The pH tolerance of Daphnia pulex (Leydig, emend., Richard)

1969 ◽  
Vol 47 (6) ◽  
pp. 1173-1175 ◽  
Author(s):  
P. Davis ◽  
G. W. Ozburn
Keyword(s):  
River Water ◽  
Tap Water ◽  
Daphnia Pulex ◽  
Distilled Water ◽  
Ph Values ◽  
Ph Tolerance ◽  
Dilute Sodium Hydroxide ◽  
Aquarium Water ◽  
Ph Range ◽  
Sulfuric Acid Solutions

The survival time and reproduction of female Daphnia pulex in solutions varying in pH have been observed. Dilute sodium hydroxide or sulfuric acid solutions were added to four different diluent waters: distilled water, aerated tap water, aerated and filtered tap water from an aquarium containing dace minnows, and McIntyre River water. D. pulex (initially up to 72 hours old) survived for the duration of the experiment (32 hours) in river water within a pH range of 6.1–10.3; in aquarium water within a pH range of 4.3–10.4; only at pH 6.4 and pH 7.6 in distilled water; and in none of the solutions using aerated tap water. The dissolved oxygen content was measured at the beginning and end of every experiment and was found never to fall below 6.2 p.p.m. Those individuals which survived were cultured in the laboratory and parthenogenesis was observed at pH values between 7.0 and 8.7.

scholarly journals New Electropositive Filter for Concentrating Enteroviruses and Noroviruses from Large Volumes of Water

2009 ◽  
Vol 75 (8) ◽  
pp. 2393-2399 ◽  
Author(s):  
Mohammad R. Karim ◽  
Eric R. Rhodes ◽  
Nichole Brinkman ◽  
Larry Wymer ◽  
G. Shay Fout
Keyword(s):  
River Water ◽  
Tap Water ◽  
Water Flow Rate ◽  
Cost Effective ◽  
Ohio River ◽  
Norwalk Virus ◽  
Significant Difference ◽  
Flow Rate Range ◽  
Ph Range ◽  
Virus Recovery

ABSTRACT The U.S. Environmental Protection Agency's information collection rule requires the use of 1MDS electropositive filters for concentrating enteric viruses from water, but unfortunately, these filters are not cost-effective for routine viral monitoring. In this study, an inexpensive electropositive cartridge filter, the NanoCeram filter, was evaluated for its ability to concentrate enteroviruses and noroviruses from large volumes of water. Seeded viruses were concentrated using the adsorption-elution procedure. The mean percent retention of seeded polioviruses by NanoCeram filters was 84%. To optimize the elution procedure, six protocols, each comprising two successive elutions with various lengths of filter immersion, were evaluated. The highest virus recovery (77%) was obtained by immersing the filters in beef extract for 1 minute during the first elution and for 15 min during the second elution. The recovery efficiencies of poliovirus, coxsackievirus B5, and echovirus 7 from 100-liter samples of seeded tap water were 54%, 27%, and 32%, respectively. There was no significant difference in virus recovery from tap water with a pH range of 6 to 9.5 and a water flow rate range of 5.5 liters/min to 20 liters/min. Finally, poliovirus and Norwalk virus recoveries by NanoCeram filters were compared to those by 1MDS filters, using tap water and Ohio River water. Poliovirus and Norwalk virus recoveries by NanoCeram filters from tap and river water were similar to or higher than those by the 1MDS filters. These data suggest that NanoCeram filters can be used as an inexpensive alternative to 1MDS filters for routine viral monitoring of water.

scholarly journals Zeta-potential and flotability of the scheelite mineral in different type of waters, Part 1: Zeta-potential

2009 ◽  
Vol 63 (5) ◽  
pp. 369-376
Author(s):  
Dragan Milanovic ◽  
Zoran Markovic
Keyword(s):  
Zeta Potential ◽  
Tap Water ◽  
Spring Water ◽  
Rain Water ◽  
Proper Choice ◽  
Distilled Water ◽  
Ph Values ◽  
Different Types

The aim of this work is the investigation of zeta-potential of the mineral scheelite from mine 'Rudnik', located in central Serbia. Electrophoresis measurements using zeta-meter were carried out on four different types of water, namely: tap water, distilled water, rain water and spring water. All types of water had different hardness and conductivity as well as natural pH values. It was found that the zeta-potential of mineral scheelite depends on the hardness and electro-conductivity of the chosen type of water as well as on Ca2+ content. The results obtained reveal the importance of proper choice of water as well as the type of reagents for flotation processes.

scholarly journals Application of Ferrate as Coagulant and Oxidant Alternative for Purifying Saigon River Water

