untitled European Journal of Chemistry 4 (4) (2013) 408‐413 European Journal of Chemistry ISSN 2153‐2249 (Print) / ISSN 2153‐2257 (Online)  2013 EURJCHEM DOI:10.5155/eurjchem.4.4.408‐413.806 European Journal of Chemistry Journal homepage: www.eurjchem.com Kinetics and mechanism of oxidation of amido black by sodium N‐halo‐p‐toluenesulfonamides in acidic medium: Spectrophotometric approach Jayachamarajapura Pranesh Shubha a,*, Kotabagi Vinutha a and Puttaswamy Puttaswamy b a Department of Chemistry, Don Bosco Institute of Technology, Kumbalagodu, Bangalore‐560074, India b Department of Chemistry, Central College Campus, Bangalore University, Bangalore‐560001, India *Corresponding author at: Department of Chemistry, Don Bosco Institute of Technology, Kumbalagodu, Bangalore‐560 074, India. Tel.: +91.802.8437028; fax: +91.802.8437031. E‐mail address: shubhapranesh@gmail.com (J.P. Shubha). ARTICLE INFORMATION ABSTRACT Received: 22 April 2013 Received in revised form: 17 July 2013 Accepted: 06 August 2013 Online: 31 December 2013 KEYWORDS The kinetics of oxidative decolorization of amido black (AB, Naphthol blue black) by chloramine‐T (CAT) and bromamine‐T (BAT) in acidic medium has been investigated spectrophotometrically (λmax = 618 nm) at 298 K. Kinetic runs were performed under pseudo first‐order conditions of [Oxidant]o >> [AB]o. Under identical experimental conditions, reactions with both the oxidants follow identical kinetics with a first‐order dependence on each [Oxidant]o and [AB] and a fractional‐order dependence on [HClO4]. Stoichiometry of the reaction was found to be 1:4 and the oxidation products were identified. The reaction was studied at different temperatures and various activation parameters have been computed. Effects of p‐toluenesulfonamide, halide ions, ionic strength and dielectric constant of the medium have been investigated. Reaction mixture fails to induce polymerization of acrylonitrile. The rate of oxidation of AB is about three‐fold faster with BAT as compared to CAT. This may be attributed to the difference in electrophilicity of Cl+ and Br+ ions and also the Vander Waals radii of chlorine and bromine. Plausible mechanism and related rate law have been deliberated for the observed kinetics. Azo dye Amido black Chloramine‐T Bromamine‐T Acidic medium Oxidation kinetics 1. Introduction Variety of dyes used in textile industry usually have a synthetic origin and multifaceted aromatic molecular structures, which make them more stable and less amenable to biodegradation [1‐3]. Colored industrial effluent is the most apparent indicator of water pollution and the discharge of highly colored synthetic dye effluents is aesthetically displeasing and cause considerable damage to the aquatic life. These effluents not only created environmental and aesthetic problems, but also pose a great potentially toxic threat to ecological and human health, as most of these dyes are toxic and carcinogenic. Predominantlyazo dyes which contain one or more nitrogen to nitrogen double bonds (‐N=N‐) constitutes a significant portion that are widely used in industries today. The strong electron‐withdrawing character of the azo group stabilizes these aromatic pollutants against conversions by oxygenases. Therefore, azo dyes are not readily degraded under aerobic conditions. Hence, removal of azo dye effluents generated by food and dye industries is a main issue in waste water treatment. These effluents are commonly treated using physico‐chemical methods such as adsorption, photo degradation and coagulation. All of these processes are expensive and complicated. Therefore, there is a need for economical and simple methods to abolish harmful dyes in effluents [1‐9]. Amido black (AB, Naphthol blue black) is chemically known as 4‐amino‐5‐hydroxy‐3‐[(4‐nitrophenyl)azo]‐6‐(phenyl azo]‐ 2,7‐napthalene disulfonic acid