Impact of water quality and reactor hydrodynamics on wastewater disinfection by UV, use of CFD modeling for performance optimization

1998 ◽  
Vol 38 (6) ◽  
1998 ◽  
Vol 38 (6) ◽  
pp. 71-78 ◽  
Author(s):  
M. L. Janex ◽  
P. Savoye ◽  
Z. Do-Quang ◽  
E. Blatchley ◽  
J. M. Laîné

In order to ensure reliable operating conditions for adequate wastewater disinfection in a UV reactor, two aspects were investigated as having a critical impact on the disinfection performances: water quality and hydrodynamics of the water flow through the system. Tests performed with a collimator on several wastewater effluents enabled us to relate the UV inactivation to the total suspended solids content of the water to be treated, the influence being decisive under 5 mg/l TSS. On the other hand, a CFD (Computational Fluid Dynamics) numerical tool was used to provide an accurate characterization of the flow pattern within a vertical flow reactor. On the basis of such modeling, modifications in the geometry of the reactor could be proposed aiming at reducing zones of low dose and therefore improving disinfection performances. Side-by-side experimental comparisons between modified and unmodified pilots enabled us to validate that approach.


2013 ◽  
Vol 634-638 ◽  
pp. 267-270
Author(s):  
Hong Yan Lin ◽  
Chun Cai Wang ◽  
Lian Bao Kan

The suitability of Daqing oilfield wastewater disinfection by electrolysis technology was analyzed. The results show that electrolysis disinfection method is applicable to the water quality of Daqing oilfield. The effect of current, wastewater flow, and electrolysis time on the disinfection effect and power consumption was studied. The results show that the disinfection effect is good and economical for Daqing oilfield wastewater when the current is 2A and the flow is 40L/h.


Revista DAE ◽  
2019 ◽  
Vol 221 (68) ◽  
pp. 87-100
Author(s):  
Juscelino Alves Henriques ◽  
Marcelo Libânio ◽  
Veber Afonso Figueiredo Costa ◽  
Mariângela Dutra de Oliveira

As estações de tratamento de água (ETAs) têm um papel fundamental e estratégico no controle de doenças transmitidas pela água por meio da potabilização da água, para atender às necessidades da população que é abastecida por ela. Nesse contexto, a avaliação do desempenho dessas estações é primordial, particularmente para as entidades responsáveis pelo estágio de controle da qualidade da água, uma vez que a ETA deve apre- sentar e operar com condições mínimas necessárias para alcançar seu objetivo. Para o desenvolvimento dos modelos (Modelo 1 - com base na turbidez da água tratada e Modelo 2 - com base na cor aparente da água tratada) foram utilizados dados referentes à qualidade da água bruta e tratada, fatores operacionais e parâme- tros hidráulicos de 3 ETAs, com taxas de fluxo de 50 L.s-1 ou menos. Os modelos foram desenvolvidos usando a caixa de ferramentas do Matlab®, a partir da rede neural do tipo de camadas recorrentes, com função de ativação tansig e purelin. Como resultados, os modelos apresentaram coeficientes de determinação de 0,928 e 0,823 para turbidez e cor aparente da água tratada, respectivamente. Os resultados corroboram a aplicação da Inteligência Artificial em estações de tratamento de água, com o objetivo de otimizar processos e garantir uma maior operabilidade da ETAs, gerando um produto cada vez mais confiável. Palavras-chave: Desempenho da planta de tratamento de água. Processos de otimização. Rede neural artificial. Abstract The water treatment plants (WTP) have a fundamental and strategic role in the control of waterborne diseases through the potabilization of water, to meet the needs of the population that is supplied by it. In this context, evaluating the performance of these stations is paramount, particularly for the entities responsible for the water quality control stage, since WTP must present and operate with minimum conditions necessary to achieve its ob- jective. For the development of the models (Model 1 - based on turbidity of treated water and Model 2 - based on the apparent color of the treated water) data were used referring to raw and treated water quality, operational factors and hydraulic parameters of 3 WTPs, with flow rates of 50 L.s-1 or less. The models were developed usingthe Matlab® toolbox, from the neural network of the recurrent layers type, with activation function tansig and purelin. As results, the models presented regression coefficients of 0.928 and 0.823 for turbidity and apparent color of treated water, respectively. The results corroborate for the application of Artificial Intelligence in water treatment plants, with a view to optimizing processes and guaranteeing greater WTPs operability, generating an increasingly reliable product. Keywords: Water treatment plant performance. Optimization processes. Artificial Neural Network.


Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 939
Author(s):  
Tea In Ohm ◽  
Jong Seong Cae ◽  
Meng Yu Zhang ◽  
Jin Chul Joo

In this study, non-powered hydraulic mixing with three layers of baffles and holes was evaluated as an alternative to vertical shaft impellers in a rapid mixing process through both computational fluid dynamics (CFD) modeling and field applications. From the CFD modeling, the turbulence (i.e., vortex rings) caused by excess kinetic energy between the inlet and second-layer baffle ensures rapid mixing of the coagulants throughout the total water flow and overcomes the damping effect of the components in a mixing basin. Although optimal inlet velocity needs to be investigated for sufficient mixing between coagulants and pollutants in raw water with relatively low energy consumption and maintenance costs, non-powered hydraulic mixing developed in this study was proved to create strong turbulence and can be applied in any water treatment plants that involves coagulation-flocculation processes. Based on the comparison of the water quality between two water treatment plants using identical raw water and coagulant operated from 2014 to 2016, no difference in water quality of treated water indicated that non-powered hydraulic mixing can be replaced with vertical shaft impellers, hence, both energy consumption and maintenance costs can be reduced. Further study is warranted to optimize non-powered hydraulic mixing for the tradeoff between mixing efficiency and energy consumption in the water treatment plants.


2007 ◽  
Vol 2007 (1) ◽  
pp. 434-448
Author(s):  
Domenico Santoro ◽  
Timothy A. Bartrand ◽  
Lorenzo Liberti ◽  
Michele Notarnicola ◽  
Charles N. Haas

2001 ◽  
Vol 43 (10) ◽  
pp. 163-171 ◽  
Author(s):  
P. Savoye ◽  
M. L. Janex ◽  
V. Lazarova

Disinfection processes are known to be very sensitive to wastewater quality. This paper discusses the parameters that impact the UV light (UV) and ozone disinfection processes and the related mechanisms based on literature review. Low-pressure UV and ozone technologies were investigated on effluents that covered a wide range of water quality. The results are given in terms of design doses required to meet three major disinfection standards. Both processes were found eligible for the majority of effluents tested. Although cost-effectiveness is usually considered more favourable to UV, the ozone alternative should be examined in cases such as the disinfection of low-quality effluents or large treatment plants. Ozonation was also found capable of meeting the stringent Title 22 standard with no coagulation at a dose of 10 mg/l.


2000 ◽  
Vol 22 (2) ◽  
pp. 113-121 ◽  
Author(s):  
M.L Janex ◽  
P Savoye ◽  
M. Roustan ◽  
Z. Do-Quang ◽  
J.M. Laîné ◽  
...  

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