Dr D V Prabhu is Adjunct Professor and former Head of Chemistry Department of Wilson College (University of Mumbai)Mumbai.He served as the Dean of the Faculty of Science of University of Mumbai. His research interests are Reaction kinetics, catalysis and Environmental Chemistry.He has to date published 45 papers in peer reviewed journal and has 11 conference papers besides 76 presentations in National and International Conferences.Dr Prabhu was the Editor of International Journal of Chemistry (ISSN 2249 2119,CODEN IJCML6 during 2012-2016 and at present, is Chief Editor of Green Chemistry and Technology Letters (E-journal) e ISSN 2455 3611 and Editor in Chief of GP Globalize Research Journal of Chemistry ISSN 2481 5911.He has been awarded the Best Chemistry Teacher Award by the Chemical Research Society of India in 2006.He is General Secretary of Association of Chemistry Teachers (India) Supervisors: Research Advisor Phone: +91 22 28811497, 09870226899 Address: Department of Chemistry , Wilson College Mumbai 400007,India
GP Globalize Research Journal of Chemistry is an international peer reviewed journal which publis... more GP Globalize Research Journal of Chemistry is an international peer reviewed journal which publishes full length research papers, short communications, review articles and book reviews covering all areas of Chemistry including Environmental Chemistry. G P Globalize Research Journal of Chemistry is a biannual journal published in English in print and online versions. (1) Manuscript Preparation a) Page Layout: A4 (21 cm x 29.7 cm) leaving 2.5 cm margin on all sides of the text. All the text should be in Times New Roman font, double spaced and pages should be numbered consecutively.
Lakes are very important part of urban ecosystem. Though relatively small in size, lakes perform ... more Lakes are very important part of urban ecosystem. Though relatively small in size, lakes perform significant environmental, social and economic functions. Lake water are sources of potable water, recharging ground water, acting as sponges to control flood and supporting biodiversity 1. Lakes whether man made, natural, fresh water, or brackish play a very vital role in maintaining environmental sustainability particularly in urban environments. Despite knowing their environmental social and economic significance, city planner have wilfully neglected and destroyed these water bodies. In Mumbai lakes are varying degree of environmental degradation. The degradation is due to encroachment eutrophication (from domestic and industrial effluents) and silt. There has been quantum jump in population during the last century without corresponding expansion of civic facilities resulting in lakes and reservoir, especially the urban ones, becoming sink for contaminants. The main causes for the impaired conditions of the lake could be due to fixed point and non-point sources. The human settlement and public affluent sources are the chief factors for the degradation of the lakes, particularly urban lakes 2. In case of Powai lake front property has societal prestige, which cause
Aluminium (Al) is the most abundant metal in the earth's crust, comprising about 7% of its mass. ... more Aluminium (Al) is the most abundant metal in the earth's crust, comprising about 7% of its mass. A large amount of Al is incorporated into aluminosilicate soil minerals and very small quantities appear in the soluble form. Aluminium toxicity is one of the major factors that limit plant growth and development in many acid soils which differs strikingly in their chemical form. Al has been shown to interfere with cell division in plant roots, decrease root respiration, increase cell wall rigidity and interfere with the uptake and transport of Ca, Mg, K, P and water supply to plants, alter cell-wall Donnan free space, the plasma membrane, membrane transport proteins etc. Al toxicity is mainly associated with severe changes in root morphology, resulting in curved, swollen, cracked, brownish, stubby and stiff root apices. It has been known that plants which exist in the presence of potentially toxic Al concentrations must be able to avoid direct contact of vital structures and metabolic processes with high activities of Al ions. The physiological mechanisms of Al resistance can either be mediated via exclusion of Al from the root apex or via intracellular tolerance of Al transported into the plant symplasm. The approaches like metal uptake and transportation in various plant parts, mechanism behind the interaction with mineral nutrients, specific genes responsible for tolerance levels and kinds of organic and amino acids which act as metal chelators and detoxifiers, level and forms of enzymes, and changes in root permeabilities to ions and molecules and their mechanisms are used to study Al toxicity in tolerant and sensitive plant genotypes.
