Ridha Lessoued, Ahmet Azizi, M. Lati, T. Ahmed Zaid
Electrocoagulation has lately received much interest as an effective method for the treatment of landfill leachate because of its ease of use, low cost, and environmental friendliness. The present study aimed to investigate the reduction of chemical organic demand (COD), biological organic demand (BOD 5 ), and turbidity from leachate by electrocoagulation process using alumin - ium electrodes. In order to achieve the maximum removal of pollutants, highlight the key effects of the variables and their simultaneous relationships, full central composite design was applied. Moreover, the backward model selection method using Bayesian Information Criterion and Akaike Information Criterion was carried out to determine the most suitable model with relevant effects. The optimum conditions indicated by the estimated quadratic models were initial pH (5.04), current density (407 A m −2 ), reaction time (74.6 min), and stirring speed (150 rpm), adjusted R 2 of 99.82 %, 99.93 %, and 99.95 % for COD, BOD 5 , and turbidity, respectively. Electrocoagulation was also successful in achieving 90 % COD, 92.3 % BOD 5 , and 99.6 % turbidity removal efficiency. The findings indicated a satisfactory agreement between model forecasts and experimental values.
电絮凝作为一种处理垃圾渗滤液的有效方法，因其易于使用、成本低、环境友好而受到广泛关注。本研究旨在探讨铝电极电絮凝工艺对渗滤液中化学有机需氧量(COD)、生物有机需氧量(bod5)和浊度的降低效果。为了最大限度地去除污染物，突出变量的关键影响及其同时存在的关系，采用了全中心复合设计。采用贝叶斯信息准则和赤池信息准则对模型进行逆向选择，以确定最适合的模型和相关效果。通过二次模型计算得到最佳条件为初始pH(5.04)、电流密度(407 A m−2)、反应时间(74.6 min)和搅拌速度(150 rpm)，调整后的r2对COD、BOD 5和浊度的影响分别为99.82%、99.93%和99.95%。电絮凝的COD去除率为90%，bod5去除率为92.3%，浊度去除率为99.6%。结果表明，模型预测值与实验值吻合较好。
{"title":"Modelling and Multi-response Optimisation of Leachate Treatment by Electrocoagulation using Full Central Composite Design","authors":"Ridha Lessoued, Ahmet Azizi, M. Lati, T. Ahmed Zaid","doi":"10.15255/kui.2021.085","DOIUrl":"https://doi.org/10.15255/kui.2021.085","url":null,"abstract":"Electrocoagulation has lately received much interest as an effective method for the treatment of landfill leachate because of its ease of use, low cost, and environmental friendliness. The present study aimed to investigate the reduction of chemical organic demand (COD), biological organic demand (BOD 5 ), and turbidity from leachate by electrocoagulation process using alumin - ium electrodes. In order to achieve the maximum removal of pollutants, highlight the key effects of the variables and their simultaneous relationships, full central composite design was applied. Moreover, the backward model selection method using Bayesian Information Criterion and Akaike Information Criterion was carried out to determine the most suitable model with relevant effects. The optimum conditions indicated by the estimated quadratic models were initial pH (5.04), current density (407 A m −2 ), reaction time (74.6 min), and stirring speed (150 rpm), adjusted R 2 of 99.82 %, 99.93 %, and 99.95 % for COD, BOD 5 , and turbidity, respectively. Electrocoagulation was also successful in achieving 90 % COD, 92.3 % BOD 5 , and 99.6 % turbidity removal efficiency. The findings indicated a satisfactory agreement between model forecasts and experimental values.","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43196558","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}
One of the possible options for carbon footprint reduction in ammonia production is energy intensification of the natural gas reformer furnace. This paper addresses how process modelling and simulation concepts can be combined with proven meth-ods such as minimum energy consumption analysis and heat exchanger networks to identify and optimise the main bottlenecks in natural gas reformer furnaces. The main outcome is finding the best possible reconstruction options for natural gas savings and related CO 2 reduction. The applied method delivered an overall reduction of natural gas of 834 m 3 h −1 or 0.51 GJ with accompanying carbon footprint reduction of 0.026 t CO 2 per ton of NH 3 produced. A large part of EU’s ammonia producers will be able to reach net zero emissions by 2050 by following the policy initiatives of the “Green Deal” thanks to this case study. In addition, it provides the basis for the further execution of other possible non-conventional retrofit measures.
