation with the Jar Test simulation tool, there was a decrease of 4.1% to an average of 6.99. This result is in accordance with Minister of Health Regulation No 492/MENKES/PER/10/2010 April 19 2020, namely turbidity of no more than 5 NTU and a pH of 6.5 – 8.5. [ABSTRACT FROM AUTHOR]

The work aims to investigate the Water Quality Index (WQI) of the Shatt-al-Hilla River, a branch of the Euphrates river in Babel city, Iraq. Twelve important and influential parameters were taken into account to evaluate the WQI, namely the temperature of water (Temp), total hardness (TH), electrical conductivity (EC), acidity (PH), total dissolved solids (TDS), sulfate (So4−2), calcium (Ca+2), magnesium (Mg+2), sodium (Na+1), biological oxygen demand (BOD), potassium (K) and turbidity. Raw and treated water quality was evaluated using two models, Weighted Calculation and Canadian Cabinet for the Environmental Water Quality Index (CCME WQI). The study area included three water treatment plants, namely New Hilla (NH), Al-Hussein (HE), and Al- Hashimyah (HA), which discharge their treated water into the Shatt-al-Hilla river. Raw and treated water samples were collected and tested regularly for nine months, from October 2020 to June 2021. The results showed all chemical and physical parameters (for both raw and treated water) met the Iraqi standards except Ca+2, turbidity and EC for raw water and temperature for treated water. HIGHLIGHTS This paper studied Water Quality Index for the Shatt-al-Hilla River in Babel city, Iraq.; Twelve parameters were considered in this study.; Three Water Treatment Plants were included in this study.; All parameters were within the Iraqi standards, except the Ca, Turbidity and EC.;

Introduction: Enteric viruses have been associated with the production of a variety of diseases transmitted by the fecal-oral route and carried through contaminated food and water. Given their structure and composition, they are highly resistant to environmental conditions and most of the chemical agents used in the purification processes. Therefore, the systematic monitoring of raw water is necessary to ensure its quality especially when it is used for producing drinking water for human consumption. Objective: We identified the presence of rotavirus and hepatitis A virus by means of the fluoro-immuno-magnetic separation technique (FIMS) in raw water taken from four purification plants and their water supplies in the department of Norte de Santander. Materials and methods: The viruses were captured and separated from the water samples using magnetic microparticles functionalized with monoclonal anti-Hepatitis A and anti-Rotavirus antibodies. Confocal microscopy was used to monitor the viral concentration process and transmission electron microscopy for the morphological visualization of the separated viruses. The reverse transcriptase-coupled polymerase chain reaction (RT-PCR) was applied to confirm the presence of pathogens. Results: The two enteric viruses were identified in the majority of the analyzed water samples including water supply sources. Conclusion: We determined that the FIMS technique together with RT-PCR is highly effective for the detection of viral pathogens in complex matrices such as raw water.

The goal of the current study was to use the Water Quality Index (WQI) to evaluate the overall drinking water quality status in Erbil City, Kurdistan Region of Iraq, by estimating the quality of the Greater Zab River (raw water) and the water treatment plant WTP at Ifraz-2 on the Greater Zab River, a tributary of the Tigris River. Thirteen physicochemical parameters, including turbidity, pH, electrical conductivity, total dissolved solids, total hardness, calcium, magnesium, alkalinity, chloride, sodium, potassium, nitrate, and sulfate, were evaluated between 2010 and 2021 using the WQI. The calculated WQI for the Greater Zab River's raw water quality ranged from (140.532) to (422.455) and the calculated WQI for WTP (Ifraz-2) ranged from (44.197) to (69.118). Accordingly, the results of Greater Zab River water were categorized as "very poor," "poor," and "unsuitable" for drinking purposes during the studied period (2010–2021). Furthermore, the results of the computed WQI for WTP of (Ifraz-2) are classified as "Excellent" and "Good". According to WQI, the WTP of Ifraz-2 from the current study was of good quality and suitable for consumption by humans. As a result, the efficiency (E%) of the Ifraz-2 WTP was found to be more efficient in 2016 (89.49%) than in other years and suitable for drinking. Except for a few samples, the physicochemical quality of most drinking water samples during the current study was within WHO limits.

