Concentration Addition, Independent Action, and QSAR for Chemical Mixture Toxicities of the Disinfection Byproducts of Haloacetic Acids on the Green Alga Raphidocelis subcapitata

2021 ◽  
Author(s):  
Li‐Tang Qin ◽  
Min Liu ◽  
Xin Zhang ◽  
Ling‐Yun Mo ◽  
Hong‐Hu Zeng ◽  
...  
Keyword(s):  
Green Alga ◽  
Disinfection Byproducts ◽  
Haloacetic Acids ◽  
Concentration Addition ◽  
Independent Action ◽  
Chemical Mixture ◽  
Raphidocelis Subcapitata

Control of disinfection and halogenated disinfection byproducts by the electrochemical process

2007 ◽  
Vol 55 (12) ◽  
pp. 213-219 ◽  
Author(s):  
Y.J. Jung ◽  
B.S. Oh ◽  
J.W. Kang ◽  
M.A. Page ◽  
M.J. Phillips ◽  
...  
Keyword(s):  
Kinetic Studies ◽  
Disinfection Byproducts ◽  
Electrochemical Process ◽  
Free Chlorine ◽  
Haloacetic Acids ◽  
Oh Radicals ◽  
Inactivation Kinetic ◽  
E Coli ◽  
Electrochemical Processes

The aim of this study was to investigate some aspects of the performance of electrochemical process as an alternative disinfection strategy, while minimising DBPs, for water purification. The study of electrochemical processes has shown free chlorine to be produced, but smaller amounts of stronger oxidants, such as ozone, hydrogen peroxide and OH radicals (•OH), were also generated. The formation of mixed oxidants increased with increasing electric conductivity, but was limited at conductivities greater than 0.6 mS/cm. Using several microorganisms, such as E. coli and MS2 bacteriophage, inactivation kinetic studies were performed. With the exception of free chlorine, the role of mixed oxidants, especially OH radicals, was investigated for enhancement of the inactivation rate. Additionally, the formation and reduction of DBPs was studied by monitoring the concentration of haloacetic acids (HAAs) during the process.

scholarly journals Concentration Addition, Independent Action and Generalized Concentration Addition Models for Mixture Effect Prediction of Sex Hormone Synthesis In Vitro

PLoS ONE ◽  
2013 ◽  
Vol 8 (8) ◽  
pp. e70490 ◽  
Author(s):  
Niels Hadrup ◽  
Camilla Taxvig ◽  
Mikael Pedersen ◽  
Christine Nellemann ◽  
Ulla Hass ◽  
...  
Keyword(s):  
Sex Hormone ◽  
Concentration Addition ◽  
Independent Action ◽  
Mixture Effect ◽  
Hormone Synthesis

Assessment and Prediction of Joint Toxicity of Aniline Derivatives

2013 ◽  
Vol 448-453 ◽  
pp. 217-220
Author(s):  
Hui Lin Ge ◽  
Shu Shen Liu ◽  
Hong Qiu Yuan ◽  
Gui Hao Yin ◽  
Yi Xie ◽  
...  
Keyword(s):  
Mixture Toxicity ◽  
Joint Effect ◽  
Concentration Addition ◽  
Joint Toxicity ◽  
Independent Action ◽  
Similarity Parameter ◽  
Toxicity Index ◽  
Aniline Derivatives ◽  
Toxic Units

The joint toxicity of aniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 2-nitroaniline, 3-nitroaniline, 4-nitroaniline, 2-chloroaniline, 3-chloroaniline, and 4-chloroaniline on photobacterium were predicted and evaluated by using concentration addition (CA) and independent action (IA) models, and joint effect indices including toxic units, additive index, mixture toxicity index, and similarity parameter. The tested mixture presented synergism.

scholarly journals Medicines, shaken and stirred: a critical review on the ecotoxicology of pharmaceutical mixtures

2014 ◽  
Author(s):  
Thomas Backhaus
Keyword(s):  
Empirical Data ◽  
Critical Review ◽  
Mixture Toxicity ◽  
Toxicity Assessment ◽  
Concentration Addition ◽  
Ecological Interactions ◽  
Independent Action ◽  
Soil Organisms ◽  
Analytical Monitoring ◽  
Marine Flora

