The use of «coasorption» concept while describing the effect of coagulants on the wastewater aqua systems

Author(s):  
Е.В. Алексеев

Широкое распространение реагентного коагулирования в технологии очистки природных и промышленных сточных вод обусловлено, с одной стороны, сложностью химического состава и фазово-дисперсного состояния их аквасистем, с другой – многофакторностью действия на них коагулянтов. Рассмотрены основные механизмы взаимодействия коагулянтов и загрязняющих веществ на примере очистки промышленных сточных вод, содержащих органические вещества (поверхностно-активные вещества и синтетические красители). Физико-химическое понятие «коагуляция» отражает только один из механизмов действия коагулянтов на загрязнители. Принятые в настоящее время технологические показатели «доза коагулянта» и «удельная доза коагулянта» также не отражают многообразие взаимодействий загрязняющих веществ с солями коагулянтов и не привязаны к результату коагулирования. Это обусловливает трудность описания совокупного действия физико-химических процессов при добавлении коагулянтов в очищаемые воды и его количественной оценки. Решение проблемы возможно введением понятия «коасорбция», определяющего многофакторность взаимодействия коагулянтов с загрязняющими веществами в процессах очистки сточных вод коагулированием, и технологического показателя «удельная коасорбция», устанавливающего количественную взаимосвязь между величинами загрязняющих веществ в исходной и очищенной воде с дозой коагулянта. Графически представлены функции удельной коасорбции в форме изотерм коасорбции для двух типов поверхностно-активных веществ и синтетических красителей. На основании результатов анализа особенностей изотерм показано, что они отражают разные механизмы взаимодействия коагулянтов и загрязняющих веществ. Использование коасорбции как технологического понятия способствует выявлению механизмов взаимодействия загрязняющих веществ с коагулянтом и созданию наилучших условий для осуществления процесса коагулирования. Функциональное описание изотерм коасорбции позволяет экстраполировать результаты пробного коагулирования в широком интервале концентраций загрязняющих веществ. Практическое значение изотерм удельной коасорбции состоит в возможности определения доз реагентов при коагулировании воды по начальному содержанию загрязняющих веществ и требуемому в очищенных водах. The widespread use of chemical coagulation in purification of natural water and industrial wastewater is due, on the one hand, to the complex chemical composition and phase-disperse state of their aqua systems, and on the other hand, to the multifactorial effect of coagulants on them. The main mechanisms of interaction between coagulants and pollutants are considered through the example of industrial wastewater treatment containing organic substances (surfactants and synthetic dyes). The physicochemical term «coagulation» reflects only one of the mechanisms of the effect of coagulants on pollutants. The currently accepted process parameters «dose of coagulant» and «specific dose of coagulant» do not reflect the variety of interactions of pollutants with coagulant salts either, and are not linked to the result of coagulation. This makes it difficult to describe the collective effect of physicochemical processes while adding coagulants to the treated water and to quantify it. The solution to the problem is possible introducing the concept of «coasorption» that determines the multifactorial origin of the interaction of coagulants and pollutants in the processes of wastewater treatment by coagulation; and the process parameter «specific coasorption» that establishes a quantitative relationship between the concentrations of pollutants in raw wastewater and effluent with a dose of coagulant. The specific coasorption functions are graphically presented in the form of coasorption isotherms for two types of surfactants and synthetic dyes. Based on the results of the analysis of the features of the isotherms, it is shown that they reflect different mechanisms of interaction between coagulants and pollutants. The use of coasorption as a technological concept provides for identifying the mechanisms of interaction of pollutants with a coagulant and establishing the best conditions for the coagulation process. The functional description of the coasorption isotherms allows extrapolating the results of trial coagulation in a wide range of pollutant concentrations. The practical importance of specific coasorption isotherms provides for determining the dosages of chemicals during coagulation of water based on the initial concentration of pollutants and effluent standard.

2018 ◽  
Vol 42 (6) ◽  
pp. 4372-4383 ◽  
Author(s):  
Shanmugam Mahalingam ◽  
Young-Ho Ahn

In situsurfactant free synthesis of rGO–Fe3O4–NiO hybrid nanocomposite for improving photocatalytic degradation of synthetic dyes (MR and CV) and real industrial dye wastewater.


