scholarly journals Investigation of the influence of chlorine-containing disinfectant type on the quality of drinking water and the effectiveness of water treatment technology

Author(s):  
Tamara Krasnova ◽  
Yuri Skolubovich ◽  
Elena Gogina ◽  
Dmitry Volkov

Introduction. Effectiveness and applicability of chlorine-containing disinfectants used in the practice of water treatment were studied for the purpose of solving urgent environmental problems associated with the formation of secondary pollutants generated during the chlorination of natural water. Such contaminations are mostly represented by organohalogen compounds producing strong negative effect on the physiological state of living organisms, including human beings. To solve this problem, it is proposed to use technical grade sodium hypochlorite instead of traditional liquid chlorine when selecting disinfectants for natural water. Technical grade sodium hypochlorite is obtained by saturating solutions of diaphragmatic sodium hydroxide with chlorine gas at the stage of liquefaction of chlorine and caustic soda production. Sodium hypochlorite solution is significantly less toxic, non-flammable and not explosive. Materials and methods. A comparative study was conducted as to changes in the content of organohalogen compounds and heavy metals in water treated with sodium hypochlorite and liquid chlorine of one year duration. Analyses of water samples of water treated with liquid chlorine and sodium hypochlorite were made to measure concentrations of heavy metals, organohalogen compounds and other drinking water quality indicators, as specified by current regulations. Results. The obtained data demonstrate that the use of sodium hypochlorite for disinfection provides a higher quality of drinking water, therefore, it is advisable to replace liquid chlorine with technical grade sodium hypochlorite in the process of water treatment as potable water. Conclusions. The results of the study formed the basis for numerous industrial tests and subsequent implementation in existing water treatment plants in many large cities of Russia.

Author(s):  
Rifahat Muntaha

Abstract: Disinfection of treated water is a necessary process. For this, chlorine and its products are widely used. During the treatment process, chlorine is added to drinking water as elemental chlorine, sodium hypochlorite solution or dry calcium hypochlorite. When applied to water, each of these forms “free chlorine”, which destroys pathogenic organisms. If adequate water treatment is not readily available, the impact on public health can be devastating. Worldwide, about 1.2 billion people lack access to safe drinking water, and about 2.4 billion people lack sanitation. As per WHO, 3.4 million people die from waterrelated diseases. Drinking water chlorination will remain a cornerstone of disinfection. This is because of the wide range of benefits provided by chlorine. However, alternative disinfectants including ozone and UV radiation are available, all disinfection methods have unique benefits, limitations and costs. So, an engineer has to consider all the pros and cons of a disinfectant method properly before deciding the one to adopt. Keywords: Disinfection, Gaseous Chlorination, Sodium Hypochlorite, Calcium Hypochlorite, Ultraviolet, Ozone, Chlorine dioxide


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.


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.


Author(s):  
L. R. Junussova ◽  
S. K. Abildinova ◽  
M. B. Aliyarova ◽  
S. V. Chicherin ◽  
T. Ja. Junussov

The subject matter of the paper is related to scientific-and-theoretical basis of power engineering characteristics of heat pump directly depending on the quality of treated water for reliable and uninterrupted operation of heat pump evaporator and compressor. On the basis of experimental data, energy parameters of the heat pump are calculated. The method of the combined technology of the heat pump “water – air” operation is considеred, the efficiency of which is based on the preliminary improvement of the quality of water softened with the use of a membrane ultrafiltration unit. This solution made it possible to reduce the load on the filters and to exclude the use of chemical reagents used in the classical schemes of water heating facilities. In order to improve the operation of the heat pump compressor, a method based on altering the speed of rotation of the shaft by means of electronic microprocessor devices has been proposed. To regulate the compressor performance, a frequency converter with a wide range of alternating current frequency is used. The intervals of alteration of frequency of the alternating current corresponding to energy-efficient values of coefficient of transformation of energy of the heat pump are investigated. The values of the energy conversion coefficient of the heat pump obtained in the course of experiments and determined by calculation are consistent within the experimental errors with the regulation of the compressor performance. The suggested experimental device made it possible to determine the dependence of the main characteristics of the unit of the heat pump unit on the number of revolutions of the compressor and to find out an effective range of its control (50–180 %). The development of advanced technologies for natural water treatment under conditions of increased anthropogenic loads on natural water sources is a priority one among the fundamental and applied research in the field of water treatment.


