Preozonation coupled with flotation filtration: successful removal of algae

1998 ◽  
Vol 37 (2) ◽  
pp. 65-73 ◽  
Author(s):  
Antoine Montiel ◽  
Bénédicte Welté

The renovating of a new water treatment plant in Paris which produces 15% of the capital's drinking water supply is described: an original treatment plant consisting of a preozonation, a flotation with a low level of coagulant coupled with contact coagulation. Coagulation on filter has been tested on a pilot plant. The results are excellent (95 to 99%) and have led to the building of a new water treatment plant with very flexible operating conditions depending on the quality of the water.

2016 ◽  
Vol 16 (4) ◽  
pp. 922-930 ◽  
Author(s):  
L. Richard ◽  
E. Mayr ◽  
M. Zunabovic ◽  
R. Allabashi ◽  
R. Perfler

The implementation and evaluation of biological nitrification as a possible treatment option for the small-scale drinking water supply of a rural Upper Austrian community was investigated. The drinking water supply of this community (average system input volume: 20 m3/d) is based on the use of deep anaerobic groundwater with a high ammonium content of geogenic origin (up to 5 mg/l) which must be treated to prevent the formation of nitrites in the drinking water supply system. This paper describes the implementation and operation of biological nitrification despite several constraints including space availability, location and financial and manpower resources. A pilot drinking water treatment plant, including biological nitrification implemented in sand filters, was designed and constructed for a maximum treatment capacity of 1.2 m3/h. Online monitoring of selected physicochemical parameters has provided continuous treatment performance data. Treatment performance of the plant was evaluated under standard operation as well as in the case of selected malfunction events.


Author(s):  
С.Е. Алексеев ◽  
Е.В. Корса-Вавилова ◽  
А.Я. Шмелев

Источники питьевого водоснабжения (реки Великая, Волга, Вычегда, Которосль, Лименда, Солда, Северная Двина, Томь и Тура) характеризуются повышенным содержанием органических соединений природного и антропогенного происхождения. Традиционная технология двухступенчатого осветления воды коагулированием в данном случае по своей эффективности не соответствует качеству воды источника, в результате по некоторым показателям питьевая вода периодически не отвечает современным требованиям стандарта. Особенно сложно обеспечивать в питьевой воде предельно допустимые концентрации органических веществ, а также соединений железа, марганца и остаточного алюминия. Для очистки такой воды были изучены дополнительные методы окисления и сорбции. Результаты исследований показали, что предварительное озонирование речной воды и (или) постозонирование воды после фильтров станции водоподготовки повышают эффективность очистки по цветности, мутности, удалению соединений железа и марганца, уменьшают концентрацию остаточного алюминия, улучшают органолептические показатели. Сорбционная очистка с озонированием существенно улучшает качество очищенной воды и позволяет обеспечить допустимый уровень содержания органических загрязнителей в питьевой воде. Sources of drinking water supply (the Velikaia, Volga, Vychegda, Kotorosl’, Limenda, Solda, Severnaia Dvina, Tom’ and Tura rivers) are characterized by increased concentrations of organic compounds of natural and anthropogenic origin. The traditional technology of two-stage water clarification by coagulation in terms of the efficiency, in this case, is not applicable to the quality of the source water; as a result, by some indicators, drinking water periodically does not meet the current standard requirements. It is especially difficult to ensure the permissible maximum concentrations of organic substances in drinking water, as well as of compounds of iron, manganese and residual aluminum. To provide for the purification of such water, additional oxidation and sorption methods have been studied. The research results showed that preliminary ozonation of river water and (or) post-ozonation of water after filtration at a water treatment plant provide for increasing the efficiency of purification in terms of color, turbidity, removal of iron and manganese compounds; for reducing the concentration of residual aluminum, and improving the organoleptic characteristics. Sorption with ozonation significantly improves the quality of treated water and allows to ensure the permissible level of organic pollutants in drinking water.


2002 ◽  
Vol 2 (5-6) ◽  
pp. 185-191
Author(s):  
T. Hanamoto ◽  
D. Nagashio ◽  
T. Sasaki

The Hanshin Water Supply Authority (HWSA) supplies drinking water to approximately 2.4 million consumers in the Hanshin area, including the city of Kobe. The HWSA has completed a project integrating two aging plants into a new water treatment plant (Amagasaki WTP) with a capacity of 373,000 m3 per day. The Amagasaki WTP has three significant special merits: water treatment, environmental, and information technology. The water treatment system is based on a multiple-barrier concept that estimates the value of water treatment technology not by individual processes, but by the overall performance of the system. The treatment train consists of coagulation/sedimentation, ozonation/activated carbon fluidized-bed adsorption, and coagulation/high-rate filtration, most of which fully utilize upward-flow. The key environmental technology characteristic of the new WTP is its achievement of zero-emissions. This design reduces CO2 discharge from the plant, as well as making it possible to completely recycle the sludge as an alternate material of agricultural and horticultural soils. Improvement of customer relations is a feature of the information technology. The authority provides information on the safety of the finished drinking water, watershed management, and the maintenance of source water quality. A visitors' area and emergency water supply facility for use in disasters have also been set up at the WTP. The Amagasaki WTP started commercial operation in April 2001. The completion of this renovated plant will significantly raise the quality of service to the customers.


