FeOOH supported on organo-bentonite was prepared by organo-bentonite with good absorptive property,and the effects of dosage of the composite adsorbent,temperature,and Cr(Ⅵ)concentration on the removal rate of Cr(Ⅵ)...FeOOH supported on organo-bentonite was prepared by organo-bentonite with good absorptive property,and the effects of dosage of the composite adsorbent,temperature,and Cr(Ⅵ)concentration on the removal rate of Cr(Ⅵ)in the simulated wastewater were studied.The results indicated that the removal effect of Cr(Ⅵ)was good when the mass fraction of organo-bentonite was 3‰.The removal rate of Cr(Ⅵ)from the simulated wastewater could reach the maximum 98.37% under the following conditions:the dosage of the composite adsorbent was 1.0g;the temperature was 25℃;Cr(Ⅵ)concentration was 10mg/L;the oscillating time was 4h.展开更多
Pyrolysis has the potential of transforming waste into valuable recyclable products. Pyrolytic char(PC) is one of the most important products from the pyrolysis of used tires. One of the most significant applications ...Pyrolysis has the potential of transforming waste into valuable recyclable products. Pyrolytic char(PC) is one of the most important products from the pyrolysis of used tires. One of the most significant applications for pyrolytic char recovered is used for the removal of Cr(Ⅵ) in the wastewater effluent to control waste by waste. The surface chemistry properties of surface element distribution / concentration and chemical structure were examined for the pyrolytic char and the commercial activated carbon(CAC) respectively. The results showed that surfaces of PC possesses a large amount of ester and hydrocarbon graft, whereas there are mainly carbon functional components of C—OH, C O and COOH on the surface of CAC. Therefore the surface electronegativity of PC is lower than that of CAC in the water. The repulsive interactions between the surfaces of PC and the negatively charged Cr(Ⅵ) ion are weaker than that of CAC, which results in an intensification of the adsorption process by the utilization of PC. The adsorption isotherms of Cr(Ⅵ) ion on the two kinds of carbons were determined experimentally. The larger adsorption amount on the PC in the case of Cr(Ⅵ) may be attributed mainly to its special surface micro-chemical environment. The mechanism of the removal Cr(Ⅵ) from aqueous solution was assumed to be the integration of adsorption and redox reaction. The adsorption was the rate-controlled step for Cr(Ⅵ) removal. The adsorption of Cr(Ⅵ) was identified as pseudo-second-order kinetics. The rate constants of adsorption were evaluated.展开更多
文摘FeOOH supported on organo-bentonite was prepared by organo-bentonite with good absorptive property,and the effects of dosage of the composite adsorbent,temperature,and Cr(Ⅵ)concentration on the removal rate of Cr(Ⅵ)in the simulated wastewater were studied.The results indicated that the removal effect of Cr(Ⅵ)was good when the mass fraction of organo-bentonite was 3‰.The removal rate of Cr(Ⅵ)from the simulated wastewater could reach the maximum 98.37% under the following conditions:the dosage of the composite adsorbent was 1.0g;the temperature was 25℃;Cr(Ⅵ)concentration was 10mg/L;the oscillating time was 4h.
文摘Pyrolysis has the potential of transforming waste into valuable recyclable products. Pyrolytic char(PC) is one of the most important products from the pyrolysis of used tires. One of the most significant applications for pyrolytic char recovered is used for the removal of Cr(Ⅵ) in the wastewater effluent to control waste by waste. The surface chemistry properties of surface element distribution / concentration and chemical structure were examined for the pyrolytic char and the commercial activated carbon(CAC) respectively. The results showed that surfaces of PC possesses a large amount of ester and hydrocarbon graft, whereas there are mainly carbon functional components of C—OH, C O and COOH on the surface of CAC. Therefore the surface electronegativity of PC is lower than that of CAC in the water. The repulsive interactions between the surfaces of PC and the negatively charged Cr(Ⅵ) ion are weaker than that of CAC, which results in an intensification of the adsorption process by the utilization of PC. The adsorption isotherms of Cr(Ⅵ) ion on the two kinds of carbons were determined experimentally. The larger adsorption amount on the PC in the case of Cr(Ⅵ) may be attributed mainly to its special surface micro-chemical environment. The mechanism of the removal Cr(Ⅵ) from aqueous solution was assumed to be the integration of adsorption and redox reaction. The adsorption was the rate-controlled step for Cr(Ⅵ) removal. The adsorption of Cr(Ⅵ) was identified as pseudo-second-order kinetics. The rate constants of adsorption were evaluated.
