Fuzzy logic modeling of Pb (II) sorption onto mesoporous NiO/ZnCl2-Rosa Canina-L seeds activated carbon nanocomposite prepared by ultrasound-assisted co-precipitation technique

In this study, NiO/Rosa Canina-L seeds activated carbon nanocomposite (NiO/ACNC) was prepared by adding dropwise NaOH solution (2 mol/L) to raise the suspension pH to around 9 at room temperature under ultrasonic irradiation (200 W) as an efficient method and characterized by FE-SEM, FTIR and N2 adsorption-desorption isotherm. The effect of different parameters such as contact time (0–120 min), initial metal ion concentration (25–200 mg/L), temperature (298, 318 and 333 K), amount of adsorbent (0.002–0.007 g) and the solution's initial pH (1–7) on the adsorption of Pb (II) was investigated in batch-scale experiments. The equilibrium data were well fitted by Langmuir model type 1 (R2 > 0.99). The maximum monolayer adsorption capacity (qm) of NiO/ACNC was 1428.57 mg/L. Thermodynamic parameters (¿G°, ¿H° and ¿S°) were also calculated. The results showed that the adsorption of Pb (II) onto NiO/ACNC was feasible, spontaneous and exothermic under studied conditions. In addition, a fuzzy-logic-based model including multiple inputs and one output was developed to predict the removal efficiency of Pb (II) from aqueous solution. Four input variables including pH, contact time (min), dosage (g) and initial concentration of Pb (II) were fuzzified using an artificial intelligence-based approach. The fuzzy subsets consisted of triangular membership functions with eight levels and a total of 26 rules in the IF-THEN approach which was implemented on a Mamdani-type of fuzzy inference system. Fuzzy data exhibited small deviation with satisfactory coefficient of determination (R2 > 0.98) that clearly proved very good performance of fuzzy-logic-based model in prediction of removal efficiency of Pb (II). It was confirmed that NiO/ACNC had a great potential as a novel adsorbent to remove Pb (II) from aqueous solution.Postprint (author's final draft

Performance and Fouling during Bioreactor Harvesting

Tangential flow filtration has many advantages for bioreactor harvesting as the permeate could be introduced directly to the subsequent capture step, the process is easy to scale up, and fouling of the filter is limited by the cross flow. However, membrane fouling has limited its widespread use. This is particularly problematic given the high cell densities encountered today. Here a reverse asymmetric commercial membrane, BioOptimal™ MF-SL (Asahi Kasei), where the more open surface faces the feed stream, and the tighter barrier layer faces the permeate stream, has been investigated for bioreactor harvesting. The open surface contains pores up to 40 µm in diameter, while the tighter barrier layer has an average pore size of 0.4 µm. The filtration performance, including fouling analysis conducted in this dissertation, involves using different feed streams, comparison of the filter performance with other filters possessing different membrane structures, mathematical modeling to predict the flux and fouling, fouling visualization using confocal laser scanning microscopy, and fouling identification using liquid chromatography-mass spectrometry. For the feed streams studies, filtration of yeast suspensions and Chinese hamster ovary cell culture has been conducted under various conditions. The yeast cells are trapped in the open pore structure, while CHO cells are more externally deposited. The membrane stabilizes an internal porous cake that acts as a depth filter. This stabilized cake layer removes particulate matter that fouls the barrier layer, protecting the fine pores from the large aggregates. As filtration continues, a cake layer forms on the membrane surface. Resistance-in-series model has been developed to describe the permeate flux during tangential flow filtration. The model contains three fitted parameters, which can easily be determined from constant pressure normal flow filtration experiments and total recycle constant flux tangential flow filtration experiments. The model can be used to estimate the filter\u27s capacity for a given feed stream. Our results suggest that using a reverse asymmetric membrane could avoid severe flux decline associated with fouling of the barrier during bioreactor harvesting. Laser scanning confocal microscopy is used to observe the location of particle entrapment. The throughput of the reverse asymmetric membrane is significantly greater than the symmetric membranes. The membrane stabilizes an internal high permeability cake that acts as a depth filter. Confocal imaging helps visualize the secondary membrane directly by staining the DNA and membrane proteins using fluorescent dyes. Host cell proteins are the most challenging impurities for downstream purification processes. In order to investigate the fouling during cell clarification, HCPs in the bioreactor, harvest, and backwash are identified and quantified using different methods. A dataset is established using the identified HCPs and used to train the deep learning model. The model predicts unknown HCPs on fouling potential with an accuracy of 76%. The dataset of identified HCPs in this study provides insights into the characterization of membrane fouling, membrane selection, and process development. This approach could be used to screen cell lines or hosts to select those with reduced HCP profiles or identify HCPs that are problematic and difficult to remove

