Probabilistic assessment of water quality in terms of oxidability

Abstract

There has been analyzed the nature of the distribution of the oxidability of water. It is revealed that the nature of the distribution of indicator values during the year depends largely on the seasonal factor, and therefore the analysis of the distribution of oxidability is proposed to be studied separately for each month. A variation series is constructed and empirical distribution functions of oxidability distribution is derived. It is established that the law of water oxidability distribution differs from the normal and lognormal distributions, but it is described with sufficient accuracy by the gamma distribution or by a cubic polynomial function (being the simplest). The hypothesis about the distribution law is confirmed by the Kolmogorov–Smirnov test. The water oxidability distribution function allows to determine the probability of exceeding the specified values of the indicator and quantitatively assess the risks of exceeding them, which can become the basis for developing solutions for managing water quality and increasing the efficiency of the water treatment process.

Prediction of optimal coagulant and flocculant dosage for water treatment at surface water intake

“…We have selected the specific periods when the water quality of the source water is different, taking into account the probabilities of indicators in question exceeding of the standards and maximum allowable concentrations (MAC) (calculated using the gamma distribution) [16][17]. The probability of exceeding the standards by the indicator is higher the closer the probabilities are to 0.…”

“…Thus, calculation and adjustment of the correct dosage of the aforementioned chemicals presents a major issue in water treatment processes and is often carried out manually based on current water sample analysis and running tests. This, in turn, contributes to changes in water samples composition, sample contamination and certain indices rising [7][8][9][10][11][12][13][14][15][16][17]; this may result in violation of hygienic requirements and drinking water quality standards, in terms of turbidity, color, oxidizability and general hardness [18]. Therefore, it is necessary to thoroughly study the multifactorial dependences of the chemical agent dosage on water quality indicators.…”

Оптимизация Теоретической Функции Распределения Для Оценки Превышения Нормативов По Общей Жесткости, Цветности И Окисляемости Речной Воды

“…Природная вода содержит различные примеси и является многофазной средой [1][2][3][4][5]. Поэтому в периоды, характеризующиеся ухудшением некоторых показателей необходимо контролировать качество воды.…”

“…Оценка вероятности появления неблагоприятных событий, связанных с ухудшением некоторых показателей, например, общей жесткости, цветности и окисляемости воды, поможет выработать решения для управления качеством воды и оптимизировать возможности водопроводных станций [3][4][5].…”

“…Ранее нами проводилось изучение сезонного характера распределения окисляемости и общей жесткости воды в створе поверхностного водозабора [3,4]…”