Raw Surface Water Research Articles

Phenolic Ecotoxins in River Water: Survey on Knowledge and Practices of Road-Side Food Vendors Operating Along River Chania Bank Fringes in Thika Sub- County, Kenya

Purpose: Phenolic ecotoxins consumed in raw surface water from river sources has been implicated in causing diseases of high burden such as cancers, in Kenya. This study was conducted in Thika Sub County, and data collected from roadside food vendors and food hawkers who operate small scale street food business along the fringes and banks of River Chania. The study’s objective was to establish the knowledge on Phenolic ecotoxins present in river water and practices of the study respondents. Methodology: A crossectional descriptive study design was used, in which combined interviews and questionnaire enquiries conducted from, n=341, small-scale road side food vendors and hawkers was analyzed. Findings: Data reveals that none of the respondents had knowledge on Phenolic ecotoxin contaminants and additionally a strongly associated correlation (P<0.001, χ222.6 and df 1), further augments the disclosure that, poor knowledge of raw river water safety and hygiene does result to body harm and ill health. Unique Contribution to Theory, Policy and Practice: There is increased need and effort to scale up the sensitization and awareness on exposure to harmful ecotoxin contaminants from the use of raw river water. Water decontamination mobile units should be considered and introduced especially in urban areas of high population density, transversed by rivers.

Land-Use Pattern-Based Spatial Variation of Physicochemical Parameters and Efficacy of Safe Drinking Water Supply along the Mahaweli River, Sri Lanka

Exploration of the pollution status of river-based water sources is important to ensure quality and safe drinking water supply for the public. The present study investigated physicochemical parameters of surface water in the upper segment of River Mahaweli, which provides drinking water to the Nuwara Eliya and Kandy districts of Sri Lanka. River surface water from 15 intakes and treated water from 14 Water Treatment Plants (WTPs) were tested for pH, water temperature, turbidity, EC, COD, 6 anions, 21 cations, 3 pesticides, and 30 antibiotics once every 3 months from June 2022 to July 2023. Except for turbidity and iron concentrations, all other parameters were within the permissible range as per the Sri Lanka Standard Specification for Potable Water (SLS 614:2013). The uppermost Kotagala WTP raw water had a high concentration of iron due to runoff from areas with abundant iron-bearing minerals. Turbidity increased as the river flowed downstream, reaching its highest value of 13.43 NTU at the lowermost Haragama. Four intakes had raw surface water suitable for drinking as per the Water Quality Index (WQI). Pollution increased gradually towards downstream mainly due to agricultural runoff, industrial effluents, and urbanization. Poor water quality at the upstream Thalawakale-Nanuoya intake was due to highly contaminated effluent water coming from Lake Gregory in Nuwara Eliya. Cluster analysis categorized WTP locations in the river segment into 3 clusters as low, moderate, and high based on contaminations. Principal component analysis revealed that the significance of the 41.56% variance of the raw water was due to the pH and the presence of heavy metals V, Cr, Ni, Rb, Co, Sr, and As. All treated water from 15 WTPs had very good to excellent quality. In general, heavy metal contamination was low as indicated by the heavy metal pollution index (HPI) and heavy metal evaluation index (HEI). The treatment process could remove up to 94.7% of the turbidity. This is the first attempt to cluster the river catchment of the Mahaweli River based on physicochemical parameters of river water. We present here the land-use pattern-based pollution of the river and efficacy of the water treatment process using the Mahaweli River Basin as a case study. Regular monitoring and treatment adjustments at identified points are recommended to maintain the delivery of safe drinking water.