The pollution of coastal waters around cities is largely due to unregulated discharge of industri... more The pollution of coastal waters around cities is largely due to unregulated discharge of industrial, agricultural and domestic wastes. Mumbai City has a large dairy industry which processes raw milk into several food products and in the process, large amounts of water effluents containing dissolved sugars, proteins and fats are produced. These effluents are released into the marine waters after a meagre preliminary treatment. Thus, the marine environment is adversely affected and marine life gets depleted. The health of a water body is defined by physicochemical parameters like BOD, COD, DO and pH. Dairy waste is rich in microorganisms which help in its biodegradation by wet oxidation. The carbonaceous organic matter in dairy waste is oxidized in the presence of microorganisms: Carbon in organic matter + O2 -------> CO2 + H2O + Biomass. The kinetics of biodegradation of dairy waste by wet oxidation has been studied in detail with particular reference to the effects of i) salinity [(Cl-)= 0 to 20000 mg per litre] and ii) temperature on the rate of biodegradation. The biodegradation follows first order kinetics and the oxidation rate was monitored by estimating the dissolved oxygen present initially and at regular time intervals during the reaction using the Alsteberg azide modification of the Winkler method. The study confirmed the negative impact of salinity on the rate of biodegradation of dairy waste. Thermodynamics plays an important role in chemical reactions occurring in the oceans during degradation of organic wastes. The effect of temperature (20 and 27 degrees Celsius) on the rate of degradation of dairy waste was studied and the energy of activation and other thermodynamic activation parameters like enthalpy of activation, free energy of activation and entropy of activation were evaluated using the Arrhenius equation, and correlated with the reaction mechanism of the biodegradation reaction. From the dissolved oxygen values obtained, the BOD values were calculated at different salinities and temperatures and correlated with the rates of biodegradation of the organic wastes under study. The kinetics of biodegradation of a synthetic sample, Lactose-Peptone was also studied.
Environmental Monitoring and Assessment, Sep 23, 2011
With urbanization of coastal cities, marine pollution is becoming a severe problem. The rates of ... more With urbanization of coastal cities, marine pollution is becoming a severe problem. The rates of biodegradation, decomposition, and ratification of pollutants get slowed down due to salinity. The higher temperatures prevalent in tropical regions significantly affect reaction rates. Multiple factors influence the rate of biodegradation, making the process complex. Hence, prediction and evaluation of the assimilative capacity of the marine environment due to wastewater discharges is becoming a difficult task. Biochemical oxygen demand (BOD) is a wet oxidation process, which follows firstorder kinetics. The values of kinetic rate constants are expected to differ with varying salinities and temperatures. Research is carried out using glucose-glutamic acid and domestic wastewater to evaluate the impact of salinity on biodegradation of carbonaceous waste at 20°C and 27°C. The findings confirm the hypothesis of slow biodegradation of carbonaceous organic matter in marine waters. An inverse relationship between rate of biodegradation and salinity was observed. BOD exertion at 20°C (5 days) and 27°C (3 days) for the marine environment is comparable at selected salinities thereby confirming the validity of BOD test of shorter duration at elevated temperature.
Green chemistry & technology letters, Mar 10, 2016
Marine pollution occurs due to the entry of organized or unorganized, point or nonpoint land base... more Marine pollution occurs due to the entry of organized or unorganized, point or nonpoint land based releases of industrial, agricultural and residential waste. Biodegradable organic waste rich in microorganisms lead to potentially harmful effects and alter oxygen cycle, where as excessive inputs of nutrients like nitrogen and phosphorus stimulate algal growth leading to eutrophication. Thermodynamics play an important role in chemicals reactions occurring in ocean during degradation of organic waste. The rate of reactions is altered due to temperature and high salinities. This aspect is very crucial while predicting the self purification capacity of the water body. Adequate experimental work pertaining to the order of reaction and thermodynamic constants is essential to prove the basis of the predicted assimilative capacity of the system. In Mumbai, huge quantity of domestic waste is generated. Due to land restrictions, complete treatment of tertiary level is not feasible. The Municipal administrators take the advantage of coastal location and discharge this waste into the ocean with just meagre preliminary treatment. The disposal practices are advanced and well planned but still expected purification or dilution is not achieved in the near shore region. This has resulted in spoiling the impact zone of coastal areas creating stress on the living biota and non compliance of the marine water quality standards. Three major issues in coastal system, viz. Operation and control of waste discharges, degradation patterns of pollutants and self purification capacity needs systematic evaluation to maintain favorable conditions for aquatic life. Hence it is essential to study the reaction kinetics and thermodynamic behaviour of the biodegradation of carbonaceous waste occurring under highly saline conditions. Experiments are conducted to confirm the kinetics and thermodynamics of biodegradation of domestic waste water into marine water at variable salinities. The paper presents the findings of kinetic behaviour particularly the values for rate of reaction, Activation energy and related constants.
The oxidation of secondary cyclic alcohols, Cyclopentanol, Cyclohexanol and Cyclooctanol has been... more The oxidation of secondary cyclic alcohols, Cyclopentanol, Cyclohexanol and Cyclooctanol has been investigated using Sodium-N-chloro-p-toluenesulphonyamide (Chloramine T) in alkaline medium. Cyclopentanol is used in the manufacture of perfumes and pharmaceuticals and Cyclohexanol is an important feedstock in the manufacture of polymers especially nylons and plasticizers. Cyclooctanol is also used in the preparation of perfumes.The kinetics of oxidation of alcohols was studied under first order conditions with respect to the organic oxidant i.e. [CAT] << [alc.].The progress of oxidation was followed by iodometric estimation of the unreacted oxidant at regular time intervals during the course of the reaction. The effects of alcohol concentration, oxidant concentration, temperature and ionic strength on the reaction rate have been studied and suitable reaction mechanisms and rate laws have been suggested. The thermodynamic activation parameters of the oxidation reaction have been...
