Monitoring for Cryptosporidium risk: do particle counters help?

2002 ◽  
Vol 2 (1) ◽  
pp. 171-180
Author(s):  
A. Morse ◽  
R. Wilson ◽  
A. Hull ◽  
J. Simms
Keyword(s):  
Loading Rate ◽  
Size Range ◽  
Raw Water ◽  
Water Turbidity ◽  
Particle Count ◽  
Water Particle ◽  
Increased Risk ◽  
Process Failure ◽  
Particle Counts ◽  
Clarified Water

Turbidity measurements are used extensively for monitoring water quality, and as a warning for process failure which may carry a risk of Cryptosporidium breakthrough. However, turbidity is most sensitive to particles in the submicrometre size range, whereas Cryptosporidium is 4-6 μm in diameter. The question therefore remains - do particle counters help in monitoring for the risk of Cryptosporidium breakthrough? A full year study was undertaken at a direct river abstraction works. The project aimed to establish whether particle counts can be used to predict an increased risk of Cryptosporidium breakthrough. Although protozoan (oo)cysts were often present in low numbers in the raw water, none was detected in the final water. Particle counts and turbidity measurements were carried out on three RGFs and the raw and clarified water. Online Cryptosporidium and Giardia samples were also taken daily from the three RGFs being monitored for particles, and bacteriological analyses were carried out on the same sample points. Other plant parameters and environmental factors were also monitored. Particle counts from RGFs varied significantly. The main factors influencing the filtered water particle count appeared to be raw water turbidity and algal counts, and the particulate loading rate to the filters.

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.

scholarly journals Using sulfuric acid (H2SO4) for pH adjustment in water treatment

2021 ◽  
Vol 11 (3) ◽  
pp. 19-27
Author(s):  
Ali Salim Abd Al-Hussein
Keyword(s):  
Sulfuric Acid ◽  
Water Treatment ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Strong Acid ◽  
Raw Water ◽  
Water Turbidity ◽  
Ph Adjustment ◽  
Oil Company ◽  
Clarified Water

The aim of this paper is to explain the advantages of using sulfuric acid in Qarmat Ali water treatment plant belong to Basrah Oil Company, which produces water for injection into the Rumaila reservoirs. Sulfuric acid is a strong acid providing rapid and effective pH reduction. Maintaining the coagulation pH within the optimum value (6.4) by inject specific value of sulfuric acid to RAW water enhances the clarification performances by reducing the clarified water turbidity to minimum value (5.1). It was preferable for  operating at a pH below the saturation pH to prevent the precipitation of minerals such as calcium carbonate which are contributing to blocking the surface filters installed downstream (auto back wash filters) and The clarifiers that cause increased the feed from 500 MBD  to 1000 MBD. With a fast and rapid dissociation in Water, Sulfuric acid is an effective and practical way to lower the pH on Qarmat Ali plant which producing in excess of 1,000MBD of export water.

Particle counts and size distribution in system design for removal of turbidity by granular deep bed filtration

1997 ◽  
Vol 36 (4) ◽  
pp. 225-230 ◽  
Author(s):  
S. Hatukai ◽  
Y. Ben-Tzur ◽  
M. Rebhun
Keyword(s):  
Treatment Process ◽  
Size Range ◽  
Cationic Polymer ◽  
Particle Removal ◽  
Filtration Process ◽  
Water Turbidity ◽  
Direct Filtration ◽  
Surface Water Treatment ◽  
Cryptosporidium Oocysts ◽  
Particle Counts

Surface water treatment plants are required to reduce filtered water turbidities down to 0.1 NTU. Turbidity measurement is not sensitive to particles in the size range of Giardia cysts and Cryptosporidium oocysts; furthermore, low treated water turbidity does not necessarily indicate their absence in the water. Particle removal measurement in the Giardia and Cryptosporidium size range was used for treatment process evaluation and optimization. Pilot plant experiments demonstrated that preoxidant type and dosing rate of alum and a cationic polymer affected removal efficiency of particles during direct filtration process more than any other process parameter.

