Enhanced treatment of endocrine disrupting chemicals by a granular bed electrochemical reactor

2010 ◽  
Vol 62 (10) ◽  
pp. 2218-2224 ◽  
Author(s):  
Y. Sakakibara ◽  
T. Kounoike ◽  
H. Kashimura
Keyword(s):  
Endocrine Disrupting Chemicals ◽  
Electrochemical Reactor ◽  
Granular Bed ◽  
Reactor Performance ◽  
Rate Limiting Step ◽  
Endocrine Disrupting ◽  
Film Mass Transfer ◽  
17Β Estradiol ◽  
Rate Limiting ◽  
Good Agreement

Continuous treatments of trace endocrine disrupting chemicals (EDCs) such as 17β-estradiol (E2), bisphenol-A, nonylephenol, 4-t-octyl phenol and pentachlorophenol were carried out using a granular bed electrolytic reactor. Experimental results showed that the EDCs were removed by the reactor over 150 days and removal efficiencies were nearly the same in the presence and absence of humic substance. Energy consumption for the treatment was around several Wh/m3. For longer operation or higher loading conditions, Fenton oxidation was effective to regenerate electrodes. Calculated results by a mathematical model developed assuming liquid film mass-transfer as a rate-limiting step were in good agreement with observed results. Based on the model, enhancement of reactor performance was discussed.

Electrolytic Treatment of Trace Natural and Synthetic Estrogens

2014 ◽  
Vol 17 (1) ◽  
Author(s):  
Vo Huu Cong ◽  
Yutaka Sakakibara
Keyword(s):  
Reference Electrode ◽  
Rate Limiting Step ◽  
Film Mass Transfer ◽  
Synthetic Estrogens ◽  
17Β Estradiol ◽  
And Control ◽  
Electrochemical Removal ◽  
Rate Limiting ◽  
Voltammetric Technique ◽  
Natural And Synthetic

AbstractElectrochemical removals of natural and synthetic estrogens, Estrone (E1), 17β-Estradiol (E2) and Ethynylestradiol (EE2), were experimentally studied using granular electrolytic reactor in combination with a cyclic voltammetric technique. Experimental results showed that by an application of electric current, the estrogens were oxidized at 600-800 mV (vs. Ag/AgCl reference electrode) on the surface of anode and then removed through polymerization of estrogens. Moreover, the electrochemical removal of the estrogens could be reasonably well simulated by a mathematical model developed assuming the external liquid-film mass transfer as a rate-limiting step. Furthermore, it was found that E1 was produced and then removed during the treatment of E2. Further study will be needed to quantify and control the electro-polymerization of estrogens.

Assessing Estrogenic Activities of Selected Endocrine Disrupting Chemicals and their Combination Effects

2013 ◽  
Vol 765-767 ◽  
pp. 2944-2948 ◽  
Author(s):  
Xiao Ling Shao ◽  
Wen Qi Zhong ◽  
Xiao Yan Ma ◽  
Ang Gao ◽  
Xiang Yang Wu ◽  
...  
Keyword(s):  
Binary Systems ◽  
Endocrine Disrupting Chemicals ◽  
Concentration Addition ◽  
Multicomponent Mixtures ◽  
Yeast Two Hybrid ◽  
Yeast Two Hybrid System ◽  
Endocrine Disrupting ◽  
17Β Estradiol ◽  
Ethylhexyl Phthalate ◽  
Two Hybrid

Yeast two-hybrid system was used to investigate the estrogenic activities of 13 kinds of representative endocrine disrupting chemicals (EDCs) and their combinary effects. Results show that the order of estrogenic potencies for these chemicals is: 17α-ethynylestradiol>diethylstilbestrol >17β-estradiol>estrone>estriol>branchedp-nonylphenol>4-t-octylphenol>bisphenol A>diethyl phthalate>4-n-nonylphenol>di-(2-ethylhexyl) phthalate>dibutyl phthalate>dimethyl phthalate. The mixture effects of multiple EDCs were compared to those obtained from individual chemicals, using the model of concentration addition. Results reveal that the estrogenicities of multicomponent mixtures of more than three (including three) of EDCs follow antagonistic effects, while there is no definite conclusion for binary systems. The less than additive effects were also confirmed in the spiked experiments conducted in the extracts of real water samples.

