Section 3. Objectives of Water Treatment

2022 ◽  
pp. 6-13
Author(s):  

The absence of adequate external and internal treatment can lead to operational upsets or unscheduled outages and is ill-advised from the point of view of safety, economy, and reliability. Where a choice is available, the reduction or removal of objectionable constituents by pretreatment external to the boiler is always preferable to, and more reliable than, management of these constituents within the boiler by internal chemical treatment, which involves boiler blowdown and chemical feed to the boiler system.

2014 ◽  
Vol 998-999 ◽  
pp. 414-417
Author(s):  
Jun Wang

Biological invasions caused by Ballast water is always one of the diffcult problems of marine environmental protection, and the technology of ballast water treatment is an effective way to solve biological invasion. This article introduce many equipments of ballast water treatment, introduce physical ballast water treatment, chemical treatment and comprehensive treatment, then describes the advantages and disadvantages of these metheods.


Author(s):  
Avinash Panda

It is necessary to utilize a clarifier when the wastewater contains a significant amount of particles that must be filtered out. It works by allowing particles to fall to the bottom of a plate and flow freely past as they settle. Adding polyelectrolyte and coagulant may speed up this natural process of settling. In contrast, coagulants neutralize charges and conglomerate solids into micro-flocs as a result of the polyelectrolyte. Fine filtration, assisted by the use of lamella clarifier settler, or the use of microorganisms, which consume organics as a source of energy, are two common methods of chemical treatment.


2018 ◽  
Vol 6 (4) ◽  
pp. 5369-5388 ◽  
Author(s):  
Pratik Kumar ◽  
Krishnamoorthy Hegde ◽  
Satinder Kaur Brar ◽  
Maximiliano Cledon ◽  
Azadeh Kermanshahi pour

2021 ◽  
Vol 13 (24) ◽  
pp. 277-293
Author(s):  
Tomasz Szczepański ◽  
Urszula Więckiewicz ◽  
Barbara Konior ◽  
Patryk Pucułek

W artykule przedstawiono wyniki badań, których celem było określenie, w jakim stopniu ozon wykorzystywany do dezynfekcji pomieszczeń wpływa na możliwość ujawnienia metodą DFO śladów linii papilarnych na podłożach papierowych. Gwałtowny wzrost zachorowani na COVID-19 skierował uwagę na dezynfekcję pomieszczeń technikami, które zapewniają bezpieczeństwo ich użytkownikom. Istotne staje się także zapewnienie bezpieczeństwa osobom otrzymującym przesyłki, na których mogą się znajdować patogeny. Ich inaktywacja powinna być dokonana w taki sposób, aby można było przeprowadzić badania pozwalające na identyfikację nadawcy, co jest istotne z punktu widzenia kryminalistyki. Ozonowanie jest techniką dezynfekcji wykorzystywaną od wielu lat, szczególnie do uzdatniania wody, w przemyśle spożywczym. Eksperymenty wykonano w pomieszczeniach o kubaturze ok. 20 m3 przy użyciu generatora ozonu dostępnego na rynku. Uzyskiwane stężenie gazowego ozonu nie przekraczało 10 ppm. Przeprowadzone badania potwierdziły, że ślady linii papilarnych pozostawione na papierze kserograficznym umieszczonym w pomieszczeniu poddanym ozonowaniu w stężeniu nieprzekraczającym 10 ppm nie ulegają zniszczeniu i z powodzeniem mogą być ujawnione metodą DFO. The effect of ozone disinfection of rooms on the efficacy of revealing dactyloscopic traces on the surface of the paper using the DFO method during the SARS-CoV-2 pandemic The article presents the results of research aimed at determining the extent to which ozone used for disinfecting rooms affects the possibility of developing fingerprints on paper using the DFO method. A sudden increase in COVID-19 cases has placed the focus on disinfection techniques for user safety. It is also becoming important to ensure the safety of parcels addressed to various recipients by inactivating pathogens, while maintaining the possibility of examination that can identify the sender, which is important from the point of view of forensics. Ozonation is a disinfection technique that has been used for many years, in particular for water treatment or in the food industry. The experiments were carried out in rooms with a cubature of approx. 20 m3 using an ozone generator available on the market. The obtained ozone gas concentration did not exceed 10 ppm. The conducted research confirmed that the traces of fingerprints left on xerographic paper placed in a room subjected to ozonation in a concentration not exceeding 10 ppm are not damaged and can be successfully developed with the DFO method.