Assessment of fouling in native and surface-modified water purification membranes

textFouling is a major obstacle to the implementation of membranes in water purification applications. Hydrophilization of the membrane surface tends to mitigate fouling because hydrophobic interactions between foulants and the membrane are reduced. Polydopamine was deposited onto membranes to render their surfaces hydrophilic. The chemical structure of polydopamine, which was previously ambiguous, was investigated by many spectroscopic techniques. While previously thought to consist of covalently-linked monomers, polydopamine was found to be an aggregate of partly-oxidized dopamine units linked by strong, non-covalent secondary interactions. Polydopamine was also used as a platform for the molecular conjugation of other anti-fouling materials, such as poly(ethylene glycol), to the membrane surface. Membrane fouling was assessed by constant permeate flux crossflow filtration with an oil/water emulsion feed. The threshold flux--the flux at which the rate of fouling significantly increases--was determined by a well-established flux stepping technique. Membrane resistance evolution during fouling was compared for constant flux and constant transmembrane pressure operation using unmodified membranes. Below the threshold flux (slow fouling), good agreement in resistance evolution was found between the two operational modes; above the threshold flux, significant deviation was observed. The effect of polydopamine and polydopamine-g-poly(ethylene glycol) surface modifications was studied under constant flux crossflow fouling conditions. The surface modifications were found to increase the membrane resistance, resulting in higher transmembrane pressures in the modified membranes than in the unmodified membranes at fluxes below the threshold flux. Modified membranes were also compared to unmodified membranes with the same pure water permeance (same initial resistance). In this case, the modified membranes had lower transmembrane pressures during fouling than the unmodified membranes, suggesting that a preferred method of membrane surface modification is to begin with a membrane of higher permeance than required, and then surface-modify it to achieve the desired permeance. The efficacy of polydopamine and polydopamine-g-poly(ethylene glycol) surface modifications in reducing biofouling was also evaluated. Modified membranes showed reduced protein and bacterial adhesion in short-term tests, which are commonly used to assess biofouling propensity. However, long-term operation under hydrodynamic conditions mimicking those of an industrial module showed no benefit of the hydrophilic coatings in limiting biofouling.Chemical Engineerin

Developing magnetic functionalized multi-walled carbon nanotubes-based buckypaper for the removal of Furazolid

Magnetic f-MWCNTs-based BP/PVA membrane was fabricated and utilized for the elimination of furazolidone (FZD) from aqueous solution. Characterisation and adsorption studies were performed to evaluate the performance and adsorptive efficiency, respectively of the membrane. Furthermore, statistical and machine learning technique were also applied to predict the removal efficiency of FZD on the membrane. The results revealed that magnetic f-MWCNTs-based BP/PVA membrane has the potential to be used as an efficient membrane for practical applications

Advances in Membrane Technologies

Membrane technologies are currently the most effective and sustainable methods utilized in diversified water filtration, wastewater treatment, as well as industrial and sustainable energy applications. This book covers essential subsections of membrane separation and bioseparation processes from the perspectives of technical innovation, novelty, and sustainability. The book offers a comprehensive overview of the latest improvements and concerns with respect to membrane fouling remediation techniques, issues of bioincompatibility for biomedical applications, and various subareas of membrane separation processes, which will be an efficient resource for engineers