减少氨生产中碳足迹的可能选择之一是天然气重整炉的能源强化。本文介绍了如何将过程建模和模拟概念与已证实的方法相结合，如最小能耗分析和换热器网络，以识别和优化天然气转化炉的主要瓶颈。主要结果是找到了节省天然气和减少相关二氧化碳的最佳重建方案。所应用的方法使天然气的总减少量为834 m 3 h−1或0.51 GJ，同时每生产一吨NH3，碳足迹减少0.026 t CO2。得益于这一案例研究，通过遵循“绿色协议”的政策举措，到2050年，欧盟大部分氨生产商将能够实现净零排放。此外，它还为进一步执行其他可能的非常规改造措施提供了基础。
{"title":"Transition towards Carbon Footprint Reduction and Energy Intensification in Natural Gas Reforming","authors":"N. Zečević, O. Brasseur","doi":"10.15255/kui.2022.037","DOIUrl":"https://doi.org/10.15255/kui.2022.037","url":null,"abstract":"One of the possible options for carbon footprint reduction in ammonia production is energy intensification of the natural gas reformer furnace. This paper addresses how process modelling and simulation concepts can be combined with proven meth-ods such as minimum energy consumption analysis and heat exchanger networks to identify and optimise the main bottlenecks in natural gas reformer furnaces. The main outcome is finding the best possible reconstruction options for natural gas savings and related CO 2 reduction. The applied method delivered an overall reduction of natural gas of 834 m 3 h −1 or 0.51 GJ with accompanying carbon footprint reduction of 0.026 t CO 2 per ton of NH 3 produced. A large part of EU’s ammonia producers will be able to reach net zero emissions by 2050 by following the policy initiatives of the “Green Deal” thanks to this case study. In addition, it provides the basis for the further execution of other possible non-conventional retrofit measures.","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41278613","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}
Amina Lachenani, M. Bentchikou, Mouloud Boumahdi, S. Hanini, M. Laidi
In this paper, six novel mathematical models based on semi-empirical calculus are proposed and applied to characterise the oven-drying process of cement mortar composites reinforced with cellulosic fibres (CMCRCFs). The drying experiments were carried out on four levels of oven-drying temperatures (70, 85, 105, and 120 ° C), with four different cellulosic fibres content (0, 5, 10, and 20 %). Obtained results were compared to those derived by regression analysis of six most typically used math ematical drying models (Newton, Page, Page modified1, Page modified2, Handerson Pabis, and Logarithmic) in addition to six proposed models. The regression accuracy of the drying process was evaluated by the coefficient of determination ( R 2 ), low mean square error (MSE), low root mean squared error (RMSE), and mean absolute error (MAE). Additional criteria were used to ensure more validity of the selected models. The obtained values indicate a highly accurate fit of the proposed model MR9, meaning that the proposed model can clearly interpret the experimental drying data and predict the dry state of CMCRCFs.
{"title":"Drying Process of Cement Mortar Composites Reinforced with Cellulosic Fibres: Experiment and Mathematical Modelling","authors":"Amina Lachenani, M. Bentchikou, Mouloud Boumahdi, S. Hanini, M. Laidi","doi":"10.15255/kui.2022.010","DOIUrl":"https://doi.org/10.15255/kui.2022.010","url":null,"abstract":"In this paper, six novel mathematical models based on semi-empirical calculus are proposed and applied to characterise the oven-drying process of cement mortar composites reinforced with cellulosic fibres (CMCRCFs). The drying experiments were carried out on four levels of oven-drying temperatures (70, 85, 105, and 120 ° C), with four different cellulosic fibres content (0, 5, 10, and 20 %). Obtained results were compared to those derived by regression analysis of six most typically used math ematical drying models (Newton, Page, Page modified1, Page modified2, Handerson Pabis, and Logarithmic) in addition to six proposed models. The regression accuracy of the drying process was evaluated by the coefficient of determination ( R 2 ), low mean square error (MSE), low root mean squared error (RMSE), and mean absolute error (MAE). Additional criteria were used to ensure more validity of the selected models. The obtained values indicate a highly accurate fit of the proposed model MR9, meaning that the proposed model can clearly interpret the experimental drying data and predict the dry state of CMCRCFs.","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48386381","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}
Luka Dornjak, Karla Ostojić, Teodoro Klaser, Inga Urlić, Anamarija Rogina
