Supercapacitor material is an alternative in energy storage. Supercapacitors are charge storage devices that have a high energy density, fast charge/discharge rates, long service life, wide operating temperature range, and are environmentally friendly. Graphene is a nanomaterial that can be used as a supercapacitor because it has high conductivity and a large surface area, but graphene can experience agglomeration so it can affect its capacitance properties. The microwave-assisted method can be used in the synthesis of graphene. Several microwave-based techniques are becoming more popular for producing graphene and altering it. Due to its quick, precise, uniform, and volumetric heating, microwave heating is a promising method for the thermochemical treatment and reduction of graphene oxide to graphene. This research aimed to examine the effect of microwave irradiation time on the capacitive properties of graphene synthesis as a supercapacitor. Graphene oxide (GO) can be reduced into graphene quickly and easily using microwave pulses lasting 15 to 30minutes to produce high-quality graphene fabrication. The characterization test was performed using UV-Vis, FTIR, SEM-EDX and cyclic voltammetry (CV). As a result, the optimum time is 25 minutes, and it showed an absorption peak at the 282 nm wavelength dan the CV analysis showed that the graphene has double capacitor properties with a specific capacitance of 140.7 F/g in 20 mV/s. Besides, the result of SEM indicated that graphene could be formed successfully. Its potential applications are also illustrated by emphasizing its usage as electrode material. Finally, its main challenges and prospects are considerably pointed out.
{"title":"The Effect of Microwave Irradiation on the Synthesis of Graphene from Battery Waste on Capacitance Properties","authors":"E. Rahayu, B. Budiyono, Hadiyanto Hadiyanto","doi":"10.3311/ppch.21377","DOIUrl":"https://doi.org/10.3311/ppch.21377","url":null,"abstract":"Supercapacitor material is an alternative in energy storage. Supercapacitors are charge storage devices that have a high energy density, fast charge/discharge rates, long service life, wide operating temperature range, and are environmentally friendly. Graphene is a nanomaterial that can be used as a supercapacitor because it has high conductivity and a large surface area, but graphene can experience agglomeration so it can affect its capacitance properties. The microwave-assisted method can be used in the synthesis of graphene. Several microwave-based techniques are becoming more popular for producing graphene and altering it. Due to its quick, precise, uniform, and volumetric heating, microwave heating is a promising method for the thermochemical treatment and reduction of graphene oxide to graphene. This research aimed to examine the effect of microwave irradiation time on the capacitive properties of graphene synthesis as a supercapacitor. Graphene oxide (GO) can be reduced into graphene quickly and easily using microwave pulses lasting 15 to 30minutes to produce high-quality graphene fabrication. The characterization test was performed using UV-Vis, FTIR, SEM-EDX and cyclic voltammetry (CV). As a result, the optimum time is 25 minutes, and it showed an absorption peak at the 282 nm wavelength dan the CV analysis showed that the graphene has double capacitor properties with a specific capacitance of 140.7 F/g in 20 mV/s. Besides, the result of SEM indicated that graphene could be formed successfully. Its potential applications are also illustrated by emphasizing its usage as electrode material. Finally, its main challenges and prospects are considerably pointed out.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"14 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78450968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In our research, seven 624-type capillary columns were investigated. All the columns were the same in length, internal diameter, and film thickness (30 m × 0.32 mm × 1.0 µm). However, they were produced by different manufacturers or the same manufacturer but in different batches. Even though the manufacturers recommend them as "equivalent columns" this equivalence did not prevail even in the case of columns produced by the same manufacturer. Our examination criteria centered on the quantitative determination ability of the columns. A homemade column test mixture was compiled to represent all the second-order interactions that can occur between the analyte and stationary phase. Although theoretically these columns have the same stationary phase quality, they did not result in the same chromatograms. In addition to the origin and batch of the column, the "history of the column" contributes likewise to the different peak symmetry, retention order, and even peak areas that affect the quantitative determination. We quantified this quantitative determination ability with the effective carbon number (ECN) and the Limit of Quantitation (LoQ) values. Based on our results the attainable LoQ and ECN values depend at least as much on the origin and actual state of the stationary phase as on the measurement conditions to be optimized. In our paper, we demonstrate the extent to which the same stationary phases offered by different companies and/or different backgrounds can influence our detection limit and detector response even if the relevant columns have theoretically the same chemical structure.
