Acute toxicity of chlorobenzenes in Tetrahymena: Estimated by microcalorimetry and mechanism

Zhang, Tian; Li, Xi; Min, Xinmin; Fang, Tingting; Zhang, Zhijun; Yang, Lu; Liu, Peng

doi:10.1016/j.etap.2012.01.009

Cited by 20 publications

(9 citation statements)

References 22 publications

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“…Chlorobenzenes are widely used in chemical industry as organic synthesis intermediates, pesticides, dye carrier, dielectric fluids, degreasing solvents, and synthetic transformer oils [1,2]. However, their increasing use leads to a concomitant increase released to the environment.…”

Section: Introductionmentioning

confidence: 99%

Study on 1,2,3‐trichlorobenzene destruction in a binary (Na,K)₂CO₃ molten salt oxidation system

Yao

Zhao

2013

Env Prog and Sustain Energy

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This work focused on the destruction of 1,2,3-trichlorobenzene (1,2,3-TCB) in a binary molten salt oxidation (MSO) system. The effects of MSO reactor temperatures, additive amounts of TCB, and salt mixture on destruction and removal efficiency (DRE) of TCB and chlorine retention efficiency (CRE) were investigated. The drained salt was characterized by X-ray diffraction (XRD) analysis, and the reaction mechanism and pathway were proposed as well. The results showed that the DRE and CRE reached more than 99 and 95%, respectively, at temperatures above 900 C. The reaction by-products included C 6 H 6 , CH 4 , and CO, while chlorinated species were not detected. Larger amounts of salt mixture meant prolonging the gas residence time and were helpful for reaction. When TCB loading increased from 5 to 25 g, the DRE decreased by 6, <1, and <1%, and the CRE also decreased. The XRD analysis of drained salt confirmed the capture of chlorine in TCB by the molten salt. V C 2013American Institute of Chemical Engineers Environ Prog, 33: 65-69, 2014 Keywords: 1,2,3-TCB; molten salt oxidation (MSO); chlorine retention; reaction pathway INTRODUCTIONChlorobenzenes are widely used in chemical industry as organic synthesis intermediates, pesticides, dye carrier, dielectric fluids, degreasing solvents, and synthetic transformer oils [1,2]. However, their increasing use leads to a concomitant increase released to the environment. These toxic compounds are environmentally stable and easily distributed due to their volatility and resistance to degradation, therefore they have been ranked as prior pollutants by USEPA [3,4]. Numerous studies have certified their existence in soil [5][6][7][8][9][10][11]; therefore, it is highly necessary to develop appropriate treatment and remediation technologies.Molten salt oxidation (MSO) is a versatile and promising technology for the destruction of chlorinated organics. It is capable of trapping chlorine during the destruction of organics and has been tested for the destruction of polychlorinated biphenyls, hexachlorobenzene, carbon tetrachloride, and poly(vinyl chloride) (PVC) with high destruction efficiency [12]. Yang et al.[13] investigated the destruction of chlorobenzene and trichloroethylene in a two-stage molten salt reactor. Incomplete products (PIs) such as C 6 H 6 , C 6 H 5 Cl, CCl 4 , and C 2 H 2 were produced in the first reactor and substantially destroyed in the second reactor. A 2,4 dichlorophenol-spiked organic was also selected and tested. The results showed that off-gas quality was very good with CO and NO x less than 10 and 110 ppm, respectively. Other PIs such as polychlorinated dibenzo-p-dioxins and dibenzofurans were not detected. Yang et al. [14] also confirmed the capture of chlorine and fluorine during the destruction of PVC plastics and polytetrafluoroethene (PTFE) tubes in a bench-scale MSO reactor. These reports indicated that MSO is a robust, controllable technology and has good prospects for the treatment of chlorinated organics. Thus, it can be used as a second ch...

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Section: Introductionmentioning

confidence: 99%

Study on 1,2,3‐trichlorobenzene destruction in a binary (Na,K)₂CO₃ molten salt oxidation system

Yao

Zhao

2013

Env Prog and Sustain Energy

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“…This microcalorimeter is an eight-channel twin instrument and is thermostated in the range of 5-60°C with the long-term stability better than ±0.02°C over 24 h. It allows continuous and simultaneous recording, as a function of time, of the thermal flux produced by living cells, with a limit of detection of 2 μW and baseline draft <20 μW over 24 h. A schematic representation of the instrument was reported by Wadsö (Wadsö 2002) and Zhang et al (Zhang et al 2012). The temperature of the microcalorimeter system and the isothermal box was controlled at 37°C.…”

Section: Instrumentationmentioning

confidence: 97%

Antibacterial evaluation of flavonoid compounds against E. coli by microcalorimetry and chemometrics

