Anodic dissolution behaviour of Ni in mono-, di- and trichloroacetic acids has been investigated by measuring current densities of Ni electrode (versus SCE) at different potentials. Effects of acid concentration, pH, ...Anodic dissolution behaviour of Ni in mono-, di- and trichloroacetic acids has been investigated by measuring current densities of Ni electrode (versus SCE) at different potentials. Effects of acid concentration, pH, scan rate and additive inhibitor on the potential were studied and they revealed that there is a considerable shift of potential. Potentiodynamic polarization measurements show that the corrosion rate of Ni in chloroacetic acid solutions increases by increasing the previous factors. However, by adding inhibitor, it decreases.展开更多
This study presents a phenomenological model that can be used by the water professionals to quantify chlorine decay and disinfection byproduct(DBP)formation in water.The kinetic model was developed by introducing the ...This study presents a phenomenological model that can be used by the water professionals to quantify chlorine decay and disinfection byproduct(DBP)formation in water.The kinetic model was developed by introducing the concept of limiting chlorine demand and extending an established reactive species approach.The limiting chlorine demand,which quantifies chlorine reactive natural organic matter(NOM)on an equivalent basis,was mathematically defined by the relation between ultimate chlorine residue and initial chlorine dose.It was found experimentally that NOM in water has limiting chlorine demand that increases with chlorine dose once the ultimate residue is established.These results indicated that the complex NOM has a unique ability to adjust chemically to the change in redox condition caused by the free chlorine.It is attributed mainly to the redundant functional groups that persist in heterogeneous NOM molecules.The results also demonstrated that the effect of chlorine dose on the rate of chlorine decay can be quantitatively interpreted with the limiting chlorine demand.The kinetic model developed was validated for chlorine decay and chloroacetic acid formation in finished drinking water.展开更多
An equation describing the state of weak acid mixtures was derived from the relationships between mole balance and charge balance. The equation was solved with numerical method and the compositions of the acid mixture...An equation describing the state of weak acid mixtures was derived from the relationships between mole balance and charge balance. The equation was solved with numerical method and the compositions of the acid mixtures were determined. The advantages of this treatment were demonstrated by analyzing binary mixtures of chloroacetic, formic and acetic acids.展开更多
Practicability of method for the Hydra regeneration assay on the prescreening teratogenic potential of chlorinated drinking water disinfection by products was studied through both the assays of toxicity of adult ...Practicability of method for the Hydra regeneration assay on the prescreening teratogenic potential of chlorinated drinking water disinfection by products was studied through both the assays of toxicity of adult Hydra (T) and inhibition of the growth of regeneration Hydra (I) by using chloroform, dichloromethane and chloroacetic acid. The results showed that T 50 / I 50 ratios of chloroform and chloroacetic acid were 2 77 and 6 16 respectively, with teratogenic potential. T 50 / I 50 ratio of dichloromethane was 1.69, with weaker teratogenic potential. These experimental results indicated preliminarily that the Hydra regeneration assay has certainly applied value as a prescreening assay for developmental toxicity.展开更多
Attapulgite(APT) has been frequently used for the adsorptive removal of dyes from aqueous solution owing to its unique one-dimensional nanoscale structure and low-cost, abundant,eco-friendly advantages. In this work...Attapulgite(APT) has been frequently used for the adsorptive removal of dyes from aqueous solution owing to its unique one-dimensional nanoscale structure and low-cost, abundant,eco-friendly advantages. In this work, APT was functionalized under mild hydrothermal condition using chloroacetic acid(CA) with /COOH functional groups to improve its adsorption properties. The effect of hydrothermal modification on the microstructure and physicochemical features of APT was investigated by Fourier transform infrared spectroscopy, X-ray diffraction and Field-emission scanning electron microscopy analyses. The effects of hydrothermal reaction parameters on the adsorption properties of modified APT were intensively investigated. It was revealed that the rearrangement of crystal structure and the surface functionalization of APT with /COOH groups cause the surprising increase of adsorption capability for Methylene Blue(MB). The removal ratio of raw APT for MB is only 59.52%, while modified APT could almost completely remove MB in the 200 mg/L of MB solution with a removal ratio of 99.8%. The adsorption kinetics fitted pseudo second-order kinetic model, and the adsorption isotherm could be described with Langmuir isotherm model very well. The hydrogen-bonding interaction, electrostatic attraction and chemical association are the main driving force for the adsorption process.展开更多
文摘Anodic dissolution behaviour of Ni in mono-, di- and trichloroacetic acids has been investigated by measuring current densities of Ni electrode (versus SCE) at different potentials. Effects of acid concentration, pH, scan rate and additive inhibitor on the potential were studied and they revealed that there is a considerable shift of potential. Potentiodynamic polarization measurements show that the corrosion rate of Ni in chloroacetic acid solutions increases by increasing the previous factors. However, by adding inhibitor, it decreases.