本研究对7根624型毛细管柱进行了研究。所有色谱柱的长度、内径、膜厚均相同(30 m × 0.32 mm × 1.0µm)。但是，它们是由不同的制造商生产的，或者是同一制造商生产的，但批次不同。尽管制造商将它们推荐为“等效列”，但即使在同一制造商生产的列的情况下，这种等效性也不普遍。我们的检验标准集中在色谱柱的定量测定能力上。自制的柱测试混合物被编译来表示所有的二级相互作用，可以发生在分析物和固定相之间。虽然理论上这些色谱柱具有相同的固定相质量，但它们不能产生相同的色谱图。除了色谱柱的来源和批次不同之外，“色谱柱的历史”同样会导致不同的峰对称性、保留顺序，甚至峰面积的不同，从而影响定量测定。我们用有效碳数(ECN)和定量限(LoQ)值对这种定量测定能力进行了量化。根据我们的结果，可达到的LoQ和ECN值至少取决于固定相的起源和实际状态，而不是要优化的测量条件。在我们的论文中，我们证明了不同公司和/或不同背景提供的相同固定相可以影响我们的检测限和检测器响应的程度，即使相关色谱在理论上具有相同的化学结构。
{"title":"Comparison of 624-type Capillary Columns","authors":"G. Nyerges, Judit Mátyási, J. Balla","doi":"10.3311/ppch.21611","DOIUrl":"https://doi.org/10.3311/ppch.21611","url":null,"abstract":"In our research, seven 624-type capillary columns were investigated. All the columns were the same in length, internal diameter, and film thickness (30 m × 0.32 mm × 1.0 µm). However, they were produced by different manufacturers or the same manufacturer but in different batches. Even though the manufacturers recommend them as \"equivalent columns\" this equivalence did not prevail even in the case of columns produced by the same manufacturer. Our examination criteria centered on the quantitative determination ability of the columns. A homemade column test mixture was compiled to represent all the second-order interactions that can occur between the analyte and stationary phase. Although theoretically these columns have the same stationary phase quality, they did not result in the same chromatograms. In addition to the origin and batch of the column, the \"history of the column\" contributes likewise to the different peak symmetry, retention order, and even peak areas that affect the quantitative determination. We quantified this quantitative determination ability with the effective carbon number (ECN) and the Limit of Quantitation (LoQ) values. Based on our results the attainable LoQ and ECN values depend at least as much on the origin and actual state of the stationary phase as on the measurement conditions to be optimized. In our paper, we demonstrate the extent to which the same stationary phases offered by different companies and/or different backgrounds can influence our detection limit and detector response even if the relevant columns have theoretically the same chemical structure.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"40 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78801251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, the novel TPA@C-NiZr-MOF catalyst is synthesized by the impregnation of tungstophosphoric acid (TPA) on the NiZr-based metal-organic framework (NiZr-MOF) followed by calcination up to 300 °C. The as-prepared catalyst materials were structurally, morphologically, and texturally characterized by XRD, FTIR, temperature programmed desorption of NH3 ( TPD-NH3 ), N2 physisorption, SEM, TEM, and XPS. The prepared catalyst can be used as an efficient heterogeneous catalyst for biodiesel production from oleic acid (OA) with methanol. The results indicated that, in comparison to TPA@NiZr-MOF, the TPA@C-NiZr-MOF catalyst calcined at 300 °C exhibits excellent catalytic performance probably owing to the synergistic effect between TPA and metal oxide skeletons, high acidity, as well as larger surface area and pore size. Additionally, the TPA@C-NiZr-MOF catalyst can be reused in up to six cycles with an acceptable conversion. This study showed that the bimetallic MOF-derived composite materials can be used as an alternative potential heterogeneous catalyst toward biorefinery applications.