2020 ◽  
Vol 36 (4) ◽  
Author(s):  
Tran Tien Khoi ◽  
Nguyen Dang Hoang Chuong ◽  
Hoang Gia Phuc ◽  
Nguyen Thi Thuy ◽  
Nguyen Nhat Huy
Keyword(s):  
Surface Water ◽  
River Water ◽  
Water Purification ◽  
High Efficiency ◽  
Tap Water ◽  
Optimum Concentration ◽  
Promising Alternative ◽  
Ph Values ◽  
By Products ◽  
Iron And Manganese

In this study, we aimed to use ferrate as an all-in-one alternative for the removal of chlorine-consumed compositions such as organic, color, turbidity, iron, and manganese in river water for water supply purposes. Ferrate (FeO42-) was simultaneously employed as coagulant and oxidant for purification of Saigon River water in order to reduce the formation of disinfection by-products in the produced tap water. The Jartest was conducted using both ferrate for raw river water and poly-aluminum chloride (PAC) for chlorinated water to determine the optimum concentration of chemicals and pH values as well as comparing the effectiveness of ferrate and traditional coagulation with pre-chlorination technology for surface water purification. Results showed that ferrate could be used to remove organic compounds with high efficiency of 86.2% at pH 5 - 6 and ferrate concentration of 16 mgFe/L. Moreover, the removal efficiency for turbidity, color, and iron were at least 90%, indicating that ferrate would be a very promising alternative for chlorine and PAC for water purification.

scholarly journals Zeta-potential and flotability of the scheelite mineral in different type of waters, Part 2: Flotability

2009 ◽  
Vol 63 (5) ◽  
pp. 377-385
Author(s):  
Dragan Milanovic ◽  
Zoran Markovic
Keyword(s):  
Tap Water ◽  
Size Fraction ◽  
Spring Water ◽  
Distilled Water ◽  
Particle Size Fraction ◽  
Proper Selection ◽  
Ph Values ◽  
Different Types ◽  
Tube Cell ◽  
Selection Of

The aim of this work was to study floatability of the mineral sheelite from mine 'Rudnik', central Serbia. Flotation tests of the mineral in a Hallimond tube cell were carried out in four different types of water, namely: tap water, distilled water, rain water and spring water. All types of water had different hardness and conductivity as well as natural pH values. It was found that the flotability of mineral scheelite depends on the hardness and electro-conductivity of the chosen type of water as well as on Ca2+ content. Also, it was found the floatability of mineral depends on the scheelite particle size fraction used in microflotation experiments. Presented results may be useful for proper selection of type of water, as well of the type of reagents used in flotation processes.

The Malachite Green Biodegradation in Bioreactors on Various pH Domains

2019 ◽  
Vol 70 (8) ◽  
pp. 2996-2999
Author(s):  
Viorel Gheorghe ◽  
Catalina Gabriela Gheorghe ◽  
Andreea Bondarev ◽  
Vasile Matei ◽  
Mihaela Bombos
Keyword(s):  
Malachite Green ◽  
Contact Time ◽  
Dominant Species ◽  
Wastewater Treatment Plants ◽  
Organic Substances ◽  
Biological Degradation ◽  
Growth Promoters ◽  
Ph Values ◽  
Biological Sludge ◽  
Ph Range

In the experimental study was studied the malachite green colorant biodegradation in biological sludge with biological activity. The biodegradability tests were carried out in laboratory bioreactors, on aqueous solutions of green malachite contacted with microorganisms in which the dominant species is Paramecium caudatum, in a pH range between 8 and 12, temperatures in the ranges 25-350C, using pH neutralizing substances and biomass growth promoters. The colorant initial concentrations and those obtained after biological degradation depending on the contact time, at certain pH values, were established through UV-Vis spectrometry. The studies have shown the measure of possible biological degradation of some organic substances with extended uses, with largely aromatic structure, resistance to biodegradation of microorganisms, commonly used in wastewater treatment plants.

Study on desorption of Mn, Fe, and Mg from TMP and evaluation of the complexing strength of different chelating agents using side reaction coefficients 10th EWLP, Stockholm, Sweden, August 25–28, 2008

Holzforschung ◽  
2009 ◽  
Vol 63 (6) ◽  
Author(s):  
Kim Granholm ◽  
Pingping Su ◽  
Leo Harju ◽  
Ari Ivaska
Keyword(s):  
Citric Acid ◽  
Metal Ions ◽  
Chelating Agents ◽  
Side Reaction ◽  
Sodium Dithionite ◽  
Thermomechanical Pulp ◽  
Peroxide Bleaching ◽  
Ph Values ◽  
Reducing Environment ◽  
Ph Range