This article proposes a decision model to identify the most sustainable solution(s) to ensure the availability of raw water to be subsequently treated to be converted into drinking water as a consequence of the climate change scenario, particularly the drought currently experienced by the Metropolitan Region in Chile, derived from the technical and regulatory requirements associated with the availability of water resources from its capture to its drink ability to meet the future demand of the region. From the perspective of drought, the solution must provide security levels that guarantee the availability of raw water is one of the main concerns of the stakeholders. In turn, the need to adapt current regulations regarding raw water sources, as well as community acceptance of some proposals for converting raw water into potable water and climate dependency, involve qualitative as well as technical aspects that may affect the investment and operating costs of the different solutions required to ensure raw water availability. Therefore, through a multi-criteria approach, it is possible to incorporate quantifiable and intangible aspects and to address conflicting objectives. Through a case study, we present a decision model based on the Analytic Hierarchy Process to define and evaluate the most sustainable solution(s) to secure raw water for drinking. This study proposes to integrate technical and qualitative attributes to identify the challenging criteria and the associated linkage to the problem of selecting proposals for the most sustainable solution(s) to secure raw water, being a guide to decide the implementation of the most appropriate solution. [ABSTRACT FROM AUTHOR]

Since the 1990s, the raw water of Huangpu River in Shanghai, China, has intermittently encountered off-flavor contamination. In this work, the concentrations of typical odor, geosmin, in raw water of Huangpu River are found to shift along with the seasons. However, microbes recognized as the producer of geosmin such as Cyanobacteria and Actinobacteria are not consistent with the shift of geosmin. Cyanobacteria blooms in summer rather than winter, whereas Actinobacteria thrives in winter. Representational difference analysis (RDA) reveals that microbes associated with blooming algae have positive co-occurrence correlations with the concentrations of geosmin and nutrients in winter, whereas those within Cyanobacteria and Planctomycete are in a positive correlation with temperature and thrive in summer. This causes the concentration of geosmin in raw water to appear to depend on the abundance of Actinobacteria rather than that of Cyanobacteria. However, combining with the synthesis and storage properties of geosmin in algae, as well as the decomposition properties of algae with Actinobacteria, geosmin might be synthesized by Cyanobacteria in summer, which is stored in cells of Cyanobacteria and released only via the decomposition of Actinobacteria in winter. This potential olfactory mechanism of geosmin is quite different from that derived from pure culture of odor producers or correlation analysis of bacteria and odors; thus, providing insights into the mechanism of practical off-flavor events. [ABSTRACT FROM AUTHOR]