2014 ◽  
Vol 70 (2) ◽  
pp. 279-288 ◽  
Author(s):  
Asun Larrea ◽  
Andre Rambor ◽  
Malcolm Fabiyi

The use of membrane bioreactors (MBRs) in activated sludge wastewater treatment has grown significantly in the last decade. While there is growing awareness and knowledge about the application of MBR technology in municipal wastewater treatment, not much information is available on the application of MBRs in industrial wastewater treatment. A comparative study of design data, operating conditions and the major challenges associated with MBR operations in 24 MBR plants treating both municipal and industrial wastewater, built by and/or operated by Praxair, Inc., is presented. Of the 24 MBR systems described, 12 of the plants used high purity oxygen (HPO). By enabling a wide range of food/microorganism ratios and loading conditions in the same system, HPO MBR systems can extend the options available to industrial plant operators to meet the challenges of wide fluctuations in organic loading and footprint limitations. While fouling in industrial MBR systems can be an issue, adequate flux and permeability values can be reliably maintained by the use of good maintenance strategies and effective process controls (pretreatment, cleaning and membrane autopsies).


2020 ◽  
Vol 26 (4) ◽  
pp. 200254-0
Author(s):  
Gaijuan GUO ◽  
Wei GUO ◽  
Xia DU ◽  
Qie FENG ◽  
Jinda LI ◽  
...  

This study found a new type of immobilized mycelial pellet GX-1310, which can better treat industrial wastewater. Among them, Aspergillus fumigatus G-13 (degradable lignin) was combined with Bacillus cereus X10-1-2 (having the ability to produce cellulase), and the two synergistically produce strong degradation ability. Taking combined mycelial pellet as the research object, its ability to treat papermaking wastewater, heavy metal wastewater and dye wastewater was investigated. The combined mycelial pellet was superior to the single fungal mycelium in the degradation of lignocellulose, removal of heavy metal ions and adsorption capacity of dyes. And the combined mycelial pellet has a wide range of application conditions (temperature range 28-34°C and pH range 4-8), which can maintain high processing capacity for papermaking wastewater, heavy metal wastewater and dye wastewater. After three batches of wastewater treatment, the combined mycelial pellet still maintains high activity and can continuously treat wastewater. The study fixed the single fungal mycelium together with cellulose-degrading bacteria, the strains producing different enzymes were combined to form a multi-functional combined mycelial pellet. This method provides a new way for industrial wastewater treatment.


2021 ◽  
Vol 263 ◽  
pp. 04011
Author(s):  
Evgeny Alekseev ◽  
Svetlana Shambina

The widespread use of reagent coagulation in the technology of purification of natural and waste waters is due to the complexity of the chemical composition and phase-dispersed state of the aqua systems of these waters, on the one hand, and the multifactorial action of coagulants on them, on the other. The mechanisms of interaction between coagulants and pollutants of wastewater which are in different phase-dispersed states include the physicochemical phenomena of coagulation, heterocoagulation, adagulation and sorption. The physicochemical concept “coagulation” reflects only one mechanism of coagulants’ action on pollutants. This leads to the appearing of the problem in terminological description of the physicochemical processes’ combined action when adding coagulants to the water being cleaned. The purpose of the study is to justify the use of universal indicators characterizing the multifactorial nature of the coagulation process, its formalization and quantitative assessment. The solution of the problem is to use the concept of “coasorption”, which determines the multifactorial nature of the interaction between coagulants and pollutants, and to use the technological indicator “specific coasorption”, which establishes a quantitative relationship between the pollutants’ indicators and the dose of coagulant. The test coagulation’s results of two different types of synthetic dyes’ solutions using aluminum salts reflect the difference in the mechanisms of their interaction with the coagulant. The formula for coasorption isotherm can be used to determine the required doses of reagents for coagulation of water basing on the initial and residual content of pollutants in the purified waters.


2021 ◽  
Author(s):  
Ricardo Mejía ◽  
Aymer Maturana ◽  
Diego Gómez ◽  
Christian Quintero ◽  
Luis Arismendy ◽  
...  