{"title":"Facile Preparation of Bimetallic MOF-derived Supported Tungstophosphoric Acid Composites for Biodiesel Production","authors":"Qiuyun Zhang, Linmin Luo, Jiaxin Jin, Yaping Wu, Yutao Zhang","doi":"10.3311/ppch.21975","DOIUrl":"https://doi.org/10.3311/ppch.21975","url":null,"abstract":"In this work, the novel TPA@C-NiZr-MOF catalyst is synthesized by the impregnation of tungstophosphoric acid (TPA) on the NiZr-based metal-organic framework (NiZr-MOF) followed by calcination up to 300 °C. The as-prepared catalyst materials were structurally, morphologically, and texturally characterized by XRD, FTIR, temperature programmed desorption of NH3 ( TPD-NH3 ), N2 physisorption, SEM, TEM, and XPS. The prepared catalyst can be used as an efficient heterogeneous catalyst for biodiesel production from oleic acid (OA) with methanol. The results indicated that, in comparison to TPA@NiZr-MOF, the TPA@C-NiZr-MOF catalyst calcined at 300 °C exhibits excellent catalytic performance probably owing to the synergistic effect between TPA and metal oxide skeletons, high acidity, as well as larger surface area and pore size. Additionally, the TPA@C-NiZr-MOF catalyst can be reused in up to six cycles with an acceptable conversion. This study showed that the bimetallic MOF-derived composite materials can be used as an alternative potential heterogeneous catalyst toward biorefinery applications.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"4 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75977941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Ivanov, Mariya Ekaterincheva, A. Kalashnikov, Ksenya Baca, Anton S. Mazur
One of the urgent scientific and technical objectives in the technologies of plywood and wood boards is the search for ways to reduce of hot pressing time without increasing the formaldehyde emission from finished products. To solve this problem was developed the new modifier-curing agent MC-4SF, is mainly a product of interaction of citric acid with urea and ammonia. Compared to traditional ammonium salts, the modifier-curing agent combines the properties of both direct and latent catalysts. Determination of the composition of residual methylol groups in the aqueous extracts obtained by treating the resin cured at 100 °C showed that the modifier-curing agent provides relatively high hydrolytic stability of the UF-polymer during extraction. Spectra of solid-state 13C NMR showed that in resins cured with MC-4SF increased the compound of methylene bridges compared to resins cured with standard catalysts. It is possible that the amino groups of urea (or its derivatives) included in the modifier-curing agent, react with the methylol groups of UF oligomers, fitting urea into the structure of the resulting polymer. Thus explains the increased hydrolytic stability and reduced toxicity of the cured resin. Manufacturing tests of nine-layer plywood made with a modifier-curing agent showed that replacing ammonium sulfate with MC-4SF allows a significant reduction in pressing time at 110 °C without loss of quality of the finished product. With the same pressing time, it was possible to increase the line shear strength by 14% and to reduce formaldehyde emission by 45%.