Water quality assessment plays a significant role in ensuring the availability of clean and safe water. The Water Quality Index (WQI) model method has been developed to provide a basis for assessing water quality by integrating various water quality parameters. However, existing WQIs do not "actively" consider the difficulty of water treatment from raw water to specific water use scenarios. This study proposes a novel model framework, named as Purification Resistance Index (PRI), quantitatively evaluating not only the exceedance of pollutants but also how difficult they can be removed in the water treatment process. The framework is built based on the conventional drinking water treatment processes, with sub-indices for coagulation-sedimentation (r c ), filtration (r f ), disinfection (r d ), and advanced treatment (r a ). The model considers appropriate weights assigned to each sub-index to calculate the purification resistance, resulting in a comprehensive index for water quality evaluation. Case studies on nationwide and citywide water source reservoirs demonstrated the applicability of PRI approach. PRI breakthrough the traditional water quality risk assessment paradigm and extents to engineering region and provide useful tools for water source supervision, drinking water treatment plant planning and updating, operation control, and other purposes. Water authority, water utility and municipal design institute will all benefit. It is open for more localized practices validation and discussion., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper, (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Raw water quality deterioration has affected capabilities of Conventional Water Treatment Processes (CWTP) in many countries. CWTP used at Morton Jaffray Water Treatment Works (MJWTW) in Harare have proven ineffective due to pollution. The study investigated the use of chlorine dioxide (ClO2) as an alternative pre-treatment chemical. Its effectiveness was compared to that of calcium hypochlorite (Ca(CIO)2) used at MJWTW. Grab raw water samples from MJWTW were collected between January and March 2020 and pre-treated with ClO2 and Ca(CIO)2 followed by jar tests with alum to determine pre-treatment effectiveness. Parameters analyzed included electrical conductivity (EC), total dissolved solids (TDS), total solids (TS), turbidity, chemical oxygen demand (COD), pH and total algae counts (TAC). The raw water had mean TDS (264 mg/L), TS (440 mg/L), turbidity (7.1 NTU), COD (85 mg/L), pH (7.9) and TAC (28.4 × 106 cells/mL). The optimum alum dosage without pre-oxidation was 80 mg/L. Pre-oxidation with 0.075 mg/L ClO2 reduced alum dosage to 60 mg/L. This ClO2 dosage was compared to a Ca(CIO)2 dosage of the same concentration and strength at 5 and 15-minutes contact time before alum dosage at 60 mg/L. The treated water quality parameter levels proved better performance for ClO2 compared to calcium hypochlorite. HIGHLIGHTS Raw water quality deterioration in Lake Chivero has complicated treatment and treatment costs.; Chemicals currently used have become ineffective including calcium hypochlorite, which creates risk of formation of carcinogenic compounds.; Chlorine dioxide was considered an an alternative as it has been used widely elsewhere, enhances coagulation compared to calcium hypochlorite, and thus is likely to be economic.;

Continuous water monitoring is expensive and time consuming. Because it requires sampling information throughout 12 months and restricts the conduct of water aid management studies as well as the calibration and validation of excellent water models. To overcome this obstacle to better water quality management, improving water quality models is a necessary step. Various modelling strategies have been developed in recent years to improve the accuracy of predictions of major water parameters. In this work, for the prediction of raw water sulfate, we used five machine learning models were considered in this work: artificial neural network (ANN), support vector machine (SVM), Gaussian process regression (GPR), and decision tree (DT) and ensemble tree (ET). Moreover, the DT model was used to know the influence of the other physicochemical parameters (inputs) on the, and the ET model to improve the DT result and ensure the influence of the other physicochemical parameters on the sulfate. The experimental results indicate that all models were found to be effective in predicting sulfate levels, due to their very high correlation coefficients (close to 1) and very low statistical errors (close to 0); however, the most suitable water quality models were GPR and ANN, as their coefficients and statistical indicators do not show much difference between them. Indeed, the coefficients and the statistical indicators of the GPR model were R = 0.9991, R2 = 0.9982, R2adj = 0.9978, RMSE = 0.0182, MSE = 0, 0003, MAE = 0.0073 and EPM = 1.5386; while those of the ANN model were: R = 0.9989, R2 = 0.9978, R2adj = 0.9972, RMSE = 0.0124, MSE = 0.0001, MAE = 0.0083 and EPM = 2.0639. The only difference that favored the GPR model if compared to the ANN was the number of parameters, namely 70 parameters and a very weak loss, 3.3404e-04. In contrast, the ANN model was run with 190 parameters. The model tests (interpolation) confirmed this result, owing to the values of the the correlation coefficient (R = 0.99834) and the coefficient of determination (R2 = 0.9966), as well as that of statistical indicators (RMSE = 0.0309, MSE = 9.5219e-04, EPM = 3.0267 and MAE = 0.0122). In light of these results it can be concluded that the GPR model is the more efficient to predict sulfate in raw water. Additionally, its ability to deal with missing values, outliers, and the updating ability shows its relevance, which should be kept in the future. This efficiency seems to be due to the fact that the sulfate concentration in the raw water is linked to the physico-chemical characteristics of the environment by non-linear relationships. It is confirmed by a tree and ensemble model decision which provided information on how sulfate reacts with other physicochemical characteristics. [ABSTRACT FROM AUTHOR]

