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 Fate and fractionation of aluminum in a full-scale Al-based drinking water treatment plant

2020 ◽  
Vol 69 (5) ◽  
pp. 469-477
Author(s):  
Hongyuan Liu ◽  
Haoran Liu ◽  
Yawei Xie
Keyword(s):  
Drinking Water ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
Aluminum Concentration ◽  
Average Water Temperature ◽  
Treated Water ◽  
Residual Aluminum ◽  
Average Water ◽  
Particle Counts

Abstract Residual aluminum in drinking water is widely concerning due to its potentially harmful effect on human health and drinking water distribution systems. The fate and fractionation of aluminum and the factors influencing residual aluminum in a full-scale Al-based drinking water treatment plant (DWTP) was presented in Jiaxing, China. The results showed that treated water residual aluminum concentration was less than 0.1 mg/L regardless of the seasonal change of raw water aluminum concentration. The addition of secondary flocculation had a negligible influence on treated water residual aluminum concentration due to the efficient removal of particulate aluminum by sand filter. Residual aluminum concentration of treated water was lower (mean 0.037 mg/L) in summer (average water temperature was 29 °C) than that (mean 0.067 mg/L) in winter (average water temperature was 16 °C). Significant positive relationships between particulate aluminum concentration and particle counts, as well as the total aluminum concentration of treated water and turbidity, were found. Those relationships provided the possibility to estimate residual aluminum concentration by monitoring particle counts and turbidity.

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.

Thermal delousing with cold water: Effects on salmon lice removal and salmon welfare

Aquaculture ◽  
2019 ◽  
Vol 505 ◽  
pp. 41-46 ◽  
Author(s):  
Kathy Overton ◽  
Frode Oppedal ◽  
Lars H. Stien ◽  
Lene Moltumyr ◽  
Daniel W. Wright ◽  
...  
Keyword(s):  
Cold Water ◽  
Salmon Lice ◽  
Water Effects

scholarly journals Minimizing residual aluminum concentration in treated water by tailoring properties of polyaluminum coagulants

2013 ◽  
Vol 47 (6) ◽  
pp. 2075-2084 ◽  
Author(s):  
Masaoki Kimura ◽  
Yoshihiko Matsui ◽  
Kenta Kondo ◽  
Tairyo B. Ishikawa ◽  
Taku Matsushita ◽  
...  
Keyword(s):  
Aluminum Concentration ◽  
Treated Water ◽  
Residual Aluminum

Impact of Electronic Faucets and Water Quality on the Occurrence ofPseudomonas aeruginosain Water: A Multi-Hospital Study

2014 ◽  
Vol 36 (3) ◽  
pp. 311-319 ◽  
Author(s):  
Dominique Charron ◽  
Emilie Bédard ◽  
Cindy Lalancette ◽  
Céline Laferrière ◽  
Michèle Prévost
Keyword(s):  
Water Quality ◽  
Flow Rate ◽  
Water Samples ◽  
Cold Water ◽  
Residual Chlorine ◽  
Increased Risk ◽  
High Concentrations ◽  
Enzymatic Detection ◽  
Enzyme Detection ◽  
Hospital Study

OBJECTIVETo comparePseudomonas aeruginosaprevalence in electronic and manual faucets and assess the influence of connecting pipes and water quality.SETTINGFaucets in 4 healthcare centers in Quebec, Canada.METHODSWater samples from 105 electronic, 90 manual, and 14 foot-operated faucets were analyzed forP. aeruginosaby culture and enzymatic detection, and swab samples from drains and aerators were analyzed by culture. Copper and residual chlorine concentrations, temperature, and flow rate were measured.P. aeruginosaconcentrations were analyzed in 4 consecutive volumes of cold water and a laboratory study was conducted on copper pipes and flexible hoses.RESULTSP. aeruginosacontamination was found in drains more frequently (51%) than in aerators (1%) or water (culture: 4%, enzyme detection: 16%). Prevalence in water samples was comparable between manual (14%) and 2 types of electronic faucets (16%) while higher for foot-operated faucets (29%). However, type 2 electronic faucets were more often contaminated (31%) than type 1 (14%), suggesting that faucet architecture and mitigated volume (30 mL vs 10 mL) influenceP. aeruginosagrowth. Concentrations were 100 times higher in the first 250 mL than after flushing. Flexible hoses were more favorable toP. aeruginosagrowth than copper and a temperature of 40°C led to higher counts.CONCLUSIONSThe types of faucets and connecting pipes, flow rate, and water quality are important parameters influencing the prevalence and the concentrations ofP. aeruginosain faucets. High concentrations ofP. aeruginosain the first 250 mL suggest increased risk of exposure when using the first flush.Infect Control Hosp Epidemiol 2014;00(0): 1–9

scholarly journals Laboratory Study of Physical Barrier Efficiency for Worker Protection against SARS-CoV-2 while Standing or Sitting

2021 ◽  
Author(s):  
Jacob Bartels ◽  
Cheryl Fairfield Estill ◽  
I-Chen Chen ◽  
Dylan Neu
Keyword(s):  
Laboratory Study ◽  
Grocery Stores ◽  
Physical Barrier ◽  
Particle Count ◽  
Engineering Control ◽  
Transparent Barrier ◽  
Particle Counts ◽  
Barrier Efficiency ◽  
Number Of Particles ◽  
Nail Salons

Transparent barriers were installed as a response to the SARS-COV-2 pandemic in many customer-facing industries. Transparent barriers are an engineering control that are utilized to intercept air traveling between customers to workers. Information on the effectiveness of these barriers against aerosols is limited. In this study, a cough simulator was used to represent a cough from a customer. Two optical particle counters were used (one on each side of the barrier, labeled reference and worker) to determine the number of particles that migrated around a transparent barrier. Nine barrier sizes and a no barrier configuration were tested with six replicates each. Tests of these 10 configurations were conducted for both sitting and standing scenarios to represent configurations common to nail salons and grocery stores, respectively. Barrier efficiency was calculated using a ratio of the particle count results (reference/worker). Barriers had better efficiency when they were 9 to 39 cm (3.5 to 15.5 inches) above cough height and at least 91 cm (36 inches) wide, 92% and 93% respectively. Barriers that were 91 cm (36 inches) above table height for both scenarios blocked 71% or more of the particles between 0.35–0.725 µm and 68% for particles between 1 to 3 µm. A barrier that blocked an initial cough was effective at reducing particle counts. While the width of barriers was not as significant as height in determining barrier efficiency it was important that a barrier be placed where interactions between customers and workers are most frequent.

Relationship between suint and the sweat glands

1963 ◽  
Vol 14 (3) ◽  
pp. 340 ◽  
Author(s):  
BD Stacy ◽  
AH Brook ◽  
BF Short
Keyword(s):  
Cold Water ◽  
Water Extract ◽  
Sweat Glands ◽  
Different Types ◽  
High Concentrations

In the fleece of sheep with different types of skin, suint (cold water extract of the greasy fleece) was shown to be associated with the presence and size of the sweat glands. In the absence of sweat glands, suint was produced in substantially less than normal quantities, whereas the amount was much greater where the sweat glands were large.Similarly, the amount of potassium in suint, in skin, and in fluid from dermal cysts was much larger in the presence of sweat glands. The conclusion that suint is therefore largely produced by sweat glands was substantiated by the detection of high concentrations of potassium in sheep sweat.

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