Pharmaceuticals in raw and treated water from drinking water treatment plants nationwide: Insights into their sources and exposure risk assessment

Due to the large amounts of pharmaceuticals and personal care products (PPCPs) currently being consumed and released into the environment, this study provides a comprehensive analysis of pharmaceutical pollution in both raw and treated water from full-scale drinking water treatment plants nationwide. Our investigation revealed that 30 out of 37 PPCPs were present in raw water with mean concentrations ranging from 0.01–131 ng/L. The raw water sources, surface water (ND – 147 ng/L), subsurface water (ND – 123 ng/L) and reservoir sources (ND – 135 ng/L) exhibited higher mean concentration levels of pharmaceutical residues compared to groundwater sources (ND – 1.89 ng/L). Meanwhile, in treated water, 17 of the 37 analyzed PPCPs were present with carbamazepine, clarithromycin, fluconazole, telmisartan, valsartan, and cotinine being the most common (detection frequency > 40 %), and having mean concentrations of 1.22, 0.12, 3.48, 40.1, 6.36, and 3.73 ng/L, respectively. These findings highlight that, while water treatment processes are effective, there are some persistent compounds that prove challenging to fully eliminate. Using Monte Carlo simulations, risk assessment indicated that most of these compounds are likely to have negligible impact on human health, except for the antihypertensives. Telmisartan was identified as posing the highest ecological risk (RQ > 1), warranting further investigation, and monitoring. The study concludes by prioritizing specific 14 pharmaceuticals, including telmisartan, clarithromycin, lamotrigine, cotinine, lidocaine, tramadol, and others, for future monitoring to safeguard both ecological and human health.

Waterborne Cryptosporidium species and Giardia duodenalis in resources of MENA: A systematic review and meta-analysis.

This review explores our understanding of Cryptosporidium species and Giardia duodenalis distribution in Middle East and North African (MENA) water resources. Results emphasize that Cryptosporidium species (sp.) and G. duodenalis (oo)cysts are present in distinct categories of water in ten MENA countries. Cryptosporidium sp. proportional prevalence in the MENA region was 24.5% (95% CI 16.3-33.8), while G. duodenalis prevalence was 37.7% (95% CI 21.9-55.1). Raw wastewater and surface water were the water categories most significantly impacted. Both parasites were reported in the various types of MENA drinking waters. The most frequent species/genotypes reported were C. hominis, C. parvum, and G. duodenalis assemblage A. Despite the high prevalence of (oo)cysts reported, we should consider the absence of waterborne outbreaks. This indicates significant underestimation and underreporting of both parasites in MENA. Stakeholders should apply water contamination legislation to eradicate Cryptosporidium sp. and G. duodenalis (oo)cysts from water resources/categories.

Identification of Cryptosporidium oocyst and Giardia cyst in of the samples of raw surface water of Kan River in Tehran

Background: Giardia and Cryptosporidium are considered the most important causal agents of non-bloody diarrhea, especially among primary school children, in many countries, including Iran. Many rivers are contaminated with Cryptosporidium oocyst and Giardia lamblia cysts due to domestic wastewater or farm wastewater and also the living of rodents on their margins. The present study aims to evaluate Kan River contamination with Cryptosporidium oocyst and Giardia cyst in Tehran by molecular method. Materials and Methods: Sampling was conducted from different parts of the Kan River in different seasons in 2019. Firstly, the smear has been prepared from sediments after filtering the water and collecting the sediment, stained with trichrome and acid-fast methods, and finally examined microscopically. Then, they were amplified with the Nested-PCR method by using the specific primers: the giardian gene from Giardia and the 18s rRNA gene from Cryptosporidium. Positive samples were sequenced, and a phylogenetic tree was drawn. Results: 12 suspected samples of Giardia cyst and 2 suspected samples of Cryptosporidium oocyst were detected, but only 4 samples infected with Giardia lamblia were molecularly found, and no Cryptosporidium infection was observed. In terms of genotype, the identified Giardia was 100% consistent with human isolates of genotype B. Conclusion: The presence of Giardia lamblia cysts in the water of the Kan River indicates the contamination of this river by human-contaminating parasites.