Copyright of Gaceta Médica de Caracas is the property of Academia Nacional de Medicina and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Water outages caused by elevated ammonium (NH 4 +-N) levels are a prevalent problem faced by conventional raw water treatment plants in developing countries. A treatment solution requires a short hydraulic retention time (HRT) to overcome nitrification rate limitation in oligotrophic conditions. In this study, the performance of polluted raw water treatment using a green downflow sponge biofilm (DSB) technology was evaluated. We operated two DSB reactors, DSB-1 and DSB-2 under different NH 4 +-N concentration ranges (DSB-1: 3.2–5.0 mg L−1; DSB-2: 1.7–2.6 mg L−1) over 360 days and monitored their performance under short HRT (60 min, 30 min, 20 min, and 15 min). The experimental results revealed vertical segregation of organic removal in the upper reactor depths and nitrification in the lower depths. Under the shortest HRT of 15 min, both DSB reactors achieved stable NH 4 +-N and chemical oxygen demand removal (≥95%) and produced minimal effluent nitrite (NO 2 −-N). DSB system could facilitate complete NH 4 +-N oxidation to nitrate (NO 3 −-N) without external aeration energy requirement. The 16S rRNA sequencing data revealed that nitrifying bacteria Nitrosomonas and Nitrospira in the reactor were stratified. Putative comammox bacteria with high ammonia affinity was successfully enriched in DSB-2 operating at a lower NH 4 +-N loading rate, which is advantageous in oligotrophic treatment. This study suggests that a high hydraulic rate DSB system with efficient ammonia removal could incorporate ammonia treatment capability into polluted raw water treatment process and ensure safe water supply in many developing countries. [Display omitted] • DSB reactor achieved high hydraulic rate NH 4 +-N removal from polluted raw water. • DSB can offset aeration energy demand through passive aeration. • A 75% decrease in HRT did not adversely impact DSB performance or nitrifying consortia. • Sponge's high biomass retention favoured slow-growing Nitrosomonas and Nitrospira. • Low influent NH 4 +-N shaped comammox bacterial community with high NH 4 +-N affinity. [ABSTRACT FROM AUTHOR]

In this research, the XDLVO (extended Derjaguin-Landau-Verwey-Overbeek) theory was employed to analyze the fouling status of nanofiltration (NF) membrane caused by hydrophilic and hydrophobic organic matters. Quantitative analysis was conducted on six types of hydrophilic and hydrophobic organic matters with different molecular weight ranges (less than 100 kDa, less than 50 kDa, less than 3 kDa, respectively) and the interfacial free energy of NF membrane was analyzed, in a bid to figure out the performance of the membrane fouling. Furthermore, the corresponding relationship between flux decay and interfacial free energy was verified by NF experiment. The results show that the degree of membrane fouling caused by the above-mentioned six hydrophilic or hydrophobic organic matters with different molecular weights in this study was consistent with the XDLVO theoretical analysis, in which the hydrophobic ones with the molecular weight less than 100 kDa showed the slightest repulsive interaction against the membrane and led to the most serious fouling. Besides, the degree of membrane fouling was ordered in a descending way as follows: (hydrophobic organic matter with the molecular weight less than 100 kDa) > (hydrophobic organic matter with the molecular weight less than 50 kDa) > (hydrophobic organic matter with the molecular weight less than 3 kDa) > (hydrophilic organic matter with the molecular weight less than 3 kDa) > (hydrophilic organic matter with the molecular weight less than 50 kDa) > (hydrophilic organic matter with the molecular weight less than 100 kDa). [ABSTRACT FROM AUTHOR]

The potential for hydrothermal energy of the river, raw water, and reservoir water, which were located near the three major metropolitan cities in Korea, was predicted. The natural energy potential was defined by the flow rate of each water source, utilizing the temperature difference of 5 °C. Exceptionally, the amount of flow for the reservoir water was assumed to be 1 % of the dam's storage amount for month. The technical potential for the hydrothermal energy for each water source was calculated by simulation of the whole water-source heat pump system through TRNSYS. The hydrothermal energy potential of the Han River in Seoul, Nakdong River in Busan, and Gapcheon in Daejeon are (227678, 247360, and 14600) TJ/year, respectively. In estimating the technical potential for the Han river, the average COP for the river-water heat pump system is 4.40 for cooling and 3.11 for heating, with a monthly maximum COP of 5.79, and a minimum COP of 3.01. One of the raw water pipelines in Seoul is connected in the form of the Gangbuk water purification plant-Gangbuk water intake plant. The technical hydrothermal energy potential is 5682 TJ/year. For Paldang Dam, the average COP for the reservoir water heat pump system is 3.28 for heating, and 4.26 for cooling, while the technical potential is 595 TJ/year. [ABSTRACT FROM AUTHOR]

