Pub Date : 2020-01-01DOI: 10.17159/0379-4350/2020/v73a13
Sharlott N. Qwane, P. S. Mdluli, L. Madikizela
Abacavir is an antiretroviral drug (ARVD), which has been identified as a water pollutant. To find a selective adsorbent for its extraction from water, a molecularly imprinted polymer (MIP) is proposed for its selective uptake. A 24-hour bulk polymerization process was performed for imprinting abacavir with aliquat 336 and ethylene glycol dimethacrylate, as functional monomer and cross-linking agent, respectively. Uptake of abacavir from 10 mL of aqueous solutions was performed with 40 mg of MIP at pH 5 within 60 min of contact time. MIP selectively adsorbed abacavir from water in the presence of other ARVDs (tenofovir disoproxil and efavirenz). The maximum adsorption capacity obtained for abacavir was 5.98 mg g. The adsorption mechanism was best described by the Freundlich isotherm and pseudo-second-order kinetic model, which were translated to multilayer coverage and chemisorption influenced by electrostatic attractions, respectively. The extraction efficiencies achieved for abacavir in wastewater influent, effluent and estuarine water were 67, 74 and 76 %, respectively. The synthesized MIP can be reused at least 10 consecutive times for adsorption of abacavir from polluted water without losing its extraction efficiency. This is the first study to report the application of aliquat 336 as the functional monomer in the synthesis of MIP for selective extraction of abacavir from
{"title":"Synthesis, Characterization and Application of a Molecularly Imprinted Polymer in Selective Adsorption of Abacavir from Polluted Water","authors":"Sharlott N. Qwane, P. S. Mdluli, L. Madikizela","doi":"10.17159/0379-4350/2020/v73a13","DOIUrl":"https://doi.org/10.17159/0379-4350/2020/v73a13","url":null,"abstract":"Abacavir is an antiretroviral drug (ARVD), which has been identified as a water pollutant. To find a selective adsorbent for its extraction from water, a molecularly imprinted polymer (MIP) is proposed for its selective uptake. A 24-hour bulk polymerization process was performed for imprinting abacavir with aliquat 336 and ethylene glycol dimethacrylate, as functional monomer and cross-linking agent, respectively. Uptake of abacavir from 10 mL of aqueous solutions was performed with 40 mg of MIP at pH 5 within 60 min of contact time. MIP selectively adsorbed abacavir from water in the presence of other ARVDs (tenofovir disoproxil and efavirenz). The maximum adsorption capacity obtained for abacavir was 5.98 mg g. The adsorption mechanism was best described by the Freundlich isotherm and pseudo-second-order kinetic model, which were translated to multilayer coverage and chemisorption influenced by electrostatic attractions, respectively. The extraction efficiencies achieved for abacavir in wastewater influent, effluent and estuarine water were 67, 74 and 76 %, respectively. The synthesized MIP can be reused at least 10 consecutive times for adsorption of abacavir from polluted water without losing its extraction efficiency. This is the first study to report the application of aliquat 336 as the functional monomer in the synthesis of MIP for selective extraction of abacavir from","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":"73 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67463466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.17159/0379-4350/2020/v73a3
Kevin J Visagie, Luke Hodson, G. Arnott
C–H activation offers an intriguing access into inherently chiral calix[4]arenes, but has been little explored in the literature. In this article, we report our investigation into a published C–H activation method that uses carbamates to direct a palladium catalyzed C–H activation and subsequent reaction with N-bromosuccinimide. However, we show that this report is unfortunately flawed on a number of points. An earlier reported study revealed the more likely SEAr mechanism of the bromination reaction, which did not involve palladium catalysis. We nevertheless employed the SEAr bromination in an attempt to form inherently chiral calix[4]arenes, using a chiral (+)-menthyl carbamate as a directing group. Unfortunately, although the reaction was high yielding, the diastereomers formed were inseparable and we were unable to quantify their ratio. Subsequent removal of the chiral (+)-menthyl carbamate, returned a small positive optical rotation, suggesting that at least a level of asymmetric induction was achieved in the bromination to afford a non-racemic product.