India has a large perfumery industry and a worldwide market for perfumes, fragrances and cosmetic... more India has a large perfumery industry and a worldwide market for perfumes, fragrances and cosmetic formulations. Many of these perfumery chemicals are extracted from Indian plants and hence the study of perfumery alcohols becomes relevant. The quantitative aspects of the oxidation of alcohols to the corresponding carbonyl compounds has been extensively reported. But literature survey shows relatively few reports of the kinetic and thermodynamic studies of oxidation of perfumery alcohols. This paper reports the kinetics of the controlled oxidation of 1) primary acyclic alcohols, Geraniol, Nerol and Citronellol and 2) secondary cyclic alcohols, Cyclopentanol and Cyclohexanol using N-Bromosuccinimde in alkaline medium. The oxidation was carried out under first order kinetic conditions with respect to the organic oxidant i.e. [oxidant] << alc.]. The effects of alcohol and oxidant concentrations, ionic strength and temperature on the rates of oxidation of alcohols has been studied. The thermodynamic activation parameters were determined from the change of oxidation rate of alcohol with temperature and interpreted in terms of the rection mechanism proposed for the oxidation.
Recent Progress in Chemical Science Research Vol. 6, Jan 16, 2023
The oxidation of the isomeric perfumery phenols,Eugenol and Isoeugenol found in Indian spices has... more The oxidation of the isomeric perfumery phenols,Eugenol and Isoeugenol found in Indian spices has been carried out using 1) inorganic oxidants in acidic medium and 2) organic oxidants in alkaline medium. The kinetic aspects of the oxidation have been studied with respect to the effects of phenol and oxidant concentration and temperature on the oxidation rate. Suitable reaction mechanisms have been suggested for the oxidation of the phenols under study.The Thermodynamic activation parameters have been evaluated and interpreted in terms of the reaction mechanisms suggested.
For all the oxidants used, the sequence of oxidation rates of phenols is Isoeugenol > Eugenol.
The quantitative aspects of the oxidation of phenols to the corresponding quinones have been stud... more The quantitative aspects of the oxidation of phenols to the corresponding quinones have been studied and reported in literature but there are few reports of the kinetic, thermodynamic and mechanistic studies of the oxidation of phenols.This chapter deals with the oxidation of some perfumery phenols found in Indian spices by a variety of inorganic and organic oxidants using kinetic methods. The oxidation of the perfumery isomeric phenols, Eugenol (4-Allyl-2-methoxy phenol) and Isoeugenol (2-Methoxy-4(prop-1-en-1-yl) phenol) has been carried out using 1) inorganic oxidants,KBrO3,KIO3 and K2S2O8 in acidic medium and 2)N-Bromosuccinimide and Sodium chloro(4-methylbenzene-1-sulfonyl)azanide (Chloramine T) in alkaline medium.These phenols are found in the Indian spices,clove (Syzygium aromaticum), nutmeg (Myristicafragrans), Cinnamon (Cinnamomum zeylanicum) and Basil (Tulsi) (Ocimum basilium) and are used in the manufacture of perfumes,fragrances and flavouring agents. The oxidation was studied under first order kinetic conditions with respect to the oxidant ie.[oxidant]<<[phenol].For both the phenols studied,the oxidation rate increased with phenol concentration but decreased with oxidant concentration.The sequences of oxidation rates of the phenols for the different oxidants has been explained on the basis of their steric factors,isomeric and structural features. From the variation of oxidation rate with temperature, the energy of activation and other thermodynamic activation parameters were evaluated and interpreted in terms of the molecular dynamics of the oxidation process.Suitable reaction mechanisms have been suggested for the oxidation of the phenols under study.
The oxidation of secondary cyclic alcohols, Cyclopentanol, Cyclohexanol and Cyclooctanol has been... more The oxidation of secondary cyclic alcohols, Cyclopentanol, Cyclohexanol and Cyclooctanol has been investigated using Sodium-N-chloro-p-toluenesulphonyamide (Chloramine T) in alkaline medium. Cyclopentanol is used in the manufacture of perfumes and pharmaceuticals and Cyclohexanol is an important feedstock in the manufacture of polymers especially nylons and plasticizers. Cyclooctanol is also used in the preparation of perfumes.The kinetics of oxidation of alcohols was studied under first order conditions with respect to the organic oxidant i.e. [CAT] << [alc.].The progress of oxidation was followed by iodometric estimation of the unreacted oxidant at regular time intervals during the course of the reaction. The effects of alcohol concentration, oxidant concentration, temperature and ionic strength on the reaction rate have been studied and suitable reaction mechanisms and rate laws have been suggested. The thermodynamic activation parameters of the oxidation reaction have been...