2019 ◽  
Vol 96 (11) ◽  
pp. 1038-1044 ◽  
Author(s):  
N. V. Zaitseva ◽  
Irina V. May ◽  
S. V. Klein ◽  
S. S. Khankharev ◽  
A. A. Boloshinova

There are described an algorithm and methods for collecting the evidential base for causing hazard to the health of the population of Zakamensk (the Republic of Buryatia) in the zone of influence of the waste of the past activities of the Dzhidinsky tungsten-molybdenum combine. The source of danger is lying sands, containing a complex of toxic heavy metals - lead, cadmium, manganese, nickel, chromium, etc. The algorithm for the formation of the evidential base included: a general analysis of the sanitary and hygienic situation; assessment in the dynamics of the quality of atmospheric air, drinking water, soil, food; assessment of the risk to the health of the population; epidemiological studies; in-depth clinical surveys of a representative group of city residents (280 people). In the blood of the examinees, heavy metals were identified as biological markers of the exposure. There was evaluated a complex of the response (effect) adequate to effects of laboratory markers. By methods of mathematical statistics there was established the presence of reliable relationships in the system “source of hazard - the quality of the environment - exposure to risk factors - health status.” The hazard to the health of a citizen, due to the negative impact of the factor, was considered to be proven if it was possible to build a continuous step-by-step logical chain of relationships between the source of the harmful effect, the quality of the habitat and the establishment of the fact of the disease. The quality of the habitat of the population of Zakamensk was shown to give rise in unacceptable risks to the health of residents. The main influencing factor is the pollution of atmospheric air, local food products and drinking water from public and private wells. Risks are realized in terms of a level of the primary morbidity rate of the population of the respiratory diseases, endocrine system, digestive organs that is relatively high compared to the matched area. The relationship between health hazard and environmental factors has been fully proved in 14% of the surveyed persons. At the same time, the territory was shown not be characterized as a zone of “ecological disaster” or “an emergency environmental situation”.


2020 ◽  
Vol 19 (1) ◽  
pp. 22-29
Author(s):  
Yosua Natalianto ◽  
Eko Pujiyanto ◽  
Wahyudi Sutopo

SPAM (Sistem Pengolahan Air Minum or Drinking Water Treatment System) UNS was established in 2015 to meet the drinking water needs of the UNS academic community by providing 129 dispensers and water tap machines spread across buildings at UNS. A survey conducted by UNS students in 2017 showed that 54 % of students were not sure of the quality of UNS SPAM water. So the service quality questionnaire was distributed to 160 UNS students randomly and it was found that only 3 % of respondents stated that they used SPAM UNS water dispenser very often. Processing results shown the highest gap value is in the reliability dimension, with CTS namely cleanliness and flow of water. From the survey regarding the cleanliness and flow of the water carried out the DPMO value of the process was 332,589 (1, 930 sigma) . Recommendations for improvement are in the form of several SOPs to improve the cleanliness and quality of SPAM UNS water dispenser services.


2019 ◽  
Vol 13 (28) ◽  
pp. 116-124
Author(s):  
Zainab Bahaa Mohammed

In this research, the water quality of the potable water network inAl-Shuala Baghdad city were evaluated and compare them with theIraqi standards (IQS) for drinking water and World HealthOrganization standards (WHO), then water quality index (WQI) werecalculator: pH, heavy metals (lead, cadmium and iron), chlorides,total hardness, turbidity, dissolved oxygen, total dissolved solid andelectrical conductivity. Water samples are collected weekly duringthe period from February 2015 to April 2015 from ten sites. Resultsshow that the chlorides, total dissolved solid and electricalconductivity less than acceptable limit of standards, but totalhardness and heavy metals in some samples higher than acceptablelimit of standards while the other parameter is good.WQI shows thatresults is excellent and good for drinking for all location and monthsexcept site (2) gave higher value (65.184) in March and site (9) gavehigh value (57.78, 57.23) at March and April indicate that sites ispoor for drinking water.


2020 ◽  
Vol 18 (4) ◽  
pp. 595-601
Author(s):  
Dawit Debebe ◽  
Fiseha Behulu ◽  
Zerihun Getaneh

Abstract Human beings could be exposed to impacts associated with heavy metals such as lead (Pb) through drinking water. The objective of this study was to evaluate quality of water consumed by kindergarten school children in Addis Ababa city, who are highly susceptible to issues related to heavy metals in water. Through conducting chemical analysis, using microwave plasma atomic emission spectrophotometry (MP-AES), the level of lead (Pb) was measured at 38 selected schools in the city. Drinking water samples were taken from three water supply sub-systems: Akaki, Legedadi, and Gefersa. Results revealed the average Pb concentration in the city was 62.37 μg/L which is significantly higher than the World Health Organization (WHO) recommended threshold value of 10 μg/L. The children's blood lead levels and exposure to Pb were also calculated using the integrated exposure uptake bio-kinetic (IEUBK) model as per USEPA guidelines. Estimated geometric mean blood lead levels (BLLs) for each school ranged from 4.4 to 13.2 μg/dL. On average, the model predicted that 20% of children in the city will have blood lead levels above the WHO recommended 10 μg/dL. The study can be considered as an unprecedented piece of work as it addresses critical issues and methods to mitigate problems caused by high concentration of Pb in water supply distribution infrastructure.


2016 ◽  
Vol 31 (1) ◽  
Author(s):  
Margaret-Ann Armour

AbstractDrinking water is essential to us as human beings. According to the World Health Organization “The quality of drinking-water is a powerful environmental determinant of health” (


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