Biomass production potential of materials in contact with drinking water: method and practical importance

2001 ◽  
Vol 1 (3) ◽  
pp. 39-45 ◽  
Author(s):  
D. van der Kooij ◽  
H.R. Veenendaal
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Biomass Production ◽  
Biofilm Formation ◽  
Practical Importance ◽  
Volume Ratio ◽  
Total Biomass ◽  
Production Potential ◽  
Suspended Biomass ◽  
Growth Promoting

Synthetic materials in contact with drinking water may affect microbial water quality by releasing growth-promoting substances. Various tests are being used for assessing the microbial growth-supporting potential of such materials. The biofilm formation potential (BFP) method is based on determining the concentration of active biomass (as adenosine triphosphate (ATP)) on the surface of a material incubated in slow sand filtrate (surface to volume ratio 0.15/cm) at 25°C during a period of 16 weeks. In addition to attached biomass (biofilm), suspended biomass is also produced. The amount of suspended biomass is a significant fraction (20-70%) of the total biomass production, depending of the type of material. Therefore, it is concluded that the production of suspended biomass should be included in evaluating the growth-promoting properties of materials in contact with drinking water. Consequently, the BFP test has been adapted to the biomass production potential (BPP) test, with BPP including BFP and suspended biomass production (SBP), as pg ATP/cm2. The defining criteria for BPP values for materials require further investigation into the effects of water quality on biofilm formation and the relationship between BPP values and regrowth problems.

The effect of the surface-to-volume contact ratio on the biomass production potential of the pipe products in contact with drinking water

2010 ◽  
Vol 10 (1) ◽  
pp. 105-112 ◽  
Author(s):  
Z. G. Tsvetanova ◽  
E. J. Hoekstra
Keyword(s):  
Drinking Water ◽  
Biomass Production ◽  
Microbial Growth ◽  
Biomass Concentration ◽  
Point Of View ◽  
Contact Ratio ◽  
Production Potential ◽  
Static Test ◽  
Growth Promoting ◽  
Construction Product

The biomass production potential (BPP) test is a semi-static test for assessment of microbial growth promoting properties of construction products in contact with drinking water (CPDW). In 2003 the test was selected for incorporation into a scheme for acceptance of CPDW in the framework of implementation of the European Construction Product Directive and Drinking Water Directive. The pass/fail criterion for the BPP test is based on the sum of microbial growth in water and in biofilm caused by substances released from CPDW. The test is performed at a surface-to-volume contact ratio (S/V) of 0.17 cm−1, that is quite different from the practice in buildings and domestic installations, where the usual ratios are 2.1 cm−1 for 3/4 inches pipe, 1.6 cm−1 for 1 inches pipe or 1.0 cm−1 for 1.5 inches pipe. The goal of the study was to evaluate the importance of S/V ratio for performance of the BPP test and for correct assessment of the growth promoting properties of CPDW. The BPP of 10 pipe products were compared under the S/V ratios of 0.17 cm−1 and 1.7 cm−1. The BPP of most polymer products were higher under the S/V ratio of 1.7 cm−1 in individual trials, but the differences were insignificant. However, the planktonic biomass concentrations were 4–14 fold higher at larger S/V ratio and this can be important from hygienic point of view. For acceptance of CPDW, besides a pass/fail criterion for the BPP, the planktonic biomass concentration could be taken as a second criterion for evaluation.

A study on assessment of biomass production potential of pipe materials in contact with drinking water

2009 ◽  
Vol 9 (4) ◽  
pp. 423-429 ◽  
Author(s):  
Z. G. Tsvetanova ◽  
E. J. Hoekstra
Keyword(s):  
Drinking Water ◽  
Biomass Production ◽  
Distribution Systems ◽  
Microbial Growth ◽  
Production Potential ◽  
Construction Products ◽  
Growth Promoting ◽  
Materials Used ◽  
Pipe Materials

