China
Africa
Explore chapters and articles related to this topic
Bionanotechnology in Resource Recovery from Wastewater and Agro Waste into Valuable Products
Published in Naveen Dwivedi, Shubha Dwivedi, Bionanotechnology Towards Sustainable Management of Environmental Pollution, 2023
Shruti Awasthi, Preethi Rajesh
Membranes that can provide a physical barrier and have the capability to remove pollutants from water are extensively used for water treatment. The membrane performance largely depends on the membrane material used. The incorporation of functional nanomaterials into membranes offers a great opportunity to improve membrane permeability, fouling resistance, and mechanical and thermal stability (Xiaolei Qu et al., 2013). The electrospinning method is used to generate a nonwoven web of micro- or nanofiber mats which have complex pore structures. In this technique, high voltage electricity is applied to the liquid solution and a collector, which lets the solution extrude from a nozzle forming a jet. The jet-formed fibers are deposited on the collector during drying. Nanofibers are commercially used for air filtration; they can be used as pretreatment prior to ultrafiltration or reverse osmosis.
Sustainable Eco-Friendly Polymer-Based Membranes Used in Water Depollution for Life-Quality Improvement
Published in Neha Kanwar Rawat, Iuliana Stoica, A. K. Haghi, Green Polymer Chemistry and Composites, 2021
Adina Maria Dobos, Mihaela Dorina Onofrei, Anca Filimon
Since 1960, the membrane technology has been transformed from laboratory development to proven industrial applications.12 More than 95% of applications are for liquid separations. Thus, the membranes are used for desalination of the seawater and brackish water, for potable water production and treating industrial effluents, and for water reclamation and reuse. Additionally, the membranes are used for the concentration and purification of food and pharmaceutical products, in base chemicals production, and energy conversion devices such as fuel cells. Membranes are also used in medical devices, namely hemodialysis, blood oxygenators, and controlled drug delivery products. The membrane separation processes are increasingly integrated with the conventional technologies as hybrid membrane systems to reduce the energy consumption and to minimize the environmental impact. Therefore, the utilization of membranes leads to the improvement of the industrial design. This makes the membrane technology to be more economical for the water filtration, separation, and catalysis.13
Technologies and Advancements for Gas Effluent Treatment of Various Industries
Published in Mihir Kumar Purkait, Piyal Mondal, Chang-Tang Chang, Treatment of Industrial Effluents, 2019
Mihir Kumar Purkait, Piyal Mondal, Chang-Tang Chang
Advantages offered by the membrane gas separation include: reduced environmental impact due to the absence of chemical systems; easy up- and downscaling; ease of operation and control; no moving parts; low energy consumption, since no additional energy is required besides the one required for gas flow; and low capital and operating costs. Common drawbacks are the need for multistage separations to achieve high purities and recoveries, leading to higher capital and operating costs; interactions between some gas components under real flue gas conditions, leading to lower performances than predicted by pure gas tests; and gas treatment can be heavy and thus expensive for some applications (Favre, 2010; Baker and Low, 2014).
Electric Vehicle Advancements, Barriers, and Potential: A Comprehensive Review
Published in Electric Power Components and Systems, 2023
Alperen Mustafa Çolak, Erdal Irmak
The operational principle of FCEVs is based on the conversion of chemical energy in hydrogen into electrical energy through the process of electrochemical reaction [1,78,87,88]. As clearly seen in Figure 5, the heart of an FCEV is its fuel cell stack, which contains several fuel cells that convert hydrogen into electricity. Each fuel cell consists of an anode, cathode, and an electrolyte membrane. Hydrogen gas is fed into the anode of the fuel cell, where it is split into protons and electrons. The protons pass through the electrolyte membrane to the cathode, while the electrons are used to generate electrical power. The electrons then flow through an external circuit to provide power to the vehicle’s electric motor. The protons combine with oxygen from the air that is fed into the cathode, producing water vapor as the only emission.
Lithium Extraction Techniques and the Application Potential of Different Sorbents for Lithium Recovery from Brines
Published in Mineral Processing and Extractive Metallurgy Review, 2023
Rebekka Reich, Klemens Slunitschek, Rosa Micaela Danisi, Elisabeth Eiche, Jochen Kolb
Nanofiltration describes ion filtration through membranes with different selectivity for mono- and divalent ions (Figure 2)), which is often also called “near reverse osmosis” or “near ultrafiltration” (Gaikwad, Misal and Gupta 2011; Van der Bruggen 2013). The membranes can be made of polymers, ceramics, or polymeric-ceramic combinations (Van der Bruggen 2013). To reduce the osmotic pressure on the membranes prior to the separation of monovalent Li+ from divalent ions, such as Mg2+ or Ca2+, the brine must be diluted (Figure 2); Somrani, Hamzaoui and Pontie 2013; Song et al. 2017; Sun et al. 2015; Wen et al. 2006). Furthermore, Sun et al. (2015) found that an increase in temperature to >18–20°C negatively affects the selectivity of the membrane due to an increased osmotic pressure, decreasing viscosity of the solution and a change in the membrane pore size. Wen et al. (2006) and Somrani, Hamzaoui and Pontie (2013) show that nanofiltration is not applicable for Li separation of high Mg- and B-brines and it also fails to separate Li+ from Na+ (Figure 2)).
Effect of solar radiation on natural organic matter composition in surface waters and resulting impacts on drinking water treatment
Published in Environmental Technology, 2023
I. Slavik, D. Kostrowski, W. Uhl
To enhance NOM removal in water treatment, membrane filtration processes can be applied [87]. Since LMW organic compounds are not removed in ultrafiltration (UF) membranes, only nanofiltration (NF) and reverse osmosis (RO) applications make sense in order to adapt water treatment to raw water quality changes associated with shifts in molecular weight distribution of DOC. For NF applications, attention should be paid to the fact that at high NOM concentrations, the effect of concentration polarisation will be more pronounced, resulting in enhanced rejection, as shown by Jarusutthirak et al. [88]. Basically, the biggest drawback of membrane applications in water treatment is membrane fouling, which causes a considerable decline in productivity over time [89]. Fouling means an accumulation of colloidal matter, organic and inorganic compounds and microorganisms on membrane surfaces and within membrane pores, which often results in an irreversible loss of permeate flux. In particular, the hydrophilic fraction of NOM causes irreversible fouling, as described by Yamamura et al. [90]. Kennedy et al. [91] showed that the reversibility of fouling due to the hydrophilic fraction was very poor. Therefore, it must be expected that NF and RO filtration will experience enhanced irreversible fouling when the molecular weight distribution of NOM shifts towards LMW substances due to solar radiation.