Pub Date : 2023-11-16DOI: 10.15377/2409-983x.2023.10.2
M. C. Jena, Sarat Mishra, H. S. Moharana
One of the most pressing global challenges we face today is the rapid growth of the population. As the population continues to expand, the need for rapid industrialization has become paramount. However, this industrialization and urbanization have given rise to a significant and detrimental consequence: environmental pollution. This pollution, in turn, has led to various crises, including those related to water, food, and air quality. Water, being an essential element for human existence, is of utmost importance. Without access to clean and sufficient water, life on Earth would be unsustainable. Unfortunately, India has been grappling with a prominent water crisis, particularly during the summer seasons, resulting in the loss of countless lives each year. Even during other seasons, the availability of water is often satisfactory, but the quality of water remains a concern in many parts of the country. The shortage of water can be attributed primarily to the declining levels of underground water and the ever-increasing demand for this precious resource. India receives ample rainfall during the monsoon season; however, a significant portion of this water flows into the oceans, causing floods in various regions. Conversely, during the summer months, the scarcity of water leads to droughts in many areas. Therefore, it is imperative to initiate sustainable water management practices, including rainwater harvesting, to address this water crisis. This review article delves into various types of water sustainability initiatives with a structured approach and analyzes the associated challenges. Additionally, it proposes detailed systems that can be implemented to enhance water availability and distribution throughout the country. These measures are crucial steps toward mitigating the water crisis and ensuring a sustainable water future for India.
{"title":"Water Sustainability Initiatives to Meet the Water Crisis in India","authors":"M. C. Jena, Sarat Mishra, H. S. Moharana","doi":"10.15377/2409-983x.2023.10.2","DOIUrl":"https://doi.org/10.15377/2409-983x.2023.10.2","url":null,"abstract":"One of the most pressing global challenges we face today is the rapid growth of the population. As the population continues to expand, the need for rapid industrialization has become paramount. However, this industrialization and urbanization have given rise to a significant and detrimental consequence: environmental pollution. This pollution, in turn, has led to various crises, including those related to water, food, and air quality. Water, being an essential element for human existence, is of utmost importance. Without access to clean and sufficient water, life on Earth would be unsustainable. Unfortunately, India has been grappling with a prominent water crisis, particularly during the summer seasons, resulting in the loss of countless lives each year. Even during other seasons, the availability of water is often satisfactory, but the quality of water remains a concern in many parts of the country. The shortage of water can be attributed primarily to the declining levels of underground water and the ever-increasing demand for this precious resource. India receives ample rainfall during the monsoon season; however, a significant portion of this water flows into the oceans, causing floods in various regions. Conversely, during the summer months, the scarcity of water leads to droughts in many areas. Therefore, it is imperative to initiate sustainable water management practices, including rainwater harvesting, to address this water crisis. This review article delves into various types of water sustainability initiatives with a structured approach and analyzes the associated challenges. Additionally, it proposes detailed systems that can be implemented to enhance water availability and distribution throughout the country. These measures are crucial steps toward mitigating the water crisis and ensuring a sustainable water future for India.","PeriodicalId":335890,"journal":{"name":"Journal of Chemical Engineering Research Updates","volume":"45 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139267211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-16DOI: 10.15377/2409-983x.2023.10.3
A. Rafikov, Kamola Fayzullaeva, Tulkin E. Shonakhunov, D. Soyibova, Nataliya N. Yasinskaya
The possibility of softening the conditions of biochemical treatment to remove the sizing agent from the surface of the fibers in the preparation of cotton fabric for dyeing has been studied. The efficiency of the α-amylase enzyme was evaluated by the amount of sugars reduced in the modifying solution, as well as by the capillarity of the samples of the treated fabrics. The enzyme used is active towards starch starting from a low concentration (0.02 g/l) and low temperature (32°C). The effect of enzyme concentration from 0.02 to 6.0 g/l, solution pH from 4.5 to 8.5, temperature from 32 to 60°C on the amount of sugars in the solution after enzymatic treatment, and fabric capillarity was determined. Almost complete removal of sizing from the surface of fibers of the original fabric was achieved under moderate and mild processing conditions: α-amylase concentration 1.0÷5.0 g/l, pH=6.0÷7.0, temperature 50-55°C. Based on the dependence of the logarithm of the reaction rate on the reciprocal temperature, the activation energy of the desizing reaction was calculated, which turned out to be equal to E = 17.5 kJ/mol. The low activation energy shows that the desizing process is carried out under energetically favorable conditions with moderate heating. The surface morphology of treated and untreated samples of cotton fabric was studied by scanning electron microscopy. The removal of the adhesive substance from the surface of the fibers, the separation of individual fibers, and the smoothing of the fabric surface after treatment with an amylase solution were recorded.
