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.

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.

Assessment of microbial growth potential of PVC flexible tubing in contact with drinking water

2012 ◽  
Vol 12 (4) ◽  
pp. 489-495
Author(s):  
Z. G. Tsvetanova ◽  
E. J. Hoekstra
Keyword(s):  
Drinking Water ◽  
Microbial Growth ◽  
Immersion Test ◽  
Operating Conditions ◽  
Growth Potential ◽  
Contact Ratio ◽  
Contact Materials ◽  
Vending Machines ◽  
Tube Filling ◽  
Materials Used

Plasticized polyvinyl chloride (PVCp) tubes are commonly used to transport drinking water to public coffee vending machines, ice machines or water fountains. In contrast to pipe materials, the materials used beyond the consumer's tap are considered to be in contact with food and need to comply with the European Regulation for food contact materials; this, however, does not contain specific requirements about the enhancement of microbial growth. The aims of this study were to estimate microbial growth on PVCp tubes which were used to transport water to the types of machines noted above and to compare two methods of evaluating their net microbial growth potential. Four PVCp brands were tested for enhancement of microbial growth using a tube immersion test (the original Biomass Production Potential test) and a new tube filling test. Under field operating conditions, significant amounts of active biofilm accumulated on the PVCp-I tubes thereby impacting on water quality. In the laboratory test, the amount of biofilms on PVCp tubes and bacterial regrowth in the water depended on brand and were influenced by the surface-to-volume (S/V) contact ratio. To protect consumers' health, the microbial growth promoting potential of PVCp tubes should be taken into consideration when these products are in contact with drinking water.

scholarly journals Regional Diversification of Potential, Production and Efficiency of Use of Biogas and Biomass in Poland

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 742
Author(s):  
Grzegorz Ślusarz ◽  
Barbara Gołębiewska ◽  
Marek Cierpiał-Wolan ◽  
Jarosław Gołębiewski ◽  
Dariusz Twaróg ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Biomass Production ◽  
Biogas Production ◽  
Renewable Energy Sources ◽  
Energy Sources ◽  
Efficiency Frontier ◽  
The European Union ◽  
Production Potential ◽  
Solid Biomass ◽  
High Share

Energy obtained from renewable sources is an important element of the sustainable development strategy of the European Union and its member states. The aim of this research is, therefore, to assess the potential and use of renewable energy sources and their effectiveness from the regional perspective in Poland. The research covered the years 2012 and 2018. The diversification of production and potential of renewable energy sources was defined on the basis of biogas and biomass. Calculations made using the data envelopment analysis (DEA) method showed that, in 2012, only three voivodeships achieved the highest efficiency in terms of the use of biogas and biomass resources; in 2018, this number increased to four. Comparing the effective units in 2012 and 2018, it can be seen that their efficiency frontier moved upwards by 56% in terms of biogas and 21% in terms of to biomass. Despite a large relative increase in the production of heat from biogas by 99% compared to the production of heat from biomass by 38%, the efficiency frontier for biogas did not change considerably. It was found that the resources of solid biomass are used far more intensively than the resources of biogas. However, in the case of biogas, a significant increase in the utilization of the production potential was observed: from 3.3% in 2012 to 6.4% in 2018, whereas in the same years, the utilization of solid biomass production potential remained at the same level (15.3% in 2012, 15.4% in 2018). It was also observed that, at the level of voivodeships, the utilization of biogas and biomass production potential is negatively correlated with the size of this potential. The combined potential of solid biomass and biogas can cover the demand of each of the studied regions in Poland in terms of thermal energy. The coverage ranges from 104% to 1402%. The results show that when comparing biomass and biogas, the production of both electricity and heat was dominated by solid biomass. Its high share occurred especially in voivodeships characterized by a high share of forest area and a low potential for biogas production (Lubuskie Voivodeship, Zachodniopomorskie Voivodeship).

