Reducing free residual chlorine using four simple physical methods in drinking water: effect of different parameters, monitoring microbial regrowth of culturable heterotrophic bacteria, and kinetic and thermodynamic studies

Geosmin and 2-methylisoborneol (MIB) are two of the causative compounds responsible for the musty odor problem in drinking water. Geosmin and MIB in raw water were present both in solution and in a suspended form mostly associated with the host cyanobacteria. Geosmin and MIB in suspended form were well removed by coagulation and sedimentation alone. Geosmin present in solution could be removed almost to an undetectable level in the rapid sand filter of the pilot plant where no pre-chlorination was practiced. Breakpoint pre-chlorination, however, forced geosmin and MIB present inside of the host algae to leak into the water. The concentration of MIB decreased in a sedimentation basin during the daytime, but not at night in the plant practicing breakpoint pre-chlorination. Geosmin and MIB were both decomposed under sunlight in the presence of free residual chlorine.

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Study of the free residual chlorine concentration in drinking water in Benin: case of Cotonou municipality

International Journal of Biological and Chemical Sciences ◽

10.4314/ijbcs.v14i9.32 ◽

2021 ◽

Vol 14 (9) ◽

pp. 3372-3390

Author(s):

Sydney M.S. Coffi ◽

Nicaise Yalo ◽

Bernard Ahamide ◽

Daouda Mama

Keyword(s):

Drinking Water ◽

Water Samples ◽

Water Distribution ◽

Water Distribution Network ◽

Chlorine Concentration ◽

Assay Method ◽

Residual Chlorine ◽

Critical Thresholds ◽

Drinking Water Distribution ◽

Free Residual Chlorine

The drinking water is very qualitatively monitored. Despite this monitoring, there is a deterioration in the Free Residual Chlorine Concentration (CCRL) along the drinking water distribution network of the commune of Cotonou. The objective of studying areas of consumer vulnerability where the CCRL reaches critical thresholds (<0.1 mg / l). To achieve this, water samples were taken from various locations in the supply network every day, from 04/30/2018. The assay method used is called N-Diethyl-P-phenylene Diamine (DPD) with the use of a DR / 890 colorimeter. This work reveal that the CCRL undergoes degradation during its delivery to the consumer's taps with average concentrations mainly above the standard in force [0.1; 0.8 mg / l] at the 5% threshold. The work made it possible to establish a linear model for predicting CCRL concentration as a function of distance and to identify areas of vulnerability in the study area. L’eau de consommation est très surveillée sur le plan qualitatif. En dépit de cette surveillance, on constate une dégradation de la Concentration en Chlore Résiduel Libre (CCRL) le long du réseau de distribution d’eau potable de la commune de Cotonou. L’objectif d’étudier les zones de vulnérabilité du consommateur où la CCRL atteint des seuils critiques (< à 0,1 mg /l). Pour y parvenir, des prélèvements d’échantillons d’eau ont été pris à divers endroits du réseau d’approvisionnement chaque jour, du 1er au 30/04/2018. La méthode de dosage utilisée est dénommée N-Diéthyl-P-phénylèneDiamine (DPD) avec usage d'un colorimètre DR/890. Ce travail à révéler, que la CCRL subi une dégradation lors de son acheminement vers les robinets du consommateur avec des concentrations moyennes majoritairement supérieures à la norme en vigueur [0,1 ; 0,8 mg/l] au seuil de 5%. Le travail a permis d’établir un modèle linéaire de prédiction de la concentration en CCRL en fonction de la distance et d’identifier les zones de vulnérabilité de la zone d’étude.