{"title":"C-H activation: a Critical Evaluation of a Published Method and its Application Towards Inherently Chiral Calix[4]arenes","authors":"Kevin J Visagie, Luke Hodson, G. Arnott","doi":"10.17159/0379-4350/2020/v73a3","DOIUrl":"https://doi.org/10.17159/0379-4350/2020/v73a3","url":null,"abstract":"C–H activation offers an intriguing access into inherently chiral calix[4]arenes, but has been little explored in the literature. In this article, we report our investigation into a published C–H activation method that uses carbamates to direct a palladium catalyzed C–H activation and subsequent reaction with N-bromosuccinimide. However, we show that this report is unfortunately flawed on a number of points. An earlier reported study revealed the more likely SEAr mechanism of the bromination reaction, which did not involve palladium catalysis. We nevertheless employed the SEAr bromination in an attempt to form inherently chiral calix[4]arenes, using a chiral (+)-menthyl carbamate as a directing group. Unfortunately, although the reaction was high yielding, the diastereomers formed were inseparable and we were unable to quantify their ratio. Subsequent removal of the chiral (+)-menthyl carbamate, returned a small positive optical rotation, suggesting that at least a level of asymmetric induction was achieved in the bromination to afford a non-racemic product.","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":"780 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67463600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.17159/0379-4350/2020/v73a5
I. Sabbagh, P. Kaye
The structure and origin of the major by-product in the synthesis of 8-bromocamphor from (+)-3,3,8-tribromocamphor has been confirmed using NMR, coset and single crystal X-ray analysis and DFT-level computational techniques.
{"title":"Formation of 3,3,4-Trimethyl-1,7-dibromonorbornane-2-one: a Spectroscopic and Computational Study","authors":"I. Sabbagh, P. Kaye","doi":"10.17159/0379-4350/2020/v73a5","DOIUrl":"https://doi.org/10.17159/0379-4350/2020/v73a5","url":null,"abstract":"The structure and origin of the major by-product in the synthesis of 8-bromocamphor from (+)-3,3,8-tribromocamphor has been confirmed using NMR, coset and single crystal X-ray analysis and DFT-level computational techniques.","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":"73 1","pages":"30-34"},"PeriodicalIF":1.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67463153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.17159/0379-4350/2020/v73a11
S. Bapat, D. Jaspal
Finding an economical, efficient and easy handling alternative for commercial grade activated charcoal (AC) in textile wastewater treatment is a dire need. To address this, a noxious weed water hyacinth (WH) has been explored as a ‘biosorbent’ for the decolorization of the hazardous textile dye, Remazol Brilliant Red 3BS (RBR 3BS) in wastewater. A novel surface modification has been carried out using the quaternary ammonium salt, N-Cetyl-N,N,N–trimethyl ammonium bromide, to enhance the dye decolorization capacity of raw WH. The impact of several process parameters, viz. pH, dosage of adsorbent, temperature, concentration and contact time have been examined. Batch adsorption studies, kinetic-thermodynamics, isothermal modelling and error analysis have been studied to ascertain the efficacy of the adsorbent. A comparison of the results has been carried out with activated carbon (AC). Surface-modified WH showed the highest dye uptake of 104.26 mg g, at 27 °C, which was about 10 times more than that of AC. Isothermal, kinetic and thermodynamic studies were conducted for identification of adsorption type taking place for dye–adsorbent systems. Energy of activation was 8.65 kJ mol for treated WH and 8.98 kJ mol for AC. It was proven that surface-modified WH had a high capability to replace AC for adsorption treatments.
