Évolution du nombre de particules dans l'eau filtrée d'une filière de filtration directe utilisant le polychlorure d'aluminium

1999 ◽  
Vol 26 (6) ◽  
pp. 771-781
Author(s):  
Souleymane Ndiongue ◽  
Raymond Desjardins ◽  
Michèle Prévost ◽  
Chantal Morissette
Keyword(s):  
The Other ◽  
Raw Water ◽  
Polyaluminum Chloride ◽  
Direct Filtration ◽  
Total Particle ◽  
High Turbidity ◽  
Particle Counts ◽  
St Lawrence River ◽  
Do So

This text presents and discusses the performances of direct filtration evaluated by means of particle counts and turbidity of raw water in periods of low and high turbidity. It also deals with the relationships between the removals of particles measuring from 2 to 150 µm (total counts) and those of particles in the other size ranges, which vary from 2 to 5 and from 5 to 15 µm. The tests were carried out on a pilot plant (20 m3/h) that treats waters from the St. Lawrence River (Canada) using the polyaluminum chloride (PACl) coagulation method followed by rapid filtration at 10 m/h. The results show that when the turbidity of the raw water is low, it is not always possible to predict a filter breakthrough based on the turbidity of its effluent, whereas it is possible to do so by observing the evolution of the particle counts. There exist good correlations between the removals of the total particle counts (2-150 µm) and those of the counts of particles in the other size ranges (2-5 and 5-15 µm). Furthermore, the evolution of all these ranges of particle size reveals the same tendencies with respect to the quality of the filtered water.Key words: direct filtration, in-line filtration, filtration, particle counts, turbidity, polyaluminum chloride.

Observations of blanket characteristics in full-scale floc blanket clarifiers

2003 ◽  
Vol 47 (1) ◽  
pp. 197-204 ◽  
Author(s):  
L.C. Chen ◽  
S.S. Sung ◽  
W.W. Lin ◽  
D.J. Lee ◽  
C. Huang ◽  
...  
Keyword(s):  
Treatment Process ◽  
Combined Treatment ◽  
The Other ◽  
Raw Water ◽  
Water Turbidity ◽  
Capillary Suction ◽  
Zeta Potentials ◽  
High Turbidity ◽  
Water Supply Company ◽  
Clarified Water

We monitored the changes in concentrations, zeta potentials, sizes and capillary suction times of the solids flocs in the clarified water from eight floc blanket clarifiers of PingTsan Water Works of Taiwan Water Supply Company with low (<10 NTU) and high (>100 NTU) turbidity raw water. For the former, one-stage coagulation-sedimentation treatment was adopted which yielded a rather unstable blanket. Complete washout was noticeable when the PACl dosage was insufficient. On the treatment of high-turbidity raw water, on the other hand, the Works adopted the combined treatment process, that is, the raw water was first coagulated and settled in a pre-sedimentation tank, afterwards, its effluent was coagulated again and clarified in the clarifiers. The resulting flocs could form a networked blanket that was relatively stable to the shock load in raw water turbidity.

Pre-Ozonation-Coagulant Interactions in Direct Filtration

2010 ◽  
Vol 45 (3) ◽  
pp. 317-326 ◽  
Author(s):  
Murat Eyvaz ◽  
Hatice Deniz ◽  
Tuğrul S. Aktaş ◽  
Ebubekir Yüksel ◽  
Ahmet M. Saatçi
Keyword(s):  
Ferric Chloride ◽  
Aluminum Sulfate ◽  
Pilot Scale ◽  
The Other ◽  
Design Parameters ◽  
Dimensionless Number ◽  
Raw Water ◽  
Direct Filtration ◽  
Effluent Quality ◽  
Sulfate Application

Abstract Pre-ozonation–coagulant interactions effects in relation to the coagulant type and dosage in direct filtration of surface waters were investigated. The performance of the process was evaluated by monitoring the effluent quality and head loss development through the filter bed. Two identical pilot scale filter columns filtering the same raw water were operated in parallel. The raw water was brought from Ömerli Reservoir in Istanbul. Before filtering, the raw water flow was split into two equal flows. One of the streams was pre-ozonated and the other was aerated using contact chambers with equal volumes equipped with same number and type of diffusers. In coagulation experiments, one of the filters was operated using aluminum sulfate as a coagulant while the other one was run with ferric chloride. For similar filter run times, the effluent quality was always better with pre-ozonation compared to aeration. It was also observed that, aluminum sulfate application gave more favorable results for both particle and turbidity removal compared to ferric chloride. Ives’ filterability index which incorporates the important filtration design parameters such as: effluent quality, the headloss and the velocity of filtration into a dimensionless number was used for the comparison of the experimental results.