disodium salt. It is an amino acid staining diazo dye used in criminal investigations to detect blood present with latent fingerprints. It can also be used to stain collagen and reticulin [1]. An extensive literature survey reveals that there are no reports on the oxidation of AB by any oxidants from the standpoint of the kinetic and mechanistic approach. Hence, it was felt advisable to investigate the oxidative decolorization of AB with N‐haloamines to explore the kinetic and mechanistic aspects of its redox chemistry. The most important aim of this work was to promote the decolorization of AB by environmentally friendly N‐haloamine, has a low energy cost and is economical. The effectiveness of the proposed process was evaluated by its capability to promote decreases in color and total organic carbon content. The high efficiency observed with the dye model showed that this economic, easily operated and maintained treatment process could also be employed in the remediation of effluents. The sodium salts of arylhalosulfonamides usually recognized as organic haloamines have engrossed the concentration of chemists, as adaptable redox titrants [10]. The miscellaneous chemical behavior of organic haloamines is credited in common to their capability to act as halonium cations, hypohalites, N‐anions which act both as bases and nucleophiles, and nitrenoids in restrictive cases [11]. As a result, these compounds react with anample range of functional groups and influence a variety of molecular changes. Organic haloamines are gentle oxidants containing a strongly polarized N‐linked halogen, which is in +1 state. The area under discussion has been broadly reviewed and well deliberated [10‐14]. The vital chlorine compound of this set is sodium N‐ chloro‐p‐toluenesulfonamide or chloramine‐T (CAT), is a byproduct in the manufacture of saccharin. This reagent has been subjugated as an oxidant for a diversity of substrates in both acidic and alkaline media [10‐20]. Shubha et al. / European Journal of Chemistry 4 (4) (2013) 408‐413 409 X: Cl or Br Scheme 1 The bromine analogue of CAT, bromamine‐T (BAT) is gaining significance as a mild oxidant and is found to be an enhanced oxidizing agent than the chloro derivative [12‐14,21‐ 23]. This reagent can be easily prepared by the bromination of CAT. Although BAT is animproved oxidant compare to CAT, an extensive literature analysis reveals that only intermittent references are accessible about the oxidative behavior of BAT from the kinetic and mechanistic points of vision. This aroused our attention to carry out the detailed kinetic study on the oxidation of AB by the closely associated reagents CAT and BAT in acid medium to discover the mechanistic aspects of these oxidations and also to assess their relative rates. The studies extended to the pertinent kinetic features of CAT and BAT and to identify the reactive oxidizing species of these oxidants in aqueous acid medium. In the light of existing information and in continuation of our research interest on the kinetic and mechanistic investigations of oxidation of various substrates in general and dyes in particular by CAT and BAT, the title reaction was undertaken. Accordingly, in this communication we report on the comprehensive kinetics of AB oxidation by CAT and BAT in HClO4 medium at 298 K. 2. Experimental 2.1. Materials Chloramine‐T (E. Merck) was used as received. Bromamine‐T was obtained [24] by the partial debromination of dibromamine‐T (DBT) by 4 M NaOH. The purity of these reagents was checked iodometrically to determine the active halogen content. Aqueous solution of these oxidants was standardized by the iodometric method and stored in brown bottles to prevent any of its photochemical corrosion. Amido Black (Sigma Chemical Company) was used as received. Solvent isotope studies were made with D2O (99.4%) supplied by BARC, Mumbai, India. Analytical grade chemicals and double distilled water was used throughout. 