Cold Water Effects on Enhanced Coagulation of High DOC, Low Turbidity Water

2001 ◽  
Vol 36 (4) ◽  
pp. 701-717 ◽  
Author(s):  
Larry Braul ◽  
T. Viraraghavan ◽  
Darrell Corkal
Keyword(s):  
Aluminum Sulfate ◽  
Cold Water ◽  
Enhanced Coagulation ◽  
Treated Water ◽  
Particle Count ◽  
Water Particle ◽  
Residual Aluminum ◽  
Water Effects ◽  
Particle Counts ◽  
High Concentrations

Abstract Prairie farm reservoirs are usually low in turbidity and contain high concentrations of dissolved organic carbon (DOC). Some are treated with aluminum sulfate in late fall when the water drops below 3°C, often with poor turbidity reduction results. Jar tests using aluminum sulfate were conducted to study the effect of water temperature on enhanced coagulation of a typical high DOC prairie water. Jar tests showed that temperature affects turbidity, particle counts and total residual aluminum but does not affect DOC, UV254 absorbance and colour reduction. Turbidity of the treated water increased consistently as the temperature decreased. Particle counts in the 1 to 10 μm range were reduced by two logs at 20°C but only by one log at 1.5°C indicating inferior oocyst removal at low temperatures. Bentonite addition at 1.5°C did not affect the treated water particle counts but because the bentonite increased the raw water particle count, the reduction of the particles could be increased by one log. Coagulant demand for the water tested without pH adjustment is one to two mg Al per mg of DOC at all temperatures tested. The optimum pH for all temperatures was about 6.0 for DOC removal and about 6.5 for turbidity removal based on a dosage increment of 0.5 pH units. UV254 absorbance is well suited to predict optimum aluminum sulfate dosage for DOC removal.

scholarly journals The Optimum of Detention Time on Flocculation Unit Using A Laboratory Scale Prototype

2020 ◽  
Vol 5 (2) ◽  
pp. 101
Author(s):  
Regita Nurul Anggraeni
Keyword(s):  
Main Parameter ◽  
Pipe Diameter ◽  
Raw Water ◽  
Water Turbidity ◽  
Detention Time ◽  
Coagulation And Flocculation ◽  
Different Characteristics ◽  
Flocculation Process ◽  
Clarified Water

<strong>Abstract. </strong>Water used to meet the daily needs of human has different characteristics depending on the quality and amount of substances found in it. Turbidity can performance the quality of the water. The raw water used in this research comes from Kalimalang River. Coagulation and flocculation are one of the most important processes to remove the substances in raw water. Detention time is the main parameter for the flocculation process. <strong>Objectives. </strong>This research aims to find out the optimum of detention time in the flocculation prototype unit. <strong>Methods and result. </strong>Designing and assembling the flocculator lab-scale prototype using 20 cm of pipe diameter. Running the prototype and analysis the effect of detention time to the clarified water turbidity in 30 minutes of 1 Liter imhoff cone with raw water range 41-60 NTU in a long dry season. The result is the optimum clarified water turbidity is found in the 19,7 minutes detention time appropriate to the 41-60 NTU raw water turbidity range.<strong> Conclusion.</strong> The result shows, that the optimum detention time was obtained in 19,7 minutes for 41-60 NTU raw water turbidity range.

scholarly journals Optimization of ACH Coagulant, Settling Time and Powdered Activated Carbon as Coagulant Aid with Economic Analysis

2021 ◽  
Keyword(s):  
Activated Carbon ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Settling Time ◽  
Raw Water ◽  
Economic Study ◽  
Optimal Process ◽  
Water Turbidity ◽  
Aluminum Sulphate ◽  
Actived Carbon

<p>Regular water treatment-plant (WTP) comprises of a number of units. Of course, problems exist throughout design and operation of the WTP units. Consequently, the current re-search aimed to minimize the shortcomings of the coagulation, sedimentation, and the adsorption methods through applying optimal process for these units. Additionally, eco-nomic analysis and the derivation mathematical models for the new coagulant (Aluminum Chlorohydrate (ACH)) and the traditional aluminum sulphate coagulant (Alum) were an-other objective of this work. Optimum coagulants for alum and ACH were obtained and presented for different raw water turbidities. The optimum settling time of 30 minutes and 40 minutes have been found for the settling of 1000 and 2000 NTU raw water sam-ples. Best dosages of 0.1 and 0.25 g/L of powdered actived carbon (PAC) were obtained for raw water turbidity of 419, and 1000 NTU which increased the removal efficiency of 28.95%, and 25.71%, respectively. Furthermore, the economic study for alum and ACH revealed that using ACH instead of alum led to reduction of cost by 32%. Commonly, it can be concluded that using ACH instead of alum is better because it is cheaper and more efficient. The predicted equations for the optimum dosages (Y) for alum (mg/L) and ACH (µl/L) dosages (X) were Y= 0.04 X + 14.42, and Y = 0.01 X + 0.72, respectively.</p>