scholarly journals Indian Psycho‐Philosophy and Human Response in Organizations

1987 ◽  
Vol 12 (1) ◽  
pp. 33-42
Author(s):  
L.N. Jhunjhunwala
Keyword(s):  
The Other ◽  
Quality Of Work Life ◽  
Human Response ◽  
Organizational Life ◽  
Letters To The Editor ◽  
Managerial Practices ◽  
Quality Of Work ◽  
The Will ◽  
Do So

The ideas S K Chakraborty presented in his article “The Will-to-Yoga: Key to- Better Quality of Work Life,” published in the April-June 1986 issue, have drawn several responses from our readers. Some of them were published in the Letters to the Editor in the October-December 1986 issue along with a reply from the author. In this issue we publish three more responses. In the first instance, L N Jhunjhunwala narrates his experiences of putting some of Chakraborty's ideas into practice in his company. In the second response, R Jayaraman Iyer wonders whether a majority of the executives who need to practise the yoga concepts can do so. On the other hand, a minority of executives who can, do not specifically need the concepts, he states. Even so, he feels that the dissemination of concepts themselves and attempts at praGtising them would help. The final piece by P K Srivastava provjdes additional insights into some of the concepts of yoga and their impact on organizational life when they are put into practice. Vikalpa hopes that this exchange of ideas and experiences clarifies the issues and improves managerial practices.

Suspended Solids Removal Efficiencies of a Barrier Board that Pre-Treats High-Turbidity Raw Water

2012 ◽  
Vol 253-255 ◽  
pp. 969-974
Author(s):  
Jian Liang Chen ◽  
Yi Kuo Chang ◽  
Chin Hsing Lai ◽  
Yun Hwei Shen
Keyword(s):  
Suspended Solids ◽  
Removal Rate ◽  
Initial Period ◽  
Raw Water ◽  
High Concentration ◽  
Solids Concentration ◽  
Gravity Settling ◽  
High Turbidity ◽  
Solids Removal

It tends to produce high-turbidity raw water during the initial period of typhoons or storms and affect the operation of the purifying system. In this research, Raw water suspended solids roughly to 5,000-9,000 mg/l, the removal rate can be to about 70%-90 %, and reduced to 800 mg/l or less, 8 ml/s minimum about 100-400 mg/l. Overall, the quality of effluent water with the overflow water height increased removal rate rose gradually reduce the suspended solids concentration, gravity settling and effective appear, especially the section Ⅳ region (40 cm) removal are more than 80 %, flow 100 ml/s to 84 %, compared with I (10 cm) with 100 ml/s for 74 %, with obvious benefits. The overflow height of the flow of 8 ml/s, and suspended solids by the inlet concentration at 7,400 mg/l to 8,700 mg/l, down to the effluent concentrations are below 300 mg/l, which overflow height of 20, 30, and 40 cm can be reduced to below 200 mg/l, showing that gravitational sedimentation can significantly remove the high concentration of suspended solids.

Recycling of Paper and Bulk Properties of Recycled Fiber

1992 ◽  
Vol 266 ◽  
Author(s):  
Luigi Silveri
Keyword(s):  
System Design ◽  
The Other ◽  
Bulk Properties ◽  
Unit Operations ◽  
Contaminant Level ◽  
Other Hand ◽  
Recycled Fiber ◽  
The One ◽  
Do So

AbstractThere are several clear trends in the recycling of paper. Firstly, the amount of recycle is increasing and will continue to do so. Secondly, recycled fiber is being used in greater quantities. Finally the recycled fiber is being introduced into higher quality paper grades which previously did not have any recycled content.This means that on the one hand the quality of the recycled furnish is deteriorating in terms of contaminant level and strength, while on the other hand there is an increased expectation in terms of properties of the end product, the recycled fiber.The major unit operations of recycling and general principles of system design are reviewed, methods for enhancing these properties and limits which can be achieved are discussed.

Research on the Implementation and Analysis of High-Turbidity Raw Water Pre-Treatment with a Barrier Board

2012 ◽  
Vol 610-613 ◽  
pp. 1402-1408
Author(s):  
Jian Liang Chen ◽  
Yi Kuo Chang ◽  
Yun Hwei Shen ◽  
Kun Liao Chen
Keyword(s):  
Removal Rate ◽  
Experimental Result ◽  
Raw Water ◽  
Turbidity Removal ◽  
Gravity Settling ◽  
Bottom Mud ◽  
High Turbidity ◽  
Different Depths ◽  
Pre Treatment

The purpose of this Research is to simulate the water quality of varied High-turbidity Raw Water at different depths under the water’s surface. During the experiment, a Barrier Board was used to extend the flowing route and to change the overflow level for carrying out the pre-treatment of High-turbidity Raw Water through the changes of varied flow rates in order to study the changes and the removal rate of the turbidity for the influent and effluent; with the settled bottom mud surveyed, the operating requirements of the Surface Overflow Rate (SOR). The experimental result indicated that the turbidity of High-turbidity Water can be reduced by means of an inertia restrained flow, extending the flowing route and heightening the overflow level. The results indicated that the turbidity of the effluent was mostly between 380-1,000 NTU in presenting an over 50% removal rate and even up to 93%. When the SOR of the Sedimentation Basin is set at 19.l m/d, a 54-86% turbidity removal rate can be achieved; whereas, a 50-72% removal rate can be achieved when set at 38.3 m/ d. It has indicated that a significant effect could be achieved for turbidity treatment by employing the properties of high-turbidity substances and the convenient physical theory of gravity settling. As such, a visible removal effect could be achieved to exhibit the effect of pre-treatment.