{"title":"Usage of the New Modifier-curing Agent in Plywood Technology: The Influence to Urea-formaldehyde Resin Curing and Formaldehyde Emission","authors":"D. Ivanov, Mariya Ekaterincheva, A. Kalashnikov, Ksenya Baca, Anton S. Mazur","doi":"10.3311/ppch.21369","DOIUrl":"https://doi.org/10.3311/ppch.21369","url":null,"abstract":"One of the urgent scientific and technical objectives in the technologies of plywood and wood boards is the search for ways to reduce of hot pressing time without increasing the formaldehyde emission from finished products. To solve this problem was developed the new modifier-curing agent MC-4SF, is mainly a product of interaction of citric acid with urea and ammonia. Compared to traditional ammonium salts, the modifier-curing agent combines the properties of both direct and latent catalysts. Determination of the composition of residual methylol groups in the aqueous extracts obtained by treating the resin cured at 100 °C showed that the modifier-curing agent provides relatively high hydrolytic stability of the UF-polymer during extraction. Spectra of solid-state 13C NMR showed that in resins cured with MC-4SF increased the compound of methylene bridges compared to resins cured with standard catalysts. It is possible that the amino groups of urea (or its derivatives) included in the modifier-curing agent, react with the methylol groups of UF oligomers, fitting urea into the structure of the resulting polymer. Thus explains the increased hydrolytic stability and reduced toxicity of the cured resin. Manufacturing tests of nine-layer plywood made with a modifier-curing agent showed that replacing ammonium sulfate with MC-4SF allows a significant reduction in pressing time at 110 °C without loss of quality of the finished product. With the same pressing time, it was possible to increase the line shear strength by 14% and to reduce formaldehyde emission by 45%.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"76 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72842891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Amit Singh, V. Anand, Attila Bai, Zoltán Gabnai, Sanjeev Kumar Prajapati
Eutrophication has a significant negative impact on the ecosystem since it depletes the planet's biological resources and is further responsible for climate change. It is caused by both endogenous and exogenous nutrient enrichment. This phenomenon degrades the water quality and simultaneously increases the greenhouse gases emission from waterbodies resulting in climate change Inland waterbodies contain enormous amounts of nutrients such as phosphorous, nitrogen, and carbon. Thus, it becomes essential to restore these nutrients using proper sustainable approaches. Algae-based technologies have received a lot of attention these days because of environmentally friendly and inexpensive treatment. About 70% of the nutrient load from wastewater can be removed using such technology. The recovered algal biomass after wastewater treatment contains various biomolecules which can be used for the producing of value-added products such as bioenergy in the form of biomethane and biodiesel, cosmetics and pharmaceuticals along with the synthesis of nanoparticles. Therefore, the primary goal of this review is to inform readers about the possibilities of a low-cost integrated biorefinery based on microalgae for resource recovery and to mitigate eutrophication and greenhouse gas emission from water bodies.
{"title":"Waste Algae for Bioenergy Generation to Mitigate Eutrophication and Greenhouse Emissions in Water Bodies","authors":"Amit Singh, V. Anand, Attila Bai, Zoltán Gabnai, Sanjeev Kumar Prajapati","doi":"10.3311/ppch.22005","DOIUrl":"https://doi.org/10.3311/ppch.22005","url":null,"abstract":"Eutrophication has a significant negative impact on the ecosystem since it depletes the planet's biological resources and is further responsible for climate change. It is caused by both endogenous and exogenous nutrient enrichment. This phenomenon degrades the water quality and simultaneously increases the greenhouse gases emission from waterbodies resulting in climate change Inland waterbodies contain enormous amounts of nutrients such as phosphorous, nitrogen, and carbon. Thus, it becomes essential to restore these nutrients using proper sustainable approaches. Algae-based technologies have received a lot of attention these days because of environmentally friendly and inexpensive treatment. About 70% of the nutrient load from wastewater can be removed using such technology. The recovered algal biomass after wastewater treatment contains various biomolecules which can be used for the producing of value-added products such as bioenergy in the form of biomethane and biodiesel, cosmetics and pharmaceuticals along with the synthesis of nanoparticles. Therefore, the primary goal of this review is to inform readers about the possibilities of a low-cost integrated biorefinery based on microalgae for resource recovery and to mitigate eutrophication and greenhouse gas emission from water bodies.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"48 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75210039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sabariah Rozali, Nurul Hannan Mohd Safari, Abdul Rahman Hassan, Roslan Umar
In this study, the performance and structural properties of enhanced skinned asymmetric nanofiltration (NF) membranes were experimentally and theoretically analyzed. Based on Donnan and steric-hindrance transport mechanism, the relationship of performances and key properties of the fabricated nanofiltration membranes were examined. At the optimum concentration of polymer, the skinned nanofiltration membranes achieved high salt rejection up to 85% and high solutes separation efficacy. Moreover, morphological and modeling analysis discovered that, the optimum membranes produced good pore size and fine key properties with 1.20 nm of pore radius, 4.96 µm of ratio of thickness to porosity (∆x/Ak) and −1.56 of surface charge, ζ as well as uniform pore size distributions. The findings from this study proved that the strategic utilization and manipulation of good membranes material is a simple and good attempt to upgrade the membranes capability and usability which lead towards the application in various membrane separation processes.