The scarcity of the planet's water resources is a concern of several international entities and governments. Smart solutions for water quality monitoring are gaining prominence with advances in communication technology. This work's primary goal is to develop a new online system to monitor and manage water resources, called Internet of Water Things (IoWT). The proposed system's objective would be to control and manage raw water resources. Thus, it has developed a platform based on the server-less architecture and Internet of Things Architectural Reference Model, in which it is applied in a simulation environment, considering several electronic devices to validate its performance. For this research, there is a system for capturing raw water from tubular wells. Each well has a level sensor, a temperature sensor and a rain gauge. The data is collected every minute by an electronic device and sent every hour to the IoWT system. From data analysis, the amount of memory allocated to functions minimally interferes with efficiency. The IoWT system, applied in a real case, consists of connecting a device installed in a water well to the platform, where the data is transmitted through a 3G network and then processed. Thus, the proposed approach has great potential to be considered a complementary tool in monitoring raw water and assisting in decision-making for the management of water resources.

Organizing raw (make-up) water in the condensers of cogeneration turbine plants with the simultaneous supply of circulating water through the main bundles is one of the most reliable ways to increase the efficiency of a combined heat and power plant (CHPP). At most CHPPs, the temperature of raw water supplied to the chemical water treatment workshop should not exceed 30°C-40°C. This condition is not always met, and it is necessary to analyze and adjust the operating modes of turbines to provide the most effective heating of water in the built-in bundles. Such an analysis can be performed based on operational data and a mathematical model of the condenser developed at the Department of Heat Engineering and Hydraulics of the Virginia State Univeristy. This paper presents an analysis algorithm based on the actual data obtained during the tests of the condenser of the PT-80-130 turbine plant in the mode of its operation according to the electrical schedule, and conclusions are drawn based on the analysis. [ABSTRACT FROM AUTHOR]

Introduction: Enteric viruses have been associated with the production of a variety of diseases transmitted by the fecal-oral route and carried through contaminated food and water. Given their structure and composition, they are highly resistant to environmental conditions and most of the chemical agents used In the purification processes. Therefore, the systematic monitoring of raw water is necessary to ensure its quality especially when it Is used for producing drinking water for human consumption. Objective: We identified the presence of rotavirus and hepatitis A virus by means of the fluoro-immuno-magnetic separation technique (FIMS) in raw water taken from four purification plants and their water supplies in the department of Norte de Santander. Materials and methods: The viruses were captured and separated from the water samples using magnetic mlcroparticles functionalized with monoclonal anti-Hepatitis A and anti-Rotavirus antibodies. Confocal microscopy was used to monitor the viral concentration process and transmission electron microscopy for the morphological visualization of the separated viruses. The reverse transcriptase-coupled polymerase chain reaction (RT-PCR) was applied to confirm the presence of pathogens. Results: The two enteric viruses were identified in the majority of the analyzed water samples including water supply sources. Conclusion: We determined that the FIMS technique together with RT-PCR is highly effective for the detection of viral pathogens in complex matrices such as raw water. [ABSTRACT FROM AUTHOR]