Chitosan scaffolds are an effective biologically active material with versatile application in chemistry and medicine. Chitosan is a linear polysaccharide, a derivative of chitin, with great biocompatibility due to the possession of functional groups such as −OH and −NH 2 , which allow for biodegradability and antibacterial function. Chitosan has a polycation nature allowing complex formation with metal ions and many biomolecules such as DNA, proteins and lipids, while its specific structure and functional groups are responsible for antibacterial, hemostatic, and analgesic properties. To improve its angiogenic and antimi- crobial potential, chitosan can be modified by boron (borate ions). The aim of this work was to prepare boric acid modified chitosan scaffolds, using boric acid as a boron precursor, as potential bioactive scaffolds for tissue regeneration. Borate ions tend to form complexes with hydroxyl groups, however, such physical interactions between boron and chitosan functional groups result in poor encapsulation efficiency. To ensure higher boron incorporation, chitosan scaffolds were cross-linked by genipin, a cross linker with lower cytotoxicity in contrast to glutaraldehyde commonly used to prepare stable chitosan-based materials. The degree of deacetylation ( DD ) and concentration of chitosan solution as well as the concentration of a solvent are impor tant parameters that affect the crosslinking process. Moreover, the addition of boric acid could interfere with the crosslinking process by occupying chitosan functional groups. Here, chitosan scaffolds were modified with different concentrations of boric acid, while the concentrations of chitosan solution (1.2 w/v), genipin (2 % w/w), and acetic acid (0.5 % v/v) were kept constant. Obtained scaffolds were characterised by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), differential scanning calorimetry (DSC), Fourier transformation infrared spectroscopy (FTIR), while cytotoxicity was evaluated as a function of materials concentration and exposure time. The results indicated successful incorporation of boron into crosslinked chitosan scaffolds with highly porous structure and low cytotoxicity.
{"title":"Boric Acid Modified Chitosan Scaffolds Chemically Crosslinked by Genipin","authors":"Luka Dornjak, Karla Ostojić, Teodoro Klaser, Inga Urlić, Anamarija Rogina","doi":"10.15255/kui.2022.018","DOIUrl":"https://doi.org/10.15255/kui.2022.018","url":null,"abstract":"Chitosan scaffolds are an effective biologically active material with versatile application in chemistry and medicine. Chitosan is a linear polysaccharide, a derivative of chitin, with great biocompatibility due to the possession of functional groups such as −OH and −NH 2 , which allow for biodegradability and antibacterial function. Chitosan has a polycation nature allowing complex formation with metal ions and many biomolecules such as DNA, proteins and lipids, while its specific structure and functional groups are responsible for antibacterial, hemostatic, and analgesic properties. To improve its angiogenic and antimi- crobial potential, chitosan can be modified by boron (borate ions). The aim of this work was to prepare boric acid modified chitosan scaffolds, using boric acid as a boron precursor, as potential bioactive scaffolds for tissue regeneration. Borate ions tend to form complexes with hydroxyl groups, however, such physical interactions between boron and chitosan functional groups result in poor encapsulation efficiency. To ensure higher boron incorporation, chitosan scaffolds were cross-linked by genipin, a cross linker with lower cytotoxicity in contrast to glutaraldehyde commonly used to prepare stable chitosan-based materials. The degree of deacetylation ( DD ) and concentration of chitosan solution as well as the concentration of a solvent are impor tant parameters that affect the crosslinking process. Moreover, the addition of boric acid could interfere with the crosslinking process by occupying chitosan functional groups. Here, chitosan scaffolds were modified with different concentrations of boric acid, while the concentrations of chitosan solution (1.2 w/v), genipin (2 % w/w), and acetic acid (0.5 % v/v) were kept constant. Obtained scaffolds were characterised by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), differential scanning calorimetry (DSC), Fourier transformation infrared spectroscopy (FTIR), while cytotoxicity was evaluated as a function of materials concentration and exposure time. The results indicated successful incorporation of boron into crosslinked chitosan scaffolds with highly porous structure and low cytotoxicity.","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45794730","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}
Perovskites are investigated as potential working materials in new technologies, such as solid ox - ide fuel cells, thermochemical energy storage, and magnetic refrigerators. They are interesting due to their application properties, such as electrical conductivity, ferromagnetic properties, and reducibility. Properties of perovskites can be improved by doping and the formation of structural defects. The aim of this work was to investigate the possibility of preparing Sr-doped lanthanum manganite with the chemical formula La 0.5 Sr 0.5 MnO 3 by coprecipitation procedure, and to analyse the observed phase separation. The material was prepared by procedure in which sources of metal cations (La 3+ , 2+ phase, especially when in tablet form.