{"title":"Elucidation on Performance and Structural Properties of Skinned Asymmetric Nanofiltration Membrane Based on Theoretical Models","authors":"Sabariah Rozali, Nurul Hannan Mohd Safari, Abdul Rahman Hassan, Roslan Umar","doi":"10.3311/ppch.21889","DOIUrl":"https://doi.org/10.3311/ppch.21889","url":null,"abstract":"In this study, the performance and structural properties of enhanced skinned asymmetric nanofiltration (NF) membranes were experimentally and theoretically analyzed. Based on Donnan and steric-hindrance transport mechanism, the relationship of performances and key properties of the fabricated nanofiltration membranes were examined. At the optimum concentration of polymer, the skinned nanofiltration membranes achieved high salt rejection up to 85% and high solutes separation efficacy. Moreover, morphological and modeling analysis discovered that, the optimum membranes produced good pore size and fine key properties with 1.20 nm of pore radius, 4.96 µm of ratio of thickness to porosity (∆x/Ak) and −1.56 of surface charge, ζ as well as uniform pore size distributions. The findings from this study proved that the strategic utilization and manipulation of good membranes material is a simple and good attempt to upgrade the membranes capability and usability which lead towards the application in various membrane separation processes.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"23 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83239528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Benjámin Csorba, L. Farkas, Andrea Mihalkó, R. Z. Boros, I. Gresits
The previously widespread mercury cell technology in chlorine production has now been replaced by more environmentally friendly membrane cell electrolysis which is a Best Available Techniques (BAT) technology. However, this requires a much cleaner brine containing contaminants (Al, Ca, Mg, etc.) in the order of ng/g at most. For this reason, it’s very important to detect trace amounts of aluminum in concentrated saline media in the simplest and fastest way. To the best of our knowledge, no one has previously developed a spectrophotometric method capable of detecting aluminum in ionic forms selectively in the order of ng/g in concentrated saline media, without any preconcentration or separation step. Our advanced analytical method provides an opportunity for this. During the analytical procedure, a colored complex ion is formed from the dissolved aluminum content of the sample with eriochrome cyanine R (ECR) ligand in buffered pH medium. The sensitivity of the measurement is increased by adding quaternary ammonium salt. The colored complex ion is formed in 15 minutes, then the absorbance measurement can be performed for 90 minutes. The effect of rock salt interference was eliminated by proper calibration. In our work the dependence of the signal on temperature, pH, time elapsed after the addition of reactants, the dosing sequence, the salinity of the medium was examined, furthermore, we studied which wavelength-absorbance values give the best fit (highest R2 value) and the highest sensitivity in case of linear calibration. Surprisingly, increasing the salinity significantly improves the sensitivity of the measurement.