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Physical-chemical and microbiological quality of water used for public supply in the municipality of Alvorada D’Oeste, Rondônia, Brazil

Research Society and Development ◽

10.33448/rsd-v10i11.19357 ◽

2021 ◽

Vol 10 (11) ◽

pp. e198101119357

Author(s):

Thander Jacson Nunes Calente ◽

Grazieli Nunes Calente Santos ◽

Wesclen Vilar Nogueira

Keyword(s):

Reference Values ◽

Heterotrophic Bacteria ◽

Microbiological Quality ◽

Residual Chlorine ◽

Human Consumption ◽

Physical Chemical ◽

Quality Of Water ◽

Microbiological Parameters ◽

Thermotolerant Coliforms ◽

Free Residual Chlorine

The study analyzed the physical-chemical and microbiological parameters carried out by the Autonomous Water and Sewage Service (AWSS) of the Municipality of Alvorada D’Oeste, Rondônia, Brazil. The parameters analyzed were: pH, turbidity, free residual chlorine, total coliforms (TC), thermotolerant coliforms (TTC) and heterotrophic bacteria. The values of hydrogen potential (pH) were obtained with a digital pH meter. The analyzes were carried out the 2013 to 2019. The turbidity and free residual chlorine values were obtained according to the method of the Practical Manual of Water Analysis of the National Health Foundation (FUNASA). To determine the microbiological parameters, PetrifilmTM plates (3MTM do Brasil Ltda) were used, following the manufacturer's guidelines. The analyzed values were compared with reference values described in Consolidation Ordinance nº. 5, of September 28, 2017, of the Ministry of Health (MS) which sets the standards for potability of water intended for human consumption. The results varied for all parameters evaluated: pH (3.11 to 8.24), turbidez (0.02 to 3,01), TC (0 to 100%), TTC (0 to 100%) and heterotrophic bacteria (85 to 100%). The values obtained for free residual chlorine were the only parameter to follow the reference values. The highest contamination for TC and heterotrophic bacteria were reported in 2019, higher the limits established in Brazilian legislation. Thus, the water was characterized as unfit for consumption and requires severe control for TC and heterotrophic bacteria.

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Evaluation of water quality and sanitation of reservoirs used in field activities of a military unit in the state of Rio de Janeiro

Ambiente e Agua - An Interdisciplinary Journal of Applied Science ◽

10.4136/ambi-agua.2573 ◽

2020 ◽

Vol 15 (4) ◽

pp. 1

Author(s):

Adriana Mendonça Gallotti ◽

Hélio Fernandes Machado Júnior ◽

Arlene Gaspar

Keyword(s):

Water Quality ◽

Rio De Janeiro ◽

Heterotrophic Bacteria ◽

Armed Forces ◽

The State ◽

Coliform Bacteria ◽

Residual Chlorine ◽

Training Activities ◽

Free Residual Chlorine ◽

Microbiological Analyses

In the Armed Forces' campaign activities, large troops may be exposed to serious health risks even before war itself. In 2010, for example, the Brazilian Army sent nearly 2,000 men to join the United Nations peacekeeping mission in Haiti, which was experiencing a cholera epidemic. This work therefore investigated the water quality and sanitation of the various types of reservoirs used in four field-training activities of a Brazilian Army Unit located in the state of Rio de Janeiro. Physicochemical and microbiological analyses of the water were carried out, and visual inspections and swab samples were collected from the inner surface of these reservoirs for counting coliform bacteria and counting mesophilic aerobic microorganisms. Physicochemical and microbiological analyses of water from different types of reservoirs revealed a lack of conformity with American Public Health Association and Ordinance Number 518, of 03/25/04, of the Brazilian Ministry of Health . It was observed that 50% of the collective and individual reservoirs did not have the desirable minimum levels of Free Residual Chlorine. In addition, in 35.7% of the total collective and individual reservoirs evaluated there was growth of coliform group bacteria and in 28.57% of them the number of heterotrophic bacteria exceeded the maximum recommendation. According to the swabs performed on the inner surfaces, results of the total viable mesophilic aerobic counts were above the recommended levels in 78.57% of the total evaluated reservoirs. Besides that, in the Lyster bags of activities 1 and 2, there was growth of coliforms, or 14.28% of the total evaluated reservoirs. It was concluded that there were failures in the management of multiple barriers during storage and / or distribution, as well as in the maintenance of disinfection to prevent or eliminate microbial contamination, indicating the need for corrective measures.