2.2. Kinetic measurements Kinetic measurements were carried out using a UV‐Visible spectrophotometer (Digital Spectrophotometer 166, Systronics, India). In the present study, the kinetic experiments were carried out between 288 and 308 K. For this purpose, a Raagaa Ultra Cold Chamber with digital temperature control (Chennai, India) was used. The temperature was maintained constant with an accuracy of ±0.1 °C. Detailed kinetic runs were performed under pseudo first‐order conditions of [Oxidant]0 >> [AB]0 at 298 K. Reactions were conceded in glass stoppered pyrex boiling tubes whose outer surfaces were coated black to prevent photochemical effects. The oxidant as well as the requisite amounts of AB, HClO4 solutions and water (to keep the total volume constant for all runs) taken in separate tubes were thermostatted for 30 min at 298 K. The reaction was initiated by the rapid addition of a measured amount of oxidant to the stirred reaction mixture. Instantaneously, 4 cm3 of the solution was pipetted into a cuvette placed in the UV‐vis spectrophotometer and absorbance measurements were made at 618 nm (λmax for AB) for more than two half‐lives. The absorbance readings at t = 0 and t = t are D0 and Dt. Plots of log D0/Dt versus time were made to evaluate the pseudo first‐order rate constants (k′) which were found reproducible within ±4‐ 5%. 2.3. Reaction stoichiometry Reaction mixtures containing different ratios of oxidant to AB in presence of 1.2 x 10‐3 M HClO4 were equilibrated at 293 K for 24 h. The unreacted oxidant in the reaction mixture was determined by iodometric titration. This analysis showed that in both the cases one mole of AB consumed four mole of oxidant and the observed reaction stoichiometry is represented in Scheme 1. 2.4. Product analysis In the stoichiometric proportion, the reaction mixtures containing different concentrations of oxidant and substrate in 1.2 x 10‐3 M HClO4 under stirred condition was allowed to react for 24 h at 298 K. After completion of the reaction (monitored by thin layer chromatography), the reaction products were neutralized with alkali and extracted with ether. The organic products were subjected to spot tests and chromatographic analysis, which revealed the formation of nitroso benzene, nitroso nitrobenzene and corresponding dinitroso compound as the oxidation products of AB and p‐toluenesulfonamide as the reduction product of the oxidant. The presence of nitroso benzene (Figure 1) was confirmed by Mass spectral analysis and other products were identified by spot tests [25]. Further, it was noticed that there was no reaction between the products and oxidant under the current set of experimental conditions. p‐Toluenesulfonamide was extracted with ethyl acetate and detected by paper chromatography [26]. Benzyl alcohol saturated with water was used as the solvent system with 0.5 %vanillin in 1 %HCl solution in ethanol as spray reagent (Rf = 0.905) and it was further confirmed by GC‐MS analysis (Figure 2). 410 Shubha et al. / European Journal of Chemistry 4 (4) (2013) 408‐413 Figure 1. GC‐Mass spectrum of nitrosobenzene with its molecular ion peak at 107 amu. Figure 2. GC‐Mass spectrum of p‐toluenesulfonamide with its molecular ion peak at 171 amu. 3. Results and discussion 3.1. Effect of reactant concentration on the rate The kinetics of oxidation of AB by CAT and BAT (here after a bridged as oxidant) have been investigated at several initial concentrations of the reactants, under pseudo first‐order conditions of [Oxidant]o >> [Substrate]o, in presence of HClO4 at 298 K in both cases. The kinetic and mechanistic features for the oxidation of AB with the closely related compounds CAT and BAT in HClO4 medium are same under identical experimental conditions but