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Global Water Crisis, Nanofiltration, The Vast Innovations, And The Vision For The Future
Published in Alexander V. Vakhrushev, Suresh C. Ameta, Heru Susanto, A. K. Haghi, Advances in Nanotechnology and the Environmental Sciences, 2019
The science of nanofiltration and reverse osmosis are today surpassing vast and versatile scientific boundaries. Nanofiltration is a relatively recent membrane filtration process used most often with low dissolved solids in water such as surface water and fresh groundwater with the purpose of softening (polyvalent cation removal) and removal of disinfection by-product precursors such as natural organic matter and synthetic organic matter. Nanofiltration is also used in food processing applications such as dairy, for simultaneous concentration and partial demineralization. The world of science today stands in the midst of scientific failures, and scientific difficulties as heavy groundwater metal and arsenic groundwater contamination challenges the scientific firmament. Technology and engineering science have practically no answers to the marauding impact of arsenic drinking water contamination in developing as well as developed countries around the world. Thus, the need of membrane science and nanofiltration.
Transport Mechanisms and Membrane Separation Processes
Published in Mihir Kumar Purkait, Randeep Singh, Membrane Technology in Separation Science, 2018
Mihir Kumar Purkait, Randeep Singh
In the case of nanofiltration membranes, the choice of material is very crucial as it directly affects the performance of the membrane, unlike the micro- and ultrafiltration membranes. The material chosen for nanofiltration membranes should have a high permeability coefficient and a low solute permeability coefficient to achieve a satisfactory selectivity. Thus, it can be said that for nanofiltration membranes, unlike micro- or ultrafiltration membranes, the intrinsic properties of the membranes play a major role in its separation performance and the pores play a sleek role in the overall performance of the nanofiltration membranes. Therefore, nanofiltration membrane materials should be chosen very carefully.
Cellulosic Nanofibers: A Renewable Nanomaterial for Polymer Nanocomposites
Published in Mangala Joshi, Nanotechnology in Textiles, 2020
Mrunalini K. Gaydhane, Chandra S. Sharma
Generally, a nanofiltration membrane has a pore size 0.5–2 nm in diameter, through which a small-sized positively charged metal ion can pass [88]. The anions formed on the membrane precipitate out these metal ions from the flowing water. Thus, filtration takes place through the nanofiltration membrane. The various factors affecting the efficiency of nanofiltration are temperature, pressure, cross flow velocity, pH, salinity, etc. [88].
Nanomaterials and nanotechnology for water treatment: recent advances
Published in Inorganic and Nano-Metal Chemistry, 2021
Membrane separation processes are rapidly advancing applications for water and wastewater treatment as they provide a physical barrier for substances depending on their pore size and molecule size. Membrane technology is well established in the water and wastewater area as a reliable and largely automated process. Novel research activities with regard to nanotechnology focus on improving selectivity and flux efficiency, e.g., by developing antifouling layers. The following sections describe the state of the art in the field of nano-engineered membrane filtration. Nanofiltration is one of the membrane filtration techniques and can be defined as a pressure-driven process wherein molecules and particles less than 0.5 nm to 1 nm are rejected by the membrane and are characterized by a unique charge-based repulsion mechanism allowing the separation of various ions. They are mostly applied for the reduction of hardness, color, odor, and heavy metal ions from groundwater. The conversion of sea water into potable water (desalination) is another thriving field of application since comparable desalination technologies are very cost-intensive.[227,228]
Resource recovery and utilization of bittern wastewater from salt production: a review of recovery technologies and their potential applications
Published in Environmental Technology Reviews, 2021
Arseto Yekti Bagastyo, Afrah Zhafirah Sinatria, Anita Dwi Anggrainy, Komala Affiyanti Affandi, Sucahyaning Wahyu Trihasti Kartika, Ervin Nurhayati
Nanofiltration is a pressure-driven membrane separation technology, and is similar to microfiltration, ultrafiltration, and reverse osmosis. It involves a pore size in the range 0.5–2 nm, a low operating pressure (5–40 bar), and a molecular weight cut-off of between 300–500 g mol–1 (equivalent to 200–1000 Da) [21,81]. Due to these characteristics, nanofiltration can be applied for the selective removal of monovalent ions. This leads to ionic separation within different valences and the separation of substances containing components with low and high molecular weights. Of the pressure-driven membrane techniques, nanofiltration is the most widely used for bittern/brine recovery, and particularly in the separation of lithium from brine containing a high proportion of magnesium, with Mg2+/Li+ mass ratio of up to 64 [74].
Efficiency of polymer/nanocarbon-based nanocomposite membranes in water treatment techniques
Published in Journal of the Chinese Advanced Materials Society, 2018
Nanofiltration has been considered as a latest technology for waste treatment, which is advanced, economical, and environmentally friendly. The integration of nanoparticle in polymers yields optimal results in wastewater management. Moreover, higher rejection rate compared with ultrafiltration membranes and lower energy consumption relative to reverse osmosis and desalination membranes render nanofiltration membranes highly effective. Nanofiltration has become a promising technology not only for wastewater treatment but also for reusing the resulting water. Performance of these membranes have been greatly affected by membrane characteristics, operating conditions, and feed characteristics, as discussed in the following sections of this review. Characteristics of various nanofiltration membranes discussed have been presented in Table 1.