Quality assessment of drinking water in the communities of São Francisco do Conde, Baiacu, Santo Amaro and Cachoeira

2021 ◽  
Author(s):  
JOSEINA MOUTINHO TAVARES ◽  
Anderson Silva de Oliveira ◽  
Paulo Moutinho Andrade de Souza ◽  
Walter da Silva Junior
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Quality Assessment ◽  
Continuous Monitoring ◽  
Point Of View ◽  
Chlorine Content ◽  
Contaminated Water ◽  
Public Agencies ◽  
Total Coliforms

This work aims to evaluate the quality of drinking water in the communities of Baiacu, Sao Francisco do Conde, Santo Amaro and Cachoeira. It was verified that in some places of Santo Amaro and Sao Francisco do Conde, from the microbiological point of view, it is not appropriate for consumption, because it was found that the presence of total coliforms in 50% of the samples and that the chlorine content is below the values indicated by the standards in 75% of the analyzed samples. Thus, the consumption of contaminated water can cause diseases, so it is recommended cleaning of residential reservoirs, maintenance in pipes periodically, as well as the need for continuous monitoring of water quality and the intense participation of public agencies in these actions. Through these actions and the active participation of the population, one can preserve the environment and the lives of all those who transit in the communities of the Bay of All Saints

Occurrences and changes in bacterial growth-promoting nutrients in drinking water from source to tap: A review

2021 ◽  
Author(s):  
Jiwon Park ◽  
Jin Hyung Noh ◽  
Thi Huyen Duong ◽  
Sang-Yeop Chung ◽  
Heejong Son ◽  
...  
Keyword(s):  
Drinking Water ◽  
Organic Carbon ◽  
Bacterial Growth ◽  
Assimilable Organic Carbon ◽  
Growth Promoting ◽  
Community Changes

Biostable drinking water, which does not support bacterial growth and community changes, is obtained by removing bacterial growth-promoting nutrients, such as assimilable organic carbon (AOC), through a range of treatment...

scholarly journals Disinfection exhibits systematic impacts on the drinking water microbiome

2019 ◽  
Author(s):  
Zihan Dai ◽  
Maria C. Sevillano-Rivera ◽  
Szymon T. Calus ◽  
Q. Melina Bautista-de los Santos ◽  
A. Murat Eren ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Distribution ◽  
Microbial Growth ◽  
Glyoxylate Cycle ◽  
Water Systems ◽  
Chemical Compositions ◽  
Functional Potential ◽  
Decay Products ◽  
The Impact ◽  
Drinking Water Systems

ABSTRACTLimiting microbial growth during drinking water distribution is achieved either by maintaining a disinfectant residual or through nutrient limitation without the use of a disinfectant. The impact of these contrasting approaches on the drinking water microbiome is not systematically understood. We utilized genome-resolved metagenomics to compare the structure, metabolic traits, and population genomes of drinking water microbiomes across multiple full-scale drinking water systems utilizing these two-distinct microbial growth control strategies. Microbial communities cluster together at the structural- and functional potential-level based on the presence or absence of a disinfectant residual. Disinfectant residual concentrations alone explained 17 and 6.5% of the variance in structure and functional potential of the drinking water microbiome, respectively, despite including samples from multiple drinking water systems with variable source waters and source water communities, treatment strategies, and chemical compositions. The drinking water microbiome is structurally and functionally less diverse and less variable across disinfected systems as compared to non-disinfected systems. While bacteria were the most abundant domain, archaea and eukaryota were more abundant in non-disinfected and disinfected systems, respectively. Community-level differences in functional potential were driven by enrichment of genes associated with carbon and nitrogen fixation in non-disinfected systems and γ-aminobutyrate metabolism in disinfected systems which may be associated with the recycling of amino acids. Metagenome-assembled genome-level analyses for a subset of phylogenetically related microorganisms suggests that disinfection may select for microorganisms capable of using fatty acids, presumably from microbial decay products, via the glyoxylate cycle. Overall, we find that disinfection exhibits systematic and consistent selective pressures on the drinking water microbiome and may select for microorganisms able to utilize microbial decay products originating from disinfection inactivated microorganisms.