Pathways to Water Sector Decarbonization, Carbon Capture and Utilization

The water sector is in the middle of a paradigm shift from focusing on treatment and meeting discharge permit limits to integrated operation that also enables a circular water economy via water reuse, resource recovery, and system level planning and operation. While the sector has gone through different stages of such revolution, from improving energy efficiency to recovering renewable energy and resources, when it comes to the next step of achieving carbon neutrality or negative emission, it falls behind other infrastructure sectors such as energy and transportation. The water sector carries tremendous potential to decarbonize, from technological advancements, to operational optimization, to policy and behavioural changes. This book aims to fill an important gap for different stakeholders to gain knowledge and skills in this area and equip the water community to further decarbonize the industry and build a carbon-free society and economy. The book goes beyond technology overviews, rather it aims to provide a system level blueprint for decarbonization. It can be a reference book and textbook for graduate students, researchers, practitioners, consultants and policy makers, and it will provide practical guidance for stakeholders to analyse and implement decarbonization measures in their professions

Pathways to Water Sector Decarbonization, Carbon Capture and Utilization

The water sector is in the middle of a paradigm shift from focusing on treatment and meeting discharge permit limits to integrated operation that also enables a circular water economy via water reuse, resource recovery, and system level planning and operation. While the sector has gone through different stages of such revolution, from improving energy efficiency to recovering renewable energy and resources, when it comes to the next step of achieving carbon neutrality or negative emission, it falls behind other infrastructure sectors such as energy and transportation. The water sector carries tremendous potential to decarbonize, from technological advancements, to operational optimization, to policy and behavioural changes. This book aims to fill an important gap for different stakeholders to gain knowledge and skills in this area and equip the water community to further decarbonize the industry and build a carbon-free society and economy. The book goes beyond technology overviews, rather it aims to provide a system level blueprint for decarbonization. It can be a reference book and textbook for graduate students, researchers, practitioners, consultants and policy makers, and it will provide practical guidance for stakeholders to analyse and implement decarbonization measures in their professions

Design and Evaluation of Processes to Obtain Antioxidant-Rich Extracts from tropical fruits cultivated in Amazon, Caldas and Northern Tolima Regions