the comparative rates of oxidation of AB by BAT are about three‐fold faster than CAT. Under the conditions [Oxidant]0 >> [AB]0 at constant [oxidant]0, [HClO4], temperature, plots of Log (absorbance) versus time were linear (r > 0.9889) indicating a first‐order dependence of rate on [AB]0 in both the cases. The linearity of these plots in both cases, together with the constancy of the slopes obtained at different [AB]0, substantiates the first‐order dependence of rate on [AB]0. The pseudo first‐order rate constants (k′) obtained is recorded in Table 1. Under the same experimental conditions the rate of reaction increased in [Oxidant]0 (Table 1) and plots of Log k′ versus Log [Oxidant] were linear (r > 0.9965) with unit slopes in both the cases. This establishes that the order of the reaction is first‐order with respect to [Oxidant]0. Further, plots of k′ versus [Oxidant]0 were linear (r > 0.9990) passing through the origin corroborate the first‐order dependence on [Oxidant]0. The rate of reaction augmented with increase in [HClO4] (Table 1) and plots of Log k′ versus Log [HClO4] were linear (r> 0.9975) with slopes of 0.65 and 0.52 for CAT and BAT, showing a fractional‐order dependence on [HClO4]. Table 1. Effect of Variation of oxidant, AB and HClO4 concentrations on the reaction rate at 298 K. 103 [oxidant]o (M) 104 [AB]o (M) 104 [HClO4] (M) 104 k′ (s‐1) CAT BAT 0.5 1.8 1.2 0.61 1.83 1.0 1.8 1.2 1.40 4.18 2.0 1.8 1.2 2.72 8.17 3.6 1.8 1.2 3.53 10.6 5.0 1.8 1.2 6.02 17.9 2.0 0.5 1.2 2.80 8.20 2.0 1.0 1.2 3.02 7.98 2.0 1.8 1.2 2.72 8.17 2.0 3.0 1.2 3.10 8.26 2.0 5.0 1.2 2.52 8.08 2.0 1.8 0.2 1.33 4.02 2.0 1.8 0.5 1.95 5.88 2.0 1.8 1.2 2.72 8.17 2.0 1.8 3.0 3.84 11.4 2.0 1.8 4.0 5.60 16.5 [Oxidant]o = 2.0 x 10‐3 M; [AB]o = 1.8 x 10‐4 M; [HClO4] = 1.2 x 10‐4 M. 3.2. Effects of halide ions and p‐toluenesulfonamide concentration on the rate Addition of halide ions, Cl‐ or Br‐, in the form of their sodium salts (1.0 x 10‐3 ‐ 8.0 x 10‐3 M) showed no pronounced effect on the rate. This indicates that the halide ions play no role in the reaction. The ionic strength of the reaction medium was varied from 0.1 to 0.3 M with NaClO4 solution keeping other experimental conditions constant. It was found that addition of NaClO4 showed negligible effect on the reaction rate, representing the participation of nonionic species in the rate‐determining step. Hence no attempts were made to maintain the ionic strength of the medium stable for kinetic runs. Addition of p‐toluenesulfonamide (TsNH2) to the reaction mixture (5.0 x 10‐3 M) did not influence the rate significantly indicates that TsNH2 is not involved in any step prior to the rate determining step of the proposed scheme. 3.3. Effect of dielectric constant of the medium on the rate The dielectric constant (D) of the medium was mottled by adding MeOH (0‐30%,v:v) to the reaction mixture with all other experimental conditions being held constant but the rates were not considerably altered with both the oxidants. 3.4. Effect of solvent isotope on the rate Since the oxidation of AB by CAT and BAT was increased with H+ ions, the solvent isotope effect was studied in D2O as the solvent medium for both the oxidants. The rate constants for CAT and BAT revealed that k′ (H2O) was equal to 2.72 x 10‐4 s‐1 and 8.17 x 10‐4 s‐1, and k′ (D2O) was 2.95 x 10‐4 s‐1 and 11.2 x 10‐4 s‐1, respectively. Thus, the solvent isotope effect, k′ (H2O) / k′ (D2O) were found to be 0.68 and 0.74 for CAT and BAT. 3.5. Effect of temperature on the rate The reaction was studied at different temperatures (288‐ 313 K), keeping other experimental conditions constant. From Arrhenius plots of Log k′ vs. 1/T (r > 0.9934), composite activation parameters (Ea, ∆H≠, ∆S≠, ∆G≠ and Log A) were computed for the oxidation of AB by CAT and BAT. These data are summarized in Table 2. 