Current Topics on Chemistry and Biochemistry Vol. 4, 2022
The Catalytic impact of inexpensive and less hazardous transition metal ions on the oxidation of ... more The Catalytic impact of inexpensive and less hazardous transition metal ions on the oxidation of perfumery alcohols has been investigated.As a green initiative ,transition metal ions Mn(II), Co(II),Ni(II),Cu(II) and Zn(II) have been used to catalyze the oxidation of primary acyclic alcohols, secondary cyclic alcohols and primary unsaturated alcohol, Cinnamyl alcohol by Ce(IV) in an acidic medium. The effect of temperature on oxidation has been studied and the thermodynamic activation parameters of the oxidation have been evaluated.Suitable reaction mechanisms have been suggested for the oxidation of alcohols in the presence and absence of the transition metal ion catalysts.
Kinetics of h3-drol)sis of the SchilT base, N-salic}'Iidene-o-methylaniline (HL) have been studie... more Kinetics of h3-drol)sis of the SchilT base, N-salic}'Iidene-o-methylaniline (HL) have been studied in the pH range 3.57-12.65 in the temperature range 29-45". A rate proOle diagram of pH vs rate constant, shows a rate minimum in the pH range 6.31}..12.00 and reaches a plateau at pH > 12.30. Suitable reaction mechanisms ha\'e been suggested for the hydrolyses of the SrhiiT base in acidic, neutral and basic media. From the effect of temperature on the rate, various thermodynamic parameters have been evaluated.
Physical Chemistry Research Laboratory, Department of Chemistry, Wilson College, Mumbai-400 007, ... more Physical Chemistry Research Laboratory, Department of Chemistry, Wilson College, Mumbai-400 007, India<br> <em>E-mail</em> : dvprabhu@rediffmail.com; prabhu_s@vsnl.com <em> Fax </em>: 91-22-3633088<br> Physical Chemistry Section, Department of Chemistry, Institute of Science, Mumbai-400 007, India<br> <em>Manuscript received 5 October 2004</em> A kinetic study of the hydrolysis of the imines, salicylanil, its methyl and chloro derivatives and <em>N,N'</em> -disalicylidene-<em>p,p'</em>diamino<br> diphenyl methane has been done in the pH range 2.20-12.65 in the temperature range 25-55ºC. The comparative<br> rates of hydrolysis are in the sequence, salicylanil ><em>meta</em>> <em>para</em>> <em>ortho</em> and salicylanil > <em>N,N'</em>-disalicylidene-<em>p,p'</em>-diamino<br> diphenyl methane. The synth...
A systematic study has been carried out to explore the water quality index of ground water of var... more A systematic study has been carried out to explore the water quality index of ground water of various tehsils of Rampur district. Twenty five water samples from tube wells, open wells and hand pumps at various locations were collected and analyzed for pH, nitrate, turbidity, total dissolve solid, chlorides, total hardness, alkalinity and fluoride. In this study overall water quality of Rampur district is very poor and unsuitable for drinking purpose. Water quality of Bilaspur, Shahabad and Rampur city shows that water may not be used for drinking as well as domestic purpose. Present study recommends that the top priority should be given to water quality monitoring and indigenous technologies should be adopted to make water fit for drinking after treatment such as defluoridation, desalination.
GP Globalize Research Journal of Chemistry is an international peer reviewed journal which publis... more GP Globalize Research Journal of Chemistry is an international peer reviewed journal which publishes full length research papers, short communications, review articles and book reviews covering all areas of Chemistry including Environmental Chemistry. G P Globalize Research Journal of Chemistry is a biannual journal published in English in print and online versions. (1) Manuscript Preparation a) Page Layout: A4 (21 cm x 29.7 cm) leaving 2.5 cm margin on all sides of the text. All the text should be in Times New Roman font, double spaced and pages should be numbered consecutively.
Lakes are very important part of urban ecosystem. Though relatively small in size, lakes perform ... more Lakes are very important part of urban ecosystem. Though relatively small in size, lakes perform significant environmental, social and economic functions. Lake water are sources of potable water, recharging ground water, acting as sponges to control flood and supporting biodiversity 1. Lakes whether man made, natural, fresh water, or brackish play a very vital role in maintaining environmental sustainability particularly in urban environments. Despite knowing their environmental social and economic significance, city planner have wilfully neglected and destroyed these water bodies. In Mumbai lakes are varying degree of environmental degradation. The degradation is due to encroachment eutrophication (from domestic and industrial effluents) and silt. There has been quantum jump in population during the last century without corresponding expansion of civic facilities resulting in lakes and reservoir, especially the urban ones, becoming sink for contaminants. The main causes for the impaired conditions of the lake could be due to fixed point and non-point sources. The human settlement and public affluent sources are the chief factors for the degradation of the lakes, particularly urban lakes 2. In case of Powai lake front property has societal prestige, which cause
Aluminium (Al) is the most abundant metal in the earth's crust, comprising about 7% of its mass. ... more Aluminium (Al) is the most abundant metal in the earth's crust, comprising about 7% of its mass. A large amount of Al is incorporated into aluminosilicate soil minerals and very small quantities appear in the soluble form. Aluminium toxicity is one of the major factors that limit plant growth and development in many acid soils which differs strikingly in their chemical form. Al has been shown to interfere with cell division in plant roots, decrease root respiration, increase cell wall rigidity and interfere with the uptake and transport of Ca, Mg, K, P and water supply to plants, alter cell-wall Donnan free space, the plasma membrane, membrane transport proteins etc. Al toxicity is mainly associated with severe changes in root morphology, resulting in curved, swollen, cracked, brownish, stubby and stiff root apices. It has been known that plants which exist in the presence of potentially toxic Al concentrations must be able to avoid direct contact of vital structures and metabolic processes with high activities of Al ions. The physiological mechanisms of Al resistance can either be mediated via exclusion of Al from the root apex or via intracellular tolerance of Al transported into the plant symplasm. The approaches like metal uptake and transportation in various plant parts, mechanism behind the interaction with mineral nutrients, specific genes responsible for tolerance levels and kinds of organic and amino acids which act as metal chelators and detoxifiers, level and forms of enzymes, and changes in root permeabilities to ions and molecules and their mechanisms are used to study Al toxicity in tolerant and sensitive plant genotypes.
