The role of algae in causing coliform problems within the distribution system

2002 ◽  
Vol 2 (4) ◽  
pp. 105-110
Author(s):  
R. Lake ◽  
S. Driver
Keyword(s):  
Drinking Water ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Distribution System ◽  
Algal Bloom ◽  
Strong Link ◽  
Chlorine Residual ◽  
Pass Through ◽  
High Level

Coliforms are used as indicators of faecal pollution in water. Therefore, the presence of coliforms in drinking water causes concern as it indicates the potential presence of other bacteria. Coliforms have been seen in water within the Vivendi Water UK area during the summer months and their presence has previously been explained by localised pipe renovation. In this study, the influence that the algal bloom has on the presence of coliforms has been assessed. It has been shown that there is a strong link between the end of the algal bloom and coliforms being found in the distribution system. The algal bloom does not allow coliforms to pass through the treatment works. However, the high level of total organic carbon (TOC) in the treated water, made up of algal breakdown products, provides a good nutritional source for regrowth in the distribution system. Where there are high TOC levels, coliforms can grow even with high chlorine concentrations. However, where there is little TOC, then even a very low chlorine residual is adequate to prevent coliform growth.

Approaches to Regulating Organic Carbon and the Necessity of Its Obligatory Monitoring in Drinking Water

2020 ◽  
pp. 61-66
Author(s):  
IA Khlystov ◽  
DA Schukina ◽  
EA Kuzmina ◽  
EG Plotko ◽  
LА Brusnicyna
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Surface Waters ◽  
Distribution System ◽  
Design Stage ◽  
Treatment Technique ◽  
Important Indicator ◽  
By Products

Background: Current accumulation of organogenic elements in surface waters is mainly attributed to intensive anthropogenic activities. Waterborne organic matter may endanger human health when using surface waters for drinking and recreational purposes. Applied techniques of water treatment fail to ensure complete water purification and part of organic substances (their low molecular weight fraction) still remains. Chlorination of drinking water can generate a variety of halogenated by-products having adverse health effects in humans including carcinogenic ones. Our objective was to substantiate the reference value for total organic carbon (TOC) in water disinfected by chlorine. Materials and methods: We analyzed the results of laboratory testing of surface and treated water samples taken in Yekaterinburg in 2013–2014 and 2017, carried out health risk assessment, and built predicative models of by-products formation. Results: We established that, following chlorination, TOC concentrations became 1.5 times lower while chloroform and total trihalomethane concentrations became 24.5–80.2 and 22.9–54.5 times higher than initial values, respectively. The most significant non-carcinogenic risks were estimated for children aged 0-6 years from exposures to chloroform (HQ = 1.150). Individual carcinogenic risks from exposures to bromoform and dibromochloromethane as measured in water before its supplying to the distribution system, referred to the first value range (less than 1×10–6) while risks from bromodichloromethane and chloroform exposures fell in the second range (from 1×10–6 to 1×10–4). The mathematical model of the correlation between predictors (temperature, reaction time, pH, and certain chemical compounds) and levels of by-products was built. Conclusions: Our model makes it possible to predict generation of organochlorine compounds at the design stage of water treatment technique. Total organic carbon is an important indicator that should be monitored at the stages of water treatment to ensure safety of drinking water and efficiency of its disinfection.

Characterization of NOM in a drinking water treatment process train with no disinfectant residual

2009 ◽  
Vol 9 (4) ◽  
pp. 379-386 ◽  
Author(s):  
S. A. Baghoth ◽  
M. Dignum ◽  
A. Grefte ◽  
J. Kroesbergen ◽  
G. L. Amy
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Organic Carbon ◽  
Distribution System ◽  
Chemical Properties ◽  
Drinking Water Treatment ◽  
Building Blocks ◽  
Fluorescence Excitation ◽  
Water Treatment Process ◽  
Water Treatment Plants

For drinking water treatment plants that do not use disinfectant residual in the distribution system, it is important to limit availability of easily biodegradable natural organic matter (NOM) fractions which could enhance bacterial regrowth in the distribution system. This can be achieved by optimising the removal of those fractions of interest during treatment; however, this requires a better understanding of the physical and chemical properties of these NOM components. Fluorescence excitation-emission matrix (EEM) and liquid chromatography with online organic carbon detection (LC-OCD) were used to characterize NOM in water samples from one of the two water treatment plants serving Amsterdam, The Netherlands. No disinfectant residual is applied in the distribution system. Fluorescence EEM and LC-OCD were used to track NOM fractions. Whereas fluorescence EEM shows the reduction of humic-like as well as protein-like fluorescence signatures, LC-OCD was able to quantify the changes in dissolved organic carbon (DOC) concentrations of five NOM fractions: humic substances, building blocks (hydrolysates of humics), biopolymers, low molecular weight acids and neutrals.

scholarly journals Concentration of Total Organic Carbon and Its Fractions in Surface Water in Poland and Germany

Proceedings ◽  
2020 ◽  
Vol 51 (1) ◽  
pp. 35
Author(s):  
Patrycja Sobczak ◽  
Agata Rosińska
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Total Organic Carbon ◽  
Rhine River ◽  
Bacteriological Quality ◽  
Quality Of Water ◽  
Biodegradable Dissolved Organic Carbon

Total organic carbon (TOC) present in surface water consists of different fractions like dissolved organic carbon (DOC) or biodegradable dissolved organic carbon (BDOC). BDOC may have an impact on the bacteriological quality of water as it can be a source of carbon and energy for microorganisms. It is important to consider this parameter in case of the distribution of drinking water. The aim of this research was to compare the qualities of chosen surface water in Poland and Germany in terms of concentration of total organic carbon and its fractions. The samples were taken from the reservoir in Poland and Rhine River in Germany. The first one is a source of drinking water for humans. The research showed that, considering the analyzed compounds, the water from the river has better quality.