3.6. Test for free radicals Alkene monomers such as acrylonitrile and freshly prepared 10% acryl amide solution were added to the reaction mixture to instigate polymerization by free radicals formed in situ. The lack of polymerization indicated the absence of free radicals in the reaction mixture. This clearly ruled out the possibility of free radical mechanism. Shubha et al. / European Journal of Chemistry 4 (4) (2013) 408‐413 411 (i) fast (ii) slow and rate-determining (iii) fast TsNX- + H+ TsNHX + AB Complex k2 k3 Complex + 3 TsNHX Products TsNHX K1 Scheme 2 Table 2. Temperature dependence on the reaction rate and activation parameters for the oxidation of AB by CAT and BAT in acid medium. Temperature (K) 104 k′ (s‐1) CAT BAT 283 1.43 3.62 288 1.62 4.86 298 2.72 8.17 303 3.22 12.8 313 4.30 24.8 Ea (kJ/mol) 28.43 47.01 ΔH≠ (kJ/mol) 25.97 44.55 ΔG≠ (kJ/mol) 92.97 90.61 ΔS≠ (J/K.mol) ‐226.47 ‐153.45 Log A 5.40 9.21 [Oxidant]o = 2.0 x 10‐3 M; [AB]o = 1.8 x 10‐4 M; [HClO4] = 1.2 x 10‐4 M. The controlled experiments were also performed under similar reaction conditions without oxidant. 3.7. Reactive species of sodium n‐halo‐p‐toluene sulfonamides Organic N‐haloamines are sources of positive halogens and these reagents have been exploited as oxidant for a variety of substrates in both acidic and alkaline media [11‐13]. Since organic N‐haloamines have analogous chemical properties, it is predicted that identical equilibria exist in aqueous acidic and basic solutions of these compounds [27,28]. Chloramine‐T and bromamine‐T act as oxidizing agents in acidic and alkaline media with a two electron change per mole giving p‐ toluenesulfonamide (PTS) and NaCl or NaBr. The redox potential of CAT‐PTS couple is pH dependent [22] and decreases with increase in pH of the medium (Eredox = 1.138 V, 1.778 V, 0.614 V and 0.5 V at pH = 0.65, 7.00, 9.70 and 12.00, respectively). In view of the homogeneity in properties of CAT and BAT, similar redox potential behavior can be expected for BAT also. The nature of the active oxidizing species and mechanism depends on the nature of halogen atom, the groups attached to the nitrogen and the reaction condition. The species accountable for such oxidizing character may be different depending on the pH of the medium. Chloramine‐T and bromamine‐T (TsNXNa) are moderately strong electrolytes [28] in aqueous solutions (TsNXNa ⇌ TsNX‐ + Na+), and depending on the pH of the medium, these reagents furnish different types of reactive species in solutions [24,27‐ 31]. The possible oxidizing species present in acid medium are TsNHX, TsNX2, HOX and also perhaps H2OX+. 3.8. Reaction scheme In the present studies, the first‐order dependence of rate on [Oxidant]o and no effect of rate on [TsNH2] clearly ruled out the opportunity of bothTsNX2 and HOX as reactive species. The probability of the dichlorocompound as the reactive species is ruled out, since clear first‐order plots are obtained for the desertion of the [Substrate]. Added p‐toluenesulfonamide does not hinder the reaction indicating that HOX is not primarily involved in the rate determining step. Further, Bishop and Jennings [28] have shown in their studies on aqueous solutions of CAT, that pH = ~3‐4, the concentration of anion TsN‐Cl is greater than that of the free acid. TsNCl‐ + H+ ⇌ TsNHCl (1) Hence the above protonation suggesting the anion can be assumed as the reactive oxidizing species. Since organic haloamines have similar chemical properties, the same equilibrium can be expected for BAT also (Scheme 2). 