The pollution of coastal waters around cities is largely due to unregulated discharge of industri... more The pollution of coastal waters around cities is largely due to unregulated discharge of industrial, agricultural and domestic wastes. Mumbai City has a large dairy industry which processes raw milk into several food products and in the process, large amounts of water effluents containing dissolved sugars, proteins and fats are produced. These effluents are released into the marine waters after a meagre preliminary treatment. Thus, the marine environment is adversely affected and marine life gets depleted. The health of a water body is defined by physicochemical parameters like BOD, COD, DO and pH. Dairy waste is rich in microorganisms which help in its biodegradation by wet oxidation. The carbonaceous organic matter in dairy waste is oxidized in the presence of microorganisms: Carbon in organic matter + O2 -------> CO2 + H2O + Biomass. The kinetics of biodegradation of dairy waste by wet oxidation has been studied in detail with particular reference to the effects of i) salinity [(Cl-)= 0 to 20000 mg per litre] and ii) temperature on the rate of biodegradation. The biodegradation follows first order kinetics and the oxidation rate was monitored by estimating the dissolved oxygen present initially and at regular time intervals during the reaction using the Alsteberg azide modification of the Winkler method. The study confirmed the negative impact of salinity on the rate of biodegradation of dairy waste. Thermodynamics plays an important role in chemical reactions occurring in the oceans during degradation of organic wastes. The effect of temperature (20 and 27 degrees Celsius) on the rate of degradation of dairy waste was studied and the energy of activation and other thermodynamic activation parameters like enthalpy of activation, free energy of activation and entropy of activation were evaluated using the Arrhenius equation, and correlated with the reaction mechanism of the biodegradation reaction. From the dissolved oxygen values obtained, the BOD values were calculated at different salinities and temperatures and correlated with the rates of biodegradation of the organic wastes under study. The kinetics of biodegradation of a synthetic sample, Lactose-Peptone was also studied.
Environmental Monitoring and Assessment, Sep 23, 2011
With urbanization of coastal cities, marine pollution is becoming a severe problem. The rates of ... more With urbanization of coastal cities, marine pollution is becoming a severe problem. The rates of biodegradation, decomposition, and ratification of pollutants get slowed down due to salinity. The higher temperatures prevalent in tropical regions significantly affect reaction rates. Multiple factors influence the rate of biodegradation, making the process complex. Hence, prediction and evaluation of the assimilative capacity of the marine environment due to wastewater discharges is becoming a difficult task. Biochemical oxygen demand (BOD) is a wet oxidation process, which follows firstorder kinetics. The values of kinetic rate constants are expected to differ with varying salinities and temperatures. Research is carried out using glucose-glutamic acid and domestic wastewater to evaluate the impact of salinity on biodegradation of carbonaceous waste at 20°C and 27°C. The findings confirm the hypothesis of slow biodegradation of carbonaceous organic matter in marine waters. An inverse relationship between rate of biodegradation and salinity was observed. BOD exertion at 20°C (5 days) and 27°C (3 days) for the marine environment is comparable at selected salinities thereby confirming the validity of BOD test of shorter duration at elevated temperature.
Green chemistry & technology letters, Mar 10, 2016
Marine pollution occurs due to the entry of organized or unorganized, point or nonpoint land base... more Marine pollution occurs due to the entry of organized or unorganized, point or nonpoint land based releases of industrial, agricultural and residential waste. Biodegradable organic waste rich in microorganisms lead to potentially harmful effects and alter oxygen cycle, where as excessive inputs of nutrients like nitrogen and phosphorus stimulate algal growth leading to eutrophication. Thermodynamics play an important role in chemicals reactions occurring in ocean during degradation of organic waste. The rate of reactions is altered due to temperature and high salinities. This aspect is very crucial while predicting the self purification capacity of the water body. Adequate experimental work pertaining to the order of reaction and thermodynamic constants is essential to prove the basis of the predicted assimilative capacity of the system. In Mumbai, huge quantity of domestic waste is generated. Due to land restrictions, complete treatment of tertiary level is not feasible. The Municipal administrators take the advantage of coastal location and discharge this waste into the ocean with just meagre preliminary treatment. The disposal practices are advanced and well planned but still expected purification or dilution is not achieved in the near shore region. This has resulted in spoiling the impact zone of coastal areas creating stress on the living biota and non compliance of the marine water quality standards. Three major issues in coastal system, viz. Operation and control of waste discharges, degradation patterns of pollutants and self purification capacity needs systematic evaluation to maintain favorable conditions for aquatic life. Hence it is essential to study the reaction kinetics and thermodynamic behaviour of the biodegradation of carbonaceous waste occurring under highly saline conditions. Experiments are conducted to confirm the kinetics and thermodynamics of biodegradation of domestic waste water into marine water at variable salinities. The paper presents the findings of kinetic behaviour particularly the values for rate of reaction, Activation energy and related constants.