Direct filtration with preozonation for small water treatment systems

2004 ◽  
Vol 48 (11-12) ◽  
pp. 473-479 ◽  
Author(s):  
E. Yüksel ◽  
Ö Akgiray ◽  
E. Soyer
Keyword(s):  
Treatment Method ◽  
Silica Sand ◽  
Particle Removal ◽  
Raw Water ◽  
Particle Count ◽  
Direct Filtration ◽  
Small Water ◽  
On Line ◽  
Very High ◽  
Different Water Sources

The possibility of applying preozonation followed by direct filtration without the use of a coagulant is investigated. Filtration experiments have been carried out using four different water sources within Istanbul. A 1 m deep bed of 0.8-1.2 mm silica sand was used as the filter medium. The filter was operated at a rate of 11.5 m/hr. Raw water turbidities ranged from 2.3 NTU to 10.0 NTU. Effluent turbidity and particle count values were monitored using an on-line turbidimeter and an on-line particle counter. With all the waters studied in this work, preozonation improved particle removal in direct filtration. With three of the mentioned waters, it was possible to achieve turbidity values below 1.0 NTU without a coagulant by applying ozone at a rate between 1.7-1.8 mg/L. It was not possible to reduce the turbidity of one of the waters to below 2.7 NTU even with very high ozone dosages. The need for pilot testing before deciding if this treatment method is applicable to a given water is underlined.

scholarly journals Effects of shoes on kinetics and kinematics of the squash forward lunge in male players

Kinesiology ◽  
2017 ◽  
Vol 49 (2) ◽  
pp. 178-184
Author(s):  
Jonathan Sinclair ◽  
Paul John Taylor
Keyword(s):  
Repeated Measures ◽  
Loading Rate ◽  
Motion Analysis System ◽  
Repeated Measures Anova ◽  
Increased Risk ◽  
Running Shoes ◽  
High Incidence ◽  
Chronic Injuries ◽  
Tibial Acceleration ◽  
Analysis System

Squash is associated with a high incidence of chronic injuries. Currently there is a trend in many sports for players to select minimalist footwear. The aim of the current investigation was to examine the effects of squashspecific, running shoes and minimalist footwear on the kinetics and 3-D kinematics of the lunge movement in squash players. Twelve male squash players performed lunge movements whilst wearing minimalist, running shoe and squash-specific footwear. 3-D kinematics of the lower extremities were measured using an eightcamera motion analysis system alongside kinetic and tibial acceleration information which were obtained using a force platform and an accelerometer. Differences between footwear were examined using one-way repeated measures ANOVA. The results show firstly that loading rate parameters were significantly greater in the minimalist (average = 85.36B.W/s and instantaneous = 179.09B.W/s) footwear in relation to the squashspecific (average = 38.66 B.W/s and instantaneous = 50.73B.W/s) and running footwear (average = 37.62B.W/s and instantaneous = 48.14B.W/s). In addition, tibial acceleration parameters were also significantly greater in the minimalist (peak tibial acceleration = 8.45 g and tibial acceleration slope = 422.28g/s) footwear in relation to the squash-specific (peak tibial acceleration = 4.33 g and tibial acceleration slope = 182.57g/s) and running footwear (peak tibial acceleration = 4.81 g and tibial acceleration slope = 226.72g/s). The significant increase in impact loading in the minimalist footwear therefore suggests this type of shoe may place squash players at an increased risk of developing impact-related chronic injuries.

Development of automatic coagulant dosage control technology for rapid change of raw water quality parameters

2012 ◽  
Vol 12 (6) ◽  
pp. 918-925 ◽  
Author(s):  
Y. Sangu ◽  
H. Yokoi ◽  
H. Tadokoro ◽  
T. Tachi
Keyword(s):  
Water Quality ◽  
Pilot Scale ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Control Technology ◽  
Raw Water ◽  
Control Logic ◽  
Water Turbidity ◽  
Coagulant Dosage ◽  
Raw Water Quality

An automatic coagulant dosage control technology for water purification plants was developed to deal with rapid changes of raw water quality parameters. Control logic was developed to decide coagulant dosage based on aluminum concentration in rapid mixing tank water based on results of semi-pilot scale experiments. This logic enabled quick feedback on the excess or lack of coagulant. It was found that the aluminum residual rate, which was proposed as an indicator of coagulation reactions, could be given as a function of coagulant dosage and turbidity. The effectiveness of the control logic was verified in semi-pilot scale experiments. Settled water turbidity was within ±0.5 NTU of target value even when raw water turbidity increased rapidly up to 100 NTU.

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