{"title":"Surface-modified Water Hyacinth (Eichhornia crassipes) over Activated Carbon for Wastewater Treatment: A Comparative Account","authors":"S. Bapat, D. Jaspal","doi":"10.17159/0379-4350/2020/v73a11","DOIUrl":"https://doi.org/10.17159/0379-4350/2020/v73a11","url":null,"abstract":"Finding an economical, efficient and easy handling alternative for commercial grade activated charcoal (AC) in textile wastewater treatment is a dire need. To address this, a noxious weed water hyacinth (WH) has been explored as a ‘biosorbent’ for the decolorization of the hazardous textile dye, Remazol Brilliant Red 3BS (RBR 3BS) in wastewater. A novel surface modification has been carried out using the quaternary ammonium salt, N-Cetyl-N,N,N–trimethyl ammonium bromide, to enhance the dye decolorization capacity of raw WH. The impact of several process parameters, viz. pH, dosage of adsorbent, temperature, concentration and contact time have been examined. Batch adsorption studies, kinetic-thermodynamics, isothermal modelling and error analysis have been studied to ascertain the efficacy of the adsorbent. A comparison of the results has been carried out with activated carbon (AC). Surface-modified WH showed the highest dye uptake of 104.26 mg g, at 27 °C, which was about 10 times more than that of AC. Isothermal, kinetic and thermodynamic studies were conducted for identification of adsorption type taking place for dye–adsorbent systems. Energy of activation was 8.65 kJ mol for treated WH and 8.98 kJ mol for AC. It was proven that surface-modified WH had a high capability to replace AC for adsorption treatments.","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":"73 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67463383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.17159/0379-4350/2020/v73a7
Nawaf A. Alsaif, Abdurrahman A. Al-Mehizia, A. Bakheit, Seema Zargar, T. Wani
Dapoxetine is a selective serotonin reuptake inhibitor, used to treat premature ejaculation in men. Dapoxetine may interact with the DNA and hence this study investigated dapoxetine and calf thymus DNA (ctDNA) binding interaction. The interaction study of ligands to DNA is of importance in the development of molecular probes and therapeutic agents. Spectroscopic techniques including spectrofluorometry and spectrophotometry were employed to study this interaction. Fluorescence studies indicated a static quenching mechanism between dapoxetine and ctDNA. Groove binding was suggested as the mode of interaction between dapoxetine and ctDNA based on UV absorption, circular dichroism (CD) spectroscopy, iodide quenching and molecular docking studies. The studies conducted at three different temperatures 298, 303 and 310 K indicated a strong binding interaction at higher temperatures. Thermodynamic studies conducted indicated involvement of hydrophobic interaction between ctDNA and dapoxetine and were entropy-driven. Ethidium bromide probe study suggested that dapoxetine does not bind to ctDNA in an intercalative fashion. Iodide quenching studies further proved the non-intercalative binding of ctDNA with dapoxetine. Ionic strength studies conducted ruled out the electrostatic binding mechanism between ctDNA and dapoxetine. Molecular docking analysis performed for the dapoxetine with calf thymus DNA (ctDNA) interaction and confirmed minor groove binding of dapoxetine to ctDNA. The study helped to reveal the binding interaction mechanism between dapoxetine and ctDNA.
{"title":"A Spectroscopic, Thermodynamic and Molecular Docking Study of the Binding Mechanism of Dapoxetine with Calf Thymus DNA","authors":"Nawaf A. Alsaif, Abdurrahman A. Al-Mehizia, A. Bakheit, Seema Zargar, T. Wani","doi":"10.17159/0379-4350/2020/v73a7","DOIUrl":"https://doi.org/10.17159/0379-4350/2020/v73a7","url":null,"abstract":"Dapoxetine is a selective serotonin reuptake inhibitor, used to treat premature ejaculation in men. Dapoxetine may interact with the DNA and hence this study investigated dapoxetine and calf thymus DNA (ctDNA) binding interaction. The interaction study of ligands to DNA is of importance in the development of molecular probes and therapeutic agents. Spectroscopic techniques including spectrofluorometry and spectrophotometry were employed to study this interaction. Fluorescence studies indicated a static quenching mechanism between dapoxetine and ctDNA. Groove binding was suggested as the mode of interaction between dapoxetine and ctDNA based on UV absorption, circular dichroism (CD) spectroscopy, iodide quenching and molecular docking studies. The studies conducted at three different temperatures 298, 303 and 310 K indicated a strong binding interaction at higher temperatures. Thermodynamic studies conducted indicated involvement of hydrophobic interaction between ctDNA and dapoxetine and were entropy-driven. Ethidium bromide probe study suggested that dapoxetine does not bind to ctDNA in an intercalative fashion. Iodide quenching studies further proved the non-intercalative binding of ctDNA with dapoxetine. Ionic strength studies conducted ruled out the electrostatic binding mechanism between ctDNA and dapoxetine. Molecular docking analysis performed for the dapoxetine with calf thymus DNA (ctDNA) interaction and confirmed minor groove binding of dapoxetine to ctDNA. The study helped to reveal the binding interaction mechanism between dapoxetine and ctDNA.","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":"73 1","pages":"44-50"},"PeriodicalIF":1.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67463217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.17159/0379-4350/2020/v73a12
H. Langhals
The identity and quality of liquid components for disinfectants, preferentially isopropyl alcohol and ethanol, can be determined with the naked eye using solvatochromic dyes and comparing their colour with a colour scale. Thus, any confusion with toxic methanol or other solvents can be excluded, as can also the application of raw materials in insufficient concentration or incorrect formulations. The production of a quick and easy to use simple low-cost test kit is described.