Pretreatment chemistry for dual media filtration: model simulations and experimental studies

2006 ◽  
Vol 53 (7) ◽  
pp. 167-175 ◽  
Author(s):  
J.Y. Shin ◽  
C.R. O'Melia
Keyword(s):  
Rapid Development ◽  
Experimental Studies ◽  
Raw Water ◽  
Small Particles ◽  
Model Simulations ◽  
Direct Filtration ◽  
Filter Performance ◽  
Suboptimal Dose ◽  
Particle Counts ◽  
Filtration Model

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.

scholarly journals Effect of Religious Beliefs on Quality of Translation

2017 ◽  
Vol 5 (2) ◽  
pp. 32
Author(s):  
Sarah Yousefi
Keyword(s):  
Quality Assessment ◽  
Religious Beliefs ◽  
Translation Studies ◽  
Statistical Analyses ◽  
The Other ◽  
High Quality ◽  
Religious Texts ◽  
Translation Quality ◽  
Do So

Quality of translation has become one of the main focuses in the field of Translation Studies. When it comes to the religious texts and their translations, quality of translation becomes more and more important as these texts are directly connected to the beliefs of followers of a specific religion, and since many of the religious texts have been written many years ago, and now the followers of that religion are neither able to learn the language of their religions nor have enough time to do so, delivering high quality translations is very crucial. In recent years, many translation scholars have focused on Translation Quality Assessment (TQA) to provide ways to translators and translation teachers to assess the quality of translations and consequently to overcome translation problems. In the present research, the researcher attempted to combine both of the aforementioned subjects. In order to achieve this goal, the researcher selected Waddington’s model for assessing the quality of translations, to see if the quality of translations of Islamic texts which were translated by Muslim translators were higher than those which were translated by non-Muslims. Two groups of translators were selected, one of them was Muslim and the other one was non-Muslim. Each group consisted of 10 translators, each of them translated 5 Islamic-religious texts, and after assessing the quality of translations and doing statistical analyses, researcher concluded that there was no relation between the quality of translations and the religious beliefs of translators. 

Immunoferritin localization of intracellular antigens in positively stained frozen sections

1978 ◽  
Vol 36 (2) ◽  
pp. 168-169
Author(s):  
K. T. Tokuyasu
Keyword(s):  
Surface Tension ◽  
Water Surface ◽  
Thin Layers ◽  
The Other ◽  
Positive Staining ◽  
Frozen Sections ◽  
The Past ◽  
Ultrathin Frozen Sections ◽  
Definition Of

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).

PENERAPAN iLEARNING SURVEY (iSur) DALAM MENINGKATKAN KUALITAS SISTEM INFORMASI SELAMA PROSES PEMBELAJARAN DI PERGURUAN TINGGI RAHARJA

CCIT Journal ◽  
2014 ◽  
Vol 7 (3) ◽  
pp. 335-354
Author(s):  
Untung Rahardja ◽  
Muhamad Yusup ◽  
Ana Nurmaliana
Keyword(s):  
Higher Education ◽  
Student Satisfaction ◽  
Teaching And Learning ◽  
Online Survey ◽  
The Other ◽  
Learning Activities ◽  
Faculty Performance ◽  
Satisfaction Measurement ◽  
Valid Information

The accuracy and reliability is the quality of the information. The more accurate and reliable, the more information it’s good quality. Similarly, a survey, the better the survey, the more accurate the information provided. Implementation of student satisfaction measurement to the process of teaching and learning activities on the quality of the implementation of important lectures in order to get feedback on the assessed variables and for future repair. Likewise in Higher Education Prog has undertaken the process of measuring student satisfaction through a distributed questioner finally disemester each class lecture. However, the deployment process questioner is identified there are 7 (seven) problems. However, the problem can be resolved by the 3 (three) ways of solving problems one of which is a system of iLearning Survey (Isur), that is by providing an online survey to students that can be accessed anywhere and anytime. In the implementation shown a prototype of Isur itself. It can be concluded that the contribution Isur system can maximize the decision taken by the Higher Education Prog. By using this Isur system with questions and evaluation forms are submitted and given to the students and the other colleges. To assess the extent to which the campus has grown and how faculty performance in teaching students class, and can be used as a media Isur valid information for an assessment of activities throughout college.

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