钙钛矿在固体氧化物燃料电池、热化学储能和磁性冰箱等新技术中具有潜在的应用前景。由于它们的应用特性，如导电性、铁磁性和可还原性，它们很有趣。通过掺杂和结构缺陷的形成可以改善钙钛矿的性能。本文的目的是研究用共沉淀法以La 0.5 Sr 0.5 mno3的化学式制备Sr掺杂锰酸镧的可能性，并分析所观察到的相分离情况。该材料的制备过程中，金属阳离子(la3 +， 2+相)的来源，特别是片剂形式。
{"title":"Razdvajanje faza u sustavu La0.5Sr0.5MnO3","authors":"Andreja Žužić, J. Macan","doi":"10.15255/kui.2022.016","DOIUrl":"https://doi.org/10.15255/kui.2022.016","url":null,"abstract":"Perovskites are investigated as potential working materials in new technologies, such as solid ox - ide fuel cells, thermochemical energy storage, and magnetic refrigerators. They are interesting due to their application properties, such as electrical conductivity, ferromagnetic properties, and reducibility. Properties of perovskites can be improved by doping and the formation of structural defects. The aim of this work was to investigate the possibility of preparing Sr-doped lanthanum manganite with the chemical formula La 0.5 Sr 0.5 MnO 3 by coprecipitation procedure, and to analyse the observed phase separation. The material was prepared by procedure in which sources of metal cations (La 3+ , 2+ phase, especially when in tablet form.","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43946128","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}
Marija Banožić, Silvija Šafranko, Dora Bogadi, K. Aladić, S. Jokić
{"title":"Poboljšana ekstrakcija fenolnih spojeva iz kore mandarine primjenom visokonaponskog električnog pražnjenja: Utjecaj procesnih parametara i optimizacija","authors":"Marija Banožić, Silvija Šafranko, Dora Bogadi, K. Aladić, S. Jokić","doi":"10.15255/kui.2022.023","DOIUrl":"https://doi.org/10.15255/kui.2022.023","url":null,"abstract":"","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42543216","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}
Josipa Papac Zjačić, Silvia Morović, K. Košutić, D. Ašperger
The presence of pharmaceuticals in the aquatic environment is problematic in many aspects, mainly due to their specific mode of action, and physical and chemical properties that make them highly resistant to degradation. This new group of contaminants is frequently detected in conventional wastewater treatment plants. Removal of pharmaceuticals from water by primary and secondary methods (filtration, sedimentation, biological treatment) is not satisfactory, therefore advanced methods involving membrane and advanced oxidation processes are increasingly being de -veloped. The most significant advantage of membrane technologies is their wide industrial applicability while maintaining the highest water standards. Advanced oxidation processes can effectively decompose complex pollutants into simpler ones, and mineralize organic pollutants in wastewater without generating secondary waste. In order to improve their advantages, but also to eliminate disadvantages, these technologies are increasingly complemented and combined, resulting in higher efficiency in removing pharmaceuticals from water and reducing their toxicity.