以前在氯气生产中广泛使用的汞电池技术现在已经被更环保的膜电池电解技术所取代，这是一种最佳可用技术(BAT)技术。然而，这需要更清洁的盐水，其中含有最多纳克/克量级的污染物(Al, Ca, Mg等)。因此，用最简单、最快速的方法检测浓盐水介质中的微量铝是非常重要的。据我们所知，以前还没有人开发出一种分光光度法，能够在浓盐水介质中选择性地以ng/g的顺序检测离子形式的铝，而不需要任何预浓缩或分离步骤。我们先进的分析方法为这提供了机会。在分析过程中，在缓冲pH介质中，用eriochrome cyanine R (ECR)配体溶解样品的铝含量形成有色络合离子。加入季铵盐可提高测量灵敏度。15分钟形成有色络合离子，90分钟可进行吸光度测量。通过适当的校正，消除了岩盐干扰的影响。在我们的工作中，我们考察了信号对温度、pH值、添加反应物后的时间、给药顺序、介质盐度的依赖关系，并研究了在线性校准情况下，哪些波长-吸光度值具有最佳拟合(最高R2值)和最高灵敏度。令人惊讶的是，增加盐度显著提高了测量的灵敏度。
{"title":"Photometric Determination of Trace Amounts of Aluminum in Nearly Saturated Rock Salt Solutions Used by Chlor-alkali Industry","authors":"Benjámin Csorba, L. Farkas, Andrea Mihalkó, R. Z. Boros, I. Gresits","doi":"10.3311/ppch.22051","DOIUrl":"https://doi.org/10.3311/ppch.22051","url":null,"abstract":"The previously widespread mercury cell technology in chlorine production has now been replaced by more environmentally friendly membrane cell electrolysis which is a Best Available Techniques (BAT) technology. However, this requires a much cleaner brine containing contaminants (Al, Ca, Mg, etc.) in the order of ng/g at most. For this reason, it’s very important to detect trace amounts of aluminum in concentrated saline media in the simplest and fastest way. To the best of our knowledge, no one has previously developed a spectrophotometric method capable of detecting aluminum in ionic forms selectively in the order of ng/g in concentrated saline media, without any preconcentration or separation step. Our advanced analytical method provides an opportunity for this. During the analytical procedure, a colored complex ion is formed from the dissolved aluminum content of the sample with eriochrome cyanine R (ECR) ligand in buffered pH medium. The sensitivity of the measurement is increased by adding quaternary ammonium salt. The colored complex ion is formed in 15 minutes, then the absorbance measurement can be performed for 90 minutes. The effect of rock salt interference was eliminated by proper calibration. In our work the dependence of the signal on temperature, pH, time elapsed after the addition of reactants, the dosing sequence, the salinity of the medium was examined, furthermore, we studied which wavelength-absorbance values give the best fit (highest R2 value) and the highest sensitivity in case of linear calibration. Surprisingly, increasing the salinity significantly improves the sensitivity of the measurement.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"76 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84736417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Elvita Rusdi, S. Nasir, D. Bahrin, M. Dahlan, M. Iqbal, M. Yusuf, E. Ibrahim, Nukman Nukman
Oilfield-produced water treatment using raw Kapok fiber (RKF) and a modified surface of Kapok fiber followed by an ultrafiltration membrane was conducted to reduce total dissolved solids (TDS), phenol, and barium. Variables considered in the experiment were contact times (30, 60, 90 min.), the flow rate of samples (5, 6, and 7 L/min), and trans-membrane pressure of ultrafiltration membrane (0.25, 0.35, and 0.50 bar). Raw Kapok fiber and modified surface Kapok fiber were used to investigate the effect of Kapok fiber on total dissolved solids, phenol, and barium removals from produced water. The results showed that raw KF decreased the TDS, phenol, and barium by 51.81%, 62.63%, and 54.20%, respectively. Treatment of raw Kapok fiber column filtrate using ultrafiltration membranes (UF) showed the removal of TDS, barium, and phenol achieved 73.15%, 42.44%, and 79.45%, respectively, at a flow rate of 5 L/min, TMP of 0.25 bar, and contact time of 90 min. Modifying the Kapok fiber surface using sodium hydroxide solution (5 wt%) and hot water (98.5 °C) reduced the TDS, phenol, and barium to 57.32%, 65.83%, and 79.08%, respectively. Further, at the same operating condition, the modified surface of Kapok fiber followed by UF decreased 94.31% TDS, 84.20% phenol, and 56.23% barium, respectively. The results show that modification of the Kapok fiber surface followed by UF can be used to remove the TDS, phenol, and barium from produced water.
