Removal of particles using dual media filtration: modeling and experimental studies

2001 ◽  
Vol 1 (4) ◽  
pp. 73-79 ◽  
Author(s):  
C.R. O'Melia ◽  
J.Y. Shin

The performance of packed beds using dual media for removing particles is examined using both predictive mathematical modeling and experimental column studies. Models for the effectiveness of clean filter beds were used to simulate the effects of chemical pretreatment and filtration rate on particle removal at the onset of filtration runs. Experimental studies were conducted over complete filtration runs and were evaluated using measurements of head loss development and removals of turbidity, UV254 absorbance, and particles. The results indicate that dual media beds have significant advantages over monomedia beds during both filter ripening and filter breakthrough; they are particularly helpful at high filtration rates and during periods of inadequate chemical pretreatment. Finally, particle counts provide an earlier indicator of deteriorating filter performance than turbidity measurements at the end of a run.

2015 ◽  
Vol 71 (9) ◽  
pp. 1414-1422 ◽  
Author(s):  
Siping Niu ◽  
Kisoo Park ◽  
Heidi B. Guerra ◽  
Youngchul Kim

A laboratory study was undertaken to pursue the filter performance of a micro-filter module employing highly porous fibre media under a high filtration rate (≥1,500 m/day), faster than that of any conventional filter process. The effects of filtration rate, head loss, raw water turbidity, and filter aid chemicals on filter performance were analysed. In spite of the extremely high filtration rate, the filter achieved an attractive efficiency, reducing the raw water turbidity by over 80%. As with other filter systems, the filter aid used ((polyaluminium chloride (PAC)) greatly affected the performance of this particular fibre filter. Long-term repetitive runs were additionally carried out to confirm the reproducibility of the filter performance. Also, a comparison was carried out with other high-rate filter systems which are either being tested for use in experimental studies, or are already commercially available. This study reveals that the filter performance under a high filtration speed is still attractive especially as PAC is used. Due to the high porosity of the fibre, the filter had small head loss even though the filtration rate was high. These results ascertain that it is possible to operate the filters with high filtration rate achieving reliable treatment performance.


2002 ◽  
Vol 46 (4-5) ◽  
pp. 19-26 ◽  
Author(s):  
Z. Liao ◽  
H. Ødegaard

In these experimental studies enhanced primary treatment in coarse media filters has been evaluated. The coarse media used in the filters have been plastic carriers normally used for moving bed bioreactors, a Kaldnes carrier K1 with density < 1 g/cm3 (K1L) and a bigger carrier K2, that was used both in a lighter, floating (K2L) version and a heavier, sinking one (K2H). The results demonstrated that media characteristics significantly influenced filter performance. The dosing of a high MW and high charge cationic polymer was, however, found to have an even greater effect on treatment efficiency and especially on head loss development. Both filters were found to be feasible for enhanced primary treatment at high filtration rates (20-30 m/h) especially when dosing low dosages (1-3 mg/l) of polymer. The combination of two media into a dual media filter might take the advantages of both. Further experiments were carried out on a dual media filter consisting of lighter K1L media and heavier K2H media. It was indeed found that the K1L+K2H up-flow filter resulted in better performances in terms of water production when an optimised backwash procedure was taken into account.


2006 ◽  
Vol 53 (7) ◽  
pp. 167-175 ◽  
Author(s):  
J.Y. Shin ◽  
C.R. O'Melia

Laboratory dual media filtration experiments were conducted (a) in direct filtration mode using model raw water moderate in turbidity and low in DOC, and (b) in conventional filtration mode treating water moderate in turbidity and high in DOC. Model simulations of filter performance for the removal of particles provided hypotheses for the experimental studies of dual media filtration. An increase in alum dose in direct filtration mode, while improving filter performance, also showed some disadvantages, including rapid development of head loss. Suboptimal dose in direct filtration significantly impaired the filter performance. In conventional mode, the effect of alum dose on the filter performance, while obvious, was not as dramatic as in direct filtration. Ripening indicated by particle counts occurred earlier than by turbidity and breakthrough of particle counts started earlier than breakthrough of turbidity, suggesting that turbidity can be used as a more conservative monitor of filter performance during the ripening period to minimise the risk of passage of small particles, while particle counts can be considered a more sensitive indicator of deteriorating filter performance during the breakthrough period. The lower sand layer served as a multiple barrier for particles when the performance of the anthracite layer was not effective.


