Biological Stability of Drinking Water in an Eastern China City

2011 ◽  
Vol 356-360 ◽  
pp. 2109-2113
Author(s):  
Lu Chen ◽  
Meng Hui Wang ◽  
Rui Bao Jia ◽  
Li Li

In this study, the indicators assimilable organic carbon (AOC), dissolved organic carbon (DOC), heterotrophic plate counts (HPC) and microbially available phosphorus (MAP) were measured to evaluate the biological stability of drinking water in Jinan, an east China city, which uses different water sources in its distribution system. The results were shown that the concentration of AOC below 50μg ac-C•L-1 covered the detection of 58% sampling points in the city distribution systems. The difference of source water exercised a great influence to the concentration of AOC. The lower heterotrophic colony counts were detected when the AOC values were higher, and vice versa. The value of AOC/DOC showed its irregularity. MAP was negatively correlated with the AOC. Higher values of AOC and HPC were detected in pumping water than that in pipe water, while values of MAP were equivalent to each othe

2016 ◽  
Vol 16 (4) ◽  
pp. 865-880 ◽  
Author(s):  
E. I. Prest ◽  
F. Hammes ◽  
S. Kötzsch ◽  
M. C. M. van Loosdrecht ◽  
J. S. Vrouwenvelder

A systematic approach is presented for the assessment of (i) bacterial growth-controlling factors in drinking water and (ii) the impact of distribution conditions on the extent of bacterial growth in full-scale distribution systems. The approach combines (i) quantification of changes in autochthonous bacterial cell concentrations in full-scale distribution systems with (ii) laboratory-scale batch bacterial growth potential tests of drinking water samples under defined conditions. The growth potential tests were done by direct incubation of water samples, without modification of the original bacterial flora, and with flow cytometric quantification of bacterial growth. This method was shown to be reproducible (ca. 4% relative standard deviation) and sensitive (detection of bacterial growth down to 5 µg L−1 of added assimilable organic carbon). The principle of step-wise assessment of bacterial growth-controlling factors was demonstrated on bottled water, shown to be primarily carbon limited at 133 (±18) × 103 cells mL−1 and secondarily limited by inorganic nutrients at 5,500 (±1,700) × 103 cells mL−1. Analysis of the effluent of a Dutch full-scale drinking water treatment plant showed (1) bacterial growth inhibition as a result of end-point chlorination, (2) organic carbon limitation at 192 (±72) × 103 cells mL−1 and (3) inorganic nutrient limitation at 375 (±31) × 103 cells mL−1. Significantly lower net bacterial growth was measured in the corresponding full-scale distribution system (176 (±25) × 103 cells mL−1) than in the laboratory-scale growth potential test of the same water (294 (±35) × 103 cells mL−1), highlighting the influence of distribution on bacterial growth. The systematic approach described herein provides quantitative information on the effect of drinking water properties and distribution system conditions on biological stability, which can assist water utilities in decision-making on treatment or distribution system improvements to better control bacterial growth during water distribution.


2019 ◽  
Vol 5 (10) ◽  
pp. 1689-1698
Author(s):  
Xu Ma ◽  
Guiwei Li ◽  
Ying Yu ◽  
Ruya Chen ◽  
Yao Zhang ◽  
...  

Discoloration problems have occurred in drinking water distribution systems continuously for several years in a rural area of eastern China.


2012 ◽  
Vol 518-523 ◽  
pp. 3735-3739
Author(s):  
Dong Sheng Dai ◽  
Song Hu Li ◽  
Jie Li

The Assimilable Organic Carbon (AOC), Microbially Available Phosphorus (MAP), Heterotrophic Plate Count (HPC) and Biodegradable Dissolved Organic Carbon (BDOC) of eight sampling points were analyzed for studying the biological stability of drinking water in Jinan. Biological stability of drinking water can standard basically in Jinan city. There had a certain correlation between AOC and HPC. The AOC indicator was gradual increased from April to May and June to July. There may be related to the seasonal change of Yellow River. The control of AOC was an effective way to improve the water quality.


Author(s):  
Jiang Chen ◽  
Ya Shi ◽  
Dongqing Cheng ◽  
Yan Jin ◽  
William Hutchins ◽  
...  