The point of compliance in the European Drinking Water Directive is the consumer's tap and thus a set of requirements for the quality of materials used in distribution systems is needed. On European level an approval scheme for construction products in contact with drinking water is under development. The Regulators Group proposed that the Biomass Production Potential (BPP) test should be the basis for assessment of microbial growth support properties of products in contact with drinking water. Due to a lack of data the goal of this study was to generate more information on the growth promoting properties of pipe materials of different origin using the BPP test. The pipe materials under study showed different capacity to enhance bacterial growth and their BPP values could be ranked: Cu < SS < PP < PEx < PE < PVCp. A positive correlation between the planktonic biomass (PB) and the BPP was observed. Materials with a high BPP and a relatively higher PB/BPP ratio had a higher potential to impair bacteriological water quality. The option for derivation of pass-fail criteria based on planktonic biomass was discussed.

scholarly journals Hydrologic and water quality impacts and biomass production potential on marginal land

2015 ◽  
Vol 72 ◽  
pp. 230-238 ◽  
Author(s):  
Qingyu Feng ◽  
Indrajeet Chaubey ◽  
Young Gu Her ◽  
Raj Cibin ◽  
Bernard Engel ◽  
...  
Keyword(s):  
Water Quality ◽  
Biomass Production ◽  
Marginal Land ◽  
Production Potential

Drinking Water Biofilm Management and Monitoring

2020 ◽  
Author(s):  
Frances Pick ◽  
Katherine Fish ◽  
Stewart Husband ◽  
Joby Boxall
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Asset Management ◽  
Distribution System ◽  
Biofilm Formation ◽  
Distribution Systems ◽  
Intact Cell ◽  
Line Pipe ◽  
Biofilm Growth ◽  
The Impact

<p>Biofilms within drinking water distribution systems can pose risks to consumers, especially when mobilised, as high concentrations of microorganisms and associated material can be released leading to degradation of water quality. Access and sampling of biofilms within drinking water pipelines can be difficult without disrupting supply in these extensive and buried systems. A novel biofilm monitoring device was developed to determine if biofilm formation rates can be used to assess microbiological water quality, track fouling rates and ultimately indicate distribution system performance. The device comprises a sample-line pipe with multiple, independent removable sections (allowing for biofilm sampling) that can be easily connected to sampling points in the distribution system. Biofilm is removed from the device and flow cytometry used to determine total and intact cell concentrations. The biomonitoring device was tested in a series of laboratory trials, to establish the impact of different flow rates and orientations on biofilm formation and to determine the optimum configuration that achieves accurate and repeatable results. Subsequently, these devices were installed in two operational systems, with different water qualities, and biofilms were sampled for two months to obtain biofilm growth rates. The results provide the first direct evidence of different biofilm formation rates in distribution systems with different water qualities. This evidence is now being used to investigate fouling rates via risk analysis and modelling. The use of the device has potential to improve understanding of biofilm behaviour and help inform biofilm and asset management to safeguard the quality of delivered drinking water.</p>

Investigation into the occurrence of aquatic invertebrates throughout drinking water purification plants

2012 ◽  
Vol 12 (2) ◽  
pp. 250-257 ◽  
Author(s):  
L. Ferreira ◽  
H. H. Du Preez
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Purification ◽  
Water Distribution ◽  
Water Distribution Network ◽  
Total Biomass ◽  
Purification Process ◽  
Multivariate Statistical ◽  
Drinking Water Distribution ◽  
Drinking Water Purification

World-wide, invertebrates are found in most drinking water networks; however, limited data and information are available on the occurrence of invertebrates throughout the purification process. During this investigation, temporal and spatial variations in the invertebrate composition occurring throughout a conventional Drinking Water Purification Plant (DWPP) and the abiotic drivers responsible for their occurrence were investigated. Samples destined for invertebrate and water quality analyses were collected and multivariate statistical analysis was performed on the data obtained. Copepoda, Rotatoria, Cladocera, Ostracoda and Diptera were the dominant groups found in the source water and occurred throughout the purification process. A higher total biomass occurred throughout the purification process, in particular after sedimentation and filtration, compared with the total biomass entering the DWPP. The water quality variables measured were within the optimum ranges of invertebrates. The present study proved the theory that purification plants are an important source of invertebrates occurring in the drinking water distribution network. Strategies should be implemented to improve coagulation (by using coagulants/flocculants to increase the pH above 10.5), flocculation, sedimentation (by removing sludge and algae) and filtration (by optimizing filter bed maintenance) and general filter house ‘housekeeping’.