Kong

Yan

Xing

et al. 2015

Appl Microbiol Biotechnol

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Fighting against multidrug-resistant bacteria requires reliable methods to evaluate the effect of antibacterial agents. As a universal, non-destructive, and highly sensitive tool, microcalorimetry has been used in many biological investigations to provide continuous real-time monitoring of the metabolic activity. This method, based on heat-flow output, was used to evaluate the influence of two flavonoid compounds (liquiritigenin and liquiritin) on Escherichia coli. Some crucial information, such as the thermogenic power-time curve and thermokinetic parameters of E. coli growth affected by the two compounds, was obtained and further studied by chemometric techniques including similarity analysis, multivariate analysis of variance, and principal component analysis. By comparing the values of two main parameters, k 2 (growth rate constant of the second exponential phase) and Q 1 (heat output of the first exponential growth phase) of E. coli based on the box and whisker plot, liquiritigenin and liquiritin could be differentiated according to their antibacterial effects; liquiritin with IC50 (half-inhibitory concentration) of 198.6 μg mL(-1) expressed a stronger antibacterial effect than liquiritigenin with IC50 of 337.8 μg mL(-1). The glucoside group in liquiritin containing four additional free hydroxyls in the diphenylpropane skeleton was crucial for inducing the antibacterial effect. Liquiritin might be a promising candidate against E. coli. This study provides a valuable method for searching for novel antibacterial agents using microcalorimetry with chemometrics.

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“…This list comprises pollutants as 1,1,1-trichloroethane, 1,1,2-trichloroethane, 1,2dichlorobenzene, 1,2-dichloroethane, 1,4-dichlorobenzene, 2-chlorophenol, 3-chlorophenol, 4-chlorophenol, carbon tetrachloride, chlorine, chlorobenzene, pentachlorobenzene, chloroform, dichloromethane, dioxins and furans, hexachlorobenzene, hexachlorobutadiene, hexachlorocyclohexane, pentachlorophenol, tetrachloroethylene, trichlorobenzene, trichloroethylene, and vinyl chloride [1]. However, due to their extensive use as wood preservatives, pesticide precursors, solvents, hydraulic fluids, dielectric oil, dyes, and other materials [2][3][4][5][6][7], these COCs still pose a risk for the water quality.…”

Section: Introductionmentioning

confidence: 99%

“…This COC is a semi-volatile compound with relatively high water solubility and therefore, it is easily transported in the environment. Due to its toxicity and persistence, this pollutant represents a risk for human health and environmental safety [2,4,6,42]. Thus, it is a pollutant that is highly used as a model compound in other works in literature [43].…”

Section: Introductionmentioning

confidence: 99%

Abatement of 1,2,4-Trichlorobencene by Wet Peroxide Oxidation Catalysed by Goethite and Enhanced by Visible LED Light at Neutral pH

et al. 2021

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There is significant environmental concern about chlorinated organic compounds (COCs) in wastewater, surface water, and groundwater due to their low biodegradability and high persistence. In this work, 1,2,4-trichlorobenzene (124-TCB) was selected as a model compound to study its abatement using wet peroxide oxidation at neutral pH with goethite as a heterogeneous catalyst, which was enhanced with visible monochromatic light-emitting diode (LED) light (470 nm). A systematic study of the main operating variables (oxidant and catalyst concentration and irradiance) was accomplished to investigate their influence in the abatement of 124-TCB in water. The reaction was carried out in a well-mixed reactor of glass irradiated by a visible LED light. The hydrogen peroxide concentration was tested from 0 to 18 mM, the goethite concentration within the range 0.1–1.0 g·L−1 and the irradiance from 0.10 to 0.24 W·cm−2 at neutral pH. It was found that this oxidation method is a very efficient technique to abate 124-TCB, reaching a pollutant conversion of 0.9 when using 0.1 g·L−1 of goethite, 18 mM of H2O2, and 0.24 of W·cm−2. Moreover, the system performance was evaluated using the photonic efficiency (ratio of the moles of 124-TCB abated and the moles of photons arriving at the reactor window). The maximum photonic efficiencies were obtained using the lowest lamp powers and moderate to high catalyst loads.

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Acute toxicity of chlorobenzenes in Tetrahymena: Estimated by microcalorimetry and mechanism

Cited by 20 publications

References 22 publications

Study on 1,2,3‐trichlorobenzene destruction in a binary (Na,K)₂CO₃ molten salt oxidation system

Study on 1,2,3‐trichlorobenzene destruction in a binary (Na,K)₂CO₃ molten salt oxidation system

Antibacterial evaluation of flavonoid compounds against E. coli by microcalorimetry and chemometrics

Abatement of 1,2,4-Trichlorobencene by Wet Peroxide Oxidation Catalysed by Goethite and Enhanced by Visible LED Light at Neutral pH

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Acute toxicity of chlorobenzenes in Tetrahymena: Estimated by microcalorimetry and mechanism

Cited by 20 publications

References 22 publications

Study on 1,2,3‐trichlorobenzene destruction in a binary (Na,K)2CO3 molten salt oxidation system

Study on 1,2,3‐trichlorobenzene destruction in a binary (Na,K)2CO3 molten salt oxidation system

Antibacterial evaluation of flavonoid compounds against E. coli by microcalorimetry and chemometrics

Abatement of 1,2,4-Trichlorobencene by Wet Peroxide Oxidation Catalysed by Goethite and Enhanced by Visible LED Light at Neutral pH

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Product

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Study on 1,2,3‐trichlorobenzene destruction in a binary (Na,K)₂CO₃ molten salt oxidation system

Study on 1,2,3‐trichlorobenzene destruction in a binary (Na,K)₂CO₃ molten salt oxidation system