The oxidation of secondary cyclic alcohols, Cyclopentanol, Cyclohexanol and Cyclooctanol has been... more The oxidation of secondary cyclic alcohols, Cyclopentanol, Cyclohexanol and Cyclooctanol has been investigated using Sodium-N-chloro-p-toluenesulphonyamide (Chloramine T) in alkaline medium. Cyclopentanol is used in the manufacture of perfumes and pharmaceuticals and Cyclohexanol is an important feedstock in the manufacture of polymers especially nylons and plasticizers. Cyclooctanol is also used in the preparation of perfumes.The kinetics of oxidation of alcohols was studied under first order conditions with respect to the organic oxidant i.e. [CAT] << [alc.].The progress of oxidation was followed by iodometric estimation of the unreacted oxidant at regular time intervals during the course of the reaction. The effects of alcohol concentration, oxidant concentration, temperature and ionic strength on the reaction rate have been studied and suitable reaction mechanisms and rate laws have been suggested. The thermodynamic activation parameters of the oxidation reaction have been...
India has a large perfumery industry and a worldwide market for perfumes, fragrances and cosmetic... more India has a large perfumery industry and a worldwide market for perfumes, fragrances and cosmetic formulations. Many of these perfumery chemicals are extracted from Indian plants and hence the study of perfumery alcohols becomes relevant. The quantitative aspects of the oxidation of alcohols to the corresponding carbonyl compounds has been extensively reported. But literature survey shows relatively few reports of the kinetic and thermodynamic studies of oxidation of perfumery alcohols. This paper reports the kinetics of the controlled oxidation of 1) primary acyclic alcohols, Geraniol, Nerol and Citronellol and 2) secondary cyclic alcohols, Cyclopentanol and Cyclohexanol using N-Bromosuccinimde in alkaline medium. The oxidation was carried out under first order kinetic conditions with respect to the organic oxidant i.e. [oxidant] << alc.]. The effects of alcohol and oxidant concentrations, ionic strength and temperature on the rates of oxidation of alcohols has been studied. The thermodynamic activation parameters were determined from the change of oxidation rate of alcohol with temperature and interpreted in terms of the rection mechanism proposed for the oxidation.
Recent Progress in Chemical Science Research Vol. 6, Jan 16, 2023
The oxidation of the isomeric perfumery phenols,Eugenol and Isoeugenol found in Indian spices has... more The oxidation of the isomeric perfumery phenols,Eugenol and Isoeugenol found in Indian spices has been carried out using 1) inorganic oxidants in acidic medium and 2) organic oxidants in alkaline medium. The kinetic aspects of the oxidation have been studied with respect to the effects of phenol and oxidant concentration and temperature on the oxidation rate. Suitable reaction mechanisms have been suggested for the oxidation of the phenols under study.The Thermodynamic activation parameters have been evaluated and interpreted in terms of the reaction mechanisms suggested.
For all the oxidants used, the sequence of oxidation rates of phenols is Isoeugenol > Eugenol.
The quantitative aspects of the oxidation of phenols to the corresponding quinones have been stud... more The quantitative aspects of the oxidation of phenols to the corresponding quinones have been studied and reported in literature but there are few reports of the kinetic, thermodynamic and mechanistic studies of the oxidation of phenols.This chapter deals with the oxidation of some perfumery phenols found in Indian spices by a variety of inorganic and organic oxidants using kinetic methods. The oxidation of the perfumery isomeric phenols, Eugenol (4-Allyl-2-methoxy phenol) and Isoeugenol (2-Methoxy-4(prop-1-en-1-yl) phenol) has been carried out using 1) inorganic oxidants,KBrO3,KIO3 and K2S2O8 in acidic medium and 2)N-Bromosuccinimide and Sodium chloro(4-methylbenzene-1-sulfonyl)azanide (Chloramine T) in alkaline medium.These phenols are found in the Indian spices,clove (Syzygium aromaticum), nutmeg (Myristicafragrans), Cinnamon (Cinnamomum zeylanicum) and Basil (Tulsi) (Ocimum basilium) and are used in the manufacture of perfumes,fragrances and flavouring agents. The oxidation was studied under first order kinetic conditions with respect to the oxidant ie.[oxidant]<<[phenol].For both the phenols studied,the oxidation rate increased with phenol concentration but decreased with oxidant concentration.The sequences of oxidation rates of the phenols for the different oxidants has been explained on the basis of their steric factors,isomeric and structural features. From the variation of oxidation rate with temperature, the energy of activation and other thermodynamic activation parameters were evaluated and interpreted in terms of the molecular dynamics of the oxidation process.Suitable reaction mechanisms have been suggested for the oxidation of the phenols under study.