{"title":"The Quality Control of Alcoholic Components of Disinfectants by a Simple Colour Test","authors":"H. Langhals","doi":"10.17159/0379-4350/2020/v73a12","DOIUrl":"https://doi.org/10.17159/0379-4350/2020/v73a12","url":null,"abstract":"The identity and quality of liquid components for disinfectants, preferentially isopropyl alcohol and ethanol, can be determined with the naked eye using solvatochromic dyes and comparing their colour with a colour scale. Thus, any confusion with toxic methanol or other solvents can be excluded, as can also the application of raw materials in insufficient concentration or incorrect formulations. The production of a quick and easy to use simple low-cost test kit is described.","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":"44 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67463458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.17159/0379-4350/2020/v73a6
V. A. Adole, B. Jagdale, T. B. Pawar, Abhishek A Sagane
In the present investigation, an ultrasound promoted the synthesis of a series of (E)-3-(2,3-dihydrobenzofuran 5-yl)-1-(aryl)prop2-en-1-one derivatives from 2,3-dihydrobenzofuran-5-carbaldehyde and various aromatic ketones under clean conditions. The application of ultrasound irradiation in organic reactions is one of the incredible tools of green chemistry as reactions can be carried out rapidly under neat conditions. A library of a novel (E)-3-(2,3-dihydrobenzofuran-5-yl)-1-(aryl)prop-2-en-1-one chalcone derivatives were synthesized in good to excellent yield under ultrasonic irradiation. The structures of all synthesized chalcone derivatives synthesized in this study have been established by using FT-IR, H NMR, C NMR, and HRMS techniques. The stereochemistry around C=C in the chalcones was shown to be trans by H NMR (Jab = 15.5Hz). The benefits of the present synthesis include mild reaction conditions, high yield, purification by non-chromatographic strategy and short reaction times, demonstrating the significance of this protocol in terms of waste reduction and energy efficiency.