scholarly journals Molecular Basis for Endocrine Disruption by Pesticides Targeting Aromatase and Estrogen Receptor

2020 ◽  
Vol 17 (16) ◽  
pp. 5664 ◽  
Author(s):  
Chao Zhang ◽  
Tiziana Schilirò ◽  
Marta Gea ◽  
Silvia Bianchi ◽  
Angelo Spinello ◽  
...  
Keyword(s):  
Competitive Inhibition ◽  
Estrogenic Activity ◽  
Endocrine Disrupting Chemicals ◽  
Binding Mode ◽  
Inhibition Mechanism ◽  
Aromatase Activity ◽  
Docking Simulations ◽  
Potential Binding ◽  
Endocrine Disrupting ◽  
17Β Estradiol

The intensive use of pesticides has led to their increasing presence in water, soil, and agricultural products. Mounting evidence indicates that some pesticides may be endocrine disrupting chemicals (EDCs), being therefore harmful for the human health and the environment. In this study, three pesticides, glyphosate, thiacloprid, and imidacloprid, were tested for their ability to interfere with estrogen biosynthesis and/or signaling, to evaluate their potential action as EDCs. Among the tested compounds, only glyphosate inhibited aromatase activity (up to 30%) via a non-competitive inhibition or a mixed inhibition mechanism depending on the concentration applied. Then, the ability of the three pesticides to induce an estrogenic activity was tested in MELN cells. When compared to 17β-estradiol, thiacloprid and imidacloprid induced an estrogenic activity at the highest concentrations tested with a relative potency of 5.4 × 10−10 and 3.7 × 10−9, respectively. Molecular dynamics and docking simulations predicted the potential binding sites and the binding mode of the three pesticides on the structure of the two key targets, providing a rational for their mechanism as EDCs. The results demonstrate that the three pesticides are potential EDCs as glyphosate acts as an aromatase inhibitor, whereas imidacloprid and thiacloprid can interfere with estrogen induced signaling.

Direct oxidation treatment by a novel 3-dimensional electrolytic cell reactor

2006 ◽  
Vol 6 (2) ◽  
pp. 87-91
Author(s):  
Y. Sakakibara ◽  
Y. Sena ◽  
M. Prosnansky
Keyword(s):  
Endocrine Disrupting Chemicals ◽  
Electrolytic Cell ◽  
Chlorinated Phenols ◽  
Direct Oxidation ◽  
Nonyl Phenol ◽  
Oxidation Treatment ◽  
3 Dimensional ◽  
Endocrine Disrupting ◽  
Cell Reactor ◽  
17Β Estradiol

The\ performance of a novel 3-dimensional electrolytic cell reactor for the treatment of dilute solutions was investigated using different dyes (potassium indigotrisulfonate (PI), Orange 2 and Amaranth) and endocrine disrupting chemicals (EDCs). Continuous experiments demonstrated that the present electrolytic cell reactor was able to directly oxidize the dyes on the surface of the electrode very quickly in response to a change in electric current. It is interesting to note that the energy consumption for the oxidation of PI and Orange 2 was significantly smaller than for the commercially available ozone generators. The electrolytic reactor was also successfully applied to the treatment of trace EDCs including 17β-estradiol, bisphenol-A, nonyl-phenol and chlorinated phenols.

2D/2D Bi2WO6/Protonated g-C3N4 Step-scheme Heterojunctions for Enhancing Photodegradation of 17β-Estradiol: Promotional Role of Electrostatic Interaction

2022 ◽  
Author(s):  
Yashi Qing ◽  
Yanxiang Li ◽  
Dan Hu ◽  
Zhiwei Guo ◽  
Yujie Yang ◽  
...  
Keyword(s):  
Human Health ◽  
Electrostatic Interaction ◽  
Estrogenic Activity ◽  
Endocrine Disrupting Chemicals ◽  
Endocrine Disrupting ◽  
17Β Estradiol

17β-Estradiol (E2) is a type of endocrine disrupting chemicals (EDCs) with the strongest estrogenic activity which poses a huge threat to the ecosystems and human health even at extremely low...