{"title":"Combined Application of Membrane and Advanced Oxidation Processes for Removal of Pharmaceuticals from Water","authors":"Josipa Papac Zjačić, Silvia Morović, K. Košutić, D. Ašperger","doi":"10.15255/kui.2022.008","DOIUrl":"https://doi.org/10.15255/kui.2022.008","url":null,"abstract":"The presence of pharmaceuticals in the aquatic environment is problematic in many aspects, mainly due to their specific mode of action, and physical and chemical properties that make them highly resistant to degradation. This new group of contaminants is frequently detected in conventional wastewater treatment plants. Removal of pharmaceuticals from water by primary and secondary methods (filtration, sedimentation, biological treatment) is not satisfactory, therefore advanced methods involving membrane and advanced oxidation processes are increasingly being de -veloped. The most significant advantage of membrane technologies is their wide industrial applicability while maintaining the highest water standards. Advanced oxidation processes can effectively decompose complex pollutants into simpler ones, and mineralize organic pollutants in wastewater without generating secondary waste. In order to improve their advantages, but also to eliminate disadvantages, these technologies are increasingly complemented and combined, resulting in higher efficiency in removing pharmaceuticals from water and reducing their toxicity.","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41494741","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}
Rea Janda, Nataša Mikulec, Damir Andabaka, Ksenija Vitale
Living and working environments are most often closed spaces where it is necessary to provide health protection for family members and employees. Some activities require special protection, especially during a pandemic. The living and working environments can be kept clean and tidy in three ways: by cleaning, disinfecting, and sanitising. This paper presents a review of the literature linking disinfectants, their use, and resistance of microorganisms to disinfectants. In addition, it gives an overview of critical points that have arisen in various testing laboratories in the Republic of Croatia, related to the COVID-19 pandemic, and as a consequence of the lack of guidelines in norms. The literature search was conducted based on the keyword 'disinfection' in PubMed, Science Direct, Web of Science, Scopus and Google Scholar databases, and on the CDC and HZJZ websites due to the latest recommendations regarding COVID-19 infections. Results have shown that a norm is a basic document that needs a specific upgrade depending on the type of laboratory and its activities, and it should not be an independent decision of each individual laboratory. Based on the identified needs and problems, state institutions should provide detailed instructions depending on the laboratory activity. Therefore, this situation and the experience gained should be used as a starting point for document development that could be applicable in crisis states generally. In addition, it could be used as a basis for education and training in crisis states.
生活和工作环境通常是封闭空间，因此有必要为家庭成员和雇员提供健康保护。有些活动需要特别保护，特别是在大流行期间。生活和工作环境可以通过三种方式保持干净整洁:清洁、消毒和消毒。本文综述了有关消毒剂、消毒剂的使用和微生物对消毒剂的耐药性的文献。此外，报告还概述了克罗地亚共和国各检测实验室因COVID-19大流行以及规范中缺乏指导方针而出现的关键点。根据最新的COVID-19感染建议，在PubMed、Science Direct、Web of Science、Scopus和谷歌Scholar数据库以及CDC和HZJZ网站上以“消毒”为关键词进行文献检索。结果表明，规范是一项基本文件，需要根据实验室的类型及其活动进行具体的升级，而不应由每个实验室独立决定。根据确定的需求和问题，国家机构应根据实验室活动提供详细的说明。因此，这种情况和所获得的经验应该作为文件开发的起点，可以普遍适用于危机状态。此外，它还可以作为危机国家教育和培训的基础。
{"title":"Mjere dezinfekcije i sanitacije u akreditiranom ispitnom laboratoriju – osvrt na COVID-19 infekciju","authors":"Rea Janda, Nataša Mikulec, Damir Andabaka, Ksenija Vitale","doi":"10.15255/kui.2022.015","DOIUrl":"https://doi.org/10.15255/kui.2022.015","url":null,"abstract":"Living and working environments are most often closed spaces where it is necessary to provide health protection for family members and employees. Some activities require special protection, especially during a pandemic. The living and working environments can be kept clean and tidy in three ways: by cleaning, disinfecting, and sanitising. This paper presents a review of the literature linking disinfectants, their use, and resistance of microorganisms to disinfectants. In addition, it gives an overview of critical points that have arisen in various testing laboratories in the Republic of Croatia, related to the COVID-19 pandemic, and as a consequence of the lack of guidelines in norms. The literature search was conducted based on the keyword 'disinfection' in PubMed, Science Direct, Web of Science, Scopus and Google Scholar databases, and on the CDC and HZJZ websites due to the latest recommendations regarding COVID-19 infections. Results have shown that a norm is a basic document that needs a specific upgrade depending on the type of laboratory and its activities, and it should not be an independent decision of each individual laboratory. Based on the identified needs and problems, state institutions should provide detailed instructions depending on the laboratory activity. Therefore, this situation and the experience gained should be used as a starting point for document development that could be applicable in crisis states generally. In addition, it could be used as a basis for education and training in crisis states.","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43322462","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}
Anita Štrkalj, Luka Mesek, Vesna Ocelić Bulatović, Zoran Glavaš
adsorption isotherm models. It was found that the Langmuir model is more appropriate, and that adsorption takes place as chemisorption.
