Removal of 5-Amino-2-chlorotoluene-4-sulfonic and Chlorhydric Acids from Wastewater by Weakly Basic Resin

This research deals with an investigation of the adsorption of two acids, namely, 5-amino- 2-chlorotoluene-4-sulfonic and chlorhydric acids from their solution onto weakly basic resin. The screening of res-ins, kinetics, and isotherm were studied. The results indicate that the D301R is more appropriate for the removal of acids from solution. The adsorption of acids obeys Langmuir isotherm and the first-order kinetics model. Sorptive affinity of the two acids on D301R was found to be in the order of 5-amino-2-chlorotoluene-4-sulfonic acid> chlorhydric acid. Thermodynamic parameters for the adsorption of acids were calculated and discussed. The maxi-mum removal of acids was observed around 97% and 76% at 25℃ for 5-amino-2-chlorotoluene-4-sulfonic acid and chlorhydric acid , respectively.

Removal of 5-Amino-2-chlorotoluene-4-sulfonic and Chlorhydric Acids From Wastewater by Weakly Basic Resin: Equilibrium and Kinetics

Objective To study the adsorption of 5-Amino-2-chlorotoluene-4-sulfonic (CLT) and chlorhydric (HCl) acids from wastewater by weakly basic resin. Methods The kinetics and isotherm were studied. Thermodynamic parameters for the adsorption of acids were calculated and discussed. Results The adsorption of CLT and HCl acids followed Langmuir isotherm and the first-order kinetics model. Conclusion The adsorptive affinity of the two acids on D301R is in the order of CLT acid 〉 HCl acid. CLT and HCl acids can be separated.

SYNTHESIS AND PROPERTIES OF 1-(2-IMIDAZOLYLAO)2-NAPHTHOL-4-SULFONIC ACID

Synthesis of 1-(2-imidazolylazo)-2-naphthol-4-sulfonic acid is described including its physical and chemical properties and spectroscopic data. The reagent reacts with various transition metal ions to form water-soluble and colored chelates which can be decomposed by EDTA exoept cobalt chelate. Present method has good selectivity.

Sulfonation of 1,4-diaminoanthraquinone leuco by chlorosulfonic acid:Kinetics and process intensification

The work herein employed a rotating packed bed(RPB)to intensify the sulfonation process of 1,4-diaminoanthraquinone leuco(DL)in an attempt to improve the yield of the product 1,4-diaminoanthra quinone-2-sulfonic acid(DSA).First,the effects of operating conditions in a stirred tank reactor(STR),including stirring speed,chlorosulfonic acid/DL molar ratio(η),solvent/DL mass ratio(ζ),reaction temperature and dropping speed of chlorosulfonic acid,on the yield of DSA were investigated.The yield of DSA can reach 87.34%under the optimal operating conditions:stirring speed of 500 r·min^(-1),ηof 4.5,ζof 7,reaction temperature of 150℃,dropping speed of 0.61 ml·min^(-1).In addition,the kinetics of the sulfonation process via the shrinking core model revealed that the reaction is controlled by diffusion via a product layer under the reaction temperature of 140℃.Furthermore,the RPB was employed to intensify the mass transfer between liquid and solid phases during the sulfonation reaction process.The results showed that the DSA yield of 92.69%obtained by RPB was 5.35%higher than that by STR,indicating that RPB can significantly intensify the mass transfer in the liquid-solid phase sulfonation reaction process.

Enhanced bio-decolorization of1-amino-4-bromoanthraquinone-2-sulfonic acid by Sphingomonas xenophaga with nutrient amendment

Bacterial decolorization of anthraquinone dye intermediates is a slow process under aerobic conditions. To speed up the process, in the present study, effects of various nutrients on 1-amino-4-bromoanthraquinone-2-sulfonic acid（ABAS） decolorization by Sphingomonas xenophaga QYY were investigated. The results showed that peptone, yeast extract and casamino acid amendments promoted ABAS bio-decolorization. In particular,the addition of peptone and casamino acids could improve the decolorization activity of strain QYY. Further experiments showed that L-proline had a more significant accelerating effect on ABAS decolorization compared with other amino acids. L-Proline not only supported cell growth, but also significantly increased the decolorization activity of strain QYY. Membrane proteins of strain QYY exhibited ABAS decolorization activities in the presence of L-proline or reduced nicotinamide adenine dinucleotide, while this behavior was not observed in the presence of other amino acids. Moreover, the positive correlation between L-proline concentration and the decolorization activity of membrane proteins was observed, indicating that L-proline plays an important role in ABAS decolorization. The above findings provide us not only a novel insight into bacterial ABAS decolorization, but also an L-proline-supplemented bioaugmentation strategy for enhancing ABAS bio-decolorization.

Improvement in the synthesis of 2-(5-amino-1,2,4-thiadiazol-3- yl)-2-(Z)-methoxyiminoacetic acid 2-benzothiazolyl thioester

2-(5-Amino-1,2,4-thiadiazol-3-yl)-2-(Z)-meth-oxyiminoacetic acid 2-benzothiazolyl thioester(III),an important intermediate of the fourth generation cephalos-porins,was efficiently synthesized by reacting 2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(Z)-methoxyiminoacetic acid(I)with 2,29-dibenzothiazole disulfide(II)in the presence of triphenylphosphine.Effects of reaction time,temperature,solvents,catalysts and feeding molar ratio on the yield and quality of products were investigated,and an im-proved procedure suitable for industrial production was established.Using 1,2-dichloroethane as solvent,triphe-nylphosphine as reducer,and triethylamine as catalyst,n(I):n(II):n(triphenylphosphine)51.0:1.0:1.0,the product was obtained at room temperature in 98.1%yield.The purity of the product without further purification is 98.7%determined by HPLC method.This procedure could be a suitable alternative to the traditional processes because of its easy handling,high yield and low cost.

An environmentally friendly synthesis of 1,4-dihydropyrano[2,3-c]pyrazole derivatives catalyzed by tungstate sulfuric acid

An efficient three-component synthesis of 6-amino-4-aryl-5-cyano-3-metriyl-1-phenyl-1,4-dihydropyrano[2,3-c]pyrazoles via a reaction between 3-methyl-1-phenyl-2-pyrazolin-5-one,aromatic aldehydes and malononitrile using tungstate sulfuric acid as a catalyst was described.Mild conditions,good to excellent yields,easily available catalyst and easy work-up are the key features of this method.

Improved microwave-assisted catalyst-free synthesis of9-aryl-5,9-dihydropyrimido[4,5-d][1,2,4]triazolo[1,5-a]pyrimidine-6,8(4H,7H)-dione derivatives

Agreen regioselective synthesis of some new and known 9-aryl-5,9-dihydropyrimido[4,5-d][l,2,4]triazolo[1,5-a]pyrimidine-6,8（4H,7H）-diones has been described via the microwave-assisted one-pot reaction of 3-amino-1H-1,2,4-triazoles,aromatic aldehydes and barbituric acids under solvent- and catalyst-free conditions.This operationally simple procedure is less laborious and provides a better scope than previously reported procedures.