Assessing the impact of corrosion control measures on tap drinking water of the Greater Vancouver Regional District

2005 ◽  
Vol 32 (5) ◽  
pp. 948-956 ◽  
Author(s):  
Gillian Knox ◽  
Don Mavinic ◽  
Jim Atwater ◽  
Doug MacQuarrie

A study on the quality of water distributed within the Greater Vancouver Regional District (GVRD) was carried out to evaluate the effectiveness of previously implemented corrosion controls. In addition, the effect of temperature fluctuations was investigated to determine if it influenced the efficacy of the control measures. The GVRD was divided into four distribution areas. The Capilano water had no corrosion control treatment. Seymour, Coquitlam, and Newton waters were treated with soda ash, resulting in a pH of 6.8, 6.9, and 8.1, respectively. Standing cold water and running hot and cold water samples were collected from the four zones and analyzed for lead, copper, and zinc concentrations. The source water did not influence the amount of lead at the tap. The source water did influence the amount of copper and zinc at the tap. The highest copper and zinc concentrations were found in the water with the lowest pH (Capilano) and the lowest concentrations in the water with the highest pH (Newton). Seasonal temperature fluctuations of distributed GVRD water did not affect the metal concentrations in the water.Key words: corrosion control, GVRD drinking water, copper, lead, zinc, pH adjustment.

Author(s):  
L. O. Bobor ◽  
C. M. Umeh

The indiscriminate disposal of industrial effluents and solid wastes in surface water bodies is detrimental to humans and aquatic organisms. Water quality monitoring is critical to identify pollutants of concern and develop effective management strategies. Hence, this study was conducted to assess the impact of waste disposal on the water quality of Aba Waterside River, Ogbor hill, Aba. Grab samples were collected upstream, midstream and downstream and some physicochemical and microbiological parameters were analyzed in accordance with standard methods for the analysis of water and wastewater. The results were compared with the Nigerian standard for drinking water quality and the national environmental effluent limitation regulations. Turbidity levels (10 -31mg/l) exceeded the maximum permissible levels for drinking water (5mg/l) and may be associated with higher levels of embedded disease-causing microbes and potentially harmful organic and inorganic substances. The biological oxygen demand midstream (1960mg/l) was remarkably high due to the effluent discharged from the abattoirs at that point. Fecal coliforms (3-198MPN/100ml) were detected in all samples, indicating the presence of other potentially harmful microorganisms. The findings of this study indicate that the water is unsuitable for direct drinking water purposes and stringent water quality control measures should be implemented.


1995 ◽  
Vol 52 (4) ◽  
pp. 864-874 ◽  
Author(s):  
U. Borgmann ◽  
W. P. Norwood

One-week-long metal uptake experiments with Hyalella azteca are potentially a powerful tool for rapidly assessing the impact of copper or zinc in contaminated water samples. Copper and zinc concentrations in whole body Hyalella are independent of body size for both control and metal-exposed amphipods. Uptake rates are rapid for both metals, but copper concentrations in Hyalella during continuous exposure peak at about 1 week, then gradually decline back towards control levels at an apparent rate of 0.039 d−1. Hyalella can, therefore, control body copper concentrations during exposure to elevated copper, but only gradually and after long exposure periods. Depuration rates for copper and zinc (0.16 and 0.68 d−1 respectively) are approximately five times slower than the apparent depuration rates during uptake, assuming a simple diffusion model. Uptake at increasing water concentrations results in saturation for both metals with maximum accumulations of 3.6 μmol/g dry weight above background. A mathematical model including saturation kinetics satisfactorily explains the more rapid approach to equilibrium observed during uptake than during depuration. Significant chronic mortality occurred at metal exposures that resulted in predicted accumulations of 1.8 μmol Cu/g or 1.3 μmol Zn/g above background after 1 week of uptake.