Analysing the interlinkage between diarrhoea and drinking water faecal contamination in India

ABSTRACT Diarrhoea is one of the major waterborne diseases spread through the faecal–oral route causing over 10 million cases and over 1,000 deaths per year in India. This study critically evaluates the interlinkage between bacteriological water quality, i.e. faecal coliforms and diarrhoea cases for the three pre-pandemic years 2017, 2018 and 2019 based on multiple sources. With around 17% of households tap water connectivity as of August 2019, the majority of the Indian population depends on raw groundwater (GW) and surface water sources. For this, faecal coliform (FC) levels in surface and GW have been mapped at district levels using data from India's National Water Quality Monitoring Programme. Health Management Information System's data on diarrhoea have been used to understand the monthly and district-wise variation of diarrhoea. The trends of FC, diarrhoea inpatient cases, and diarrhoea inpatient rates have been discussed. The analysis showed issues associated with the reliability and usefulness of these datasets with 43% of total India districts with no reported FC values for the study period. This study reveals a clear gap in the interlinkage between diarrhoea and bacteriological water quality with the unavailability of granular water quality data as a major challenge.

Integrating reverse osmosis to a conventional river water treatment plant as a strategy to produce drinking water after mining dam rupture events: a case study

ABSTRACT Incidents of mining dam failure have compromised the water quality, threatening the water supply. Different strategies are sought to restore the impacted area and to guarantee the water supply. One example is water treatment plants that treat high-polluted waters within the required limits for their multiple usages. The current study assesses the integration of reverse osmosis (RO) to a river water treatment plant (RWTP) installed in Brumadinho (Minas Gerais, Brazil) to treat the water from the Ferro-Carvão stream impacted by the B1 dam rupture in 2019. The RWTP started eleven months after the mining dam rupture and is equipped with eight coagulation-flocculation tanks followed by eight pressurised filters. A pilot RO plant was installed to polish the water treated by the RWTP. Water samples were collected at different points of the water treatment plant and were characterised by their physical, chemical, and biological parameters (160 in total). The results were compared with the historical data (1997–2022) to reveal the alterations in the water quality after the rupture event. The compliance with both parameters was only achieved after the RO treatment, which acted as an additional barrier to 30 contaminants. The water quality indexes (WQI) suggested that the raw surface water, even eleven months after the incident, was unfit for consumption (WQI: 133.9) whereas the reverse osmosis permeate was ranked as excellent in the rating grid (WQI: 23.7).

Risk of Ceftriaxone (Antibiotic) in the Tigris River Water, Iraq

There are several causes of hemolytic diseases, such as viral or bacterial contamination, enlarged spleen, and typhoid fever, which can be transmitted through contaminated water. Polluted wastewater samples were collected for the period of June-2022 to (May-2023) from five stations in Baghdad City such as Al- Gureat, Al-Ahdamyah, Bab Al-Muhadum, Bab Al-Sharqy and Al-Jadryah stations on the Tigris Riverbanks for the studying of Ceftriaxone antibiotic risk. The concentrations of ceftriaxone have been detected using high-performance liquid chromatography (HPLC). The results reveal that concentrations of ceftriaxone in the water fluctuated via sampling stations and seasons; so the highest concentration was 8 × 10-5 ppm in site 2 at Ahdamyah station, while the lowest concentrations was 1 × 10-7 ppm in site 5 sites at Al-Jadryah station during wet season 2023. The results of the statistical analysis showed that there were no significant differences between the study stations, except for the control station. The detection of ceftriaxone in raw surface water confirms that sewage from health institutions reaches the river without any effective treatment.

Removing bacteria contaminants from raw surface water using multiple barriers pilot-scale reactor: sand filtration, activated carbon, and advanced oxidation processes

The presence of bacteria in drinking water poses significant health risks, highlighting the global need for advanced and sustainable water treatment technologies. Our research aims to effectively control microbiological contaminants in drinking water, reducing health risks associated with pathogenic bacteria. This study focuses on developing and applying advanced water treatment techniques, including an investigation into the dynamics of bacterial communities. We evaluate a multi-barrier water treatment system, integrating advanced oxidation processes, in a pilot-scale reactor for potential drinking water production. The treatment led to substantial bacterial reduction, achieving a 2 to 4 log10 unit decrease. Post-treatment, the average count of pathogenic bacteria was reduced to 0 /100 CFU mL in the surface water. Flow Cytometry results indicated a count of 103 cells/mL injured bacteria in the treated water. Analysis using Illumina MiSeq sequencing of 16 S rRNA genes in water samples revealed that disinfectants significantly altered the microbial community structure, while filtration stages synergized with the disinfection process for treating raw surface water. Notably, bacterial groups such as Actinobacteria and Proteobacteria demonstrated notable resistance to the disinfectants. Furthermore, canonical correspondence analysis indicated that environmental factors and treatment methods influenced microbial community profiles. This study underscores the efficacy of advanced water treatment processes in eliminating bacteria, assessing their viability and potential for regrowth, and ensuring the treated water meets established drinking water guidelines relative to microbiology bacteria in drinking water.