3.9. Kinetic rate law A detailed mode of oxidation of amido black by CAT and BAT in acid medium is depicted in Scheme 3, where the structure of the intermediate complex X is shown. Assuming a total efficient concentration of oxidant [Oxidant]t = [TsN‐X] + [TsNHX] (2) By substituting for [TsN‐X] from equilibrium (i) of Scheme 2 in Equation (2) and solving for [TsNHX], we get TsNHX K1[Oxidant]t+ [H +] 1+ K1 [H +] (3) From slow and rate‐determining step of Scheme 2. Rate = ‐d[Oxidant]t / dt = k2[Oxidant] [TsNHX] (4) By substituting for [TsNHX] from Equation (3) into Equation (4), the following rate law is obtained: Rate K1 k2[Oxidant]t [AB] [H +] 1+ K1[H] + (5) Rate law equation (5) is in good conformity with the experimental information. In the present investigations, disparity of dielectric constant of the medium does not have an effect on the rate appreciably. The effect of varying solvent composition and dielectric constant on the rate of reaction has been described in several studies [32‐36]. For limiting case of zero angle of approach between two dipoles or an ion‐dipole system, Amis [35] has shown that a plot of Log k′ versus 1/D, gives a straight line with a negative slope for a reaction between a negative ion and a dipole or between two dipoles, where a positive slope results for a positive ion‐dipole interaction. The total absence of the effect of varying dielectric constant on the rate cannot be explained by the Amis theory [35]. Applying the Born equation, Laidler [36] has anticipated the following equation for a dipole‐ dipole interaction: Ln k′ = Ln ko + 3/8kT (2/D ‐ 1) [μ2A / r3A + μ2B / r3B ‐μ2≠ / r3≠] (6) where ko is the rate constant in a medium of infinite dielectric constant, μ represents the dipole moment and r refers to the radii of the reactants and activated complex. It can be seen from Equation (6) that the rates should be greater in a medium of lower dielectric constant when r3≠ = r3A + r3B representing that the extent of charge scattering in the transition state is different. 412 Shubha et al. / European Journal of Chemistry 4 (4) (2013) 408‐413 R N N OH NH2 HO3S N SO3H N R1TsNHX TsNX- + H+ TsNHX K1 R N N OH NH2 HO3S N SO3H N R1 TsNHX Complex R N N OH NH2 HO3S N SO3H N R1 TsNHX Complex H2O R N N OH NH2 HO3S N SO3H N R1 HO X R N N OH NH2 HO3S N SO3H N R1HO O H TsNHX - TsNH2 X R N N OH NH2 HO3S N SO3H N R1O O H R N N OH NH2 HO3S N SO3H N R1OO N OH NH2 HO3S N SO3H N R1O TsNHX H2O - TsNH2 N OH NH2 HO3S N SO3H N R1 O O H X H2O N OH NH2 HO3S N SO3H N R1 O O H O H TsNHX - TsNH2 N OH NH2 HO3S N SO3H N R1 O O H O X N OH NH2 HO3S N SO3H N R1 O O O - TsNH2 (i) (ii) (iii) - HX - HX - HX - HX R N N OH NH2 HO3S N SO3H N R1 HO X H2O R: ‐C6H5 R1: ‐C6H5NO2 X: Cl or Br Scheme 3 On the other hand, r3≠ ≈ r3A + r3B implies the absence of a dielectric effect of the solvent on the rate, as was observed in the present investigations, signifying that the transition state is not very much different from the reactants with respect to the size and charge of the transition state and the reactants. Reactions in aqueous medium that are vulnerable to acid‐ base catalysis have been studied in heavy water (D2O) after equilibrium. Since the majority oxidation reactions of organic compounds involve the cleavage of C‐H bond, deuterium isotope effect on such reaction gives information regarding the nature of the rate limiting step. In the present investigations, solvent isotope studies have shown that the rate of reaction is higher in D2O medium. For a reaction involving a fast equilibrium H+ or OH‐ ion transfer, the rate increases in D2O medium since D3O+ or OD‐ are a stronger acid and a stronger base respectively, than H3O+ and OH‐ ions [37‐39]. The observed solvent isotope effect of k′ (H2O) and k′ (D2O) < 1 is due to the greater acidity of D3O+ compared to H3O+. However, the magnitude value is 2‐3 ti order depend supports the p 3.10. Relative A compar shows that the compared to conditions. Th activation ene the difference ions, involved the ease with w these oxidatio and Cl+ play a 2.7, while ch electronegativ decreases. Sin these oxidatio order: Br > compared to C difference in t A similar beh substrates us present resear led to conclud CAT. The neglig addition of p