The oxidation of secondary cyclic alcohols, Cyclopentanol, Cyclohexanol and Cyclooctanol has been... more The oxidation of secondary cyclic alcohols, Cyclopentanol, Cyclohexanol and Cyclooctanol has been investigated using Sodium-N-chloro-p-toluenesulphonyamide (Chloramine T) in alkaline medium. Cyclopentanol is used in the manufacture of perfumes and pharmaceuticals and Cyclohexanol is an important feedstock in the manufacture of polymers especially nylons and plasticizers. Cyclooctanol is also used in the preparation of perfumes.The kinetics of oxidation of alcohols was studied under first order conditions with respect to the organic oxidant i.e. [CAT] << [alc.].The progress of oxidation was followed by iodometric estimation of the unreacted oxidant at regular time intervals during the course of the reaction. The effects of alcohol concentration, oxidant concentration, temperature and ionic strength on the reaction rate have been studied and suitable reaction mechanisms and rate laws have been suggested. The thermodynamic activation parameters of the oxidation reaction have been...
Current Topics on Chemistry and Biochemistry Vol. 4, 2022
The Catalytic impact of inexpensive and less hazardous transition metal ions on the oxidation of ... more The Catalytic impact of inexpensive and less hazardous transition metal ions on the oxidation of perfumery alcohols has been investigated.As a green initiative ,transition metal ions Mn(II), Co(II),Ni(II),Cu(II) and Zn(II) have been used to catalyze the oxidation of primary acyclic alcohols, secondary cyclic alcohols and primary unsaturated alcohol, Cinnamyl alcohol by Ce(IV) in an acidic medium. The effect of temperature on oxidation has been studied and the thermodynamic activation parameters of the oxidation have been evaluated.Suitable reaction mechanisms have been suggested for the oxidation of alcohols in the presence and absence of the transition metal ion catalysts.
Kinetics of h3-drol)sis of the SchilT base, N-salic}'Iidene-o-methylaniline (HL) have been studie... more Kinetics of h3-drol)sis of the SchilT base, N-salic}'Iidene-o-methylaniline (HL) have been studied in the pH range 3.57-12.65 in the temperature range 29-45". A rate proOle diagram of pH vs rate constant, shows a rate minimum in the pH range 6.31}..12.00 and reaches a plateau at pH > 12.30. Suitable reaction mechanisms ha\'e been suggested for the hydrolyses of the SrhiiT base in acidic, neutral and basic media. From the effect of temperature on the rate, various thermodynamic parameters have been evaluated.
Physical Chemistry Research Laboratory, Department of Chemistry, Wilson College, Mumbai-400 007, ... more Physical Chemistry Research Laboratory, Department of Chemistry, Wilson College, Mumbai-400 007, India<br> <em>E-mail</em> : dvprabhu@rediffmail.com; prabhu_s@vsnl.com <em> Fax </em>: 91-22-3633088<br> Physical Chemistry Section, Department of Chemistry, Institute of Science, Mumbai-400 007, India<br> <em>Manuscript received 5 October 2004</em> A kinetic study of the hydrolysis of the imines, salicylanil, its methyl and chloro derivatives and <em>N,N'</em> -disalicylidene-<em>p,p'</em>diamino<br> diphenyl methane has been done in the pH range 2.20-12.65 in the temperature range 25-55ºC. The comparative<br> rates of hydrolysis are in the sequence, salicylanil ><em>meta</em>> <em>para</em>> <em>ortho</em> and salicylanil > <em>N,N'</em>-disalicylidene-<em>p,p'</em>-diamino<br> diphenyl methane. The synth...
A systematic study has been carried out to explore the water quality index of ground water of var... more A systematic study has been carried out to explore the water quality index of ground water of various tehsils of Rampur district. Twenty five water samples from tube wells, open wells and hand pumps at various locations were collected and analyzed for pH, nitrate, turbidity, total dissolve solid, chlorides, total hardness, alkalinity and fluoride. In this study overall water quality of Rampur district is very poor and unsuitable for drinking purpose. Water quality of Bilaspur, Shahabad and Rampur city shows that water may not be used for drinking as well as domestic purpose. Present study recommends that the top priority should be given to water quality monitoring and indigenous technologies should be adopted to make water fit for drinking after treatment such as defluoridation, desalination.