{"title":"Enzymatic Treatment of Cotton Fabric for Desizing","authors":"A. Rafikov, Kamola Fayzullaeva, Tulkin E. Shonakhunov, D. Soyibova, Nataliya N. Yasinskaya","doi":"10.15377/2409-983x.2023.10.3","DOIUrl":"https://doi.org/10.15377/2409-983x.2023.10.3","url":null,"abstract":"The possibility of softening the conditions of biochemical treatment to remove the sizing agent from the surface of the fibers in the preparation of cotton fabric for dyeing has been studied. The efficiency of the α-amylase enzyme was evaluated by the amount of sugars reduced in the modifying solution, as well as by the capillarity of the samples of the treated fabrics. The enzyme used is active towards starch starting from a low concentration (0.02 g/l) and low temperature (32°C). The effect of enzyme concentration from 0.02 to 6.0 g/l, solution pH from 4.5 to 8.5, temperature from 32 to 60°C on the amount of sugars in the solution after enzymatic treatment, and fabric capillarity was determined. Almost complete removal of sizing from the surface of fibers of the original fabric was achieved under moderate and mild processing conditions: α-amylase concentration 1.0÷5.0 g/l, pH=6.0÷7.0, temperature 50-55°C. Based on the dependence of the logarithm of the reaction rate on the reciprocal temperature, the activation energy of the desizing reaction was calculated, which turned out to be equal to E = 17.5 kJ/mol. The low activation energy shows that the desizing process is carried out under energetically favorable conditions with moderate heating. The surface morphology of treated and untreated samples of cotton fabric was studied by scanning electron microscopy. The removal of the adhesive substance from the surface of the fibers, the separation of individual fibers, and the smoothing of the fabric surface after treatment with an amylase solution were recorded.","PeriodicalId":335890,"journal":{"name":"Journal of Chemical Engineering Research Updates","volume":"2 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139269050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-31DOI: 10.15377/2409-983x.2022.09.7
P. Berthod
In this work, HfC–and TaC–reinforced cast versions of the equimolar CoNiFeMnCr alloy (Cantor) were tested in oxidation at 1000°C in laboratory air. Chromium seemingly shared, with manganese, its role as a selectively oxidized element. The principal oxide to form externally was an M2O3 one in which Mn and Cr were present in various proportions depending on the proximity with the alloy’s surface. The HfC carbides close to the oxidation front were oxidized in situ in HfO2, with the release of carbon diffusing inwards after that and inducing the solid-state precipitation of blocky or acicular chromium carbides. The behavior of the TaC carbides present close to the oxidation front was different since they dissolved, and Ta diffused towards the oxidation front to form CrTaO4 oxides. Even after 50 hours at 1000°C, the subsurfaces were more or less deeply impoverished in Cr and Mn, with minimal contents meager, especially for Mn. The evaluation of the Cr and Mn quantities and the exploitation of results in terms of equivalent oxide thickness and kinetic oxidation constant demonstrates that the resistance of the alloys against oxidation is feeble and must be significantly improved to allow benefiting of the superior high-temperature mechanical resistances of such alloys in practical application. For that, some ways are proposed.