Analysis of the Potential of Watersheds as a Source of Raw Water in the Batang Integrated Industrial Area (KITB) in Cluster 1

The Batang Integrated Industrial Area (KITB) is located in Banyuputih District, Batang Regency, Central Java, with a total area of 4,300 Ha and currently what has been developed is cluster 1 covering an area of 3100 Ha. Water has a central role in human and industrial activities, with potential impacts on health, worker safety, and the environment. The main problem is the uncertainty of raw water supply which poses a risk to Environment Health Safety (EHS). Therefore, this research aims to identify and analyze water sources, by EHS objectives, because safe water supply is key to environmental and worker safety. The water balance method is used to analyze water needs and availability. Analyze water needs in industrial areas by taking into account data for each type of industry. Water availability analysis includes the identification of raw water sources, including groundwater and surface water, taking into account that excessive exploitation of groundwater can hurt EHS. In contrast, surface water and rainwater collection are sustainable alternatives that are relevant to environmental and safety concerns. The research involved calculations using rainfall data from the Subah Rain Station and climatology data from the Central Java Climatology Station during the 2021-2022 period, as well as discharge analysis using the Mock Method. The research results display the potential of the river basin and show that rainwater collection can effectively overcome EHS challenges related to water availability in the Batang Integrated Industrial Area.

Candidate biomarkers of antibiotic resistance for the monitoring of wastewater and the downstream environment

Urban wastewater treatment plants (UWTPs) are essential for reducing the pollutants load and protecting water bodies. However, wastewater catchment areas and UWTPs emit continuously antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs), with recognized impacts on the downstream environments. Recently, the European Commission recommended to monitor antibiotic resistance in UWTPs serving more than 100 000 population equivalents. Antibiotic resistance monitoring in environmental samples can be challenging. The expected complexity of these systems can jeopardize the interpretation capacity regarding, for instance, wastewater treatment efficiency, impacts of environmental contamination, or risks due to human exposure. Simplified monitoring frameworks will be essential for the successful implementation of analytical procedures, data analysis, and data sharing. This study aimed to test a set of biomarkers representative of ARG contamination, selected based on their frequent human association and, simultaneously, rare presence in pristine environments. In addition to the 16S rRNA gene, ten potential biomarkers (intI1, sul1, ermB, ermF, aph(3′’)-Ib, qacEΔ1, uidA, mefC, tetX, and crAssphage) were monitored in DNA extracts (n = 116) from raw wastewater, activated sludge, treated wastewater, and surface water (upstream and downstream of UWTPs) samples collected in the Czech Republic, Denmark, Israel, the Netherlands, and Portugal. Each biomarker was sensitive enough to measure decreases (on average by up to 2.5 log-units gene copy/mL) from raw wastewater to surface water, with variations in the same order of magnitude as for the 16S rRNA gene. The use of the 10 biomarkers allowed the typing of water samples whose origin or quality could be predicted in a blind test. The results show that, based on appropriate biomarkers, qPCR can be used for a cost-effective and technically accessible approach to monitoring wastewater and the downstream environment.