Simulation Investigations of Influence of Tooth Depth Coefficient on Dynamic Phenomena in Toothed Gear

2016 ◽  
Vol 817 ◽  
pp. 41-46
Author(s):  
Grzegorz Peruń
Keyword(s):  
Dynamic Model ◽  
Point Of View ◽  
General Level ◽  
Theoretical Point ◽  
Gear Pair ◽  
Contact Ratio ◽  
Dynamic Forces ◽  
Toothed Gears ◽  
Dynamic Phenomena

The increase of transverse contact ratio (εα) value usually allows reducing general level of gear vibroactivity. Article put to the test influence of coefficient εα value on dynamic forces in mesh zone with use of dynamic model of toothed gear. From theoretical point of view, the optimum value of transverse contact ratio is equal 2, what mean, that in mesh are always two pair of teeth. Obtainment such value of coefficient εα requires another construction of toothed wheels – wheels with HCR (High Contact Ratio) profile teeth. On result of occurrence of different deviations in toothed gears, as well as the dynamic phenomena, obtainment of continuous two-pair cooperation of gear pair is impossible and when this necessary is, solutions with near or exceed optimum value of coefficient are applied.

scholarly journals Diseño de un medio para la producción de un co-cultivo de bacterias fosfato solubilizadoras con actividad fosfatasa

2012 ◽  
Vol 17 (1) ◽  
pp. 43 ◽  
Author(s):  
Jimena Paola Angulo-Cortés ◽  
Anamaría García-Díaz ◽  
Aura Marina Pedroza ◽  
María Mercedes Martínez-Salgado ◽  
Viviana Gutiérrez-Romero
Keyword(s):  
Phosphatase Activity ◽  
Microbial Growth ◽  
Culture Media ◽  
Biomass Concentration ◽  
Soil Samples ◽  
Phosphate Solubilizing Bacteria ◽  
Bacterial Strains ◽  
Box Behnken Design ◽  
Phosphate Solubilizing ◽  
Complex Culture

<strong>Objective</strong>. To design a complex culture media for the production of biomass and acid phosphatases from phosphate-solubilizing bacteria isolated from soil. <strong>Materials</strong> <strong>and methods</strong>. Phosphate-solubilizing bacteria were isolated from oil palm crop soil samples and selected on SMRS1 agar, which were then assessed with antagonism tests to verify their aptitude to form a co-culture. A Box-Behnken experimental design was applied to<br />evaluate the effect of each one of the culture media components on the production of biomass and phosphatase enzymes at a laboratory scale. Finally, microbial growth and enzyme production curves were carried out in order to determine their production times. <strong>Results</strong>. Five phosphate-solubilizing bacterial strains were isolated and three of them were selected based on their solubilization indices.These Gram negative strains with bacillus morphology were identified as A, B and C; their solubilization indices were 2.03, 2.12, and 2.83, respectively. According to the ANOVA analyses for the Box-Behnken design, the only factor which had a significant effect on the phosphatase activity (p&lt;0.01) was hydrolyzed yeast, and the formulation that generated the highest biomass concentration and phosphatase activity (p&lt;0.01) contained 10, 15 and 2.5 gL-1 of phosphoric rock, sucrose and hydrolyzed yeast, respectively. After 24 hours of incubation at 100 rpm, the highest values of biomass and phosphatase activity were obtained: 11.8 logarithmic units of CFU and 12.9 phosphatase units. <strong>Conclusion</strong>. We determined that the culture media based on phosphoric rock 10 gL-1, hydrolyzed yeast 2.5 gL-1 and commercial sucrose 15 gL-1 was ideal for the production of biomass and phosphatases by the strains evaluated; likewise, we proved that the hydrolyzed yeast was the only factor significantly influential for the production of phosphatases.<br /><br /><strong>Key words</strong>: bio-inoculants, phosphate solubilizing microorganisms, phosphatase activity, Box Behnken design.

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