scholarly journals The profile of contamination with AlkylPhenol Ethoxylates of some Israeli watercourse rivers and their sediment layers

2020 ◽  
Author(s):  
M. Houshan ◽  
U. Zoller
Keyword(s):  
Ethylene Oxide ◽  
Nonionic Surfactants ◽  
Concentration Level ◽  
Total Concentration ◽  
Alkylphenol Ethoxylates ◽  
Hydrophilic Fraction ◽  
Deep Layers ◽  
Sediment Layers ◽  
Concentration Levels

Abstract The ‘hard’ non-biodegradable alkylphenol ethoxylates (APEOs) nonionic surfactants are environmentally persistent and widely used worldwide. The aim of this work is to determine the total concentration and the homological distribution in rivers and there sediments, in central Israel. The concentrations of APEOs in the water of these rivers and in their sediments were found to be 11.83–55.32 μg/L, and 99.68–1,176.61 μg/kg, respectively. The APEOs' concentration level decreases as the sample is taken from a deeper layer of the sediment. A possible explanation for this is that in APEOs molecules, the hydrophilic fraction (CH2-CH2-O) increases the APEOs' absorption into sediment layers close to water, being saturated with water. In addition, the organic biofilm in the sediment layers used as schmutzdecke can reduce the concentration levels of APEOs that penetrates the deep layers of the sediment. The dominant homologues of APEOs in the river watercourse were those with 9–15 units of ethylene oxide (EO). Homologues with 1–12 units of ethylene oxide were found to be the dominant ones in the sediment layers of Hadera and Alexander rivers.

Glyphosate Toxicity to Common Milkweed and Hemp Dogbane as Influenced by Surfactants

Weed Science ◽  
1977 ◽  
Vol 25 (3) ◽  
pp. 275-287 ◽  
Author(s):  
J.B. Wyrill ◽  
O.C. Burnside
Keyword(s):  
Contact Angle ◽  
Ethylene Oxide ◽  
Quaternary Ammonium ◽  
Nonionic Surfactants ◽  
Ionic Surfactants ◽  
Oxide Content ◽  
Asclepias Syriaca ◽  
Molar Basis ◽  
Dimethyl Amine ◽  
Percentage Basis

Surfactants were evaluated in the greenhouse for their ability to enhance glyphosate [N-(phosphonomethyl) glycine] toxicity to common milkweed (Asclepias syriacaL.) and hemp dogbane (Apocynum cannabinumL.). Ethoxylated amines were among the most effective groups of surfactants. Nonionic ether and ester ethoxylates combined with a dimethyl amine or a quaternary ammonium salt were more effective than any of these surfactants alone. Effectiveness of ethoxylated amine surfactants was altered by pH changes. Cat-ionic surfactants tended to be more effective than nonionic surfactants. With exceptions, surfactants were more effective with increased ethoxylation. Amine surfactant effectiveness increased with increasing concentrations up to 0.3% (w/v). Surfactant effectiveness on a molar basis was more closely related to the ethylene oxide content of the surfactant than was effectiveness on a percentage basis. Contact angle was not related to surfactant effectiveness at high or low surfactant concentrations. Ethoxylated stearyl ether and amine surfactants gave optimum effectiveness at hydrophile-lipophile balance (HLB) values of 15 to 16 and 19 to 20, respectively. Surfactants with a low HLB were usually less effective. Effectiveness of surfactant combinations was quite variable and difficult to predict. Therefore, the indiscriminate addition of surfactants to glyphosate spray mixtures which already contain a surfactant should be avoided.

Evaluation of in vitro serial antibiotic elution from meropenem-impregnated polymethylmethacrylate beads after ethylene oxide gas and autoclave sterilization

2011 ◽  
Vol 24 (01) ◽  
pp. 39-44 ◽  
Author(s):  
C. Langston ◽  
S. Givaruangsawat ◽  
R. McLaughlin ◽  
L. A. Báez
Keyword(s):  
Ethylene Oxide ◽  
Statistical Difference ◽  
Concentration Level ◽  
Negative Control ◽  
Microbiological Assay ◽  
Zone Of Inhibition ◽  
Time Periods ◽  
Pmma Beads ◽  
Ethylene Oxide Gas