Browning of Scottish surface water sources exposed to climate change

Levels of dissolved natural organic matter (DNOM) are increasing in our boreal watercourses. This is manifested by an apparent increase in its yellow to brown colour of the water, i.e., browning. Sound predictions of future changes in colour of our freshwaters is a prerequisite for predicting effects on aquatic fauna and a sustainable operation of drinking water facilities using surface waters as raw water sources. A model for the effect of climate on colour (mg Pt L-1) has been developed for two surface raw water sources in Scotland, i.e., at Bracadale and Port Charlotte. Both sites are situated far out on the Scottish west coast, without major impact of acid rain, with limited amounts of frost, and with limited recent land-use changes. The model was fitted to 15 years long data-series on colour measurements, provided by Scottish Water, at the two sites. Meteorological data were provided by UK Met. The models perform well for both sites in simulating the variation in monthly measured colour, explaining 89 and 90% of the variation at Bracadale and Port Charlotte, respectively. These well fitted models were used to predict future changes in colour due to changes in temperature and precipitation based on median climate data from a high emission climate RCP8.5 scenario from the HadCM3 climate model (UKCP18). The model predicted an increase in monthly average colour during growing season at both sites from about 150 mg Pt L-1 to about 200 mg Pt L-1 in 2050–2079. Temperature is found to be the most important positively driver for colour development at both sites.

Modelling the effect of bromide on chlorine decay in raw and coagulated surface waters

A novel and simple semi-mechanistic model describing the effect of bromide on chlorine decay was developed. A well validated two-reactant parallel second order (2R) chlorine decay model is available for planning and operation. Four parameters - reaction rate coefficients and initial concentrations of fast and slow reacting compounds - define the model. Bromide concentration varies in water bodies but considering the variability requires conducting individual tests and parameter estimation for each bromide concentration. The proposed model was developed and tested using data obtained from six water sources from the US and Australia. The samples included a mix of raw and coagulated waters with different pH (7.5–8.0), DOC (1.43–5.54 mg-C/L), SUVA (1.73–2.90), chlorine dose (2.32–8.29 mg/L), bromide (14–844 μg/L), chlorine to bromide ratios (4.7–230.4), and temperatures (20–23 °C). when it was assumed that the initial concentrations of fast and slow reacting compounds would not be affected by the addition of bromide, a linear relationship was established between fast and slow decay rate coefficients and the initial bromide concentration in each water source. The linearity coefficient (β) ranged from 1.73 ± 7.24E-04 to 3.56 ± 1.79E-03 L/μg-Br, but a common value of 3.00E-03 ± 5.79E-04 described the effect of bromide in all four tested sources (DOC 1.43–5.54 mg/L) from the US at pH 8 units and 20 °C. This model simplifies the consideration of the effect of bromide in chlorine decay and reduces the number of tests and parameters required to simulate water supply systems that incorporate the effect of bromide.

DOC signal-based alum dose control for drinking water treatment plants

This paper describes a model, based on dissolved organic carbon (DOC) input data, developed for prediction of alum dosage for targeted removal of DOC from raw surface waters. DOC, UV absorbance at 254 nm/cm (A254), colour and turbidity data were acquired for raw and treated water samples. The results show that for 17 samples jar tested, only ~57 % ± 13 % (mean ± SD) of the DOC content was coagulable. For the range of samples studied, it was found that 85 % (±8 %) removal of coagulable DOC fraction was achieved at enhanced coagulation (EnC) based on ΔDOC/ΔAlum = −0.015 mg/mg. The 85 % value was then used as a basis to develop an alum dose prediction model for application over the wide range of water qualities of the samples studied. The model outputs were compared with EnC doses (EnD) obtained through jar testing, as well as predicted EnD values obtained through mEnCo© software, that uses input data of A254 and colour. Trials of the model predictions were conducted for five drinking water treatment plants (DWTPs) over a four-month period. The results show the potential of the model for alum dose predictions with correlation coefficients of predicted alum doses versus 1) actual alum doses and 2) estimated EnD from the mEnCo© software ranging from 0.72 to 0.98 and 0.92 to 0.99, respectively. It is suggested that the DOC model has potential to be deployed for online feedforward alum dose control.