{"title":"Ultrasound Promoted Stereoselective Synthesis of 2,3-Dihydrobenzofuran Appended Chalcones at Ambient Temperature","authors":"V. A. Adole, B. Jagdale, T. B. Pawar, Abhishek A Sagane","doi":"10.17159/0379-4350/2020/v73a6","DOIUrl":"https://doi.org/10.17159/0379-4350/2020/v73a6","url":null,"abstract":"In the present investigation, an ultrasound promoted the synthesis of a series of (E)-3-(2,3-dihydrobenzofuran 5-yl)-1-(aryl)prop2-en-1-one derivatives from 2,3-dihydrobenzofuran-5-carbaldehyde and various aromatic ketones under clean conditions. The application of ultrasound irradiation in organic reactions is one of the incredible tools of green chemistry as reactions can be carried out rapidly under neat conditions. A library of a novel (E)-3-(2,3-dihydrobenzofuran-5-yl)-1-(aryl)prop-2-en-1-one chalcone derivatives were synthesized in good to excellent yield under ultrasonic irradiation. The structures of all synthesized chalcone derivatives synthesized in this study have been established by using FT-IR, H NMR, C NMR, and HRMS techniques. The stereochemistry around C=C in the chalcones was shown to be trans by H NMR (Jab = 15.5Hz). The benefits of the present synthesis include mild reaction conditions, high yield, purification by non-chromatographic strategy and short reaction times, demonstrating the significance of this protocol in terms of waste reduction and energy efficiency.","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":"73 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67463207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.17159/0379-4350/2020/v73a01
Behzad Hazizadeh Far, Parvin Gaharbani, R. R. Khojasteh
In this research, synthesized Ag NPs/Ag3VO4/AgVO3/GO was applied as a visible-light sensitive photocatalyst for photocatalytic degradation of Direct Red 16 dye (DR16) from aqueous solutions. The synthesized nanocomposite was analyzed by XRD, FESEM, TEM, EDX and Dot mapping. The effect of DR16 dye concentration, AgNPs/Ag3VO4/AgVO3/GO dosage, time and pH on photocatalytic removal of DR 16 were studied. Results revealed that pH, dosage and DR16 concentration are more important parameters than time on photocatalytic removal of the dye. The results indicate that 58.98 % of DR16 removal was obtained under the following optimized conditions: DR16 concentration = 32 mg L; Ag NPs/Ag3VO4/AgVO3/GO dosage = 0.2 g 50 mL ; pH = 4.5; 300 W visible light for 155 min. So, it was concluded that the new nanocomposite can be used as an efficient visible-light photocatalyst for degradation of Direct Red 16 dye.
{"title":"Photocatalytic Degradation of Direct Red 16 Dye using Ag/Ag3VO4/AgVO3/GO Nanocomposite","authors":"Behzad Hazizadeh Far, Parvin Gaharbani, R. R. Khojasteh","doi":"10.17159/0379-4350/2020/v73a01","DOIUrl":"https://doi.org/10.17159/0379-4350/2020/v73a01","url":null,"abstract":"In this research, synthesized Ag NPs/Ag3VO4/AgVO3/GO was applied as a visible-light sensitive photocatalyst for photocatalytic degradation of Direct Red 16 dye (DR16) from aqueous solutions. The synthesized nanocomposite was analyzed by XRD, FESEM, TEM, EDX and Dot mapping. The effect of DR16 dye concentration, AgNPs/Ag3VO4/AgVO3/GO dosage, time and pH on photocatalytic removal of DR 16 were studied. Results revealed that pH, dosage and DR16 concentration are more important parameters than time on photocatalytic removal of the dye. The results indicate that 58.98 % of DR16 removal was obtained under the following optimized conditions: DR16 concentration = 32 mg L; Ag NPs/Ag3VO4/AgVO3/GO dosage = 0.2 g 50 mL ; pH = 4.5; 300 W visible light for 155 min. So, it was concluded that the new nanocomposite can be used as an efficient visible-light photocatalyst for degradation of Direct Red 16 dye.","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":"73 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67463310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.17159/0379-4350/2020/V73A16
Victor O. Shikuku, Selly Jemutai-Kimosop
In this work, bagasse, an agricultural waste was used for the development of environmentally benign biochar (CBG) and the thermal pyrolysis product applied for adsorption of sulfamethoxazole (SMX) from water using a batch technique. The pseudo-first-order model best described the adsorption kinetics. Equilibrium adsorption data were modelled using six twoparameter and five three-parameter isotherm equations and the best-fitting models obtained using five error functions. The Sips isotherm best predicted the equilibrium data with an estimated adsorption capacity of 128.8 mg g. Error analysis showed that three-parameter isotherms best explained the experimental data. The thermodynamic functions, viz. enthalpy (ÄH = –24.72 kJ mol), Gibbs free energy (ÄG = –15.67 kJ mol), entropy (ÄS = 32.65 kJ mol), showed that the reaction is spontaneous and exothermic. The mechanism of adsorption involved charge-assisted hydrogen bonding (-)CAHB. The amount of CBG required for the removal of 99 % of SMX in a given volume of effluent was predicted. The results attest that CBG is an effective low-cost adsorbent for SMX adsorption.
