Band 32, Heft 4

In recent years, water pollution has become a major problem for the environment and human health due to the industrial effluents discharged into the water bodies. Day by day, new molecules such as pesticides, dyes, and pharmaceutical drugs are being detected in the water bodies, which are bio-refractory to microorganisms. In the last two decades, scientists have tried different advanced oxidation processes (AOPs) such as Fenton, photocatalytic, hydrodynamic, acoustic cavitation processes, etc. to mineralize such complex molecules. Among these processes, hydrodynamic cavitation (HC) has emerged as a new energy-efficient technology for the treatment of various bio-refractory pollutants present in aqueous effluent. In this review, various geometrical and operating parameters of HC process have been discussed emphasizing the effect and importance of these parameters in the designing of HC reactor. The advantages of combining HC with other oxidants and AOPs such as H 2 O 2 , ozone, Fenton process, and photocatalytic process have been discussed with some recommendation for large-scale operation. It has been observed that the geometry of the HC device and other operating parameters such as operating pressure and cavitation number are the key design parameters that ultimately decide the efficacy and potentiality of HC in degrading bio-refractory pollutants on an industrial scale.

Due to escalating power densities in electronics, information, communication, energy storage, aerospace, and automobile technologies, heat dissipation has become immensely essential for the efficient performance and reliability of photonic, electronics, optoelectronics, and other devices in order to proactively prevent premature failure due to overheating. The functionalization and synergistic inclusion of thermally conducting nanoparticles such as carbon derivatives and metallic and ceramic fillers into polymer matrices have resulted in development of thermally conducting polymer nanocomposites. This has enlarged the scope of application of these materials in areas hitherto restricted due to poor thermal conductivity and, therefore, opened broad windows of opportunities for polymer nanocomposites as emerging alternative replacements for metal components in various applications where effective heat dissipation is compulsory for device performance. Thus, this paper critically discusses globally emerging technologies applied in the development of thermally conductive polymer nanocomposites for various industrial applications.

This article provides an overview of previous research contributions and the current status of technology on the hydrothermal liquefaction (HTL) of wood biomass into liquid fuels and valuable chemicals. This process involves the direct liquefaction of biomass, which operates from 200°C to 400°C, 5 to 25 MPa, and 10 to 60 min reaction time in hot-compressed water or solvent and with or without a catalyst in the presence of inert or reducing gas. The influence of process variables, including biomass composition, temperature, residence time, pressure, heating rate, particle size, catalysts, and so on, which are significant for the bio-oil yield and product quality, has been addressed in this review. This review focuses on the HTL fundamentals based on current knowledge and summarizes the state-of-the-art knowledge of the HTL of wood biomass.