Abstract Chelation of thermomechanical pulp (TMP) was studied in this work. The desorption of Mn, Fe, and Mg due to their impact on peroxide bleaching was investigated. The desorption experiments were performed with EDTA, citric acid, oxalic acid, and formic acid as chelating agents at different pH. Chelation experiments with EDTA were carried out at pH 3–11. Sodium dithionite was used as the reducing agent in studying chelation with EDTA in a reducing environment. Mn was very effectively desorbed with EDTA from TMP at pH <10 and the reducing environment further improved the removal of all the studied metal ions from TMP with EDTA. Citric acid also removed Mn effectively from TMP at pH 5. The thermodynamic stability constants of different metal chelates do not present the correct picture of how strongly the metal ions are bound by the chelating agents in different conditions. But by means of the side reaction coefficients (α M(L)-coefficients) it is also theoretically possible to evaluate and compare the real binding strengths between the metal ions and different chelating agents at varying pH values and other solution conditions. In this study, a theory is given for the calculation of side reaction coefficients. Values of the α M(L)-coefficients, for the pH range 0–14, are presented for EDTA, DTPA, and also for some other new potential environmentally friendly chelating agents.

scholarly journals Aferição do pH de diferentes agentes clareadores indicados para o clareamento intracoronário

2018 ◽  
Author(s):  
João Felipe Besegato ◽  
Gabriela Dos Santos Ribeiro Rocha ◽  
Marlene De Sousa Amorim ◽  
Fabio Martins Salomão ◽  
Daniel Poletto ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Statistical Analysis ◽  
Multiple Comparisons ◽  
The Other ◽  
Sodium Perborate ◽  
Distilled Water ◽  
Friedman Test ◽  
Time Intervals ◽  
Ph Values ◽  
Evaluation Time

Objective: to measure pH values of bleaching agents that are indicated to intracoronal bleaching technique in different time intervals. Methods: Each group (G) received five samples (n=5): G1 – distilled water (AD); G2 – hydrogen peroxide (H2O2) 30%; G3 – sodium perborate (PbS) + AD; G4 – PbS + H2O2 30%; G5 – sodium percarbonate (PcS) + AD; and G6 – PcS + H2O2 30%. pH values were stated using a digital pHmeter, in different time intervals: immediately after handling (T0), 24 hours (T1) and 168 hours after handling (T2). The results were submitted to statistical analysis through Kruskal-Wallis and Mann Whitney tests, in this order, allowing multiple comparisons among the groups. To verify the effect of time in each group, Friedman test was applied. Results: In the evaluation of the effect of time in each group, it was observed that G2 presented acid behavior, while the other groups exhibited values close to neutrality or alkaline. Conclusions: H2O2 30% was the only agent that showed acidic behavior in every evaluation time. Meanwhile, PcS + H2O had the highest pH values.

scholarly journals Effects of pH and Aeration on Sclerotium rolfsii sacc. Mycelial Growth, Sclerotial Production and Germination

2018 ◽  
Vol 7 (3) ◽  
pp. 123-129 ◽  
Author(s):  
Fakher Ayed ◽  
Hayfa Jabnoun-Khiareddine ◽  
Rania Aydi-Ben-Abdallah ◽  
Mejda Daami-Remadi
Keyword(s):  
Mycelial Growth ◽  
Sclerotium Rolfsii ◽  
Dry Weight ◽  
Ph Values ◽  
Effects Of Ph ◽  
Ph Range ◽  
Sclerotial Development ◽  
Sclerotial Germination

Sclerotium rolfsii is one of the devastating soilborne fungus responsible for significant plant losses. The effects of pH and aeration on pathogen mycelial growth, sclerotial production and germination were investigated for three Tunisian isolates. Optimal mycelial growth occurred at pH 6 for Sr2 and Sr3 isolates and at pH 6-7 for Sr1. Dry mycelial growth was optimum at pH values ranging between 4 and 7. Sclerotial initiation started on the 3rd day of incubation at all pH values tested and mature sclerotia were formed after 6 to 12 days. Optimal sclerotial production was noted at pH 5. The dry weight of 100 sclerotia varied depending on isolates and pH and occurred at pH range 4-7. At pH 9, mycelial growth, sclerotial production and dry weight of 100 sclerotia were restricted. The optimum sclerotial germination, noted after 24 h of incubation, varied depending on isolates and pH and occurred at pH 4-9. Mycelial growth was optimum in aerated plates with a significant isolates x aeration treatments interaction. Sclerotial initiation occurred at the 3rd day of incubation and mature sclerotia were observed after 6-9 days. Sclerotial development was very slow in completely sealed plates and dark sclerotia were produced only after 15 days of incubation. The highest sclerotial yields were noted in aerated plates. The highest dry weight of 100 sclerotia for Sr1 isolate was recorded in ½ sealed, no sealed and completely sealed plates, while for Sr2, it was noted in ½ and ⅔ sealed plates. For Sr3, the maximum dry weight of 100 sclerotia was recorded in ½, ⅔ and completely sealed plates. Germination of S. rolfsii sclerotia, after 24 h of incubation, did not vary significantly depending on aeration treatments and ranged from 90 to 100% for all isolates.