Irriga ◽  
2003 ◽  
Vol 8 (3) ◽  
pp. 218-233 ◽  
Author(s):  
Rogerio Pereira da Silva Airoldi ◽  
José Euclides Stipp Paterniani ◽  
Tulio Assunção Pires Ribeiro ◽  
Marcelo Jacomini Moreira da Silva

COMPARAÇÃO ENTRE ELEMENTOS FILTRANTES DE MANTA SINTÉTICA NÃO TECIDA E DE DISCO NO TRATAMENTO DE ÁGUA PARA IRRIGAÇÃO   Rogério Pereira da Silva Airoldi José Euclides Stipp PaternianiTúlio Assunção Pires Ribeiro Marcelo Jacomini Moreira da SilvaDepartamento de Água e Solo, Faculdade de Engenharia Agrícola, Universidade Estadual de Campinas, Campinas, SP. CP 6011, CEP: 13083-970, E-mail:[email protected].  1 RESUMO  A pesquisa realizada propôs uma investigação experimental para a avaliação do desempenho dos meios filtrantes disco (130 mm) e manta sintética não tecida na filtração da água utilizada em um sistema de irrigação por gotejamento com fertirrigação organomineral. Utilizou-se água de um reservatório aberto, localizado no campo experimental da Faculdade de Engenharia Agrícola – UNICAMP, onde foi instalado um módulo de irrigação localizada para o estudo. O desempenho dos filtros foi avaliado através de análises físicas, químicas e biológicas da água afluente e efluente aos filtros, e da evolução da perda de carga nos mesmos. A pesquisa foi desenvolvida em três etapas de 30 dias, realizadas em diferentes estações do ano. Os resultados apontaram que não houve diferenças significativas entre os dois elementos filtrantes com relação à remoção de partículas em suspensão na água. No entanto, o filtro de disco apresentou menor perda de carga localizada em relação ao filtro de manta. Desta forma, concluiu-se que, para as condições experimentais de qualidade da água, o filtro de disco apresentou desempenho pouco superior ao filtro de manta. No entanto, podem-se desenvolver filtros especialmente adaptados aos elementos filtrantes de manta sintética para que a eficiência deste elemento supere a do disco, principalmente com relação à perda de carga.  UNITERMOS: irrigação localizada, fertirrigação, filtração, qualidade de água.  AIROLDI, R. P. da S.; PATERNIANI, J. E. S.; RIBEIRO, T. A. P.; SILVA, M. J. M. da COMPARISON OF NON-WOVEN SYNTHETIC FABRIC AND DISC FILTERS FOR IRRIGATION WATER TREATMENT  2 ABSTRACT  The main purpose of this research was to evaluate the disc (130 mm) and non-woven synthetic fabric filter performance in water filtration using a trickle irrigation system with fertigation. The source of water used in this experiment was from an open reservoir, located in the experimental field of the Agricultural Engineer College – UNICAMP, where an experimental trickle irrigation system has been installed.  The filter performance was evaluated through water analysis by physical, chemical and biological parameters and the head loss evolution on it. The research was developed over three phases of 30 days each in different seasons. The results have shown that there were not significant differences among filters concerning the water suspended particle removal. However, the disc filter presented lower head loss than the non-woven synthetic fabric filter. Therefore, for these water quality conditions the disc filter presented higher performance than the non-woven synthetic fabric filter, although non-woven synthetic fabric filters should be improved in order to obtain  filters with reduced head loss and increased performance.  KEYSWORDS: localized irrigation, fertigation, filtration, water quality.


2021 ◽  
Vol 1037 ◽  
pp. 369-376
Author(s):  
Maxim Ilyushkin ◽  
Kirill Savelev ◽  
Oleg Krupennikov ◽  
Evgeniy S. Kiselev

The paper presents the results of numerical experimental studies of cutting titanium blanks using mathematical modeling programs, which make it possible to completely repeat technological processes in a computer (digital twin). The LS-DYNA product was used as a program to simulate the process of stock removal from titanium blank. It has been established that the use of this method adequately describes the cutting processes, including with the introduction of the energy of an ultrasonic field into the processing zone, can significantly reduce the duration of experimental research and evaluate the influence of the elements of the cutting mode and design parameters of the tool on the thermal power aspects of the formation of new surfaces of machine parts.


2020 ◽  
Vol 8 (2) ◽  
pp. 36
Author(s):  
Racha Medjda Bouchenak Khelladi ◽  
Abdelghani Chiboub Fellah ◽  
Maxime Pontié ◽  
Fatima Zohra Guellil

Sand filtration is an eco-friendly method to treat either drinking water or wastewater ; it requires only natural granular media. It is also easy to use and to maintain ; the only problem they face is clogging that affects filter performance, that can be detected when head loss or turbidity increase. The purpose of this work is to see what are the factors that influence the performance of filter operation, for this, we used a pilot consisting on a circular column filled with sand (from South Algeria), where various parameters were tested; pressure, flow rate, sand granulometry, suspended matters and particle concentration of the water which is filtered. After eighteen weeks of operation, we have found that head loss increases by decreasing granulometry and increasing flow rate, pressure, particle size, and concentration. However, turbidity increases by decreasing particle size and increasing granulometry and particle concentration. Turbidity and head loss have different behaviour towards the same parameter; that is why it is necessary to take them into account in order to find a compromise between acceptable head loss / turbidity for a good functioning of the filter.


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