A modified method for the enumeration of aerobic spore-forming bacteria

1997 ◽  
Vol 43 (10) ◽  
pp. 976-980 ◽  
Author(s):  
Benoit Barbeau ◽  
Lina Boulos ◽  
Raymond Desjardins ◽  
Josée Coallier ◽  
Michèle Prévost ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Key Words ◽  
Membrane Filtration ◽  
Natural Waters ◽  
Optimal Conditions ◽  
Treatment Efficiency ◽  
Modified Method ◽  
Large Numbers ◽  
Spore Forming Bacteria

An optimized method for cultivating aerobic spore-forming bacteria in drinking water is described. Such organisms offer the potential as an indicator of water treatment efficiency. The various parameters evaluated were recovery media, incubation, and pasteurization conditions. The optimal conditions consisted of pasteurization for 15 min at 75 °C, followed by membrane filtration and incubation for 24 h at 35 °C on a pad to which 1.4 mL trypticase soy broth had been added. Aerobic spore-forming bacteria were detected in large numbers (1.0 × 102 − 3.2 × 103 CFU/100 mL) in raw waters and daily samples showed that in natural waters they remained stable over the test period (3 weeks).Key words: aerobic spores, method, indicator.

scholarly journals Development of a new method for measuring the abrasive potential of water: risk of membrane failure in water treatment plants

2018 ◽  
Vol 77 (12) ◽  
pp. 2781-2793
Author(s):  
Yannick Manon ◽  
Yvan Wyart ◽  
Angélique Fabre ◽  
Anne Brehant ◽  
Reynald Bonnard ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Membrane Filtration ◽  
Natural Waters ◽  
Drinking Water Treatment ◽  
Polymeric Materials ◽  
Polymeric Membrane ◽  
Feed Water ◽  
Water Treatment Plants ◽  
Different Types

Abstract The objectives of this study were to develop an analytical method to distinguish feed water used to produce drinking water, with varying concentrations of suspended solids, in terms of abrasiveness and to define an index that can assess the abrasive potential of the feed water coming in contact with a polymeric membrane. For such process configurations, membrane abrasion has been identified as one of the most recurring and major concerns in operation because the polymeric materials used in treatment plants are relatively sensitive to abrasion. Five different types of apparatus were benchmarked and were evaluated on their ability to be adapted to particles commonly found in most drinking water treatment plants at low concentrations. After comparing 10 criteria, the MCR302 with a tribological cell of Anton Paar was identified as the most relevant device. For the selected tool (MCR302), a statistical approach was used to provide a safe and robust ranking of the abrasive potential of the different types of water. An analysis of variance allowed the origin of the result variability to be explained. The newly developed methodology enables quantification of the abrasive potential of natural waters used for membrane filtration with a relevance of ranking higher than 90%.

The Use of Aluminosilicate Sorbent for the Purification of Natural Waters from Heavy Metals

2020 ◽  
Vol 24 (3) ◽  
pp. 19-23 ◽  
Author(s):  
A.S. Kutergin ◽  
T.A. Nedobukh
Keyword(s):  
Heavy Metals ◽  
Drinking Water ◽  
Water Treatment ◽  
Mechanical Strength ◽  
Natural Waters ◽  
Drinking Water Treatment ◽  
Exchange Capacity ◽  
Filtration Process ◽  
Treated Water ◽  
Dynamic Exchange

The possibilities of using natural granular glauconite in standard water treatment schemes have been investigated. Resource tests of the studied material were carried out in dynamics, simulating possible conditions of use. As a result of the experiments, it was established: during the filtration process, alkalization of water occurs, but the result does not exceed pH = 6÷9, which are the norm for drinking water; the use of a sorbent based on natural glauconite does not impair the hardness indicator of the treated water. The dynamic exchange capacity was: for iron – 3.09 mg/g of absorbent, copper – 19.15 mg/g of absorbent, zinc – 4.82 mg/g of absorbent. The resource of the filter was determined with the loading of granulate with a volume of 1 dm3: for iron – 2918 dm3, for copper – 5425 dm3, for zinc – 273 dm3. The mechanical strength acquired by the sorbent as a result of granulation made it possible to wash the load by the countercurrent method, freeing intergranular pores from the sediment accumulated in them. The revealed capabilities of granular glauconite will allow its use in drinking water treatment schemes for purifying natural waters from heavy metals: iron, zinc, copper.

scholarly journals Application of Coagulation–Membrane Rotation to Improve Ultrafiltration Performance in Drinking Water Treatment

Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 643
Author(s):  
Hongjian Yu ◽  
Weipeng Huang ◽  
Huachen Liu ◽  
Tian Li ◽  
Nianping Chi ◽  
...  
Keyword(s):  
Shear Stress ◽  
Drinking Water ◽  
Water Treatment ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Drinking Water Treatment ◽  
Permeate Flux ◽  
Organic Removal ◽  
Cake Layer ◽  
The Impact

The combination of conventional and advanced water treatment is now widely used in drinking water treatment. However, membrane fouling is still the main obstacle to extend its application. In this study, the impact of the combination of coagulation and ultrafiltration (UF) membrane rotation on both fouling control and organic removal of macro (sodium alginate, SA) and micro organic matters (tannic acid, TA) was studied comprehensively to evaluate its applicability in drinking water treatment. The results indicated that membrane rotation could generate shear stress and vortex, thus effectively reducing membrane fouling of both SA and TA solutions, especially for macro SA organics. With additional coagulation, the membrane fouling could be further reduced through the aggregation of mediate and macro organic substances into flocs and elimination by membrane retention. For example, with the membrane rotation speed of 60 r/min, the permeate flux increased by 90% and the organic removal by 35% in SA solution, with 40 mg/L coagulant dosage, with an additional 70% increase of flux and 5% increment of organic removal to 80% obtained. However, too much shear stress could intensify the potential of fiber breakage at the potting, destroying the flocs and resulting in the reduction of permeate flux and deterioration of effluent quality. Finally, the combination of coagulation and membrane rotation would lead to the shaking of the cake layer, which is beneficial for fouling mitigation and prolongation of membrane filtration lifetime. This study provides useful information on applying the combined process of conventional coagulation and the hydrodynamic shear force for drinking water treatment, which can be further explored in the future.

Do membrane filtration systems in drinking water treatment plants release nano/microplastics?

2021 ◽  
Vol 755 ◽  
pp. 142658
Author(s):  
Haojie Ding ◽  
Jian Zhang ◽  
Huan He ◽  
Ying Zhu ◽  
Dionysios D. Dionysiou ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Membrane Filtration ◽  
Drinking Water Treatment ◽  
Water Treatment Plants

Adequacy analysis of drinking water treatment technologies in regard to the parameter turbidity, considering the quality of natural waters treated by large-scale WTPs in Brazil

2019 ◽  
Vol 191 (6) ◽  
Author(s):  
Lívia Duarte Ventura Melo ◽  
Elizângela Pinheiro da Costa ◽  
Carolina Cristiane Pinto ◽  
Gabriela Rodrigues Barroso ◽  
Sílvia Corrêa Oliveira
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Large Scale ◽  
Natural Waters ◽  
Drinking Water Treatment ◽  
Treatment Technologies

Bacterial growth in batch-operated membrane filtration systems for drinking water treatment

2015 ◽  
Vol 156 ◽  
pp. 165-174 ◽  
Author(s):  
Joao Mimoso ◽  
Wouter Pronk ◽  
Eberhard Morgenroth ◽  
Frederik Hammes
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Bacterial Growth ◽  
Membrane Filtration ◽  
Drinking Water Treatment
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