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Analysis of Free Residual Chlorine in Drinking Water Distribution Systems in Ore Processing Industry

Polish Journal of Environmental Studies ◽

10.15244/pjoes/120154 ◽

2020 ◽

Vol 29 (6) ◽

pp. 4321-4330

Author(s):

Arif Susanto ◽

Uli Amrina ◽

Purwanto Purwanto ◽

Edi Putro ◽

Wiliam Yochu ◽

...

Keyword(s):

Drinking Water ◽

Distribution Systems ◽

Water Distribution ◽

Water Distribution Systems ◽

Residual Chlorine ◽

Processing Industry ◽

Drinking Water Distribution Systems ◽

Ore Processing ◽

Drinking Water Distribution ◽

Free Residual Chlorine

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Determinants of microbiological quality of drinking water in refugee camps and host communities in Gambella Region, Ethiopia

Journal of Water Sanitation and Hygiene for Development ◽

10.2166/washdev.2019.148 ◽

2019 ◽

Vol 9 (4) ◽

pp. 671-682

Author(s):

Getachew Kabew Mekonnen ◽

Bezatu Mengistie ◽

Geremew Sahilu ◽

Worku Mulat ◽

Helmut Kloos

Keyword(s):

Drinking Water ◽

Community Education ◽

Microbiological Quality ◽

Residual Chlorine ◽

P Value ◽

Refugee Camps ◽

Cross Sectional ◽

Study Objective ◽

Free Residual Chlorine

Abstract Inadequate improved water supply and sanitation, particularly in refugee camps contribute to the spread of infectious diseases. The study objective was to assess determinants of microbiological quality of drinking water in refugee camps and host communities in Gambella Region, Ethiopia. A cross-sectional study was conducted from September to December 2016 based on structured questionnaire-based interviews and testing household water using the portable Potatest+ water quality testing kit. Data were analyzed and P values <0.05 with 95% confidence interval (CI) were considered statistically significant. Results showed there were significant differences in fecal coliform count (P value = 0.009) and free residual chlorine concentration (P value = 0.01) between the source and stored water samples. Surface water source, water shortages in the previous month, and unavailability of free residual chlorine and caregivers without formal education were the main determinants of microbiological quality of stored water. Stored water was contaminated in many households in both the refugee and host communities. Designing and implementing appropriate community education and effective hygiene promotion programs are essential in improving community knowledge of water contamination and reducing diarrhea prevalence among under-five children in refugee camps and host communities in Gambella Region.

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Enhancement of the free residual chlorine concentration at the ends of the water supply network: Case study of Souk Ahras city – Algeria

Journal of Water and Land Development ◽

10.2478/jwld-2018-0036 ◽

2018 ◽

Vol 38 (1) ◽

pp. 3-9 ◽

Cited By ~ 3

Author(s):

Mohamed A. Bensoltane ◽

Lotfi Zeghadnia ◽

Lakhdar Djemili ◽

Abdalhak Gheid ◽

Yassine Djebbar

Keyword(s):

Drinking Water ◽

Water Supply ◽

Distribution Systems ◽

Drinking Water Treatment ◽

Field Measurements ◽

Residual Chlorine ◽

Water Utility ◽

The Public ◽

Point Of Use ◽

Free Residual Chlorine

AbstractThe drinking-water supply sector has mostly targeted the water-borne transmission of pathogens. The most common method employed is the chlorination of drinking-water at treatment plants and in the distribution systems. In Algeria, the use of chlorine in drinking water treatment is a widespread practice. To enhance the concentration of the residual chlorine in the public water-supply system of a part of Souk Ahras city (Faubourg) (Algeria) known by its low concentration of the free residual chlorine (according to the water utility – Algérienne des Eaux: ADE investigation) especially at the point of use, practical steps were carried out. The method is a combination between numerical simulation using EPANET2 software and field measurements. Using statistical analysis the hydraulic model was calibrated and the observed values were very closer to the simulated results. The concentration was improved throughout the network after the injection of the appropriate dose.

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