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Study of Structural Properties in Complex Fluids by Addition of Surfactants Using DPD Simulation  [PDF]
Estela Mayoral,Eduardo Nahmad-Achar,José Manuel Martínez-Magadán,Alejandro Ortega,Ismael Soto
Physics , 2014, DOI: 10.1007/978-3-642-27723-8
Abstract: In this work we study the tertiary structure of ionic surfactants when the pH in the system is modified using electrostatic dissipative particle dynamics simulations (DPD). The dependence with pH and kind of surfactant is presented. Our simulations reproduce the experimental behavior reported in the literature. The scaling for the radius of gyration with the size of the molecule as a function of pH is also obtained.
Biodegradation of synthetic surfactants by river microorganisms
Hideaki Maki,Kenrou Tokuhiro,Yasuhiro Fujiwara,Michihiko Ike,Kenji Furukawa,Masanori Fujita,
Hideaki Maki
,Kenrou Tokuhiro,Yasuhiro Fujiwar,Michihiko Ike,Kenji Furukaw,Masanori Fujita

环境科学学报(英文版) , 1996,
Abstract: Four kinds of widely used synthetic surfactants and polyethylene glycol (PEG) which corresponds to the hydrophilic moieties of polyoxyethylene-type nonionic surfactants were subjected to a complete biodegradation test using microorganisms from relatively unpolluted river waters (the TOC-Handai method). Sodium dodecyl sulfate (SDS), alcohol ethoxylate (AE) and PEG were mineralized by most of the microorganisms used as inocula, irrespective of differences in their degradation rates, which is in agreement with their biodegradabilities confirmed so far by other tests.These degradable surfactants were, however, not completely degraded by some river microorganisms. Among the surfactants tested, SDS was degraded most rapidly by microorganisms of each river in the same manner but the degradation rates of AE and PEG differed considerably according to the inoculum sampling station. Sodium linear alkylbenzensulfonate (LAS) and nonylphenol ethoxylate (NPE). which are known to be recalcitrant molecules, were not degraded completely by microorganisms of any of the river waters within the testing period; degradation of the former rarely proceeded , while that of the latter ceased leaving the well-known intermediates. The residual metabolites of NPE generated by biodegradation, which were analyzed by high-performance liquid chromatography and gas chromatography/mass spectrometry, revealed that this surfactant was transformed to carboxylated metabolites, nonylphenoxy acetic acid (NP1EC)and (nonylphenoxy)ethoxy] acetic acid (NP2EC) exclusively.
Occurrence and Biodegradation of Nonylphenol in the Environment  [PDF]
Zhen Mao,Xiao-Fei Zheng,Yan-Qiu Zhang,Xiu-Xiang Tao,Yan Li,Wei Wang
International Journal of Molecular Sciences , 2012, DOI: 10.3390/ijms13010491
Abstract: Nonylphenol (NP) is an ultimate degradation product?of nonylphenol polyethoxylates (NPE) that is primarily used in cleaning and industrial processes. Its widespread use has led to the wide existence of NP in various environmental matrices, such as water, sediment, air and soil. NP can be decreased by biodegradation through the action of microorganisms under aerobic or anaerobic conditions. Half-lives of biodegradation ranged from a few days to almost one hundred days. The degradation rate for NP was influenced by temperature, pH and additions of yeast extracts, surfactants, aluminum sulfate, acetate, pyruvate, lactate, manganese dioxide, ferric chloride, sodium chloride, hydrogen peroxide, heavy metals, and phthalic acid esters. Although NP is present at low concentrations in the environment, as an endocrine disruptor the risks of long-term exposure to low concentrations remain largely unknown. This paper reviews the occurrence of NP in the environment and its aerobic and anaerobic biodegradation in natural environments and sewage treatment plants, which is essential for assessing the potential risk associated with low level exposure to NP and other endocrine disruptors.
Jana Luká?ová,Zuzana Kňa?ická,Eva Tvrdá,Agnieszka Greń
Journal of Microbiology, Biotechnology and Food Sciences , 2012,
Abstract: Nonylphenol (NP), an environmental endocrine disruptor, is a final metabolite of nonylphenol ethoxylate (NPE) that is able to interfere with hormonal system of numerous organisms. Estrogens play a central role in female reproduction, but also affect the male reproductive system. In males, stimulate mammalian spermatozoa capacitation, acrosome reaction and fertilizing ability. The aim of this in vitro study was to determine the effect of 17β-estradiol and nonylphenol (NP) on the spermatozoa motility. Specifically, we examined the dose- and time-dependent effect of nonylphenol (1, 10, 100 and 200 μg/mL) with the addition 1 μg/mL of 17β-estradiol on the motility and progressive motility of bovine spermatozoa during two time periods (0 h and 6 h). The spermatozoa motility was determined by CASA (Computer Assisted Semen Analyzer) system using the Sperm VisionTM program. The results showed decreased average values of motility in all experimental groups during 0 h of in vitro cultivation. The motility and the progressive motility of bovine spermatozoa increased in the experimental groups using concentrations 10, 100 and 200 μg/mL after 6 h of cultivation and significant differences (P<0.05) were detected between these groups and the control group. The results suggest that the addition of 17β-estradiol could positively affect spermatozoa motility during the short-term cultivation of spermatozoa with NP.
Degradation behaviors of nonylphenol ethoxylates by isolated bacteria using improved isolation method