Copyright of Biomédica: Revista del Instituto Nacional de Salud is the property of Instituto Nacional de Salud of Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Since the 1990s, the raw water of Huangpu River in Shanghai, China, has intermittently encountered off-flavor contamination. In this work, the concentrations of typical odor, geosmin, in raw water of Huangpu River are found to shift along with the seasons. However, microbes recognized as the producer of geosmin such as Cyanobacteria and Actinobacteria are not consistent with the shift of geosmin. Cyanobacteria blooms in summer rather than winter, whereas Actinobacteria thrives in winter. Representational difference analysis (RDA) reveals that microbes associated with blooming algae have positive co-occurrence correlations with the concentrations of geosmin and nutrients in winter, whereas those within Cyanobacteria and Planctomycete are in a positive correlation with temperature and thrive in summer. This causes the concentration of geosmin in raw water to appear to depend on the abundance of Actinobacteria rather than that of Cyanobacteria. However, combining with the synthesis and storage properties of geosmin in algae, as well as the decomposition properties of algae with Actinobacteria, geosmin might be synthesized by Cyanobacteria in summer, which is stored in cells of Cyanobacteria and released only via the decomposition of Actinobacteria in winter. This potential olfactory mechanism of geosmin is quite different from that derived from pure culture of odor producers or correlation analysis of bacteria and odors; thus, providing insights into the mechanism of practical off-flavor events.

The safety of water is essential for life on earth. Drinking contaminated water can give rise to many health issues. To highlight the major causes of contamination in water, this study was carried out to determine the physicochemical and bacteriological quality of raw and chlorinated water. Raw and chlorinated water samples were obtained from three locations (zones) of a residential university (National University of Sciences and Technology, NUST). Ten physicochemical parameters were analyzed (pH, Electrical conductivity, Turbidity, Dissolved oxygen, Hardness, Alkalinity, Total suspended solids, Total dissolved solids, Total organic carbon, and Chlorine (free & total)). Bacteriological analysis was performed through the MPN technique. The results showed that all the physicochemical parameters were found within the permissible limits set by WHO and PSDWQ for raw and chlorinated water, except TSS and Chlorine (free & total). The TSS of raw and chlorinated water ranged from 3.3-14.3mg/L and 8.7-12.7mg/L, greater than the permissible limits. The free Chlorine for both raw and chlorinated water ranged from 0.04-0.09mg/L and 0.06-0.07mg/L and total Chlorine for both raw and chlorinated water in the range 0.10-0.09mg/L and 0.22-0.24mg/L, respectively, which were far below the recommended limit required for water disinfection. The MPN index for raw and chlorinated water ranged from 23 to >23MPN/100ml and 16 to >23MPN/100ml, exceeding the permissible limits. The results concluded that the water, whether raw or chlorinated, was not fit for drinking purposes. Proper dosages of Chlorine and filtration techniques are required to make the water fit for consumption.

Introduction: Toxoplasmosis is an orally-transmitted zoonosis that may appear after consuming food contaminated with any infective form of Toxoplasma gondii. Its transmission by water has been reported in several countries including Colombia. The rural population of Sincelejo could be at risk of contracting toxoplasmosis through this route given that they lack potable water. Objective: To evaluate T. gondii contamination in water for human consumption from water wells (jagüeyes) in the rural area of Sincelejo and establish its relationship with different social determinants of health in the study area. Materials and methods: Using nested PCR we evaluated 96 water samples obtained from 48 farms located in eight rural townships in Sincelejo. We took two samples in each farm: one of raw water from water wells and the other intended for direct consumption. We conducted a survey on each farm to collect information on the physical characteristics of dwellings, the presence of cats, and the availability and uses of water. Statistical relationships were evaluated through Fisher tests. Results: Of the 96 samples analyzed, 13 were contaminated with T. gondii (13.5%): Nine corresponded to raw water and four to water for direct consumption. No statistical association was found between the positive samples and the social determinants of health under evaluation (p>0.05). Conclusion: The rural population of Sincelejo could be at risk of contracting toxoplasmosis through the use and/or consumption of water from its water wells. The contamination of these water bodies by T. gondii may be influenced by unstudied social determinants. [ABSTRACT FROM AUTHOR]