文摘This study presents a phenomenological model that can be used by the water professionals to quantify chlorine decay and disinfection byproduct(DBP)formation in water.The kinetic model was developed by introducing the concept of limiting chlorine demand and extending an established reactive species approach.The limiting chlorine demand,which quantifies chlorine reactive natural organic matter(NOM)on an equivalent basis,was mathematically defined by the relation between ultimate chlorine residue and initial chlorine dose.It was found experimentally that NOM in water has limiting chlorine demand that increases with chlorine dose once the ultimate residue is established.These results indicated that the complex NOM has a unique ability to adjust chemically to the change in redox condition caused by the free chlorine.It is attributed mainly to the redundant functional groups that persist in heterogeneous NOM molecules.The results also demonstrated that the effect of chlorine dose on the rate of chlorine decay can be quantitatively interpreted with the limiting chlorine demand.The kinetic model developed was validated for chlorine decay and chloroacetic acid formation in finished drinking water.
文摘An equation describing the state of weak acid mixtures was derived from the relationships between mole balance and charge balance. The equation was solved with numerical method and the compositions of the acid mixtures were determined. The advantages of this treatment were demonstrated by analyzing binary mixtures of chloroacetic, formic and acetic acids.
文摘Practicability of method for the Hydra regeneration assay on the prescreening teratogenic potential of chlorinated drinking water disinfection by products was studied through both the assays of toxicity of adult Hydra (T) and inhibition of the growth of regeneration Hydra (I) by using chloroform, dichloromethane and chloroacetic acid. The results showed that T 50 / I 50 ratios of chloroform and chloroacetic acid were 2 77 and 6 16 respectively, with teratogenic potential. T 50 / I 50 ratio of dichloromethane was 1.69, with weaker teratogenic potential. These experimental results indicated preliminarily that the Hydra regeneration assay has certainly applied value as a prescreening assay for developmental toxicity.
基金supported by the Hi-Tech research and Development Program (863) of China (No. 2013AA032003)the West Light Foundation of the Chinese Academy of Sciences (the Science Development Talent Teach words [2012] No. 179)
文摘Attapulgite(APT) has been frequently used for the adsorptive removal of dyes from aqueous solution owing to its unique one-dimensional nanoscale structure and low-cost, abundant,eco-friendly advantages. In this work, APT was functionalized under mild hydrothermal condition using chloroacetic acid(CA) with /COOH functional groups to improve its adsorption properties. The effect of hydrothermal modification on the microstructure and physicochemical features of APT was investigated by Fourier transform infrared spectroscopy, X-ray diffraction and Field-emission scanning electron microscopy analyses. The effects of hydrothermal reaction parameters on the adsorption properties of modified APT were intensively investigated. It was revealed that the rearrangement of crystal structure and the surface functionalization of APT with /COOH groups cause the surprising increase of adsorption capability for Methylene Blue(MB). The removal ratio of raw APT for MB is only 59.52%, while modified APT could almost completely remove MB in the 200 mg/L of MB solution with a removal ratio of 99.8%. The adsorption kinetics fitted pseudo second-order kinetic model, and the adsorption isotherm could be described with Langmuir isotherm model very well. The hydrogen-bonding interaction, electrostatic attraction and chemical association are the main driving force for the adsorption process.