Author(s):  
A. Seliukov ◽  
V. Rakhimov

Приводятся основные результаты технологических изысканий, положенных в основу проекта реконструкции станции очистки подземных вод г. Ноябрьска (Ямало-Ненецкий автономный округ). Станция построена по проекту ЗАО ДАР/ВОДГЕО (Москва) и принята в постоянную эксплуатацию в сентябре 2006 г. На станции используется новая технология, предусматривающая последовательную обработку воды двумя окислителями пероксидом водорода и перманганатом калия с целью очистки от соединений железа и марганца. Недостатки проекта и неполная реализация проектных решений усложняют штатную эксплуатацию станции и затрудняют получение питьевой воды нормативного качества. Установлено, что в подземной воде присутствует сероводород в концентрациях до 0,1 мг/дм3, что требует дополнительного расхода реагентов. Ручное дозирование реагентов приводит к значительным отклонениям от необходимых доз: от 14,5 до 19,1 для пероксида водорода и от 8,5 до 9,1 для перманганата калия. Указано, что применяемые в качестве реагента технические продукты перманганата калия производства КНР создают угрозу увеличения токсичности питьевой воды. Найденное значение величины индекса Ланжелье (индекса насыщения карбонатом кальция) подземной воды (2,35 ед.) позволило сделать вывод о необходимости стабилизационной обработки путем подщелачивания. Выполненные пробные обработки воды пероксидом водорода и перманганатом калия в сочетании с подщелачиванием показали, что такой процесс обеспечивает достижение остаточных концентраций марганца 0,1 мг/дм3 и железа общего 0,10,15 мг/дм3 при отсутствии остаточного сероводорода. Однако для получения воды постоянного нормативного качества необходима высокая точность дозирования реагентов, что может быть достигнуто только путем полной автоматизации процесса. Выполненный на основе технологических изысканий проект реконструкции станции очистки подземных вод г. Ноябрьска позволяет решить существующие проблемы и обеспечить нормативное качество очищенной воды.The main results of technological surveys that form the basis for the project of reconstruction of the ground water treatment plant in Noyabrsk (Yamalo-Nenets Autonomous Okrug) are presented. The plant was built according to the project of DAR/VODGEO CJSC (Moscow) and commissioned in September 2006. The plant uses a new technology that provides for the sequential treatment of water with two oxidizing agents hydrogen peroxide and potassium permanganate to remove iron and manganese compounds. The project shortcomings and incomplete implementation of design solutions complicate the regular operation of the plant and make it difficult to ensure the standard quality of drinking water. It was stated that ground water contained hydrogen sulfide in concentrations up to 0.1 mg/dm3, which required extra consumption of chemicals. Manual dosing of chemicals causes significant deviations from the required doses: from 14.5 to 19.1 for hydrogen peroxide and from 8.5 to 9.1 for potassium permanganate. It is pointed out that crude products of potassium permanganate produced by the P. R. China used as a chemical agent in drinking water supply, pose a threat of increased toxicity of drinking water. The determined value of the Langelier index (index of saturation with calcium carbonate) of ground water (2.35 units) allowed to conclude that stabilization treatment by alkalization is required. The performed test water treatment with hydrogen peroxide and potassium permanganate in combination with alkalization showed that this process provided for achieving the residual concentrations of manganese 0.1 mg/dm3 and total iron 0.10.15 mg/dm3 in the absence of residual hydrogen sulfide. However, to produce water of constant standard quality, high accuracy of chemical dosing is required that can only be provided by completely automated dosing. The project of upgrading the ground water treatment plant in Noyabrsk designed on the basis of technological research, allows to resolve the existing problems and ensure the standard quality of drinking water.


2016 ◽  
Vol 51 (2) ◽  
pp. 81-96 ◽  
Author(s):  
Mohamed A. Hamouda ◽  
William B. Anderson ◽  
Michele I. Van Dyke ◽  
Ian P. Douglas ◽  
Stéphanie D. McFadyen ◽  
...  