{"title":"Efficient Removal of Sulfamethoxazole onto Sugarcane Bagasse-derived Biochar: Two and Three-parameter Isotherms, Kinetics and Thermodynamics","authors":"Victor O. Shikuku, Selly Jemutai-Kimosop","doi":"10.17159/0379-4350/2020/V73A16","DOIUrl":"https://doi.org/10.17159/0379-4350/2020/V73A16","url":null,"abstract":"In this work, bagasse, an agricultural waste was used for the development of environmentally benign biochar (CBG) and the thermal pyrolysis product applied for adsorption of sulfamethoxazole (SMX) from water using a batch technique. The pseudo-first-order model best described the adsorption kinetics. Equilibrium adsorption data were modelled using six twoparameter and five three-parameter isotherm equations and the best-fitting models obtained using five error functions. The Sips isotherm best predicted the equilibrium data with an estimated adsorption capacity of 128.8 mg g. Error analysis showed that three-parameter isotherms best explained the experimental data. The thermodynamic functions, viz. enthalpy (ÄH = –24.72 kJ mol), Gibbs free energy (ÄG = –15.67 kJ mol), entropy (ÄS = 32.65 kJ mol), showed that the reaction is spontaneous and exothermic. The mechanism of adsorption involved charge-assisted hydrogen bonding (-)CAHB. The amount of CBG required for the removal of 99 % of SMX in a given volume of effluent was predicted. The results attest that CBG is an effective low-cost adsorbent for SMX adsorption.","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":"73 1","pages":"111-119"},"PeriodicalIF":1.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67463523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.17159/0379-4350/2020/V73A19
Somayeh Oftadehgan, A. P. Marjani, J. Khalafy, A. Zamani
Nanoporous starch materials were successfully prepared by a sustainable synthetic process. In this method, some available economic cationic, anionic and nonionic templates like CTAB, SDS and Tween 80 in the presence of borax, as a green and low-cost cross-linker, were used to synthesize the desired cross-linked nanoporous starch in the aqueous phase at relatively low temperature. The obtained materials were characterized by SEM, FT-IR, TGA, DSC and N2 adsorption/desorption methods. While SEM analysis confirmed the porous nature of the materials, BET measurement showed that the materials can have a specific surface area of 65 m g. Cross-linked nanoporous starch was found to be an efficient, inexpensive, easy to prepare, green adsorbent in the removal of methylene blue and methyl orange from wastewater. The synthesized material was found to be highly efficient in controlled adsorption and desorption of ciprofloxacin, which can be applied in drug delivery.
{"title":"Templated Cross-linked Nanoporous Starch","authors":"Somayeh Oftadehgan, A. P. Marjani, J. Khalafy, A. Zamani","doi":"10.17159/0379-4350/2020/V73A19","DOIUrl":"https://doi.org/10.17159/0379-4350/2020/V73A19","url":null,"abstract":"Nanoporous starch materials were successfully prepared by a sustainable synthetic process. In this method, some available economic cationic, anionic and nonionic templates like CTAB, SDS and Tween 80 in the presence of borax, as a green and low-cost cross-linker, were used to synthesize the desired cross-linked nanoporous starch in the aqueous phase at relatively low temperature. The obtained materials were characterized by SEM, FT-IR, TGA, DSC and N2 adsorption/desorption methods. While SEM analysis confirmed the porous nature of the materials, BET measurement showed that the materials can have a specific surface area of 65 m g. Cross-linked nanoporous starch was found to be an efficient, inexpensive, easy to prepare, green adsorbent in the removal of methylene blue and methyl orange from wastewater. The synthesized material was found to be highly efficient in controlled adsorption and desorption of ciprofloxacin, which can be applied in drug delivery.","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":"73 1","pages":"131-136"},"PeriodicalIF":1.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67463575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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