Summary Objectives: To determine the elution properties of meropenem and to compare the elutions of meropenem-impregnated polymethylmethacrylate (PMMA) beads without sterilization (P-M-C) to those sterilized with steam (P-M-A) and ethylene oxide gas (P-M-EO). Methods: A commercial bead mould was used to produce four groups of beads: one group without antibiotic (negative control), and three groups of meropenem-impregnated beads: P-M-C, P-M-A, and P-M-EO. The beads were placed in a phosphate buffered solution and eluent samples were collected. Concentrations of the antibiotic in eluent samples from the two sterilized groups and the control beads were determined using a microbiological assay at 1, 3, 6 and 12 hours and at 1, 2, 3, 6, 9, 12, 15, 18, 22, 26, and 30 days. Results: The microbiological assay resulted in no zone of inhibition at all time periods for the P-M-A samples and the samples of PMMA without antimicrobial. The meropenem concentration on the eluent remained above 4 mcg/ml for 15 days in the P-M-C group and until day 18 for P-M-EO group. There was no statistical difference in AUC0-∞ (p <0.318), however significance did occur for MRT (p <0.005) when comparing P-M-C and P-M-EO with the later being higher. Discussion: The meropenem incorporated in the PMMA beads eluted effectively and gradually decreased after the 24 hour peak, but remained above the concentration level of 4 mcg/ml for 15 days in the P-M-C group and until day 18 for P-M-EO group. Ethylene oxide does not adversely affect meropenem’s elution from PMMA beads.

Self-Assembly Study of Polydisperse Ethylene Oxide-Based Nonionic Surfactants

Langmuir ◽  
2007 ◽  
Vol 23 (3) ◽  
pp. 1014-1017 ◽  
Author(s):  
Miklós Nagy ◽  
László Szöllösi ◽  
Sándor Kéki ◽  
Miklós Zsuga
Keyword(s):  
Ethylene Oxide ◽  
Self Assembly ◽  
Nonionic Surfactants

scholarly journals Sorptive Removal of Odorous Carbonyl Gases by Water

2010 ◽  
Vol 10 ◽  
pp. 535-545
Author(s):  
Ehsanul Kabir ◽  
Ki-Hyun Kim
Keyword(s):  
Carbonyl Compounds ◽  
Room Temperature ◽  
Concentration Level ◽  
Pure Water ◽  
Water Volume ◽  
Gas Stripping ◽  
Removal Capacity ◽  
Stripping Method ◽  
Working Standards ◽  
Concentration Levels

In this study, the removal capacity of deionized water was investigated against five gaseous carbonyl compounds (i.e., acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, and isovaleraldehyde) by means of the gas stripping method. To determine the trapping behavior of these odorants by water, gaseous working standards prepared at three different concentration levels (i.e., for acetaldehyde around 300, 500, and 1,000 ppb) were forced through pure water contained in an impinger at room temperature. The removal efficiency of the target compounds was inspected in terms of two major variables: (1) concentration levels of gaseous standard and (2) impinger water volume (20, 50, 100, and 150 mL). Although the extent of removal was affected fairly sensitively by changes in water volume, this was not the case for standard concentration level changes. Considering the efficiency of sorption media, gas stripping with aqueous solution can be employed as an effective tool for the removal of carbonyl odorants.

Relationship of non-specific commensalism in the colonization of the deep layers of sediment

2001 ◽  
Vol 81 (6) ◽  
pp. 897-901 ◽  
Author(s):  
Daniela Prevedelli ◽  
Roberto Simonini ◽  
Ivano Ansaloni
Keyword(s):  
Sampling Period ◽  
Particulate Material ◽  
Northern Adriatic Sea ◽  
Surface Deposit ◽  
Northern Adriatic ◽  
Species Association ◽  
Deep Layers ◽  
New Community ◽  
Sediment Layers ◽  
Relationship Of

The macrofauna of samples collected with a box-corer from northern Adriatic Sea muddy bottoms in five survey campaigns from 1985 to 1993 has been analysed separately in sediment strata of varying depth. Samples were collected before, during and after the dumping of large amounts of inert particulate material that covered the seabed and caused an almost total defaunation. After this disturbance the seabed was recolonized by a new community. This new community differed from the original one mainly on account of the abundance of Mysella bidentata, a small bivalve filter or surface deposit-feeder. In the original community M. bidentata was confined to the more superficial sediment layers (0–5 cm) at low population density. In the new community it was very abundant and evenly distributed even in the deep layers (5–20 cm). Analysis of species association performed on data from each of the 54 corer samples collected in the last sampling period, points to a marked association between M. bidentata and Nephtys incisa in deeper sediment layers. Deep layer colonization by Mysella in association with the burrowing polychaete N. incisa suggests a case of commensalism between these two species.

Ethylene Oxide Solubility and Ethoxylation Kinetics in the Synthesis of Nonionic Surfactants

1995 ◽  
Vol 34 (11) ◽  
pp. 4092-4098 ◽  
Author(s):  
M. Di Serio ◽  
R. Tesser ◽  
F. Felippone ◽  
E. Santacesaria
Keyword(s):  
Ethylene Oxide ◽  
Nonionic Surfactants ◽  
Oxide Solubility
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