Analytical monitoring surveys routinely confirm that organisms in the environment are exposed to complex multi-component pharmaceutical mixtures. We are hence tasked with the challenge to take this into consideration when investigating the ecotoxicology of pharmaceuticals. This review first provides a brief overview of the fundamental approaches for mixture toxicity assessment, which is then followed by a critical review on the empirical evidence that is currently at hand on the ecotoxicology of pharmaceutical mixtures. It is concluded that, while the classical concepts of Concentration Addition and Independent Action (Response Addition) provide a robust scientific footing, several knowledge gaps remain. This includes in particular the need for more and better empirical data on the effects of pharmaceutical mixtures on soil organisms as well as marine flora and fauna, and exploring the quantitative consequences of toxicokinetic, toxicodynamic and ecological interactions. Increased focus should be put on investigating the ecotoxicology of pharmaceutical mixtures in environmentally realistic settings.

scholarly journals Metals releases and disinfection byproduct formation in domestic wells following shock chlorination

2010 ◽  
Vol 3 (1) ◽  
pp. 177-198
Author(s):  
M. Walker ◽  
J. Newman
Keyword(s):  
Trace Metals ◽  
Contact Time ◽  
Disinfection Byproducts ◽  
Oxidation Potential ◽  
Free Chlorine ◽  
Haloacetic Acids ◽  
Background Concentrations ◽  
Disinfection Byproduct ◽  
Byproduct Formation ◽  
By Products

Abstract. Shock chlorination is used for rapid disinfection to control pathogens and nuisance bacteria in domestic wells. A typical shock chlorination procedure involves adding sodium hypochlorite in liquid bleach solutions to achieve concentrations of free chlorine of up to 200 ppm in the standing water of a well. The change in pH and oxidation potential may bring trace metals from aquifer materials into solution and chlorine may react with dissolved organic carbon to form disinfection byproducts. We carried out experiments with four wells to observe and determine the persistence of increased concentrations of metals and disinfection byproducts. Water samples from shock chlorinated wells were analyzed for Pb, Cu, As, radionuclides and disinfection byproducts (haloacetic acids and trihalomethanes), immediately prior to treatment, after sufficient contact time with chlorine had elapsed, and at intervals determined by the number of casing volumes purged, for up to four times the well casing volume. Elevated concentrations of lead and copper dissipated in proportion to free chlorine (measured semi-quantitatively) during the purging process. Trihalomethanes and haloacetic acids were formed in wells during disinfection. In one of two wells tested, disinfection byproducts dissipated in proportion to free chlorine during purging. However, one well retained disinfection byproducts and free chlorine after four well volumes had been purged. Although metals returned to background concentrations in this well, disinfection byproducts remained elevated, though below the MCL, likely because purging volume was insufficient. Simple chlorine test strips may be a useful method for indicating when purging is adequate to remove metals and disinfection by-products mobilized and formed by shock chlorination.

scholarly journals The Acute Single and Mixture Toxicity of Paraquat Dichloride and Deltamethrin to Guppy (Poecillia reticulata)

2021 ◽  
Author(s):  
Rully Adi Nugroho ◽  
Cornelis van Gestel
Keyword(s):  
Dose Level ◽  
Adult Male ◽  
Surface Waters ◽  
Poecilia Reticulata ◽  
Mixture Toxicity ◽  
Concentration Addition ◽  
Independent Action ◽  
Acute Effects ◽  
Reference Models ◽  
Guppy Fish

Abstract Although herbicide and insecticide contamination of surface waters normally occurs in the form of mixtures, the toxicity interactions displayed by such mixtures have only rarely been characterized. This study evaluated the acute effects of single pesticides (paraquat dichloride and deltamethrin, tested in their commercial formulations Gramoxone 276 SL and Decis 25EC) and their equitoxic mixtures on the survival of adult male guppy fish (Poecilia reticulata). Mixture toxicity was evaluated against the reference models of Concentration Addition (CA) and Independent Action (IA). In the single treatments, the 72h LC10 and LC50 values were 1.5 and 6.0 mg a.s. L-1 and 0.53 and 3.6 µg a.s. L-1 for paraquat dichloride and deltamethrin, respectively. The equitoxic mixtures showed significant paraquat dichloride-deltamethrin antagonism, both based on the CA and the IA model, without significant dose-level dependent deviations.

Formation of trihalomethanes and haloacetic acids during chlorination of functionalized carbon nanotubes

2016 ◽  
Vol 3 (6) ◽  
pp. 1327-1339 ◽  
Author(s):  
Edgard M. Verdugo ◽  
Kyle J. Nelson ◽  
Christian M. Bako ◽  
Richard L. Valentine ◽  
David M. Cwiertny
Keyword(s):  
Carbon Nanotubes ◽  
Surface Chemistry ◽  
Disinfection Byproducts ◽  
Haloacetic Acids ◽  
Functionalized Carbon Nanotubes

Carbon nanotubes represent precursors for disinfection byproducts during chlorination, where the extent of formation is linked to their surface chemistry.

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