Abstract To reduce demand and discharge, instead of industrial wastewater being poorly treated and disposed of, it can be recycled, reused, or recovered if it is properly managed, thus having a substantial decrease in the water requirement and environmental impacts. The challenge is to select the appropriate process or combination of processes to achieve this based on the wastewater quality. Consequently, the objective of this investigation is to review every technology from conventional through advanced, for reliable and sustainable wastewater treatment and derived sludges, focusing on advantages, disadvantages, and technical gaps for development. Even though there is a wide range of possible technologies, it was evinced that there is huge potential to exploit and make them economically and sustainably viable for waste processing and circular economy, even in the mature massively implemented wastewater treatment technologies in the industry. Overall, we identify that independently from the technology to be studied, the future investigations on every unit, especially on those not vastly implemented, should be focused on: (1) The capacity in removing selected pollutants and decreasing impurities, (2) energy efficiency, (3) environmental safety, (4) economic viability, (5) hybrid processes, and (6) sustainability by waste processing.


2019 ◽  
Vol 10 (2) ◽  
pp. 67-77
Author(s):  
G. I Zubareva

The necessity of measures to prevent environmental pollution by industrial emissions, in particular sewage, is substantiated. It has been shown that one of the most promising methods for cleaning industrial wastewater is flotation. Its essence, characteristics and types of flotation are discussed. The factors that determine the use of different types of flotation for the treatment of industrial wastewater are listed. It is shown that the flotation method can be used to concentrate various in nature pollutants from industrial wastes: suspended solids, petroleum products, fats, heavy metal ions, surfactants. It has been established that pressure flotation, electroflotation and ion flotation are most widely used in the practice of cleaning industrial wastewaters. Their advantages compared with other types of flotation are considered. The reasons constraining the widespread use of flotation methods for the treatment of industrial wastewater are discussed. Examples of effective technological schemes for wastewater treatment of a number of industries (oil refineries, meat industry, hydrometallurgical industry, electroplating industry), including the stage of flotation treatment of wastewater are given. The factors that determine the use of flotation treatment of wastewater in technological schemes at a certain stage of industrial effluent treatment are determined. The conclusion was made about the universality of the flotation method, which allows to effectively remove a wide range of contaminants from industrial wastewater, and also successfully combine with widely known purification methods in technological schemes as a preliminary, basic method of purification or additional treatment of effluent up to regulatory requirements.


2016 ◽  
Vol 7 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Abdelsalam Elawwad ◽  
Mohamed Zaghloul ◽  
Hisham Abdel-Halim

In developing countries, and due to the high cost of treatment of industrial wastewater, municipal wastewater treatment facilities usually receive a mixture of municipal wastewater and partially treated industrial wastewater. As a result, an increased potential for shock loads with high pollutant concentrations is expected. The use of mathematical modelling of wastewater treatment is highly efficient in such cases. A dynamic model based on activated sludge model no. 3 (ASM3) describing the performance of the activated sludge process at a full scale wastewater treatment plant (WWTP) receiving mixed domestic–industrial wastewater located in an arid area is presented. ASM3 was extended by adding the Arrhenius equation to respond to changes in temperature. BioWin software V.4 was used as the model platform. The model was calibrated under steady-state conditions, adjusting only three kinetic and stoichiometric parameters: maximum heterotrophic growth rate (μH = 8 d−1), heterotrophic aerobic decay rate (bH, O2 = 0.18 d−1), and aerobic heterotrophic yield (YH,O2 = 0.4 (gCOD/gCOD)). ASM3 was successful in predicting the WWTP performance, as the model was validated with 10 months of routine daily measurements. ASM3 extended with the Arrhenius equation could be helpful in the design and operation of WWTPs with mixed municipal–industrial influent in arid areas.


2010 ◽  
Vol 13 (3) ◽  
pp. 54-66
Author(s):  
Phuong Thi Thanh Nguyen ◽  
Phuoc Van Nguyen ◽  
Anh Cam Thieu

This study was performed to evaluate the efficiency of tapioca processing wastewater treatment using aerobic biofilter with variety of biofilter media: coir, coal, PVC plastic and Bio - Ball BB15 plastic. Research results in the lab demonstrated all four aerobic biofilter models processed can treated completely N and COD which COD reached 90-98% and N reached 61-92%, respectively, at the organic loading rates in range of 0.5, 1, 1.5 and 2 kgCOD/m3.day. The results identified coir filter was the best in four researched materials with removal COD and specific substract utilization rate can reach 98%, and 0.6 kg COD/kgVSS.day. Research results open the new prospects for the application of the cheap materials, available for wastewater treatment.


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