Electrochemically activated peroxymonosulfate (PMS) pretreatment for fouling remediation during membrane distillation of surface water: Role of PMS concentration and dosing mode

Membrane distillation (MD) provides a potential method to supply large volumes of good quality potable water from surface water resources, avoiding the risk of long-term water shortages. However, the high abundance of dissolved natural organic matter (DOM) in surface water induces severe membrane fouling, which reduces productivity and increases energy consumption. Therefore, for the first time, electrochemically activated peroxymonosulfate (PMS) treatment was applied prior to the direct contact (DC)-MD process with the aim of reducing the deposition of organics and inorganics on the membrane and reducing membrane fouling. Results showed that supplying PMS continuously at a rate of 0.10 mM/min, eliminated 30.4% of dissolved organic carbon (DOC). Furthermore, fluorescence parallel factor (PARAFAC) analysis showed that >60% of two fluorescent substances were removed after 60 min of the electrochemically activated PMS pretreatment at a current density of 5 mA/cm2. Electrochemical activation of PMS generated •OH directly, facilitating the removal and degradation of DOM. In terms of the DCMD performance, almost no normalized flux decline was observed for the DCMS process after 0.01 mM/min pre-oxidation, while 44.8% flux decay occurred in the standalone DCMD treating raw surface water. Compared with continuous dosing, the use of a one-time dosing mode achieved a better outcome, as more small organic molecules generated in continuous dosing mode are not conducive to membrane fouling control. Therefore, electrochemically activated PMS could be an effective tool to mitigate membrane fouling in MD processes, although the characteristics of membrane and feed should be considered.

Per- and polyfluorinated alkyl substances (PFAS) in Pennsylvania surface waters: A statewide assessment, associated sources, and land-use relations

The objectives of this study are to identify per- and polyfluoroalkyl substances (PFAS) in Pennsylvania surface waters, corresponding associations with potential sources of PFAS contamination (PSOC) and other parameters, and compare raw surface water concentrations to human and ecological benchmarks. Surface water samples from 161 streams were collected in September 2019 and were analyzed for 33 target PFAS and water chemistry. Land use and physical attributes in upstream catchments and geospatial counts of PSOC in local catchments are summarized. The hydrologic yield of the sum of 33 PFAS (∑PFAS) for each stream was computed by normalizing each site's load by the drainage area of the upstream catchment. Utilizing conditional inference tree analysis, the percentage of development (>7.58 %) was identified as a primary driver of the ∑PFAS hydrologic yields. When percentage of development was removed from analysis, ∑PFAS yields were closely related to surface water chemistry associated with landscape alteration (e.g., development or agricultural cropland), such as concentrations of total nitrogen, chloride, and ammonia, but also to count of water pollution control facilities (agricultural, industrial, stormwater, and/or municipal waste pollution abatement facilities). In oil and gas development regions, ∑PFAS yields were associated with combined sewage outfalls. Sites surrounded by ≥2 electronic manufacturing facilities had elevated ∑PFAS yields (median = 241 ng/s/km2). Study results are critical to guide future research, regulatory policy, best practices that will mitigate PFAS contamination, and the communication of human health and ecological risks associated with PFAS exposure from surface waters.

Using Hyperspectral Remote Sensing to Monitor Water Quality in Drinking Water Reservoirs

At the Blankaart Water Production Center, a reservoir containing 3 million m3 of raw surface water acts as a first biologic treatment step before further processing to drinking water. Over the past decade, severe algal blooms have occurred in the reservoir, hampering the water production. Therefore, strategies (e.g., the injection of algaecide) have been looked at to prevent these from happening or try to control them. In this context, the HYperspectral Pointable System for Terrestrial and Aquatic Radiometry (HYPSTAR), installed since early 2021, helps in monitoring the effectiveness of these strategies. Indeed, the HYPSTAR provides, at a very high temporal resolution, bio-optical parameters related to the water quality, i.e., Chlorophyll-a (Chla) concentrations and suspended particulate matter (SPM). The present paper shows how the raw in situ hyperspectral data (a total of 8116 spectra recorded between 2021-02-03 and 2022-08-03, of which 2988 spectra passed the quality check) are processed to find the water-leaving reflectance and how SPM and Chla are derived from it. Based on a limited number of validation data, we also discuss the potential of retrieving phycocyanin (an accessory pigment unique to freshwater cyanobacteria). The results show the benefits of the high temporal resolution of the HYPSTAR to provide near real-time water quality indicators. The study confirms that, in conjunction with a few water sampling data used for validation, the HYPSTAR can be used as a quick and cost-effective method to detect and monitor phytoplankton blooms.