吸附等温线模型。发现Langmuir模型更为合适，吸附以化学吸附的方式进行。
{"title":"Adsorpcija Zn(II) iona na metalurškom otpadu","authors":"Anita Štrkalj, Luka Mesek, Vesna Ocelić Bulatović, Zoran Glavaš","doi":"10.15255/kui.2022.013","DOIUrl":"https://doi.org/10.15255/kui.2022.013","url":null,"abstract":"adsorption isotherm models. It was found that the Langmuir model is more appropriate, and that adsorption takes place as chemisorption.","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45507981","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}
The aim of this work was to show possibilities of applied artificial intelligence methodologies and structural causal modelling (“Structural Causal Model”, SCM) with the object of gaining a scientific level contribution to the determination of functional causal dependencies in complex ecological systems. In this work, applied was SCM for the determination of dependencies of chlo rophyll concentration on physical and chemical parameters in the northern Adriatic Sea during the period 1965 to 2015. The experimental data are the outcome of the long-term and extensive investigation as a part of the EU project “LTER Northern Adriatic Sea”, and are freely available within the EU Open Science policy. The data are a “Big Data” base with 108 687 samples and 43 descriptors. Proposed is a mathematical model with Bayes network (BN) as a directed acy - clic graph (DAG). The model structure was determined by the Hamilton-Schmidt conditional independence test with a significance level of α = 0.05. The SCM model shows that the direct causal variables for chlorophyll concentration are: temperature, salinity, pH, and concentrations of nitrogen, phosphor, and silica. The BN model was adjusted according to d-separation with the objective to block confounding and contra-causal back door interference. The functions of causal dependencies were determined as the marginal distributions with Bayes network models with a single interior layer for interpolation. The most important causal effect was due to temperature (−0.07 μg chlorophyll A/°C). The model predicted reversed positive causality between chloro phyll concentration and dissolved oxygen (0.2 mg DO 2 /μg chlorophyll A). Also evaluated was nonparametric comparative analysis of chlorophyll and abiotic parameters between Croatian and northern Adriatic Sea (Slovenia and Italy). The comparison was based on median metrics to avoid the pronounced influence of outliers due to hydrodynamic effects. The median concentration of dissolved oxygen in Croatian Adriatic was 5.8 mg O 2 /l, while in Slovenian and Italian 5.5 mg O 2 /l, and the median temperature was T = 14.6 °C compared to T = 15.1 °C. There is a significant difference in the abundance of dinoflagellates in Croatia 3 cell/l, while in Slovenia and Italian 5 cells/l. The difference is more pronounced by the number and values of “hot spots” outliers. The difference between chlorophyll concentrations is not significant (0.65 and 0.90 μg l −1 ); however, the difference in the distribution of the outliers is significant with more frequent and bigger outliers in Italian and Slovenian Adriatic. Also observed was a significant difference in SiO 4 distribution, with higher concentrations in the western Adriatic. The random forest RF decision tree models are applied for the development of the predictive models of biological parameters based on abiotic data. The RF models are validated by 5-fold cross-validation. The models have out-of-box mean relative errors of 6.5 % for chlor
