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Graphene Oxide from Natural Products and Its Applications in the Agriculture and Food Industry
Published in Amir Al-Ahmed, Inamuddin, Graphene from Natural Sources, 2023
Seyyed Sasan Mousavi, Akbar Karami
Membrane technology is a rapidly developing field with a variety of applications, including desalination and water treatment. Based on the characteristics of the membrane and the species to be filtered, a membrane may allow the passage of some species while blocking the passage of others. Researchers have been developing this technology to create a more cost-effective and accurate membrane (Joshi et al., 2015). Graphene, generally, does not let anything pass through. GO is continuing to show its great membrane features and offers great potential for various usages (Joshi et al., 2015). GO has emerged as a great membrane material. Nair et al. (2012) demonstrated that the GO membrane allows unrestricted water permeation while blocking all else in the vapor form (Nair et al., 2012). The ease in forming atomically thin GO layers can be created in the form of a membrane, which gives it an advantage over other membranes in terms of practical applications.
End-of-Pipe Treatment Techniques
Published in Guttila Yugantha Jayasinghe, Shehani Sharadha Maheepala, Prabuddhi Chathurika Wijekoon, Green Productivity and Cleaner Production, 2020
Guttila Yugantha Jayasinghe, Shehani Sharadha Maheepala, Prabuddhi Chathurika Wijekoon
Various membrane separation processes exist and these can be classified by a number of criteria. These membrane separation processes are proven for use in purification, desalination, ion separation, metal recovery, and concentration processes. Membrane technology is useful in many industries, including pharmaceuticals, medical, chemical, and food processing. According to the process driving force, filtration methods can be classified as: Reverse osmosisNanofiltrationUltrafiltrationMicrofiltration
Microfiltration Membranes: Fabrication and Application
Published in Sundergopal Sridhar, Membrane Technology, 2018
Barun Kumar Nandi, Mehabub Rahaman, Randeep Singh, Mihir Kumar Purkait
Process industries such as petroleum refineries, petrochemical, metallurgical, transportation and food processing enterprises produce large volumes of oily wastewater. Typical concentration ranges of produced oil-in-water (o/w) emulsions vary between 50–1000 mg/L of total oil and grease besides 50–350 mg/L of total suspended solids (Nandi et al., 2009a). Existing tolerance limits of total oil and grease concentrations in wastewater streams is about 10–15 mg/L. The desired discharge limits can be achieved by using conventional processes, such as thermal de-emulsification, biological methods, and chemical treatment methods. These processes are effective for the treatment of oily wastewater streams with high feed concentrations (500–5000 mg/L). On the other hand, due to the existence of smaller droplet sizes (<1 μm) of the emulsions in low oil concentrations (50–500 mg/L), these methods are ineffective. Amongst the various alternative, conceivable technologies, membrane technology is promising. The advantages of membrane technology, such as lower capital cost, higher separation factors, compact design, and the elimination of other chemical and mechanical treatment units like mechanical separation, filtration and chemical de-emulsification, render membranes a better choice for this application.
A review of demulsification technique and mechanism for emulsion liquid membrane applications
Published in Journal of Dispersion Science and Technology, 2022
Meor Muhammad Hafiz Shah Buddin, Abdul Latif Ahmad, Afiqah Tasneem Abd Khalil, Siti Wahidah Puasa
Unfortunately, fouling is the main drawback of the membrane technology where the phenomenon reduces the flux and the membrane’s lifespan, thereby resulting in expensive maintenance during application. Fouling occurred due to the adsorption of the feed solution onto the surface of the membrane. Optimum pressure and proper choice of membrane materials would reduce fouling and maintain the flux of permeate. Ceramic and polysulfone membrane suffer the worst fouling as permanent surfactant is adsorbed onto the membrane surface while demulsification takes place. Better results were shown by cellulose type.[45] Proper determination of hydrophilicity, wettability and the mode of operation of the membrane can significantly reduce fouling.[45,130]
A case study of the wastewater treatment system modification in denim textile industry
Published in The Journal of The Textile Institute, 2021
Li Zhang, Ming Lei, Te Feng, William Chang, Alice Ye, Hong Yi, Changhai Yi
In the treatment of denim textile industry wastewater, various methods are used to remove the harmful compounds in wastewater. The conventional pH adjustment, chemical precipitation, and sedimentation are always used in the pre-treatment phases. Biological treatment, also called activated sludge process, is usually used for reducing organic pollutants (Sahinkaya et al., 2008). Membrane technology is the common process for desalinization (Gebrati et al., 2019). However, the denim textile industry wastewater also exhibits low biodegradability, toxicity, and high color issues, which makes it difficult to treat with traditional methods (Tjandra et al., 2005; Yi et al., 2020; Yin et al., 2019). The combined processes received wide attention and used by some researchers (Wang et al., 2008; Yang et al., 2020). For example, the membrane bioreactor (MBR) process is a novel treatment method that combined traditional activated sludge process and membranes for solids separation (Sahinkaya et al., 2017). Yigit et al. (2009) reported that the MBR system can efficiently treat the denim textile industry wastewater, and the treated water could be reused in the production processes. While Zhu et al. (2018) reported that the ultrasonic oxidation technology showed a high efficiency for the complete decolorization of dyes. However, most researches stay in the pilot-scale, barely report a stable system used in the practical industry process (Nawaz et al., 2020; Yukseler et al., 2017).
Toward CO2 utilization: Gas–liquid reactive crystallization of lithium carbonate in concentrated KOH solution
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2021
Youfa Jiang, Chenglin Liu, Xiaqing Zhou, Ping Li, Xingfu Song, Jianguo Yu
To reduce carbon emissions into the atmosphere, methods for CO2 capture and sequestration such as absorption (Zhang et al. 2018a), adsorption (Kumar et al. 2015), membrane (Khalilpour et al. 2015), cryogenic separation (Aaron and Tsouris 2005), and a combination of these techniques (Zhang et al. 2018b) have been reported. Chemical absorption technologies implement alkaline solutions or sorbent materials, such as amine-based solvent or calcium oxide, to react with CO2, which typically comprises two distinct unit operations: adsorption and desorption (sorbent regeneration process). For adsorption method, the solid sorbents that can capture CO2 with high selectivity, such as zeolite, porous carbon, and porous metal–organic materials, are employed to separate and recover CO2 from a gas mixture, e.g. coal-combustion flue. Membrane technology is a physical separation process, in which gas mixtures consisting of two or more components are separated by a semipermeable barrier into a retentate stream and a permeate stream. Cryogenic separation relies on the difference of boiling point of different components, in which the temperature and pressure are manipulated to cause the CO2 to liquefy. Of these technologies, absorption is currently the closest to being commercially realized due to its high gas removal efficiency and high level of technological maturity, which attracts more researchers concentrated on CO2 absorption enhancement, such as nanofluids and ionic liquids. In this work, CO2 absorption into alkaline solution is investigated for carbon utilization and production of lithium carbonate, as well.