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Recent Development in Microalgal Cultivation and Biomass Harvesting Methods
Published in Shashi Kant Bhatia, Sanjeet Mehariya, Obulisamy Parthiba Karthikeyan, Algal Biorefineries and the Circular Bioeconomy, 2022
Gour Gopal Satpati, Ashutosh Kumar, Sreestha Dinesh Parambath, Trisha Bagchi, Meenakshi Singh, Murthy Chavali, K. Chandrasekhar
The tendency of fouling is due to the presence of organic materials of different shapes, sizes, and compressibility's in the biomass collected. Due to this hindrance, filter membranes made of cheap and convenient materials were developed (Tan et al., 2020). A group of researchers was successfully able to synthesize a filter membrane out of stretch cotton, which has a harvesting efficiency of 66–93% (Ebaye, 2011). On a large and commercial scale, membrane filtration is found to be less economic than centrifugation. Filtration is commonly used for low-scale harvesting and not feasible on a large scale. The different kinds of filtration techniques include magnetic filtration, vacuum filtration, pressure filtration, tangential flow filtration (TFF), and cross-flow filtration.
Filtration
Published in Subhash Verma, Varinder S. Kanwar, Siby John, Environmental Engineering, 2022
Subhash Verma, Varinder S. Kanwar, Siby John
Earlier filters were slow sand filters consisting of uniform sand with no provision for backwashing. Modern multi-media filters perform at much higher filtration rates and are cleaned by backwashing. Backwashing refers to reversing the flow of water through the bed at a rate higher than the filtration rate.
Mass Transfer
Published in Yeong Koo Yeo, Chemical Engineering Computation with MATLAB®, 2020
Filtration is used to remove solid particles from a fluid by passing the fluid through a medium. Fluid flows through the medium due to a pressure difference across the medium. The filter medium must remove the solids to be filtered from the slurry and give a clear filtrate, and allow the filter cake to be removed easily. The pressure drop of fluid through filter cake, for a laminar flow, can be estimated by the Carman-Kozeny relation as ∆pcL=−k1μv(1−ε)2S02ε3 where
Evaluation of Pressure Filtration of Coal Refuse Slurry: Effects of pH, Filtration, and Air-Blow Times
Published in Mineral Processing and Extractive Metallurgy Review, 2022
Slurry impoundments storing fine coal refuse can lead to environmental problems such as acidic water, siltation of streams, land property devaluation, and in extreme cases, dam failures (Schubert 1979). Advanced coal preparation techniques call for safer, environmental friendly, and efficient means of coal processing (Kawatra 2020; Kawatra and Eisele 2001). Pressure filtration provides a possible approach to reduce or even eliminate the need for slurry impoundments thereby providing an alternate means of handling coal refuse with potentially less environmental footprint. Filtration is the process of separating the solids in a slurry from the bulk liquid by retaining the solids (filter cake) on a porous filter medium (cloth) while allowing the liquid (filtrate) to pass through the medium. Pressure filtration operates at pressures that are greater than atmospheric. The differential pressure applied on the slurry can be several tens of atmospheres, leading to increased water recovery and drier filter cakes usually without the need for additional chemical flocculants. This process has the potential to improve water conservation, minimize environmental impact, reduce area requirements for disposal, and provide a safer operation (Alam et al., 2011). One study highlighted potential economic benefits of using pressure filtration as an alternative to the expense of capping and reclaiming the slurry impoundment area (Pepper 2012).
Advances in dewatering and drying in mineral processing
Published in Drying Technology, 2021
Benitta A. Chaedir, Jundika C. Kurnia, Agus P. Sasmito, Arun S. Mujumdar
Filtration is a solid-liquid separation process by using a porous medium (the filter) which blocks solids but pass the liquid. Cake filtration is the most common filter type used in mineral dewatering especially for the process dealing with large amounts of fine solids (<100 µm). In this process, the liquid that passes through is referred to as the “filtrate” while the accumulated solids blocked by the filter are referred to as the “filter cake.” The process is influenced by several important parameters including the properties of the suspension (e.g., size distribution, concentration),[18,19] the properties of filtering material (e.g., size and shape of pores),[20,21] and the forces applied. The filtering medium acts as a filter and as a backing for the filter cake. Selecting the best filter medium is critical for an efficient filtration. The medium should be able to blocks solids without blinding, mechanically sturdy, and corrosion proof.[3] Filter media can be made of cotton, wool, metals, rayon, nylon, silk, glass fiber, ceramic, and other materials and synthetics.
Preparation of silver nanowire/expanded polytetrafluoroethylene and polypropylene nanocomposites via all solution process method for antibacterial applications
Published in The Journal of The Textile Institute, 2020
S. H. Mirjalili, Mohammad Reza Nateghi, F. Kalantari-Fotooh
The fine particles of air could endanger health and immunity of people inhaling them. Improving the air quality of indoor and industrial environments by controlling these particles at a specific concentration is very essential. Filtration is a common method for removal of fine particles and for air purification, in which capturing particles occurs through direct interception, inertial impaction and diffusion mechanisms (Denny et al., 2010). Two types of filters are usually used for air purification. The first group, including filters such as carbon nanotubes, inorganic nanowires (Jung, Gweon, Kim, & Choe, 2011) and polymer nanofibers (Kang & Shah, 1997) are fibrous layers which can be accumulated randomly and have a one-dimensional nano-structure. The second group are filters such as foamed graphene (Bai et al., 2015), sponge ceramic (Sharmiwati, Mizan, & Noorhelinahani, 2014) and expanded ePTFE (Ebnesajjad, 2017), which have a three-dimensional porous network structure.