Abstract Bacteria, especially pathogenic bacteria, were detected in order to estimate the safety of drinking water distribution systems (DWDS). 16 biofilms and 12 water samples (6 retained and 6 flowing) were collected from a city DWDS in Eastern China. Biofilms were observed using scanning electron microscopy. Cultivable bacteria of biofilms were counted by heterotrophic plate counts, ranging from 3.61 × 101 to 1.67 × 106 CFU·cm−2. Coliforms, Salmonella, Shigella, Vibrio, and Legionella were separated by EMB agar, Salmonella chromogenic medium, Shigella chromogenic medium, TCBS agar, BCYE agar, and 13/16, 8/16, 7/16, 6/16, 0/16 biofilm samples were found positive respectively. Retained and flowing water samples were collected to estimate the influence of hydrodynamic conditions on biofilm detachment. All 6 retained water samples were positive for bacteria, count ranged from 1.2 × 103 to 2.8 × 104 CFU·mL−1 and 2/6, 3/6, 2/6, 0/6, 0/6 samples were positive for coliforms, Salmonella, Shigella, Legionella, and Vibrio, respectively. While only 3 of 6 flowing water samples were bacteria positive, counts ranged from 102 to 103 CFU·mL−1, 2/6 were coliforms positive, no pathogens under testing were detected. The results show that there are pathogens in DWDS biofilms, which can cause health related problems if detached from their surface.


2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Jenni Meirami Ikonena ◽  
Anna-Maria Hokajärvi ◽  
Jatta Heikkinen ◽  
Tarja Pitkänen ◽  
Robert Ciszek ◽  
...  

Physico-chemical and microbiological water quality in the drinking water distribution systems (DWDSs) of five waterworks in Finland with different raw water sources and treatment processes was explored. Water quality was monitored during four seasons with on-line equipment and bulk water samples were analysed in laboratory. Seasonal changes in the water quality were more evident in DWDSs of surface waterworks compared to the ground waterworks and artificially recharging ground waterworks (AGR). Between seasons, temperature changed significantly in every sys-tem but pH and EC changed only in one AGR system. Seasonal change was seen also in the absorbance values of all sys-tems. The concentration of microbially available phosphorus (MAP, μg PO₄-P/l) was the highest in drinking water origi-nating from the waterworks supplying groundwater. Total assimilable organic carbon (AOC, μg AOC-C/l) concentrations were significantly different between the DWDSs other than between the two AGR systems. This study reports differences in the water quality between surface and ground waterworks using a wide set of parameters commonly used for monitor-ing. The results confirm that every distribution system is unique, and the water quality is affected by environmental fac-tors, raw water source, treatment methods and disinfection.


2011 ◽  
Vol 11 (1) ◽  
pp. 107-112 ◽  
Author(s):  
A. Grefte ◽  
M. Dignum ◽  
S. A. Baghoth ◽  
E. R. Cornelissen ◽  
L. C. Rietveld

To guarantee a good water quality at the consumer’s tap, natural organic matter (NOM) should be (partly) removed during drinking water treatment. The objective of this research is to measure the effect of NOM removal by ion exchange on the biological stability of drinking water. Experiments were performed in two lanes of the pilot plant of Weesperkarspel in the Netherlands. The lanes consisted of ozonation, softening, biological activated carbon filtration and slow sand filtration. Ion exchange in fluidized form was used as pre-treatment in one lane and removed 50% of the dissolved organic carbon (DOC); the other lane was used as reference. Compared to the reference lane, the assimilable organic carbon (AOC) concentration of the finished water in the lane pretreated by ion exchange was 61% lower. The biofilm formation rate of the finished water was decreased with 70% to 2.0 pg ATP/cm2.day. The achieved concentration of AOC and the values of the biofilm formation rate with ion exchange pre-treatment showed that the biological stability of drinking water can be improved by extending a treatment plant with ion exchange, especially when ozonation is involved as disinfection and oxidation step.


2007 ◽  
Vol 55 (5) ◽  
pp. 161-168 ◽  
Author(s):  
T.H. Heim ◽  
A.M. Dietrich

Pipe relining via in situ epoxy lining is used to remediate corroded plumbing or distribution systems. This investigation examined the effects on odour, TOC, THM formation and disinfectant demand in water exposed to epoxy-lined copper pipes used for home plumbing. The study was conducted in accordance with the Utility Quick Test, a migration/leaching method for utilities to conduct sensory analysis of materials in contact with drinking water. The test was performed using water with no disinfectant and levels of chlorine and monochloramines representative of those found in the distribution system. Panelists repeatedly and consistently described a “plastic/adhesive/putty” odour in the water from the pipes. The odour intensity remained relatively constant for each of two subsequent flushes. Water samples stored in the epoxy-lined pipes showed a significant increase in the leaching of organic compounds (as TOC), and this TOC was demonstrated to react with free chlorine to form trichloromethane. Water stored in the pipes also showed a marked increase in disinfectant demand relative to the water stored in glass control flasks. A study conducted at a full scale installation at an apartment demonstrated that after installation and regular use, the epoxy lining did not yield detectable differences in water quality.