Bio-filtration technology is considered as one of prevention solutions for declining raw water quality. The research purpose was to identify biofilm growth formation as viability cell in acclimatization period that can be used for ammonia elimination by using various indigenous chemo-heterotroph bacteria isolated from bio-filter media specimen and moving bed bio-filter reactor performance. Reactor was configured within aerobic system comparing two biofilm–attached support–medium filters (i.e. drinking-water-bottle-PET-chips and PVC). Bacteria potency on ammonia removal in kinetics modeling was advance investigated. Kinetics determination was based on empirical approach in first order by using formula of Cout = Cin exp(-k.EBRT), where Cout is ammonia concentration in outlet, Cin is ammonia concentration in inlet, k is first-order reaction rate constant and Empty Bed Retention Time (EBRT) can be formulated about setting comparison the discharge ammonia load (Q) and volume reactor (V). Total thirteen potential biofilm bacterias were successfully isolated in 24–hours–incubation at 37oC and by using Bergey’s method successfully identified prime biofilm isolates of Bacillus sp and Pseudomonas sp, then re-selected to determine one with the best ammonia removal ability. The ammonia removal kinetics constant of each reactor was obtained as followed: (1) kPET =0.421h-1(ɳ = 62.47%-NH3) and (2) kPVC = 0.412 h-1(ɳ = 58.80%-NH3).

Surface water pollution has increased, owing to industrial development and population growth. Consequently, it is important to find alternative drinking water treatment strategies, which cater for changes in the quality of raw water. This study compared the efficiency of different coagulants in treating raw water that feeds a drinking water treatment plant (WTP). Using jar testing equipment and a number of physicochemical parameters, an investigation was conducted to establish optimum conditions for aluminium chloride (A), ferric chloride (B), and chitosan (C), and their performance compared with aluminium sulphate (D), which is the coagulant used at the WTP. The turbidity removal efficiencies for the single coagulants were in the order: B (95.7%) > A (94.7%) > C (94.4%), at optimum coagulant doses of 60, 50, and 0.6 mg/L, respectively. The coagulants achieved high removal efficiencies for turbidity, total dissolved solids (TDS), ultraviolet absorbance at 254 nm (UV254) and conductivity under acidic conditions. For dual coagulants, there was a gradual increase in the removal efficiencies of the tested parameters with increasing pH. Combined coagulants were more effective compared to single coagulants, with highest removal efficiencies being exhibited by the A/C combination. Overall, the coagulants proved to be suitable alternatives to D, since they had comparable performances. [ABSTRACT FROM AUTHOR]

Currently, the purification of raw water is relevant due to its scarcity in some regions of the world. The objective of this work was to reduce the turbidity of raw water by using cassava starch as a natural coagulant. Starch was extracted from cassava for the coagulation-flocculation tests that were carried out using a response surface type experimental design. The response variables were turbidity, colour and pH, the intermediate variables being the initial concentration of the sample, speed and time of centrifugation, cooling time, stirring speed and coagulant concentration. It was established that by adding 250 mg/L of coagulant and with a speed of 40 rpm, a higher percentage of turbidity elimination is achieved. Similarly, starch does not add or remove colour to raw water samples, being within the range used and considered acceptable for use following Decree 1575 of 2007 for drinking water. Under the conditions established during the jar test, the turbidity removal percentages were higher than 70%. Therefore, cassava starch could be used as a natural coagulant. [ABSTRACT FROM AUTHOR]

The present paper aims at determining the status of surface water quality by applying the treatability index for the raw water in four water treatment plants (WTPs), namely Vaalkop, Klipdrift, Wallmansthal, and Cullinan. These plants are based in South Africa. Sampling was conducted from July 2011 to June 2018 (7 years). The collected water samples were analysed on monthly basis over the specified period. Three Hundred and thirty six (336) water samples were collected and analysed. The Treatability Index (TI) was calculated for twenty-one physicochemical and microbial parameters, which include pH, conductivity, chloride, sodium, potassium, hardness, alkalinity, precipitation potential, turbidity, colour, E. coli, organic carbon, chlorophyll, nitrite, ammonia, nitrates, phosphate, iron, manganese, and sulphate. The computed TI values range from 0.1 to 1755.5 and the water quality was unsuitable for a number of defined uses. The data demonstrated high treatment demand for raw water. On that note, the surface water from the monitored places is not suitable for drinking purposes. The data and treatability index denoted the need for treatment prior consumption. The collected water quality data can be reused for future references, modelling, and trending of historic data to understand current and prospect future changes in the properties of our raw water qualities.