GU Xin,ZHANG Yu,ZHANG Jing,YANG Min,Hideyuki Tamaki,Yoichi Kamagata,

环境科学学报(英文版) , 2008,
Abstract: Nonylphenol ethoxylate (NPEO)-degrading bacteria were isolated from activated sludge using an improved isolation method, and the corresponding degradation behaviours were investigated. Eight NPEO-degrading strains distributed in genera Pseudomonas, Sphingomonas, Sphingobium, Cupriavidus, Ralstonia, Achromobacter, and Staphylococcus were acquired. The latter five genera have never been reported for the degradation of NPEOs. Four degradation patterns were observed for the eight pure strains. In pattern A, NPE...
Dynamical regimes in DPD  [PDF]
Pep Espa?ol,Mar Serrano
Physics , 1998,
Abstract: We discuss theoretically the behavior of the velocity autocorrelation function in the Dissipative Particle Dynamics model. Two dynamical regimes are identified depending on the dimensionless model parameters. For low frictions a mean field behavior is observed in which the kinetic theory for DPD provides good predictions. For high frictions, collective hydrodynamic effects are dominant. We have performed numerical simulations that validate the theory presented.
Behavioral Impairment and Oxidative Damage Induced by Chronic Application of Nonylphenol  [PDF]
Zhen Mao,Yuan-Lin Zheng,Yan-Qiu Zhang
International Journal of Molecular Sciences , 2011, DOI: 10.3390/ijms12010114
Abstract: Nonylphenol (NP) is a degradation product of nonylphenol polyethoxylates, which are widely used in the production of industrial and consumer surfactants. The aim of the present study was to evaluate the effect of NP on the antioxidant capacity and cognitive ability of mice. NP was given orally by gavages at doses of 0, 50, 100, and 200 mg kg ?1 d ?1 for 90?days. The results showed that NP significantly decreased the activity of superoxide dismutases (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) and at the same time increased malondialdehyde (MDA) levels in mice brains. Exploration, memory function and ability to learn a novel task were significantly decreased in NP fed mice. These results indicate that chronic high dose of NP exposure has the potential to generate oxidative stress and induce the cognitive impairment in male mice.
Hydrothermal Carbonization of Nonylphenol Ethoxylates Waste Liquid for Energy Source Generation  [PDF]
Yongquan Ge, Wenqi Zhang, Gang Xue, Pinhua Rao
American Journal of Analytical Chemistry (AJAC) , 2015, DOI: 10.4236/ajac.2015.613101
Abstract: Nonylphenol polyethoxylates (NPEOs) are widely used as nonionic surfactants in many industry fields. High concentration NPEOs waste water is produced in some production processes. It is often treated to realize reduction by distillation. Therefore, NPEOs waste liquid with higher concentration is produced and it is difficult to be treated by traditional water treatment process. In this study, hydrothermal carbonization process was used to convert NPEOs waste liquid to carbonaceous product (hydrochar) with sulfuric acid as additive in 24 h at 200°C. The hydrochar was characterized by scanning electron microscope, Fourier-transform infrared spectrometer and thermogravimetric analysis. The element composition and the high heat value of the hydrochar were similar to lignite, showing that it could be used as an alternative fuel.
DPD余氯比色器的研制  [PDF]
环境科学 , 1986,
Abstract: 余氯测定方法有十种之多,医院污水余氯测定,常用的有五种:即碘量法;碘量反滴定法;DPD亚铁滴定法和比色法(DPD即N,N-二乙基-对苯二胺);甲土立丁法.
环境科学 , 1986,
Abstract: 余氯测定方法有十种之多,医院污水余氯测定,常用的有五种:即碘量法;碘量反滴定法;DPD亚铁滴定法和比色法(DPD即N,N-二乙基-对苯二胺);甲土立丁法。 我们用碘量反滴定法,DPD亚铁滴定法和DPD比色法测定医院污水余氯,其测定结果基本一致,经统计学处理(F~1测定)三种测定方法无显著性差异。我国目前暂定碘量反滴定法作为医院污水余氯测定的标准方法。但该法操作复杂,测定时间长,不适合现场快速测定。 本文根据DPD比色法原理,研制出一种
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