Proceedings of International Conference on Designing a Sustainable Future :Advances and Opportunities, 2023
The 12 principles of Green Chemistry provide a blueprint for sustainable development. One of the ... more The 12 principles of Green Chemistry provide a blueprint for sustainable development. One of the important principles of Green Chemistry is the use of catalysts to improve reaction rate, reaction yield and atom economy. Homogeneous catalysts have been found to be more effective than Heterogeneous catalysts. The sequence of catalytic efficiencies of the transition metal ions has been determined for each alcohol under study. The oxidation rate was determined using kinetic methods and suitable reaction mechanisms have been suggested for the oxidation of perfumery alcohols in the presence and absence of transition metal ion catalysts
Chemistry is a science whose progress is exponential as it touches every aspect of our existence ... more Chemistry is a science whose progress is exponential as it touches every aspect of our existence and provides all the things required for life to survive on this planet. Chemistry is rightly called the Science of Life. Chemical processes provide food, clothing, shelter medicines, and energy to sustain life. Feeding the ever-increasing population is a big challenge calling for increased production of crops, minimizing losses during their harvesting and storage and use of new, improved varieties like Genetically modified (GM) food grains and pulses. The use of fertilizers has increased manifold over the years, leading to an increase in the production of food. Clothing is made from plant fibres like cotton and silk. New and better varieties of cotton have been developed. Nylon, produced by the polymer industry is also a critical clothing material in some parts of the world. New materials like composites, fly ash bricks, and polymeric wastes are being increasingly used for construction purposes, especially for housing and roads. Research for the synthesis of new drugs to combat diseases is a continuous activity, and the pharmaceutical industry has a considerable investment, especially in our country. Indigenous medicine systems like Ayurveda, Homoeopathy and Unani are also contributing to health welfare, especially in India. Of late, nanomedicines are emerging as an essential area of medicine. Non-conventional energy sources like solar, nuclear, hydro, biodiesel and wind energy are being increasingly tapped as possible substitutes for the fast depleting coal and oil reserves. The International Solar Alliance, initiated by India, aims at forging a strong partnership between all nations to tap and use solar energy.
Society, at large, has to realise the gravity of environmental degradation and participate fully ... more Society, at large, has to realise the gravity of environmental degradation and participate fully in the mitigation of environmental problems. This article discusses the Indian initiatives and the important milestones in the path of environmental protection and pollution abatement. The commitment of the Indian Government to the cause of public awareness of environmental conservation is reflected in its outreach and educational programmes involving its ministries, environmental monitoring agencies, NGOs, academic and research institutions. The Ministry of Environment and Forests (MoEF) has played a leading role in the national priority programmes of environmental monitoring, assessment and pollution control. All the stakeholders have succeeded to some extent in creating public interest in environmental issues but much more needs to be done. National level institutions like NEERI, NIO and TERI are actively involved in research to find feasible solutions to our environmental problems and in the dissemination of relevant information through their publications. In our country, voluntary organisations and NGOs have been contributing immensely to environmental causes. Following the directive of the Supreme Court in 1991, environmental education is a compulsory component of school and college curricula. India has contributed significantly to the deliberations at COP (Conference of the Parties) fora especially the recently held COP-21 in Paris. Our suggestions for creating a pollution-free world have always been welcomed by the participating countries especially the developing countries. This article also presents the results of an environmental study carried out in Wilson College, Mumbai in which the effect of salinity on the rate of degradation of effluents released in marine waters, was quantitatively studied using reaction kinetics.
The Catalytic impact of inexpensive and less hazardous transition metal ions on the oxidation of ... more The Catalytic impact of inexpensive and less hazardous transition metal ions on the oxidation of perfumery alcohols has been investigated.As a green initiative ,transition metal ions Mn(II), Co(II),Ni(II),Cu(II) and Zn(II) have been used to catalyze the oxidation of primary acyclic alcohols, secondary cyclic alcohols and primary unsaturated alcohol, Cinnamyl alcohol by Ce(IV) in an acidic medium. The effect of temperature on oxidation has been studied and the thermodynamic activation parameters of the oxidation have been evaluated.Suitable reaction mechanisms have been suggested for the oxidation of alcohols in the presence and absence of the transition metal ion catalysts.
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Papers by Damodar Prabhu
For all the oxidants used, the sequence of oxidation rates of phenols is Isoeugenol > Eugenol.
For all the oxidants used, the sequence of oxidation rates of phenols is Isoeugenol > Eugenol.
National level institutions like NEERI, NIO and TERI are actively involved in research to find feasible solutions to our environmental problems and in the dissemination of relevant information through their publications. In our country, voluntary organisations and NGOs have been contributing immensely to environmental causes. Following the directive of the Supreme Court in 1991, environmental education is a compulsory component of school and college curricula. India has contributed significantly to the deliberations at COP (Conference of the Parties) fora especially the recently held COP-21 in Paris. Our suggestions for creating a pollution-free world have always been welcomed by the participating countries especially the developing countries. This article also presents the results of an environmental study carried out in Wilson College, Mumbai in which the effect of salinity on the rate of degradation of effluents released in marine waters, was quantitatively studied using reaction kinetics.