scholarly journals Silver as a Residual Disinfectant To Prevent Biofilm Formation in Water Distribution Systems

2008 ◽  
Vol 74 (5) ◽  
pp. 1639-1641 ◽  
Author(s):  
Nadia Silvestry-Rodriguez ◽  
Kelly R. Bright ◽  
Donald C. Slack ◽  
Donald R. Uhlmann ◽  
Charles P. Gerba
Keyword(s):  
Water Quality ◽  
Stainless Steel ◽  
Drinking Water ◽  
Polyvinyl Chloride ◽  
Biofilm Formation ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Significant Difference ◽  
Steel Surfaces

ABSTRACT Biofilms can have deleterious effects on drinking water quality and may harbor pathogens. Experiments were conducted using 100 μg/liter silver to prevent biofilm formation in modified Robbins devices with polyvinyl chloride and stainless steel surfaces. No significant difference was observed on either surface between the silver treatment and the control.

scholarly journals Influence of phosphate dosing on biofilm development on Drinking Water Distribution Systems infrastructure surfaces

2020 ◽  
Vol 2 (7A) ◽  
Author(s):  
Gonzalo Del Olmo ◽  
Esther Rosales ◽  
Esther Karunakaran ◽  
Henriette Jensen ◽  
Carolina Calero ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Biofilm Formation ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Drinking Water Distribution Systems ◽  
Physico Chemical ◽  
Drinking Water Distribution ◽  
Biofilm Development

Phosphate is added to drinking water by UK water companies as a treatment to prevent the corrosion and metal leaching, like lead, in pipes. However, phosphate is a nutrient for microorganisms, and it can favour biofilm formation in Drinking Water Distribution Systems (DWDS), which can alter the water quality and safety. This study analyses the effect of phosphate addition on biofilm formation over different materials and its consequences for drinking water quality by i) using controlled experimental pipeline facility representative of a real-scale DWDS with high-density polyethylene coupons and ii) using a small-scale DWDS biofilm reactors with lead coupons. Biofilms developed over one month were exposed to the effect of different phosphate dosing and compare with UK normal water phosphate concentrations. During the experiment, physico-chemical analysis of water and microbial analysis of biofilms was carried out. Sequencing analysis of the 16s rRNA gene, from extracted DNA obtained from biofilms, provided information on any bacterial changes, and Scanning Electron Microscopy gave information about the biofilm organization. The results indicate that microorganisms find more difficult to establish and develop biofilms under high phosphate dosing, resulting in biofilms with less cells. Also, some physico-chemical parameter seems to be affected by phosphate dosing, like chlorine and lead. It is expected that differences in the biofilm community will be found depending on phosphate dosing. This study will provide information on the effect of phosphate on biofilm development in different pipes materials, which will facilitate to adjust an optimal phosphate dose to prevent plumbosolvency in DWDS.

scholarly journals Assessing comprehensive performance of biofilm formation and water quality in drinking water distribution systems

2016 ◽  
Vol 17 (1) ◽  
pp. 267-278 ◽  
Author(s):  
Li Liu ◽  
Yanyan Liu ◽  
Qingqing Lu ◽  
Guowei Chen ◽  
Gang Wang
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Biofilm Formation ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Drinking Water Distribution Systems ◽  
Comprehensive Performance ◽  
Environmental Fluctuations ◽  
Drinking Water Distribution

Environmental fluctuations shape biofilm formation in drinking water distribution systems (DWDSs) and therefore distributed water quality. Yet the comprehensive performance in response to complex environmental conditions remains unclear. We investigated biofilm formation and distributed water quality under various nutrients, including chlorine concentrations and hydrodynamic conditions. Results showed that environmental fluctuations collectively induced changes in microbial propagation, which were mostly associated with turbidity variations, concentrations of total organic carbon, NH4+-N and soluble phosphorus compared to the other parameters. Fuzzy pattern recognition analysis integrating multiple water quality indicators revealed that low nutrient availability and addition of mild chlorine at 0.50 mg/L at 0.50 m/s flow velocity were the most favorable conditions screened for optimized comprehensive performance, while nutrient supplements yielded significant performance deterioration. These quantitative estimations offer new insights into advanced understanding of the system performance responding to often complex environmental fluctuations, essential for optimized design and practical functioning of DWDSs.

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