{"title":"Behavior in Oxidation at 1000°C of Carbon-Containing Equimolar CoNiFeMnCr Alloys Added with Hafnium or Tantalum with High Contents","authors":"P. Berthod","doi":"10.15377/2409-983x.2022.09.7","DOIUrl":"https://doi.org/10.15377/2409-983x.2022.09.7","url":null,"abstract":"In this work, HfC–and TaC–reinforced cast versions of the equimolar CoNiFeMnCr alloy (Cantor) were tested in oxidation at 1000°C in laboratory air. Chromium seemingly shared, with manganese, its role as a selectively oxidized element. The principal oxide to form externally was an M2O3 one in which Mn and Cr were present in various proportions depending on the proximity with the alloy’s surface. The HfC carbides close to the oxidation front were oxidized in situ in HfO2, with the release of carbon diffusing inwards after that and inducing the solid-state precipitation of blocky or acicular chromium carbides. The behavior of the TaC carbides present close to the oxidation front was different since they dissolved, and Ta diffused towards the oxidation front to form CrTaO4 oxides. Even after 50 hours at 1000°C, the subsurfaces were more or less deeply impoverished in Cr and Mn, with minimal contents meager, especially for Mn. The evaluation of the Cr and Mn quantities and the exploitation of results in terms of equivalent oxide thickness and kinetic oxidation constant demonstrates that the resistance of the alloys against oxidation is feeble and must be significantly improved to allow benefiting of the superior high-temperature mechanical resistances of such alloys in practical application. For that, some ways are proposed.","PeriodicalId":335890,"journal":{"name":"Journal of Chemical Engineering Research Updates","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115234459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-14DOI: 10.15377/2409-983x.2022.09.5
Masaya Kano, Haruki Furukawa, Y. Kato, Y. Tanemori, Yuya Shudo, T. Mitome, Tsuyoshi Yamada, Kazuhiro Yamashita
Visualization of a streak line pattern in a mixing vessel is quite useful for understanding the mixing mechanism and designing an optimal mixing vessel. However, conventional experimental methods for visualizing streak lines require a lot of time to construct impellers and prepare solutions. Although various commercial fluid analysis software has been developed, there are still no examples of its use for calculating streak lines in mixing vessels. A simulation method was developed to quickly evaluate the streak line pattern in a laminar mixing vessel by numerical analysis with commercial code. A commercial CFD code can calculate streak line patterns in a laminar mixing vessel. It was found that a lattice method was more suitable than a particle method for the simulation of the streak line.
{"title":"Experimental Verification for Numerical Flow Analysis in Mixing Vessel","authors":"Masaya Kano, Haruki Furukawa, Y. Kato, Y. Tanemori, Yuya Shudo, T. Mitome, Tsuyoshi Yamada, Kazuhiro Yamashita","doi":"10.15377/2409-983x.2022.09.5","DOIUrl":"https://doi.org/10.15377/2409-983x.2022.09.5","url":null,"abstract":"Visualization of a streak line pattern in a mixing vessel is quite useful for understanding the mixing mechanism and designing an optimal mixing vessel. However, conventional experimental methods for visualizing streak lines require a lot of time to construct impellers and prepare solutions. Although various commercial fluid analysis software has been developed, there are still no examples of its use for calculating streak lines in mixing vessels. A simulation method was developed to quickly evaluate the streak line pattern in a laminar mixing vessel by numerical analysis with commercial code. A commercial CFD code can calculate streak line patterns in a laminar mixing vessel. It was found that a lattice method was more suitable than a particle method for the simulation of the streak line.","PeriodicalId":335890,"journal":{"name":"Journal of Chemical Engineering Research Updates","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125870824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-24DOI: 10.15377/2409-983x.2022.09.3
H. Soonmin
Nanostructured copper tin sulphide films have been deposited on the substrate (soda lime glass) via an economical chemical bath deposition method. The scanning electron microscopy (SEM) technique and energy dispersive X-ray analyzer (EDX) method were employed in this work to study the films’ morphology and composition. The EDX data and SEM images confirmed that the content of elements (sulfur, tin, and copper), the shape, and the grain size strongly depended on the concentration of the precursors during the formation of films. Experimental results revealed that a higher atomic percentage of the element could be observed for the films prepared using a higher concentration of solution during the experiment.