2021 ◽  
Author(s):  
Sebastian Munoz ◽  
Benjamin F. Trueman ◽  
Bofu Li ◽  
Graham A. Gagnon

AbstractSodium silicates have been studied for sequestration of iron, coagulation, and corrosion control, but their impact on biofilm formation has not been documented in detail. This study investigated the impact of sodium silicate corrosion control on biomass accumulation in drinking water systems in comparison to orthophosphate, a common corrosion inhibitor. Biofilm growth was measured by determining ATP concentrations, and the bacterial community was characterized using 16S ribosomal RNA (rRNA) sequencing. A pilot-scale study with cast-iron pipe loops, annular reactors (ARs), and polycarbonate coupons demonstrated significantly lower biofilm ATP concentrations in the sodium silicate-treated AR than the orthophosphate-treated AR when the water temperature exceeded 20°C. However, an elevated sodium silicate dose (48 mg L-1 of SiO2) disturbed and dispersed the biofilm formed inside the AR, resulting in elevated effluent ATP concentrations. Two separate experiments confirmed that biomass accumulation was higher in the presence of orthophosphate at high water temperatures (20°C) only. No significant differences were identified in biofilm ATP concentrations at lower water temperatures (below 20°C). Differences in bacterial communities between the orthophosphate- and sodium silicate-treated systems were not statistically significant, even though orthophosphate promoted higher biofilm growth. However, the genera Halomonas and Mycobacterium—which include opportunistic pathogens—were present at greater relative abundances in the orthophosphate-treated system compared to the sodium silicate system.Graphical abstractOrthophosphate promotes more biofilm growth in comparison to sodium silicates at water temperatures above 20°C.Water impact statementSodium silicates have been used in drinking water treatment for decades, both as sequestrants and as corrosion inhibitors. However, their impact on biofilm formation is poorly understood, and this risks drinking water quality. This study aims to further clarify the effects of corrosion inhibitors on biofilm development, including inhibitors that are not phosphate-based.


1986 ◽  
Vol 66 (3) ◽  
pp. 669-680 ◽  
Author(s):  
M. E. SMART ◽  
R. COHEN ◽  
D. A. CHRISTENSEN ◽  
C. M. WILLIAMS

Pregnant Hereford cows (n = 99) and heifers (n = 98) whose ration contained 10 mg Cu kg−1 DM and 20 mg Zn kg−1 DM were assigned to two treatments. The water supply (sulphated water) for one group contained 500 mg S L−1 as sulphates. The sulphates in the water (desulphated) for the other group had been decreased to 42 mg S L−1 by reverse osmosis. Changes in plasma and liver copper and zinc concentrations were monitored in the cows and their calves during the winter drylot and pasture periods. The initial plasma and liver copper concentrations in all cows indicated a deficient status. At calving, the plasma copper concentration had declined in both groups. The greatest decrease was evident in the cows on sulphated water. At calving, the liver copper concentration had declined in both water treatment groups but was lowest in the cattle on the sulphated water. After calving, plasma and liver copper concentrations in both groups increased; this increase was greatest in the cows drinking the desulphated water. Water treatment had no effect on the copper status of the nursing calves. Water purification had a positive effect on the body weights of first and second calf heifers. Although the zinc status was normal, the plasma zinc declined and liver zinc increased in the cows at calving. These changes were independent of water treatment. When the sulphur in the drinking water was decreased to 42 mg L−1 by reverse osmosis there was a positive effect on the copper status of beef cows. Further research is required into higher dietary copper intakes, as 10 mg Cu kg−1 DM was not adequate in improving the deficient copper status of these cattle. Key words: Water sulphates, copper, zinc, beef cattle


2021 ◽  
Author(s):  
Qingyuan Guo ◽  
Zhaoxia Li ◽  
Tianming Chen ◽  
Bairen Yang ◽  
Cheng Ding