{"title":"Total Dissolved Solids, Phenol, and Barium Removals from Oilfield Produced Water Using Kapok Fibers and Ultrafiltration Membrane","authors":"Elvita Rusdi, S. Nasir, D. Bahrin, M. Dahlan, M. Iqbal, M. Yusuf, E. Ibrahim, Nukman Nukman","doi":"10.3311/ppch.21802","DOIUrl":"https://doi.org/10.3311/ppch.21802","url":null,"abstract":"Oilfield-produced water treatment using raw Kapok fiber (RKF) and a modified surface of Kapok fiber followed by an ultrafiltration membrane was conducted to reduce total dissolved solids (TDS), phenol, and barium. Variables considered in the experiment were contact times (30, 60, 90 min.), the flow rate of samples (5, 6, and 7 L/min), and trans-membrane pressure of ultrafiltration membrane (0.25, 0.35, and 0.50 bar). Raw Kapok fiber and modified surface Kapok fiber were used to investigate the effect of Kapok fiber on total dissolved solids, phenol, and barium removals from produced water. The results showed that raw KF decreased the TDS, phenol, and barium by 51.81%, 62.63%, and 54.20%, respectively. Treatment of raw Kapok fiber column filtrate using ultrafiltration membranes (UF) showed the removal of TDS, barium, and phenol achieved 73.15%, 42.44%, and 79.45%, respectively, at a flow rate of 5 L/min, TMP of 0.25 bar, and contact time of 90 min. Modifying the Kapok fiber surface using sodium hydroxide solution (5 wt%) and hot water (98.5 °C) reduced the TDS, phenol, and barium to 57.32%, 65.83%, and 79.08%, respectively. Further, at the same operating condition, the modified surface of Kapok fiber followed by UF decreased 94.31% TDS, 84.20% phenol, and 56.23% barium, respectively. The results show that modification of the Kapok fiber surface followed by UF can be used to remove the TDS, phenol, and barium from produced water.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"50 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76021509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Mayer, Dominika Mária Herr, Nóra Nagy, Viktória Donkó-Tóth, Péter Keglevich, M. Weber, M. Dékány, L. Hazai
Chrysin, a well-known naturally occurring flavonoid having several biological effects including antiproliferative activity, was coupled with different pharmacophore structures. Coupling was carried out with spacers of different lengths and types. Structures selected for hybrid formation were amines, cyclic amino acid esters, and (hetero)aromatic compounds. In addition, vindoline, which is a Vinca alkaloid containing an indole skeleton, was also used. The alkylation of amines in the presence of carbonate base resulted in an interesting carbamate side product formation beside the expected amine. We also present the detailed structure elucidation of the carbamates. The in vitro anticancer activities of the synthesized derivatives were examined against 60 human tumor cell lines in National Cancer Institute (NCI, USA).