En esta tesis se presenta un análisis del diseño del proceso para la obtención de extractos ricos en antioxidantes a partir de cinco frutas tropicales (Cordata matisia, Physalis peruviana, Solanum betaceum, Theobroma grandiflorum, Renealmia alpinia). Se utilizaron procedimientos de simulación basado en la caracterización experimental para evaluar el rendimiento de las diferentes tecnologías para las etapas de pretratamiento, extracción y concentración utilizando el software Aspen Plus. Se utilizaron dos tecnologías para el pretratamiento: secado convencional y secado por liofilización; para la extracción se evaluaron extracción supercrítica y con solventes, mientras que para la etapa de concentración se utilizó destilación al vacío y procesos de separación por membranas "ultrafiltración". Teniendo en cuenta lo anterior, ocho posibles configuraciones de proceso con integración másica fueron evaluadas con y sin integración energética en términos técnicos, económicos y ambientales de cada fruta. Además, se utilizaron modelos termodinámicos para determinar las condiciones de operación para todas las tecnologías, esto permitió minimizar los altos costos y el tiempo que implican los experimentos. Las evaluaciones técnicas que se presentan, incluyen la evaluación de los impactos económicos y ambientales. No obstante, estudios posteriores son necesarios para poner en práctica este tipo de proceso a escala industrial, pero este tipo de análisis sirven como base para el desarrollo de procesos eficientes. La principal desventaja asociada con las tecnologías convencionales es la degradación de los compuestos antioxidantes dado a la oxidación de compuestos antioxidantes, mientras que las tecnologías de gama alta conservan la calidad del producto, sin embargo, su costo es relativamente alto. Una característica común en las configuraciones de proceso fue la gran influencia de los costos de las materias primas en el coste de producción total. Este trabajo es un punto de partida para mejorar la cadena productiva de frutas tropicales e integrar como posibles nuevas alternativas de transformación. Con el fin de comparar los resultados obtenidos por simulación, los compuestos polifenólicos de cada fruta tropical fueron extraídos por las diferentes configuraciones de proceso y se evaluaron la actividad antioxidante de cada extracto con el propósito de comparar la calidad del producto final. Además, se diseño una biorefinería a base de copoazu a la cual se le realizó un análisis económico y ambiental. Se encontró que el uso de los datos experimentales, junto con el procedimiento de simulación son herramientas poderosas para el diseño y análisis de los procesos de extracción de antioxidantes. Como resultado final se demostró la viabilidad de la extracción de antioxidante para todas las frutas estudiadas con excepción de la fruta copoazú. Además, es importante tener en cuenta que la cáscara de Alpinia R. contiene relativamente cantidades más altas de compuestos polifenólicos con mayor actividad antioxidante. Por último, la producción de extractos ricos en antioxidantes a partir de frutas tropicales podría ser considerada como una oportunidad para promover el desarrollo rural con la participación de los productores en pequeña escala, como proveedores de materia prima.Abstract : In this thesis, a process design to obtain antioxidant-rich extracts from five tropical fruits (i.e. Matisia cordata, Physalis peruviana, Solanum betaceum, Theobroma grandiflorum, Renealmia alpinia) is presented. Simulation procedures based on experimental characterization were used to evaluate the yield of different technologies for pretreatment, extraction and concentration procedures using the Aspen Plus software. Both the conventional and freeze drying technologies were evaluated as pretreatment methods whereas conventional solvent and supercritical fluids were used for the extraction procedure. The concentration stage was performed by using vacuum distillation or ultrafiltration processes. Eight possible process configurations with mass integration were evaluated with and without energetic integration in technical, economic and environmental terms for each fruit. In this study, thermodynamic models were used in order to provide convenient use of the operation conditions for all the technologies, this methodology permit minimize the high costs and time that involve the experiments. The technical evaluations presented in this work provide the feasibility of process configurations, which included the evaluation of economic and environmental impacts. Nonetheless, several adjustments must be done to implement this type of process at industrial scale, but this kind of analysis serve as the basis draw recommendations for the efficient development processes. In this work was also proposed several process configurations with both conventional and high-end technologies for pretreatment, extraction and concentration stages. The major disadvantage associate with the conventional technologies is the degradation of antioxidant compounds by the possibility of oxidation of antioxidant compounds while the high-end technologies retain the product quality. However, the major disadvantage of high-end technologies is its relatively high cost. A common feature found in the process configurations for all considered feedstock was the high influence of raw material costs in total production cost. This work is a starting point to improve the tropical fruits productive chain and integrate as possible new transformation alternatives. In order to compare the simulation results, the polyphenolic compounds from each tropical fruit were extracted by the different process configurations and the antioxidant activities of extracts were evaluated with the purpose of compare the quality of the final product. Additionally, a process design and an economic and environmental analysis for a biorefinery-based on an exotic fruit as copoazu were performed. It was found that the uses of experimental data together with simulation procedure are powerful tools for designing and analyzing the processes for antioxidant rich-extracts. As final results it was demonstrated the feasibility of antioxidant extraction for all fruits studied excepting the copoazu fruit. Additionally, it is important to note that the R. alpinia peel contained relatively the highest amounts of polyphenolic compounds with highest antioxidant activity. Finally, the antioxidant rich-extracts production from tropical fruits could be considered as an opportunity to promote rural development with the participation of small scale producers as feedstock suppliers.Doctorad

Pathways to Water Sector Decarbonization, Carbon Capture and Utilization

The water sector is in the middle of a paradigm shift from focusing on treatment and meeting discharge permit limits to integrated operation that also enables a circular water economy via water reuse, resource recovery, and system level planning and operation. While the sector has gone through different stages of such revolution, from improving energy efficiency to recovering renewable energy and resources, when it comes to the next step of achieving carbon neutrality or negative emission, it falls behind other infrastructure sectors such as energy and transportation. The water sector carries tremendous potential to decarbonize, from technological advancements, to operational optimization, to policy and behavioural changes. This book aims to fill an important gap for different stakeholders to gain knowledge and skills in this area and equip the water community to further decarbonize the industry and build a carbon-free society and economy. The book goes beyond technology overviews, rather it aims to provide a system level blueprint for decarbonization. It can be a reference book and textbook for graduate students, researchers, practitioners, consultants and policy makers, and it will provide practical guidance for stakeholders to analyse and implement decarbonization measures in their professions