While traditional application of quantitative microbial risk assessment (QMRA) models usually stops at analyzing the microbial risk under typical operating conditions, this paper proposes the use of scenario-based risk assessment to predict the impact of potential challenges on the expected risk. This study used a QMRA model developed by Health Canada to compare 14 scenarios created to assess the increase in risk due to potential treatment failures and unexpected variations in water quality and operating parameters of a water treatment plant. Under regular operating conditions, the annual risk of illness was found to be substantially lower than the acceptable limit. Scenario-based QMRA was shown to be useful in demonstrating which hypothetical treatment failures would be the most critical, resulting in an increased risk of illness. The analysis demonstrated that scenarios incorporating considerable failure in treatment processes resulted in risk levels surpassing the acceptable limit. This reiterates the importance of robust treatment processes and the multi-barrier approach voiced in drinking water safety studies. Knowing the probability of failure, and the risk involved, allows designers and operators to make effective plans for response to treatment failures and/or recovery actions involving potential exposures. This ensures the appropriate allocation of financial and human resources.


2018 ◽  
Vol 7 (3.14) ◽  
pp. 139
Author(s):  
H M. Zolkipli ◽  
H Juahir ◽  
G Adiana ◽  
N Zainuddin ◽  
A B. H. M. Maliki ◽  
...  

This study aims to identify the most significant parameters in drinking water quality, spatial disparities of treated water (TW) and performance of water treatment plant (WTP) in Selangor. Physico- chemical (PCPs), Inorganic (IPs), Heavy metal and organic (HMOPs) and pesticide (PPs) were selected as parameters to discriminate the source of WTP pollutant. Chemometric technique such as principle component analysis (PCA), one-way analysis of variance (ANOVA) and discriminant analysis (DA) was applied to validate the performance of water treatment plant. PCA identified the most significant parameters which are highlighted six out of eight parameters for PCPs, six out of twelve parameters for IPs, nine out of sixteen parameters for HMOPs and all seventh parameters for PP. ANOVA for distinguish two categories region in WTP and showed both of PCPs and IPs had significant differences due to their concentration (p < 0.5) and HMOPs suggested fifth of significant differences within regions (p < 0.05). PP doesn’t give any significant differences (p > 0.05). DA was suggested PCPs, IPs and HMOPs in good performance (76.96%, 91.90% and 93.27%) except PP (50.43%). We can conclude that this chemometric technique can expose which area of WTP need to be properly maintains their performance to produce high quality of drinking water.  


1999 ◽  
Vol 40 (6) ◽  
pp. 171-177 ◽  
Author(s):  
A. Montiel ◽  
S. Rigal ◽  
B. Welté;

During Autumn 1982, many consumers complained in Paris about a musty taste. Complaints were located only in a quarter of Paris which was supplied by a surface water treatment plant. The experiments and tests have shown that this taste appeared only in the network. Musty taste was detected neither on the river nor at the outlet of the plant. Some hypotheses have been made and experiments have been conducted later because this episode of complaints stopped suddenly. It appeared that some chlorophenols were produced in the plant. These compounds were biomethylated further by fungi in the network leading to chloroanisole which give a musty taste detectable a very low concentration.


2013 ◽  
Vol 5 (3) ◽  
pp. 177-184

A pilot-plant study was carried out with the water supply to Athens water works filtered through a granular activated carbon (GAC) filter- adsorber. The objective of this study was to evaluate the performance of GAC for the removal from drinking water of the two main groups of disinfection by -products (DBPs), trihalomethanes (THMs) and haloacetic acids (HAAs), as well as of dissolved organic matter. The pilot treatment facility is located at the Water Treatment Plant of EYDAP in Galatsi, Athens, and was operated as a rapid gravity filter - adsorber. It was fed with chlorinated water, coming from the overflow of the sedimentation tanks, and operated continuously in parallel with a full-scale sand filter. At regular time intervals water samples were taken from both filters and analysed for THMs, HAAs and DOC. Other parameters were measured too. The operation of the GAC filter-adsorber continued until the GAC adsorption capacity for THMs and HAAs was almost exhausted. The results of the analyses showed that GAC was more effective in removing the dissolved organic matter than the smaller molecules of THMs and HAAs, fact which is in agreement with the relevant literature. GAC was also proved more effective in removing HAAs than removing THMs. The removal of THMs and the most part of the removal of HAAs and DOC must be attributed to adsorption by GAC, while that of a smaller part of DOC and HAAs may be attributed to biological activity in the filter bed, where chlorine had been totally removed by the catalytic action of the activated carbon surface.


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