Energy, exergy and economic analyses of tubular solar still with various transparent cover materials

In order to use solar energy to convert raw ground and surface water into clean potable water, several distillation systems have been investigated so far. However, to be sustainable, the productivity of these systems must be as high as possible. Tubular solar stills (TSS) were investigated as one of the more productive solar distillation systems. The current study aims to improve the productivity of tubular solar stills by exploring different cover materials. The experimental study was carried out on four different TSS setups with cover materials made of polyvinyl chloride (PVC), polycarbonate, acrylic, and glass. In comparison to other materials, it has been observed that the TSS with glass cover gives the maximum productivity (6.23 L/m2) and daily exergy and energy efficiency (7.67%, 71.56%, respectively) for the same water depth of 0.5 cm in each basin. According to the economic analysis of all the arrangements carried out, the TSS with Acrylic cover provides the lowest cost of producing freshwater among all of the investigated combinations.

Spiral tube flocculation for drinking water treatment plants

Almost all water treatment plants for either surface raw water or water from reservoirs needs to have some kind of a system to eliminate time required for particles to settle down in the settling tanks (This occurs by increase turbidity particle size). A coagulant to be added and a flocculation’s system to inshore a good and homogenous distribution of chemicals to form up the correct size of particles to settled within the settling tanks. In water treatment plants many types of clary- flocculates are used either the mechanicals paddle or hydraulic jumps of steam water or using the spiral tubes (As on this study). In addition, a Jar Test should be used to assess the suitability of flocculation treatment for a given raw water. Unfortunately, even Jar Test suffers from a number of disadvantages. a number of study for Spiral Flocculate, has been shown I claimed to be a better method for continuous assessment of flocculation. Within multimedia sands and a spiral flocculate’s. Constant flow (generated from a tank with spill way to ensure a constant head all through the test cycles, results are recorded, and a number of remarks and suggestions are produced. This study will make use of a number of laboratory tests on a small model of treatment plants made for this purpose consist mainly of a gravity filter compares the performance of Spiral Flocculate The experiments conducted reveal that the Spiral Flocculate has a better effective energy. Even that this method need more future study and theoretical equations for the developing of chain flocs are needed. However, the size of flocs in Spiral Flocculate seems to be overestimated relative to the real flocculate and coagulations. Purpose: A continuous need for improving water treatment techniques allows for new technologies for obtaining adequate water, both in terms of quality and quantity. In order to obtain an efficient, rapid and low-cost clarification system, this study proposes the use of spired coiled tubes as a coagulation-flocculation reactor to evaluate the proposed clarification system, a number of experimental test where generated and a pumped kaolin with controlled quantities are pumped to city water and used in this study. Water with controlled head is used all the time and records are generated for the evaluation.

Bacterial composition in Swedish raw drinking water reveals three major interacting ubiquitous metacommunities.

BackgroundSurface raw water used as a source for drinking water production is a critical resource, sensitive to contamination. We conducted a study on Swedish raw water sources, aiming to identify mutually co‐occurring metacommunities of bacteria, and environmental factors driving such patterns.MethodsThe water sources were different regarding nutrient composition, water quality, and climate characteristics, and displayed various degrees of anthropogenic impact. Water inlet samples were collected at six drinking water treatment plants over 3 years, totaling 230 samples. The bacterial communities of DNA sequenced samples (n = 175), obtained by 16S metabarcoding, were analyzed using a joint model for taxa abundance.ResultsTwo major groups of well‐defined metacommunities of microorganisms were identified, in addition to a third, less distinct, and taxonomically more diverse group. These three metacommunities showed various associations to the measured environmental data. Predictions for the well‐defined metacommunities revealed differing sets of favored metabolic pathways and life strategies. In one community, taxa with methanogenic metabolism were common, while a second community was dominated by taxa with carbohydrate and lipid‐focused metabolism.ConclusionThe identification of ubiquitous persistent co‐occurring bacterial metacommunities in freshwater habitats could potentially facilitate microbial source tracking analysis of contamination issues in freshwater sources.