scholarly journals Aurantimicrobium minutum gen. nov., sp. nov., a novel ultramicrobacterium of the family Microbacteriaceae, isolated from river water

2015 ◽  
Vol 65 (Pt_11) ◽  
pp. 4072-4079 ◽  
Author(s):  
Ryosuke Nakai ◽  
Tomoya Baba ◽  
Hironori Niki ◽  
Miyuki Nishijima ◽  
Takeshi Naganuma
Keyword(s):  
River Water ◽  
Sequence Similarity ◽  
Rrna Gene ◽  
Phenotypic Characteristics ◽  
High Sequence Similarity ◽  
The Family ◽  
Western Japan ◽  
Unidentified Species ◽  
Diamino Acid ◽  
Ph Range

A Gram-stain-positive, aerobic, non-motile, curved (selenoid), rod-shaped actinobacterium, designated KNCT, was isolated from the 0.2 μm-filtrate of river water in western Japan. Cells of strain KNCT were ultramicrosized (0.04–0.05 μm3). The strain grew at 15–37 °C, with no observable growth at 10 °C or 40 °C. The pH range for growth was 7–9, with weaker growth at pH 10. Growth was impeded by the presence of NaCl at concentrations greater than 1 %. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain KNCT showed relatively high sequence similarity (97.2 %) to Alpinimonas psychrophila Cr8-25T in the family Microbacteriaceae. However, strain KNCT formed an independent cluster with cultured, but as-yet-unidentified, species and environmental clones on the phylogenetic tree. The major cellular fatty acids were anteiso-C15 : 0 (41.0 %), iso-C16 : 0 (21.8 %), C16 : 0 (18.0 %) and anteiso-C17 : 0 (12.9 %), and the major menaquinones were MK-11 (71.3 %) and MK-12 (13.6 %). The major polar lipids were phosphatidylglycerol and two unknown glycolipids. The cell-wall muramic acid acyl type was acetyl. The peptidoglycan was B-type, and contained 3-hydroxyglutamic acid, glutamic acid, aspartic acid, glycine, alanine and lysine, with the latter being the diagnostic diamino acid. The G+C content of the genome was unusually low for actinobacteria (52.1 mol%), compared with other genera in the family Microbacteriaceae. Based on the phenotypic characteristics and phylogenetic evidence, strain KNCT represents a novel species of a new genus within the family Microbacteriaceae, for which the name Aurantimicrobium minutum gen. nov., sp. nov. is proposed. The type strain of the type species is KNCT ( = NBRC 105389T = NCIMB 14875T).

scholarly journals Vermiculture as a biotechnological method of recultivation of disturbed lands in the post-mining system

2021 ◽  
Vol 315 ◽  
pp. 02008
Author(s):  
Andrei Babenko ◽  
Dmitrij Bezrukov ◽  
Saulet Karimova ◽  
Akmaral Mametova ◽  
Ludmila Zakonnova
Keyword(s):  
Leaf Litter ◽  
Calcium Ions ◽  
Tap Water ◽  
Mining System ◽  
Mining Areas ◽  
Ph Values ◽  
Disturbed Areas ◽  
Agrochemical Properties ◽  
Plant Waste ◽  
Poplar Leaf

The article shows the prospects of using the technology of vermicomposting for the biological re-cultivation of disturbed mining areas. The valuable properties of vermicompost as a component of soil-substituting mixtures for use in the re-cultivation of disturbed areas are considered. The expediency of using plant waste for the preparation of soil-substituting substrates is shown. The presence of special agrochemical properties of vermicompost obtained during the processing of plant waste (leaf litter) by the Eisenia fetida Savigny culture is experimentally established. The pH values and the content of calcium ions in the vermicompost based on poplar leaf litter were significantly higher than in the vermicompost based on horse manure – 7.61 vs. 6.98 and 112.3 vs. 83 mg-eq. / kg, respectively. Germination of wheat seeds on extracts from vermicompost obtained from poplar litter led to a statistically significant increase in the mass of the formed roots compared to seeds germinated on tap water.

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