{"title":"The Influence of Concentration on the Formation of Chemical Bath Deposited Copper Tin Sulphide Thin Films: SEM and EDX Studies","authors":"H. Soonmin","doi":"10.15377/2409-983x.2022.09.3","DOIUrl":"https://doi.org/10.15377/2409-983x.2022.09.3","url":null,"abstract":"Nanostructured copper tin sulphide films have been deposited on the substrate (soda lime glass) via an economical chemical bath deposition method. The scanning electron microscopy (SEM) technique and energy dispersive X-ray analyzer (EDX) method were employed in this work to study the films’ morphology and composition. The EDX data and SEM images confirmed that the content of elements (sulfur, tin, and copper), the shape, and the grain size strongly depended on the concentration of the precursors during the formation of films. Experimental results revealed that a higher atomic percentage of the element could be observed for the films prepared using a higher concentration of solution during the experiment.","PeriodicalId":335890,"journal":{"name":"Journal of Chemical Engineering Research Updates","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129178574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-22DOI: 10.15377/2409-983x.2022.09.2
Jude Ingham, Muskan Kanungo, Brandon Beauchamp, Michael Korbut, M. Swedish, M. Navin, Wujie Zhang
Food loss is a global issue that may be alleviated with effective dehydration strategies. Solar dehydration, rather than traditional sun-drying, is one method that could allow for the safe, efficient preservation of food materials. In this study, passive solar dehydration was achieved using a psychrometric chamber to model the environment of sub-Saharan Africa, where the temperature was the major focus (24.3 °C to 29.4 °C). A mass decrease of 88.56% was achieved within 9 hours. Microbial testing (total aerobic bacteria, Gram-negative bacteria, and total yeasts and molds) demonstrated no difference (all negative) between food stored at 4 °C and dehydrated food, indicating that the dehydrator introduced no new contamination. A 16.0% decrease in vitamin C (VC) concentration was observed due to the lability of VC. Insight into the visual appeal of the food samples was provided by measuring browning values, where it was found that dehydrated green apples are significantly less brown than the sample exposed to air for the same length of time. Passive solar dehydrators could provide a simple method to reduce food waste and maintain nutritional content and visual appeal.
{"title":"Validation of Solar Dehydrator for Food Drying Applications: A Granny Smith Apple Study","authors":"Jude Ingham, Muskan Kanungo, Brandon Beauchamp, Michael Korbut, M. Swedish, M. Navin, Wujie Zhang","doi":"10.15377/2409-983x.2022.09.2","DOIUrl":"https://doi.org/10.15377/2409-983x.2022.09.2","url":null,"abstract":"Food loss is a global issue that may be alleviated with effective dehydration strategies. Solar dehydration, rather than traditional sun-drying, is one method that could allow for the safe, efficient preservation of food materials. In this study, passive solar dehydration was achieved using a psychrometric chamber to model the environment of sub-Saharan Africa, where the temperature was the major focus (24.3 °C to 29.4 °C). A mass decrease of 88.56% was achieved within 9 hours. Microbial testing (total aerobic bacteria, Gram-negative bacteria, and total yeasts and molds) demonstrated no difference (all negative) between food stored at 4 °C and dehydrated food, indicating that the dehydrator introduced no new contamination. A 16.0% decrease in vitamin C (VC) concentration was observed due to the lability of VC. Insight into the visual appeal of the food samples was provided by measuring browning values, where it was found that dehydrated green apples are significantly less brown than the sample exposed to air for the same length of time. Passive solar dehydrators could provide a simple method to reduce food waste and maintain nutritional content and visual appeal.","PeriodicalId":335890,"journal":{"name":"Journal of Chemical Engineering Research Updates","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129698872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Photocatalytic reduction of hexavalent Cr(VI) couping oxidative degradation of organic contamination is an emerging and practical approach for water treatment. In this study, Z-scheme g-C3N4/Bi2S3 heterojunctions with intimate interface were successfully synthesized by direct growth of Bi2S3 on g-C3N4 surface. Notably, the photocatalytic performance of Z-scheme g-C3N4/Bi2S3 was influenced by g-C3N4 content. The optimized 2% g-C3N4/Bi2S3 heterojunction shows the highest photocatalytic reduction performance with 93.4% reduction efficiency of Cr(VI) under UV-visible light due to efficient separation and transfer of charge carriers and proper band structure. Furthermore, 2% g-C3N4/Bi2S3 can degrade tetracycline and Rhodamine B. Free radical capturing and quantitative tests indicate that holes and superoxide radicals are primary active species for the degradation of organic pollutants, while Cr(VI) was reduced to Cr(III) by the photogenerated electrons. Overall, this study provides new insight into the synthesis of high-performance Z-scheme heterojunctions for the future advancement of photocatalysis technology.