这项工作的目的是展示应用人工智能方法和结构因果模型（“结构因果模型”，SCM）的可能性，目的是为确定复杂生态系统中的功能因果依赖关系做出科学水平的贡献。在这项工作中，应用SCM来确定1965年至2015年期间亚得里亚海北部叶绿素浓度对物理和化学参数的依赖性。实验数据是作为欧盟项目“LTER北亚得里亚海”的一部分进行的长期广泛调查的结果，在欧盟开放科学政策范围内免费提供。这些数据是一个“大数据”库，包含108687个样本和43个描述符。提出了一种将贝叶斯网络（BN）作为有向算术图（DAG）的数学模型。模型结构通过汉密尔顿·施密特条件独立性检验确定，显著性水平为α=0.05。SCM模型表明，叶绿素浓度的直接因果变量是：温度、盐度、pH以及氮、磷和二氧化硅的浓度。BN模型根据d-separation进行调整，目的是阻断混杂因素和对抗因果后门干扰。因果依赖函数被确定为边际分布，贝叶斯网络模型具有用于插值的单个内层。最重要的因果效应是由于温度（−0.07μg叶绿素A/°C）。该模型预测了叶绿素浓度与溶解氧（0.2 mg DO 2/μg叶绿素A）之间的反向正因果关系。还评估了克罗地亚和亚得里亚海北部（斯洛文尼亚和意大利）叶绿素和非生物参数的非参数比较分析。该比较基于中值指标，以避免由于流体动力学效应而引起的异常值的显著影响。克罗地亚亚得里亚海溶解氧的中位浓度为5.8 mg O2/l，而斯洛文尼亚和意大利为5.5 mg O2/l，中位温度为T=14.6°C，而T=15.1°C。克罗地亚的甲藻丰度为3细胞/l，而斯洛文尼亚和意大利的甲藻数量为5细胞/l。差异在“热点”异常值的数量和值上更为明显。叶绿素浓度之间的差异不显著（0.65和0.90μg l−1）；然而，异常值的分布差异很大，意大利和斯洛文尼亚亚得里亚海的异常值更频繁、更大。还观察到SiO4分布的显著差异，在亚得里亚海西部的浓度更高。随机森林RF决策树模型用于开发基于非生物数据的生物参数预测模型。射频模型通过5倍交叉验证进行验证。该模型对叶绿素和光色素的开箱平均相对误差分别为6.5%和17.4%；硅藻18.8%；甲藻17.4%；球石藻为12.1%。对于每个确定的预测模型，前五个最重要的预测因子占95%的重要性。
{"title":"Kauzalni ekološki model sjevernog Jadrana temeljem podataka EU projekta “LTER Northern Adriatic Sea”","authors":"Želimir Kurtanjek","doi":"10.15255/kui.2022.033","DOIUrl":"https://doi.org/10.15255/kui.2022.033","url":null,"abstract":"The aim of this work was to show possibilities of applied artificial intelligence methodologies and structural causal modelling (“Structural Causal Model”, SCM) with the object of gaining a scientific level contribution to the determination of functional causal dependencies in complex ecological systems. In this work, applied was SCM for the determination of dependencies of chlo rophyll concentration on physical and chemical parameters in the northern Adriatic Sea during the period 1965 to 2015. The experimental data are the outcome of the long-term and extensive investigation as a part of the EU project “LTER Northern Adriatic Sea”, and are freely available within the EU Open Science policy. The data are a “Big Data” base with 108 687 samples and 43 descriptors. Proposed is a mathematical model with Bayes network (BN) as a directed acy - clic graph (DAG). The model structure was determined by the Hamilton-Schmidt conditional independence test with a significance level of α = 0.05. The SCM model shows that the direct causal variables for chlorophyll concentration are: temperature, salinity, pH, and concentrations of nitrogen, phosphor, and silica. The BN model was adjusted according to d-separation with the objective to block confounding and contra-causal back door interference. The functions of causal dependencies were determined as the marginal distributions with Bayes network models with a single interior layer for interpolation. The most important causal effect was due to temperature (−0.07 μg chlorophyll A/°C). The model predicted reversed positive causality between chloro phyll concentration and dissolved oxygen (0.2 mg DO 2 /μg chlorophyll A). Also evaluated was nonparametric comparative analysis of chlorophyll and abiotic parameters between Croatian and northern Adriatic Sea (Slovenia and Italy). The comparison was based on median metrics to avoid the pronounced influence of outliers due to hydrodynamic effects. The median concentration of dissolved oxygen in Croatian Adriatic was 5.8 mg O 2 /l, while in Slovenian and Italian 5.5 mg O 2 /l, and the median temperature was T = 14.6 °C compared to T = 15.1 °C. There is a significant difference in the abundance of dinoflagellates in Croatia 3 cell/l, while in Slovenia and Italian 5 cells/l. The difference is more pronounced by the number and values of “hot spots” outliers. The difference between chlorophyll concentrations is not significant (0.65 and 0.90 μg l −1 ); however, the difference in the distribution of the outliers is significant with more frequent and bigger outliers in Italian and Slovenian Adriatic. Also observed was a significant difference in SiO 4 distribution, with higher concentrations in the western Adriatic. The random forest RF decision tree models are applied for the development of the predictive models of biological parameters based on abiotic data. The RF models are validated by 5-fold cross-validation. The models have out-of-box mean relative errors of 6.5 % for chlor","PeriodicalId":43849,"journal":{"name":"Kemija u Industriji-Journal of Chemists and Chemical Engineers","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46896125","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}
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