2021 ◽  
Vol 958 (1) ◽  
pp. 012020
Author(s):  
M Mayacela ◽  
L Maldonado ◽  
F Morales ◽  
B Suquillo

Abstract In Ecuador, contaminated water is discharged directly into the sewage system. The treatments carried out for the elimination of wastewater pollutants are classified into three types: Physical, Chemical and Biological. One of the treatments that is frequently used is the physico-chemical treatment in which various reactive substances are used, which is why in this research several reactive substances of Ecuadorian origin, including activated carbon, peat, limestone, volcanic pyroclasts, zeolite clinoptilolite and zeolite modernite, are physically characterized. For this purpose, some laboratory tests were carried out based on national and international standards in order to obtain the granulometry, compactness coefficient, porosity, sphericity and permea-bility.


Membranes ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 773
Author(s):  
Federico A. Leon ◽  
Alejandro Ramos-Martin ◽  
David Santana

The desalination of seawater is one of the most established techniques in the world. In the middle of the 20th century this was achieved using water evaporation systems, later with reverse osmosis membranes and nowadays with the possibility of capacitive deionization membranes. Capacitive deionization and membrane capacitive deionization are an emerging technology that make it possible to obtain drinking water with an efficiency of 95%. This technology is in the development stage and consists of porous activated carbon electrodes, which have great potential for saving energy in the water desalination process and can be used for desalination using an innovative technology called capacitive deionization (CDI), or membrane capacitive deionization (MCDI) if an anion and cation membrane exchange is used. In this paper is proposed and designed a characterization system prototype for CDI and MCDI that can operate with constant current charging and discharging (galvanostatic method). Adequate precision has been achieved, as can be seen in the results obtained. These results were obtained from the performance of typical characterization tests with electrochemical double layer capacitors (EDLC), since they are electrochemical devices that behave similarly to MCDI, from the point of view of the electrical variables of the processes that take place in MCDI. A philosophy of using free software with open-source code has been followed, with software such as the Arduino and Processing programming editors (IDE), as well as the Arduino Nano board (ATmega328), the analogical-digital converter (ADC1115) and the digital-analogical converter (MCP4725). Moreover, a low-cost system has been developed. A robust and versatile system has been designed for water treatment, and a flexible system has been obtained for the specifications established, as it is shown in the results section.


scholarly journals At the moment, complex and unified solutions have not been created, with the intensification of processes and control systems in accordance with integral resource-efficient criteria, which increases the urgency of the task of developing a technological basis for a specialized combined electrotechnological complex for water treatment. The aim of the research is to substantiate the structure and parameters of the combined electrotechnological processes of wastewater treatment in paper and cardboard production. When treating wastewater, electrocoagulation processes were used, characterized by the electrochemical dissolution of metal anodes. Also, during the processing, chemical coagulation was used, which is based on the addition of active coagulants to the wastewater: ammonium, copper, and iron salts. To accelerate the precipitation processes, after coagulation, a biocidal flocculant was used, after which the clarified solution was passed through a diaphragm electrolyzer with an inactive membrane. Also, wastewater was subjected to ozonation for the purpose of additional oxidation of pollutants. To mix the coagulant and effluents, we used an atmospheric air supply. After flotation coagulation, the wastewater was separated by sedimentation and filtered, if necessary, through a polystyrene foam filter. After evaluating the results of experimental wastewater treatment of paper and cardboard production, a combined scheme of an electrotechnological water treatment complex is proposed. Calculation of technical and economic indicators showed that the financial costs of processing glue and dye washes using a combined electrotechnical complex are almost six times less than the services of specialized companies for the disposal of such wastewater. Disposal of untreated aqueous solutions of paper and cardboard production without purification is unacceptable - from the point of view of their possible critical anthropogenic load on the environment in such cases.

2020 ◽  
pp. 45-58
Author(s):  
◽  
A. Kozir ◽  
N. Zaiets ◽  
D. Alekseevskiy ◽  
◽  
...  