{"title":"Photocatalytic Reduction of Cr(VI) and Degradation of Organic Pollutants by Z-Scheme g-C3N4/Bi2S3 Heterojunction","authors":"Lin-Lin Ding, Ying Deng, Xing Liu, Lingling Liu, Jingjing Ding, Fangyuan Deng","doi":"10.15377/2409-983x.2022.09.1","DOIUrl":"https://doi.org/10.15377/2409-983x.2022.09.1","url":null,"abstract":"Photocatalytic reduction of hexavalent Cr(VI) couping oxidative degradation of organic contamination is an emerging and practical approach for water treatment. In this study, Z-scheme g-C3N4/Bi2S3 heterojunctions with intimate interface were successfully synthesized by direct growth of Bi2S3 on g-C3N4 surface. Notably, the photocatalytic performance of Z-scheme g-C3N4/Bi2S3 was influenced by g-C3N4 content. The optimized 2% g-C3N4/Bi2S3 heterojunction shows the highest photocatalytic reduction performance with 93.4% reduction efficiency of Cr(VI) under UV-visible light due to efficient separation and transfer of charge carriers and proper band structure. Furthermore, 2% g-C3N4/Bi2S3 can degrade tetracycline and Rhodamine B. Free radical capturing and quantitative tests indicate that holes and superoxide radicals are primary active species for the degradation of organic pollutants, while Cr(VI) was reduced to Cr(III) by the photogenerated electrons. Overall, this study provides new insight into the synthesis of high-performance Z-scheme heterojunctions for the future advancement of photocatalysis technology.","PeriodicalId":335890,"journal":{"name":"Journal of Chemical Engineering Research Updates","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123798307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-27DOI: 10.15377/2409-983x.2021.08.6
Mahmoud H. Abu Elella
Designing high-performance adsorbents for wastewater treatment and antibacterial materials for food and biomedical applications and excellent drug carrier to prolong time retention of the therapeutic drug based on biodegradable polymers has gained more interest in recent years. Among these materials, xanthan gum, which is a natural polysaccharide and plays a vital role in various applications such as industry, enhanced oil recovery, water-based paints, pharmaceuticals, and personal care products because it has excellent properties such as biodegradability and non-toxicity. On the other hand, it has many affected limitations, including microbially attack, poor thermal and mechanical stability, and low surface area. So, in this review, we focused on the advanced modifications on xanthan gum and their applications in wastewater treatment, protein delivery, and designing antimicrobial materials.
{"title":"Synthesis and Potential Applications of Modified Xanthan Gum","authors":"Mahmoud H. Abu Elella","doi":"10.15377/2409-983x.2021.08.6","DOIUrl":"https://doi.org/10.15377/2409-983x.2021.08.6","url":null,"abstract":"Designing high-performance adsorbents for wastewater treatment and antibacterial materials for food and biomedical applications and excellent drug carrier to prolong time retention of the therapeutic drug based on biodegradable polymers has gained more interest in recent years. Among these materials, xanthan gum, which is a natural polysaccharide and plays a vital role in various applications such as industry, enhanced oil recovery, water-based paints, pharmaceuticals, and personal care products because it has excellent properties such as biodegradability and non-toxicity. On the other hand, it has many affected limitations, including microbially attack, poor thermal and mechanical stability, and low surface area. So, in this review, we focused on the advanced modifications on xanthan gum and their applications in wastewater treatment, protein delivery, and designing antimicrobial materials.","PeriodicalId":335890,"journal":{"name":"Journal of Chemical Engineering Research Updates","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124759425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-05DOI: 10.15377/2409-983x.2021.08.5
Vasilis C. Sarasidis, K. Plakas, A. Karabelas
The assessment of a pilot-scale hybrid system coupling powdered activated carbon (PAC) adsorption with membrane ultrafiltration (UF), in respect of activated carbon regeneration and organic micropollutant removal, was investigated in this study. Field tests with two adsorbents (i.e. a commercial PAC and a PAC-Fe(II) composite), conducted in the premises of Thessaloniki Water Treatment Plant, demonstrated the high efficiency of the combined PAC/UF process. Regeneration efficiencies varying between approximately 95% and 110%, complete diclofenac (DCF) degradation and rather moderate mineralization (TOC removal) rates of up to 47%, can be achieved by UVC/H2O2 or photo-Fenton oxidation after 4 hours of treatment; this performance is attributed to the in situ generation of reactive oxidant species by photolysis of H2O2, which seems to enhance the process effectiveness. Among the two adsorbent materials tested, composite PAC-Fe(II) exhibited a higher DCF adsorption capacity than the original PAC, probably due to the improved chemisorption and/or the electrostatic attractive interactions between the negatively charged DCF molecules and the positively charged iron species, at neutral pH. Furthermore, a rather insignificant effect of PAC-Fe(II) loading on the regeneration efficiency was observed. The advantages of totally controlled H2O2 dosages and short operating times render the hybrid PAC/UF system a promising alternative to conventional and advanced drinking water purification methods.
