Enhanced Membrane Distillation by Ultrasound Application
Nice is a global company specializing in water treatment solutions. It provides chemicals for treating boiler water, chemicals for reverse osmosis, poly-electrolytes, and water for cooling chemicals. The substances are crucial since they help homes, industries, and other institutions to get access to clean water. Besides, they help other water treatment companies get access to the crucial chemicals to supply to the growing consumers. The substances produced by the company mitigate the process of fouling, which is common in distillation plants. Rice has also established several treatment options to increase efficiency and give more people access to clean water. Therefore, Nice has mastered the art of offering water cleaning services and products, making it useful to many users.
Membrane Distillation
Membrane distillation refers to a thermal process of removing salinity and waste to retain clean water. During the process, the water in the liquid state passes through the hydrophobic membrane’s pores—the hydrophobic membrane, which takes the place of a barrier to trap the waste. During the process, the water is passed through the membrane at a low pressure to allow the water to turn from liquid to vapor (Tijing et al., 2015). The pressure of the water is kept at a constant to prevent a sudden surge of the state of water. The fabric used in the fabric is usually non-polar, while water has abundant dipoles. The different features between the two surfaces make the membrane waterproof, and therefore, the water passes without wetting the membrane. The pores in the membrane are relatively large than water molecules. However, due to the high tension of liquid water, a barrier is created, hence turning it into a vapor state.
Ultrasound
Ultrasound refers to energy free from chemicals and is used in water treatment. The main ultrasound techniques used in water treatment include micro-steamers, micro-jets, and shock waves streamed through acoustic means. The methods are used infiltration of the membrane, removal of algae, disinfecting water, softening water, reducing solid waste in liquid water. During membrane distillation of water, algae develop on the membrane pores, consequently affecting the effectiveness of the process. Due to the high pressure of the ultrasound energy, the formation of algae is mitigated (Numora et al., 2000). During the water disinfection process, chemical substances such as hypochlorite, chlorine, and chloramines, as well as Ultraviolet, are used. The higher flow rate, higher electrical power, and higher specific energy rate help to increase the amount of energy help to increase the rate of algae removal in the water. Using lime-soda, electrodialysis, and electrocoagulation helps in softening hard water.
Application of Membrane Distillation
Membrane distillation is applied in several areas on water treatment. First, it is used in the DCMD system to clean water. In this process, the water evaporates and condenses when it enters the pores in the membrane pores. The DCMD system is used commercially due to several reasons. First, it is made up of fabricated and hydrophobic membranes, which increase the effectiveness of the microfiltration process, especially for commercial purposes (Shirazi, Mohammad & Kargari, 2015). The combination of a highly porous, thick structure, and being less hydrophobic makes the membrane effective in water treatment. Besides, MD is used in the SGMD process to ensure that the condensation process outside the membrane takes effective. Ammonia, which is the most significant cause of pollution in water, is removed during the process. The distilled water becomes fit for domestic consumption and industrial use. Membrane distillation is therefore applied in DCMD and SGMD to make water fit for consumption.
Foul Removal by Membrane Distillation
Foiling is a common phenomenon in water. It occurs due to salinity, chemicals, and growth of algae on the membrane pores during distillation. However, the use of membrane distillation is highly effective since it prevents fouling. Fouling mainly occurs when excess AS is used during water treatment. During the process, the AS reacts with other chemicals, resulting in a biofuel (Naji et al., 2019). As the membranes pile up with the chemicals and silt, it starts to produce a fouling layer. However, when the MD process is used, the chemicals stuck on the membrane react with chlorine or the Ultraviolet, disintegrating the chemicals in the process. When the membrane pores open up, which minimizes the fouling layer. Using the MD also reduces the rate of fouling, by reducing the hydraulic and thermal resistance in the membrane pores. Using the MD process reduces the level of wetting on the membranes.
Recommendation
From the study, it is apparent that that membrane distillation forms a crucial part of water treatment. However, it is the use of an ultrasound process that gives optimal results. Although the Ultraviolet process consumes a lot of energy, it gives optimal results, especially when used for commercial purposes. As a recommendation, before using membrane distillation to treat water, several things should be put into consideration. First, when treating water, the chemicals used should be able to disintegrate the fouling in the membrane. On the other hand, when treating water on a small scale, the ultrasound should be avoided since it increases energy consumption. Therefore, the reaction of the chemicals and energy levels should be considered when choosing the membrane treatment.
References
- Shirazi, Mohammad Mahdi & Kargari, Ali. (2015). A review on the application of membrane distillation (MD) process for wastewater treatment. Journal of Membrane Science and Research. 25.
Doosti, M & Kargar, R & Sayadi, Mohammad Hossein. (2012). Water treatment using ultrasonic assistance: A review. Proc. Int. Acad. Ecol. Environ. Sci.. 2.
Naji, Osamah & Al-juboori, Raed & Bowtell, Leslie & Alpatova, Alla & Ghaffour, Noreddine. (2019). Direct contact ultrasound for fouling control and flux enhancement in Air-Gap Membrane Distillation. Ultrasonics Sonochemistry. 61. 104816. 10.1016/j.ultsonch.2019.104816.
Nomura, Shinfuku & Murakami, Koichi & Sasaki, Yuuichi. (2000). Streaming Induced by Ultrasonic Vibration in a Water Vessel. Japanese Journal of Applied Physics. 39. 3636-3640. 10.1143/JJAP.39.3636.
Tijing, Leonard & Woo, Yun Chul & Choi, June-Seok & Lee, Sangho & Kim, Seung-Hyun & Shon, Ho Kyong. (2015). Fouling and its control in membrane distillation—A review. Journal of Membrane Science. 475. 10.1016/j.memsci.2014.09.042.