Establishing minimum free chlorine residual concentration for microbial control in a municipal drinking water distribution system

2014 ◽  
Vol 9 (4) ◽  
pp. 491-501 ◽  
Author(s):  
Jennie L. Rand ◽  
Graham A. Gagnon ◽  
Alisha Knowles
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Heterotrophic Bacteria ◽  
Full Scale ◽  
Free Chlorine ◽  
Source Analysis ◽  
Plate Count ◽  
Similar Data ◽  
Residual Concentration ◽  
Chlorine Residual

Distribution system data from a Nova Scotia municipal drinking water supply was collected over four years, including free chlorine residual concentration, heterotrophic plate count (HPC) bacteria, and temperature. These data were analyzed for occurrences of HPC bacteria greater than 500 colony forming units (CFU)/mL. The municipality was interested in determining if secondary chlorination practices were sufficient in maintaining microbial health in their distribution system. Coliform data were non-detect (total coliforms and Escherichia coli) in the distribution system over this period and thus heterotrophic bacteria were used to assess microbial health. Results were compared to similar data collected from pilot-scale studies that had been carried out using the same municipal water as the source. Analysis showed that a similar trend was observed between pilot- and full-scale samples. Full-scale data analysis revealed that the minimum disinfection requirement of 0.2 mg/L did not consistently control occurrences of heterotrophic bacteria from being greater than 500 CFU/mL. By comparison, maintaining a concentration of 0.3 mg/L or above, particularly in warm-weather systems, maintained the number of heterotrophic bacteria at below 500 CFU/mL. Fortunately the majority of samples collected in the full-scale distribution system (>89%) had a free chlorine residual concentration of greater than 0.30 mg/L. While it is recognized that this system had 100% compliance for E. coli, the goal of this work will help utilities understand how to utilize microbial data to inform operational disinfection targets for their distribution system.

Economic analysis of drinking water services, case of the city of Souk-Ahras (Algeria)

2019 ◽  
Vol 15 (1) ◽  
pp. 10-18
Author(s):  
S. Boukhari ◽  
F. S. Pinto ◽  
H. Abida ◽  
Y. Djebbar ◽  
C. de Miras
Keyword(s):  
Drinking Water ◽  
Quality Of Service ◽  
Service Provision ◽  
Economic Instruments ◽  
Sanitation Services ◽  
Tariff Structure ◽  
High Level ◽  
The City

Abstract Water Supply and Sanitation Services (WSSS) face various constraints that hinder their development. The application of sustainable economic instruments may help WSSS policymakers improving the quality of service provision for their clients. This study shows the role of these economic instruments in WSSS management for the case of the city of Souk-Ahras (Algeria). A detailed analysis of expenditures and revenues, focusing on the tariff structure and subsidies, has been carried out. The results obtained show that WSSS in Souk-Ahras suffer from a relevant budget imbalance influenced by the high level of non-revenue water and the application of pricing that does not achieve cost recovery.

ORGANOCHLORINE PESTICIDES IN THE COASTAL SEDIMENT OF CITARUM ESTUARY, JAKARTA BAY: THE IMP ORTANT ROLE OF FINE FRACTION OF THE SEDIMENT AS THEIR AGENT TRANSPORT AND PROCESSES OF THEIR EARLY DIAGENESIS

2009 ◽  
Vol 1 (2) ◽  
Author(s):  
T. Pratono ◽  
H. Razak ◽  
I. Gunawan
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Fine Fraction ◽  
Aerobic Condition ◽  
Early Diagenesis ◽  
Chemical Processes ◽  
Coastal Sediment ◽  
Sediment Samples ◽  
Transport Agent

DDT (1,1,1-Tricholor-2,2-bis(chlorophenil)ethane) and its two derivatives, DDD (1,1-Dicholor-2,2-bis(chlorophenil)ethane) and DDE (1,1-Tricholor-2,2-bis(chlorophenil)-ethylene) were identified in the coastal sediment of Citarum Estuary, Jakarta Bay.Eight stations of the sediment sampling were designed in order to obtain the changing of their concentration sadjacent to the estuary as possible input. Sediment samples were collected in the surface layer within a less than 5 cm depth. In addition to pesticides, texture of sediment and total organic carbon were analyzed. Generally, fine fractions (silt and clay) were predominant grain-size of the sediment ranging 21–35,8 % and 17,6–65,6 %, respectively, while total organic carbon (TOC) ranged from 0,30–1,49 %. Concentrations of p’,p’-DDT varied from 0,621–1,187ppb, concentrations of p’,p’-DDD ranged from 0,176–2,153 ppb and concentrations of p’,p’-DDE were from 0.181–2,254 ppb. The occurrence of total DDT (ΣDDT+DDD+DDE) tended to correlated positively to the fine fraction indicating as transport agent. DDD and DDE as DDT metabolites were formed by biological and chemical processes within predominantly aerobic condition. Keywords: pesticide, DDT, DDD, DDE, sediment, transport agent, Citarum, Jakarta Bay  

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