scholarly journals Interplay of factors involving chlorine dose, turbidity flow capacity and pH on microbial quality of drinking water in small water treatment plants

Water SA ◽  
2018 ◽  
Vol 34 (5) ◽  
pp. 565 ◽  
Author(s):  
C.L. Obi ◽  
J.O. Igumbor ◽  
M.N.B. Momba ◽  
A Samie
2018 ◽  
Vol 2 (2) ◽  
pp. 39-48
Author(s):  
Hayder Mohammed Issa ◽  
Reem Ahmed Alrwai

Safe source of drinking water is always considered as an essential factor in water supply for cities and urban areas. As a part of this issue, drinking water quality is monitored via a useful scheme: developing drinking water quality index DWQI. DWQI is preferably used as it summarizes the whole physicochemical and bacteriological properties of a drinking water sample into a single and simple term. In this study, an evaluation was made for three drinking water treatment plants DWTPs named: Efraz 1, Efraz 2 and Efraz 3 that supply drinking water to Erbil City. The assessment was made by testing thirteen physicochemical and two bacteriological parameters during a long period of (2003 – 2017). It has been found that turbidity, electrical conductivity EC, total alkalinity, total hardness, total coliform and fecal coliform have more influence on drinking water quality. DWQI results showed that the quality of drinking water supplied by the three DWTPs in Erbil City fallen within good level. Except various occasional periods where the quality was varying from good to fair. The quality of the drinking water supply never reached the level of marginal or poor over the time investigated. The applied hierarchical clustering analysis HCA classifies the drinking water dataset into three major clusters, reflecting diverse sources of the physicochemical and bacteriological parameter: natural, agriculture and urban discharges.


2009 ◽  
Vol 7 (4) ◽  
pp. 544-556 ◽  
Author(s):  
Lionel Ho ◽  
Paul Tanis-Plant ◽  
Nawal Kayal ◽  
Najwa Slyman ◽  
Gayle Newcombe

The cyanobacterium Anabaena circinalis has the ability to co-produce geosmin and saxitoxins, compounds which can compromise the quality of drinking water. This study provides pertinent information in optimising water treatment practices for the removal of geosmin and saxitoxins. In particular, it demonstrates that pre-oxidation using potassium permanganate could be applied at the head of water treatment plants without releasing intracellular geosmin and saxitoxins from A. circinalis. Furthermore, powdered activated carbon (PAC) was shown to be an effective treatment barrier for the removal of extracellular (dissolved) geosmin and saxitoxins, with similar adsorption trends of both compounds. The relative removal of the saxitoxins compared with geosmin was determined to be 0.84±0.27, which implies that saxitoxin removal with PAC can be estimated to be approximately 60 to 100% of the removal of geosmin under equivalent conditions. Chlorine was shown to be effective for the oxidation of the saxitoxins with CT values of approximately 30 mg min l−1 required for greater than 90% destruction of the saxitoxins.


2020 ◽  
Vol 99 (7) ◽  
pp. 725-732
Author(s):  
Gayane H. Babayan ◽  
Astghik G. Sakoyan

Introduction. Drinking water intended for South Armenia’s towns and rural communities is abstracted from minor mountain rivers belonging to the basins of the Voghchi and Meghri, the water of which is treated at five water treatment plants. The river basins are home to the major copper molybdenum and gold ore mining centers of the republic.The purpose of this research was to study heavy metals Ag, Al, As, Cd, Cu, Fe, Mo, Ni, Pb, Sn, Sb, Se, Zn, Hg, Te in centralized drinking water supply systems and assess drinking water-caused health risks to the population.Material and methods. In 2016-2017 from 43 sampling sites a total of 53 basic water samples were taken, including 14- from surface water supply sources, 16 - from water treatment plants, 33- from water supply networks. Heavy metals were determined by the atomic absorption method. To assess the quality of water on water abstraction sites relevant ecological (regional) norms and national and international standards were used. The risk of development of noncarcinogenic and carcinogenic effects was assessed in the case of oral intake of and dermal exposure to tap water.Results. On water abstraction sites, background regional levels of surface waters exceeded the concentration of aluminum, iron, molybdenum, tin, antimony (by as 13.3-1.1 times). Water treatment efficiency at water treatment plants is estimated at 12% - 69% depending on different metals. Concentrations of heavy metals in drinking water do not exceed the norms. The risk of development of noncarcinogenic effects in the population at chronic exposure to drinking water is insignificant (HI<1), whereas a total carcinogenic risk exceeds a safety limit for arsenic (CR=9.59×10–5).Conclusion. The acceptable quality of drinking water supplied to consumers is not yet an index of sustainable and safe water supply in the studied region because of a water pollution level on intake sites, obsolete water treatment technologies, poor sanitation and technical condition of plants and water networks.


2017 ◽  
Vol 5 (1) ◽  
pp. 57-64 ◽  
Author(s):  
Heshmatollah Nourmoradi ◽  
Neda Karami ◽  
Soraya Karami ◽  
Sajad Mazloomi ◽  
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1986 ◽  
Vol 21 (3) ◽  
pp. 447-459 ◽  
Author(s):  
K.J. Roberts ◽  
R.B. Hunsinger ◽  
A.H. Vajdic

Abstract The Drinking Water Surveillance Program (DWSP), developed by the Ontario Ministry of the Environment, is an assessment project based on standardized analytical and sampling protocol. This program was recently instituted in response to a series of contaminant occurrences in the St. Clair-Detroit River area of Southwestern Ontario. This paper outlines the details and goals of the program and provides information concerning micro-contaminants in drinking water at seven drinking water treatment plants in Southwestern Ontario.


1995 ◽  
Vol 31 (5-6) ◽  
pp. 75-79 ◽  
Author(s):  
M. Würzer ◽  
A. Wiedenmann ◽  
K. Botzenhart

In Germany the application of procedures such as flocculation and filtration in the preparation of drinking water results in the annual production of an estimated 500,000 t of sediments and sludges. Some of these residues have a potential for being reused, for example in agriculture, forestry, brickworks or waste water treatment. To assess the microbiological quality of residues from waterworks methods for the detection of enterobacteria, Escherichia coli, Salmonella, Pseudomonas aeruginosa, Legionella, poliovirus, Ascaris suis eggs and Cryptosporidium have been evaluated regarding their detection limits and were applied to various residues from German waterworks. Results show that sediments and sludges may contain pathogenic bacteria, viruses and protista. When residues from waterworks are intended to be reused in agriculture or forestry the microbiological quality should therefore be considered.


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