conformity w mechanism is activation and fairly high pos state is highly reflects the fo state. Further there is no effe strength on anticipated me In the pres controlled oxi nitroso comp Accordingly, t operation. Fur the effluents hazardous and simple metho dye present in this dye. Also, short reaction reagents, whic environmenta 4. Conclusion The kineti medium obeys [H+]x, where x Oxidation pro present metho AB with CAT a efficient and fa course simple Furthermore, in the present present in ind by this dye. e of increase i imes greater). dence of rate planned mechan e reactivity of C rison of the ra e oxidation of A o CAT, under his is endorse ergies (Table 2) in electrophili in the oxidatio which these sp on reactions, th a vital role. Bro hlorine has a vity increases nce the halo ca on reactions, th Cl. Therefore CAT. This trend the van der Waa avior has been ing CAT and rch and the lite de that BAT is gible influence p‐toluenesulfon with the propo also supported d other thermod sitive values of solvated while ormation of a r, the experim ect of p‐toluene the reaction echanism. sent redox syst idation of AB b pounds were this redox syste rthermore, AB of various in d also carcinoge d developed ca n industrial effl , this method o n time, cost ef ch make the re ally benign. ns ics of oxidation s the rate law – x= 0.52 and 0.6 oducts were id od developed f and BAT offers airly non‐toxic e, smooth and the simple and t research can b dustrial effluen Shubha et al in rate in D2O This may be d on [H+]. Henc nism. CAT and BAT ates of reaction AB is about thre identical se ed by the rela ). This trend m city of the halo on processes an ecies are gener he electronega omine has the a higher valu s the elect ations are the he electropositi the reactivity d may also be d als’s radii of br n in the oxidati BAT. The fact rature reports s a stronger ox of difference o namide and h osed mechani d by the judiciou dynamic param ΔG≠ and ΔH≠ ind e the negative e compact and ental observat esulfonamide, h rate that also tem the optimum by CAT and BA established em can be scal is one of the c ndustries and enic compound an be adopted luents to reduc offers several ad ffective and mo action process n of AB by CA d[oxidant] / dt 65 for CAT and dentified by G for the oxidativ several advan reagents, whic d environmenta d well‐designed be implemented nts to diminish l. / European Jou is small (expe due to the fract ce, this observ n of CAT and ee‐fold faster in t of experim tive magnitude may be attribut ocations, Cl+ an nd, is also relat rated in reaction ativity values o electronegativi ue of 2.8. As tropositive na reactive speci ive nature is in y of BAT is m due to the mod omine and chlo ion of several o ts furnished in [13,14,21,23,40 xidant compare f ionic strength halide ions ar sm. The prop us value of ener meters (Table 2) dicate the trans entropy of activ ordered trans tion illustrates halide ions and o substantiates m conditions fo AT to correspon in acid med led up to indu chief componen is environmen d. Hence, the pre for treating th e toxicity cause dvantages inclu oderately non‐ simple, elegan AT and BAT in t = k [oxidant]o d BAT, respect C‐MS analysis. ve decolorizatio tages including h make the rea ally compassio d method devel d for treating th the toxicity ca urnal of Chemistry ected tional vation BAT n BAT mental es of ed to d Br+ ted to ns. In of Br+ ity of the ature es in n the more erate orine. other n the 0‐42] ed to h and re in posed rgy of ). The sition vation sition that ionic s the or the nding dium. strial nts in ntally esent he AB ed by uding ‐toxic t and acid [AB]o ively. . The on of g cost action onate. loped he AB aused Ackn T Man facil Tech 13/A Refe [1]. [2]. [3]. [4]. [5]. [6]. [7]. [8]. [9]. [10]. [11]. [12]. [13]. [14]. [15]. [16]. 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