2001 ◽  
Vol 1 (4) ◽  
pp. 237-245 ◽  
Author(s):  
V. Gauthier ◽  
B. Barbeau ◽  
R. Millette ◽  
J.-C. Block ◽  
M. Prévost

The concentrations of suspended particles were measured in the drinking water of two distribution systems, and the nature of these particles documented. The concentrations of particulate matter were invariably found to be small (maximum 350 μg/L). They are globally in the very low range in comparison with dissolved matter concentrations, which are measured in several hundreds of mg/L. Except during special water quality events, such as turnover of the raw water resource, results show that organic matter represents the most important fraction of suspended solids (from 40 to 76%) in treated and distributed water. Examination of the nature of the particles made it possible to develop several hypotheses about the type of particles penetrating Montreal's distribution system during the turnover period (algae skeleton, clays). These particles were found to have been transported throughout the distribution systems quite easily, and this could result in the accumulation of deposits if their surface charge were ever even slightly destabilised, or if the particles were to penetrate the laminar flow areas that are fairly typical of remote locations in distribution systems.


2011 ◽  
Vol 57 (1) ◽  
pp. 21-30
Author(s):  
Božena Šoltysová ◽  
Martin Danilovič

Tillage in Relation to Distribution of Nutrients and Organic Carbon in the SoilChanges of total nitrogen, available phosphorus, available potassium and soil organic carbon were observed on gleyic Fluvisols (locality Milhostov) at the following crops: grain maize (2005), spring barley (2006), winter wheat (2007), soya (2008), grain maize (2009). The experiment was realized at three soil tillage technologies: conventional tillage, reduced tillage and no-tillage. Soil samples were collected from three depths (0-0.15 m; 0.15-0.30 m; 0.30-0.45 m). The ratio of soil organic carbon to total nitrogen was also calculated.Soil tillage affects significantly the content of total nitrogen in soil. The difference between the convetional tillage and soil protective tillages was significant. The balance showed that the content of total nitrogen decreased at reduced tillage by 5.2 rel.%, at no-tillage by 5.1 rel.% and at conventional tillage by 0.7 rel.%.Similarly, the content of organic matter in the soil was significantly affected by soil tillage. The content of soil organic carbon found at the end of the research period was lower by 4.1 rel.% at reduced tillage, by 4.8 rel.% at no-tillage and by 4.9 rel.% at conventional tillage compared with initial stage. The difference between the convetional tillage and soil protective tillages was significant.Less significant relationship was found between the soil tillage and the content of available phosphorus. The balance showed that the content of available phosphorus was increased at reduced tillage (by 4.1 rel.%) and was decreased at no-tillage (by 9.5 rel.%) and at conventional tillage (by 3.3 rel.%).Tillage did not significantly affect the content of available potassium in the soil.


2009 ◽  
Vol 9 (4) ◽  
pp. 379-386 ◽  
Author(s):  
S. A. Baghoth ◽  
M. Dignum ◽  
A. Grefte ◽  
J. Kroesbergen ◽  
G. L. Amy

For drinking water treatment plants that do not use disinfectant residual in the distribution system, it is important to limit availability of easily biodegradable natural organic matter (NOM) fractions which could enhance bacterial regrowth in the distribution system. This can be achieved by optimising the removal of those fractions of interest during treatment; however, this requires a better understanding of the physical and chemical properties of these NOM components. Fluorescence excitation-emission matrix (EEM) and liquid chromatography with online organic carbon detection (LC-OCD) were used to characterize NOM in water samples from one of the two water treatment plants serving Amsterdam, The Netherlands. No disinfectant residual is applied in the distribution system. Fluorescence EEM and LC-OCD were used to track NOM fractions. Whereas fluorescence EEM shows the reduction of humic-like as well as protein-like fluorescence signatures, LC-OCD was able to quantify the changes in dissolved organic carbon (DOC) concentrations of five NOM fractions: humic substances, building blocks (hydrolysates of humics), biopolymers, low molecular weight acids and neutrals.


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