This paper deals with the membrane fouling issue in the Direct Contact Membrane Distillation (DCMD) process treating a wasted sludge from an anaerobic digestion process. The main objective is to define an optimal cleaning strategy to alleviate fouling. Using a lab scale DCMD process, a cleaning strategy based on DI water flushing followed by 0.2% sodium hypochlorite (NaOCl) and 3% citric acid (CHO) cleaning was tested with different cleaning frequencies and various chemical cleaning durations at different cross-flow velocities. To avoid severe fouling, the optimal cross-flow velocity was found at 0.18 m/s (0.8 L/min). Moreover, even if higher cross-flow velocity allows higher flux, it could increase fouling risks. For a better membrane regeneration and process productivity, a cleaning of 60 min duration for each chemical cleaning applied every two days was defined as the optimal cleaning strategy. Such conditions allowed the preservation of 75.5% of the initial flux after 96 h of operation. Furthermore, the effect on membrane flux regeneration of DI water flushing, sodium hypochlorite, and citric acid cleaning registered were, 31.52%, 11.95% and 20.65%, respectively. This study revealed that in the MD process treating real wastewater both external and internal fouling are responsible of permeate flux decline due to the accumulation of organic and inorganic matter on the membrane surface as well as within the pores.
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http://dx.doi.org/10.1016/j.chemosphere.2021.130524 | DOI Listing |
Org Lett
January 2025
Leibniz-Institut für Katalyse e. V., Albert-Einstein-Straße 29a, 18059 Rostock, Germany.
A palladium-catalyzed alkoxycarbonylation with two different alcohols for the synthesis of cyclobutanecarboxylates bearing an α-quaternary carbon center is presented. The reaction utilizes readily accessible starting materials, tolerates a broad scope of functional groups, and provides a straightforward and efficient approach for the synthesis of a diverse array of cyclobutanecarboxylates bearing an α-quaternary carbon. Meanwhile, this strategy effectively prevents the transition-metal-catalyzed ring-opening of cyclobutanols, preserves the cyclobutane framework, and affords 1,1-disubstituted cyclobutanecarboxylates in high yields with excellent regioisomeric ratios.
View Article and Find Full Text PDFChembiochem
January 2025
Vilnius University: Vilniaus Universitetas, Life Sciences Center Institute of Biotechnology, Vilnius, LITHUANIA.
Enzyme functional analysis is a multifaceted process that can be used for various purposes, such as screening for specific activities, as well as developing, optimising, and validating processes or final products. Functional analysis methods are crucial for assessing enzyme performance and catalytic properties. Laccase, a well-known blue multi-copper oxidase, holds immense potential in diverse industries such as pharmaceuticals, paper and pulp, food and beverages, textiles, and biorefineries due to its clean oxidation process and versatility in handling a wide range of substrates.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Key Laboratory of Advanced Catalytic Materials and Reaction Engineering, School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009, China.
Photoelectrochemical (PEC) water splitting offers an ideal strategy for the development of clean and renewable energy. However, its practical implementation is often inhibited by the high recombination rate of photogenerated charge carriers and the instability of photoanodes. Introducing defect engineering (such as oxygen vacancies) and constructing internal electric field-modulated Z-scheme heteronanostructures (HNs) can be considered as effective approaches to overcome these obstacles.
View Article and Find Full Text PDFJ Clin Med
January 2025
Department of Cardiovascular Surgery, Ankara Yıldırım Beyazıt University Faculty of Medicine, 06010 Ankara, Türkiye.
Stuck prosthetic valves, often resulting from pannus formation or thrombus accumulation, represent a critical complication in prosthetic valve management, carrying significant risks for morbidity and mortality. This study aims to identify factors associated with stuck valve development and assess the effectiveness of interventions in restoring normal valve function. A total of 27 patients with stuck valves were analyzed, including mitral, aortic, and tricuspid valve cases.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
Hainan Institute, Zhejiang University, Sanya 572024, China.
In recent decades, Offshore Wind Turbines (OWTs) have become crucial to the clean energy transition, yet they face significant safety challenges due to harsh marine conditions. Key issues include blade damage, material corrosion, and structural degradation, necessitating advanced materials and real-time monitoring systems for enhanced reliability. Carbon fiber has emerged as a preferred material for turbine blades due to its strength-to-weight ratio, although its high cost remains a barrier.
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