菊花素是一种众所周知的天然黄酮类化合物，具有多种生物效应，包括抗增殖活性，它与不同的药效团结构偶联。采用不同长度和类型的垫片进行耦合。选择杂交形成的结构是胺、环氨基酸酯和(杂)芳香化合物。此外，还使用了vindoline，这是一种含有吲哚骨架的长春花生物碱。在碳酸盐碱的存在下，胺的烷基化反应在预期胺的旁边形成了一个有趣的氨基甲酸酯副产物。我们还对氨基甲酸酯的结构进行了详细的说明。在美国国家癌症研究所(National Cancer Institute, NCI)对60株人肿瘤细胞株进行了体外抗癌活性测定。
{"title":"Synthesis and In Vitro Anticancer Evaluation of Chrysin Containing Hybrids and Other Chrysin Derivatives","authors":"S. Mayer, Dominika Mária Herr, Nóra Nagy, Viktória Donkó-Tóth, Péter Keglevich, M. Weber, M. Dékány, L. Hazai","doi":"10.3311/ppch.21919","DOIUrl":"https://doi.org/10.3311/ppch.21919","url":null,"abstract":"Chrysin, a well-known naturally occurring flavonoid having several biological effects including antiproliferative activity, was coupled with different pharmacophore structures. Coupling was carried out with spacers of different lengths and types. Structures selected for hybrid formation were amines, cyclic amino acid esters, and (hetero)aromatic compounds. In addition, vindoline, which is a Vinca alkaloid containing an indole skeleton, was also used. The alkylation of amines in the presence of carbonate base resulted in an interesting carbamate side product formation beside the expected amine. We also present the detailed structure elucidation of the carbamates. The in vitro anticancer activities of the synthesized derivatives were examined against 60 human tumor cell lines in National Cancer Institute (NCI, USA).","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"23 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87368902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Kusworo, A. C. Kumoro, Habib Al-Aziz, D. P. Utomo
Rice husk is a promising candidate of sustainable biomass-based renewable energy source with a gross caloric content of around 19.73 MJ/kg. As an efficient thermo-conversion process, pyro-gasification has the potential to convert biomass into oil and gas fuels. However, the bio-oil and gas yields are strongly dependent on the pyro-gasification operating parameters. This study employed response surface methodology (RSM) based on central composite design (CCD) experiment to determine the optimum conditions for pyro-gasification of rice-husk. Three selected most influencing operating parameters, namely feed mass (g), nitrogen flow (mL/min), and reactor temperature (°C) were optimized through 16 individual experimental runs for their possible synergistic effects. The results show excellent model fitting criteria (R2 > 0.9 and R2-adj > 0.85) for bio-oil and gas product responses that proves the suitability of RSM based on CCD experiment for rice-husk pyro-gasification study. The optimized optimum condition for rice-husk pyro-gasification process was at 897 g of feed mass, 1.97 mL/min of N2 gas flowrate, and 593 °C of reaction temperature. These conditions allow the achievement of estimated bio-oil and gas product yield of 47.78% and 11.41%, respectively. The composition analysis revealed that the main component of bio-oil was C15 (unsaturated), whereas the gas products were C3–C4 . This study suggests that rice-husk pyro-gasification is capable to achieve maximum yield of bio-oil and gas products with low char generation.
{"title":"Pyro-gasification of Rice Husk to Bio-fuel","authors":"T. Kusworo, A. C. Kumoro, Habib Al-Aziz, D. P. Utomo","doi":"10.3311/ppch.21723","DOIUrl":"https://doi.org/10.3311/ppch.21723","url":null,"abstract":"Rice husk is a promising candidate of sustainable biomass-based renewable energy source with a gross caloric content of around 19.73 MJ/kg. As an efficient thermo-conversion process, pyro-gasification has the potential to convert biomass into oil and gas fuels. However, the bio-oil and gas yields are strongly dependent on the pyro-gasification operating parameters. This study employed response surface methodology (RSM) based on central composite design (CCD) experiment to determine the optimum conditions for pyro-gasification of rice-husk. Three selected most influencing operating parameters, namely feed mass (g), nitrogen flow (mL/min), and reactor temperature (°C) were optimized through 16 individual experimental runs for their possible synergistic effects. The results show excellent model fitting criteria (R2 > 0.9 and R2-adj > 0.85) for bio-oil and gas product responses that proves the suitability of RSM based on CCD experiment for rice-husk pyro-gasification study. The optimized optimum condition for rice-husk pyro-gasification process was at 897 g of feed mass, 1.97 mL/min of N2 gas flowrate, and 593 °C of reaction temperature. These conditions allow the achievement of estimated bio-oil and gas product yield of 47.78% and 11.41%, respectively. The composition analysis revealed that the main component of bio-oil was C15 (unsaturated), whereas the gas products were C3–C4 . This study suggests that rice-husk pyro-gasification is capable to achieve maximum yield of bio-oil and gas products with low char generation.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"15 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83361715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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