A survey of endocrine disrupting chemicals in sewage and a preliminary treatment trial

2005 ◽  
Vol 52 (8) ◽  
pp. 1-7 ◽  
Author(s):  
J.Q. Jiang ◽  
Q. Yin ◽  
P. Pearce ◽  
J. Zhou
Keyword(s):  
Endocrine Disrupting Chemicals ◽  
Sewage Treatment ◽  
Preliminary Treatment ◽  
Biological Processes ◽  
Oxidation Processes ◽  
Treatment Processes ◽  
Low Concentrations ◽  
Endocrine Disrupting ◽  
17Β Estradiol ◽  
Low Levels

This paper demonstrates that synthetic endocrine disrupting chemicals (EDCs) (e.g. bisphenol-A) and natural EDCs (e.g. estrone and 17β-estradiol) were found in the crude sewage from two sewage treatment works. Conventional biological processes can lower EDC concentrations to several hundred nanograms per litre. Because natural EDCs (e.g. estrone and 17β1-estradiol) have biological activity and an adverse impact on the environment at extremely low concentrations (several tens of nanograms per litre), and because the existing wastewater/sewage treatment processes are not adequate to reduce natural EDC concentrations lower than 100ngL−1, further treatment after conventional biological processes is required. Preliminary trials with ferrate(VI) and electrochemical oxidation processes demonstrated that the former is more effective than the latter in reducing EDC concentrations, and that both the processes can effectively reduce EDCs to very low levels, ranging between 20 and 100ngL−1.

Hydrolysis of a monocyclic oxyphosphorane containing a five-membered ring

1991 ◽  
Vol 69 (12) ◽  
pp. 2075-2083 ◽  
Author(s):  
Glenn H. McGall ◽  
Robert A. McClelland
Keyword(s):  
Rate Constant ◽  
Methoxy Group ◽  
Ring Closure ◽  
Rate Limiting Step ◽  
Acid Base Equilibrium ◽  
Reaction With Water ◽  
Effective Molarity ◽  
Rate Limiting ◽  
Hydrolysis Of ◽  
Good Agreement

A kinetic study is reported for the hydrolysis of 2,2-diphenyl-2-methoxy-1,3,2-dioxaphospholane 1. This phosphorane exists in aqueous solution in a pseudo acid–base equilibrium with an observable phosphonium ion, the ring-opened (2′-hydroxyethoxy)diphenylmethoxyphosphonium ion 5. The equilibrium constant Ka ([1][H+]/[5]) is 9 × 10−9, values determined by kinetic and spectroscopic methods being in good agreement. This phosphonium ion is, however, not involved in the overall hydrolysis reaction, which proceeds via the thermodynamically less stable cyclic five-membered phosphonium ion derived by loss of the exocyclic methoxy group from the phosphorane, the 2,2-diphenyl-1,3,2-dioxaphospholan-2-ylium ion 6. This route for the overall hydrolysis is established by analysis of the products, and by the observation that the rate constant for the disappearance of 5 in acid solutions is 40 000 times greater than that for an analog that differs only in not being able to cyclize, the (2′-methoxyethoxy)diphenylmethoxyphosphonium ion 7. At all pH, the phosphorane 1 and the ring-opened phosphonium ion 5 exist in equilibrium, and the rate-limiting step in the overall hydrolysis is the cleavage of the exocyclic methoxy group to give the cyclic phosphonium ion 6, which is rapidly converted to products by reaction with water. The actual equilibration reaction involving 1 and 5 cannot be observed at any pH, even with stopped-flow spectroscopy. The non-catalyzed ring closure of the phosphonium ion 5 reforming the phosphorane 1 occurs with a rate constant of 200–500 s−1, corresponding to an effective molarity of (2–5) × 107 M for the intramolecular hydroxy group in this reaction. The rate-limiting exocyclic cleavage is assisted by H+, with a very large rate constant 2 × 109 M−1 s−1. Catalysis by general acids is also observed. The Brønsted plot has a slope α of 1.0 for the weaker acids, with a break for acids with pKa < 3. This "Eigen"-type behavior is proposed to arise from a transition state with little phosphonium ion character, in which the proton is almost completely transferred for the weaker acids. Key words: phosphorane, phosphate, phosphonium, hydrolysis.

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