At the moment, complex and unified solutions have not been created, with the intensification of processes and control systems in accordance with integral resource-efficient criteria, which increases the urgency of the task of developing a technological basis for a specialized combined electrotechnological complex for water treatment. The aim of the research is to substantiate the structure and parameters of the combined electrotechnological processes of wastewater treatment in paper and cardboard production. When treating wastewater, electrocoagulation processes were used, characterized by the electrochemical dissolution of metal anodes. Also, during the processing, chemical coagulation was used, which is based on the addition of active coagulants to the wastewater: ammonium, copper, and iron salts. To accelerate the precipitation processes, after coagulation, a biocidal flocculant was used, after which the clarified solution was passed through a diaphragm electrolyzer with an inactive membrane. Also, wastewater was subjected to ozonation for the purpose of additional oxidation of pollutants. To mix the coagulant and effluents, we used an atmospheric air supply. After flotation coagulation, the wastewater was separated by sedimentation and filtered, if necessary, through a polystyrene foam filter. After evaluating the results of experimental wastewater treatment of paper and cardboard production, a combined scheme of an electrotechnological water treatment complex is proposed. Calculation of technical and economic indicators showed that the financial costs of processing glue and dye washes using a combined electrotechnical complex are almost six times less than the services of specialized companies for the disposal of such wastewater. Disposal of untreated aqueous solutions of paper and cardboard production without purification is unacceptable - from the point of view of their possible critical anthropogenic load on the environment in such cases.


Author(s):  
В.А. Гвоздев ◽  
Т.М. Портнова ◽  
Т.Ф. Корчиго ◽  
С.З. Морозова ◽  
Е.Н. Семиволос ◽  
...  

На водопроводных очистных сооружениях дезинфекция воды с применением хлора, наряду с ее фильтрованием, является исторически самым старым и потому рутинным технологическим процессом. Практика управления процессом дезинфекции, складывающаяся на сооружениях в течение многих лет, часто основывается на не вполне обоснованных, а иногда и на ошибочных решениях, принятых в прошлом. Главными ориентирами, как правило, являются только нормируемые параметры: остаточная концентрация хлора и микробиологические показатели на выходе станции. Между тем расположение точек ввода реагентов, их начальные концентрации и режим дозирования имеют ключевое значение с точки зрения эффективности, надежности и безопасности технологии. Точность и оперативность контроля концентраций реагентов, контроль эффективности связывания хлора в случае аммонизации воды являются определяющими факторами при автоматизации процесса. Традиционно и формально программы производственного контроля базируются на лабораторных методах, разработанных еще в начале ХХ века. В то же время прогресс в аналитическом приборостроении позволяет вести контроль технологических параметров дезинфекции в режиме реального времени. Представлены результаты опытно-промышленных испытаний оптимизации процессов хлораммонизации на основе онлайн-контроля качества воды. Испытания проведены на Южной водопроводной станции ГУП «Водоканал Санкт-Петербурга». Выполнен анализ лабораторных методов контроля концентрации активного хлора и азотсодержащих веществ с точки зрения обеспечения достоверной оценки физико-химических процессов хлораммонизации. Дана оценка возможностей современных анализаторов для повышения эффективности, точности и безопасности методов управления процессом хлораммонизации. Во введении приведены некоторые значимые события в истории развития технологии дезинфекции воды в России и в мире. Disinfection of water with chlorine, along with the filtration at water treatment facilities has been historically the oldest and therefore routine technological process. The practice of disinfection process control that has been developed at the facilities over many years is often based on not exactly justified, and sometimes on erroneous, decisions made in the past. The main reference points, as a rule, are only regulated parameters, i. e., residual chlorine concentration and microbiological indicators at the outlet of the facilities. Meanwhile, the location of the chemical injection points, initial concentrations of chemicals and the dosing rate are of key importance from the point of view of the technology efficiency, reliability and safety. Accuracy and efficiency of chemical concentration control, control of the chlorine binding efficiency in the process of water ammoniation are the decisive factors in the process automation. Traditionally and formally, production control programs are based on the laboratory methods developed back in the early twentieth century. At the same time, progress in analytical instrumentation provides for monitoring the process parameters of disinfection in real time mode. The results of pilot tests of optimizing chlorammoniation processes based on online water quality monitoring are presented. The tests were carried out at the Southern Water Treatment Plant of SUE «Vodokanal of St. Petersburg». The analysis of the laboratory methods for monitoring the concentration of active chlorine and nitrogen-containing substances from the point of view of ensuring a reliable assessment of the physicochemical processes of chlorammoniation has been carried out. An assessment of the capabilities of modern analyzers for improving the efficiency, accuracy and safety of methods for controlling the chlorammoniation process is given. Some significant events in the history of the development of water disinfection technology in Russia and in the world are given in the Introduction.


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