Abstract Sudden odor incidents occurring in the source water have been a severe problem for water suppliers. In order to apply emergency control measures effectively, it is necessary to identify the target compounds responsible for odor incidents rapidly. The present work identified the odorants and explored emergency disposal mechanisms for sudden and severe odors in the QT River's drinking water source (HZ city, China). Medicinal, chemical, septic, and musty odors with strong intensities were detected in the source water. The effect of conventional treatments of drinking water treatment plant (DWTP) on odors' removal was limited, which was evident by the presence of medicinal, chemical, and musty odors with moderate intensities in the effluent of DWTP. Total seventeen odorants were identified successfully in the source water of QT River and the effluent of DWTP. The measured OAVs and reconstituting the identified odorants explained 87%, 87%, 89%, and 94% of medicinal, chemical, septic, and musty odors, respectively, in the source water of the QT River and 90%, 87%, and 88% of medicinal, chemical, and musty odors in the effluent. Styrene, phenol, 2-chlorophenol, 2-tert-butylphenol, and 2-methylphenol were associated with the medicinal odor, while propyl sulfide, diethyl disulfide, propyl disulfide, and indole were related to the septic odor. Geosmin and 2-methylisoborneol (2-MIB) were responsible for the musty odor, and cyclohexanone, 1,4-dichlorobenzene, and nitrobenzene were involved with the chemical odor. Based on the characteristics of identified odorants, powdered activated carbon (PAC) was applied to control the odors in the QT River. The results indicated that the medicinal, chemical, septic, and musty odors could be removed entirely after adding 15 mg/L PAC, which effectively controlled emergency odor problems. Overall, the study would offer a scientific basis and operational reference for emergency odor management and control in DWTP with similar complicated odor incidents.


2018 ◽  
Vol 96 (8) ◽  
pp. 913-919 ◽  
Author(s):  
Adam T. Downie ◽  
Hannah Wallace ◽  
Samantha Taylor ◽  
James D. Kieffer

Juvenile shortnose sturgeon (Acipenser brevirostrum Lesueur, 1818) were exposed to seawater and freshwater for 24 h to evaluate the osmoregulatory capabilities over a seasonal temperature gradient (5, 10, 15, 20 °C). Additionally, juveniles were exposed to 5 °C seawater and freshwater over 72 h to evaluate survival and osmoregulatory capacity under cold water conditions. Osmoregulatory capability was evaluated using standard metrics: survival rate, mass loss, plasma chloride ion (Cl–) concentrations, osmolality, oxygen-carrying variables, and energy metabolites. Three mortalities occurred following 24 h exposure to 20 °C seawater (73% survival) and one mortality occurred within 72 h in 5 °C seawater (89% survival). Plasma Cl– concentrations and osmolality were elevated in seawater-exposed juveniles at every exposure time, regardless of temperature. The least mass was lost in juveniles exposed to 5 and 10 °C seawater, versus 15 and 20 °C seawater. Low mass loss is likely due to a lower metabolic rate and lower ventilation, which would slow the rate by which osmotic stress would occur under cold conditions.


2021 ◽  
Vol 13 (18) ◽  
pp. 10484
Author(s):  
Cara Poor ◽  
Troy Membrere ◽  
Jared Miyasato

Green stormwater infrastructure (GSI) has become increasingly common to mitigate urban stormwater runoff. However, there is limited research on the impact of age and type of GSI. This study evaluated nutrient and metals concentrations in the soil water of five different GSI systems located at the University of Portland in Portland, Oregon. The GSI systems included a bioretention curb extension (part of Portland’s Green Street project), a bioretention basin, a bioretention planter, an infiltration basin, and a bioswale ranging in age from 2 to 11 years. Samples were taken from each system during rain events over a 10-month period and analyzed for copper (Cu), zinc (Zn), phosphate (PO43−), and total phosphorus (TP). Copper and zinc concentrations were found to be impacted by GSI age, with lower concentrations in older systems. The same trend was not found with PO43− and TP, where almost all GSI systems had soil water concentrations much higher than average stormwater concentrations. Age likely played a role in phosphorus soil water concentrations, but other factors such as sources had a stronger influence. Phosphorus is likely coming from the compost in the soil mix in addition to other sources in runoff. This study shows that GSI systems can be effective for copper and zinc, but changes to the soil mix design are needed to reduce high levels of PO43− and TP in soil water.


RSC Advances ◽  
2017 ◽  
Vol 7 (36) ◽  
pp. 22433-22440 ◽  
Author(s):  
H. Ewerts ◽  
S. Barnard ◽  
A. Swanepoel

The removal efficacy ofCeratiumcells from source water was evaluated. The best ZP for coagulation were achieved with organic polymer and Ca(OH)2. Cells were able to restore their ZP after 120 and 240 minutes settling time.


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