研究了粉末活性炭(PAC)吸附与膜超滤(UF)耦合的中试混合系统在活性炭再生和有机微污染物去除方面的效果。在塞萨洛尼基水处理厂对两种吸附剂(即商用PAC和PAC- fe (II)复合材料)进行的现场试验表明，PAC/UF联合工艺的效率很高。在处理4小时后，UVC/H2O2或光- fenton氧化可实现再生效率约为95%至110%，双氯芬酸(DCF)完全降解和相当中度的矿化(TOC去除率高达47%);这种性能归因于H2O2光解在原位生成的活性氧化剂，这似乎提高了工艺的有效性。在两种吸附材料中，复合PAC- fe (II)表现出比原始PAC更高的DCF吸附能力，这可能是由于在中性ph下，带负电荷的DCF分子与带正电荷的铁分子之间的化学吸附和/或静电吸引相互作用的改善。此外，PAC- fe (II)负载对再生效率的影响相当不显著。完全控制H2O2用量和操作时间短的优点使PAC/UF混合系统成为传统和先进饮用水净化方法的有希望的替代方案。
{"title":"A Pilot Study of a Hybrid Process Involving In Situ Regenerated Activated Carbon, Membrane Separation and Advanced Oxidation for Water Pollution Abatement","authors":"Vasilis C. Sarasidis, K. Plakas, A. Karabelas","doi":"10.15377/2409-983x.2021.08.5","DOIUrl":"https://doi.org/10.15377/2409-983x.2021.08.5","url":null,"abstract":"The assessment of a pilot-scale hybrid system coupling powdered activated carbon (PAC) adsorption with membrane ultrafiltration (UF), in respect of activated carbon regeneration and organic micropollutant removal, was investigated in this study. Field tests with two adsorbents (i.e. a commercial PAC and a PAC-Fe(II) composite), conducted in the premises of Thessaloniki Water Treatment Plant, demonstrated the high efficiency of the combined PAC/UF process. Regeneration efficiencies varying between approximately 95% and 110%, complete diclofenac (DCF) degradation and rather moderate mineralization (TOC removal) rates of up to 47%, can be achieved by UVC/H2O2 or photo-Fenton oxidation after 4 hours of treatment; this performance is attributed to the in situ generation of reactive oxidant species by photolysis of H2O2, which seems to enhance the process effectiveness. Among the two adsorbent materials tested, composite PAC-Fe(II) exhibited a higher DCF adsorption capacity than the original PAC, probably due to the improved chemisorption and/or the electrostatic attractive interactions between the negatively charged DCF molecules and the positively charged iron species, at neutral pH. Furthermore, a rather insignificant effect of PAC-Fe(II) loading on the regeneration efficiency was observed. The advantages of totally controlled H2O2 dosages and short operating times render the hybrid PAC/UF system a promising alternative to conventional and advanced drinking water purification methods.","PeriodicalId":335890,"journal":{"name":"Journal of Chemical Engineering Research Updates","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134600346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-30DOI: 10.15377/2409-983x.2021.08.4
Tam Le-Minh, Nam Hoang Dong, Dzung Nguyen Tan
Seawater bittern is an important resource for production of magnesium hydroxide. It is particularly meaningful for countries of which long beaches and high temperatures are available as natural advantages. This production process bases on the main reaction between solutions containing magnesium and various alkaline agents. Among of precipitants, lime slurry is frequently used as an inexpensive reactant. However, the contamination of calcium in the final magnesium hydroxide is a major problem which limits applicability of this product in many fields required extremely high quality of magnesium hydroxide such as pharmaceuticals, and catalyst, etc. In this work, magnesium hydroxide with more than 99% purity will be recovered from natural seawater bitterns by using the design of experiment (DOE) method. Selected from nine potential factors, a full factorial design considering four main effects was applied to construct a second-order regression model which allows predicting favorable conditions to pursuit high purity of magnesium hydroxide from multi-component seawater bittern and lime milk. On the one hand, the results for a 1.0 L batch investigation proved that factors such as concentration of Ca(OH)2 in lime suspension and residence time have strong negative influences on the product purity, besides positive effects of reaction temperature. On the other hand, magnesium concentration in the bittern was absent in the regression model. At the optimal conditions, the chemical purity of the solid product was obtained at a value of 99.35%. Thus, this product, and therefore its corresponding production conditions, can be recommended for applications required high quality of magnesium hydroxide.
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