Pros And Cons Of Ultrafiltration Membranes

Osmosis itself is the tendency for water to move from a weaker saline solution to a stronger saline solution until equilibrium is reached. The molecules move through a semi-permeable membrane, which separates the two solutions. Reverse osmosis, being the opposite process, provides pressure to the water, forcing the solvent to move from a strong saline solution to a weak saline solution. The salt molecules are physically larger than the solvent molecules and can therefore not pass through the semi-permeable membrane (Water Treatment Alternatives - Reverse Osmosis). Major advantages of reverse osmosis includes the removal of all minerals too large to pass through the membrane. A comprehensive list of the elements that reverse osmosis membranes will remove includes: sodium, sulfate, calcium, potassium, nitrate, iron, zinc, mercury, selenium, phosphate, lead, arsenic, magnesium, nickel, fluoride, manganese, cadmium, barium, and cyanide (What is Reverse Osmosis?). Some disadvantages of reverse osmosis are that the process is unable to remove chlorine, and most harmful organic compounds. After completing the process, the product is mostly acidic water which can be harmful to the body in large quantities, and while not as ineffective as distillation, reverse osmosis produces one gallon of pure water for every three gallons treated (Water Treatment Alternatives - Reverse

Comparison of the features of biosorption and bioaccumulation (Dhankhar and Hooda, 2011, Chojnacka, 2010, Vijayaraghavan and Yun., 2008, Ahluwalia and Goyal, 2007)

The demand of fresh and pure water is increasing day by day and due to many problems around different areas of world the supply of fresh water is not up to the desired level. Reverse Osmosis plant, therefore, helps to prove reliable and energy efficient process in producing the fresh water with many large plants presently being used around the world. Desalination by RO requires high pumping pressure in the range of 45-80 bar which is usually supplied by electrical driven pumps in steady state. This thesis is explaining the cost analysis of replacing these electrical pumps with a wind turbine driven pumps and concluding that whether this replacement is economically feasible or not. The paper will cover the comparison of operating and capital cost for these two plants with the aim to determine that whether wind powered

Water purification is the removal of contaminants from raw water to produce drinking water that is pure enough for human consumption or for industrial use.

Pervaporation membranes can be classified depending on the material used for their construction i.e organic, inorganic and

MD is a thermally driven separation process that utilizes a hydrophobic, membrane as a contactor media between two fluids kept at different temperatures where the separation is obtained by the mass transfer of the vapor phase. The driving force of the process is given by a partial vapor pressure difference that caused from the temperature difference [13-17]. Two advantages of MD are, the process performance is not highly affected by high feed salinity as see water, and has the theoretical ability to reach 100% salt rejection [13, 18, 19]. There are commonly four types of membranes arrangements for MD process: Direct Contact Membrane Distillation (DCMD), Vacuum Membrane Distillation (VMD), Air Gap Membrane Distillation (AGMD), and the Sweeping Gas Membrane Distillation (SGMD) [18, 20-22]. AGMD configuration is appropriated for water desalination [23, 24], on the other hand water gap showed higher thermal efficiency and less internal heat loss in comparison to AGMD [18, 25]. Therefore, these two arrangements are commonly used for the see water

There is a common thinking in the academia and professional arenas that the solution to the untreated wastewater discharges into our water bodies can be prevented or mitigated mainly with the construction of wastewater sewer collection systems and wastewater treatment plants. Part of the purpose of this research is to revisit and analyze the benefits of using decentralized wastewater treatment technologies and evaluate the latest wastewater treatment technologies available.

Water disinfection means eliminating or inactivate of growth and reproduction in pathogenic microorganisms by creating cell wall corrosion in the cells of microorganisms, or changes in cell permeability. From the water treatment process, disinfection is a sufficient and the crucial process in order to inactivate bacteria, viruses and pathogenic organisms that can waterborne diseases to downstream users and the environment (USEPA, 1999). There are three most common methods of disinfection in the U.S., which are Chlorination, Ozonation, and ultraviolet (UV) disinfection. “Chlorine, the most widely used disinfectant for municipal wastewater, destroys target organisms by oxidation of cellular material. Ozone is a strong oxidizing agent that is an unstable gas that is generated by an electrical discharge through dry air or pure oxygen. Finally UV radiation generated by sunlight, tanning lamp, black lights, and electrical discharge through mercury vapor, penetrates the genetic material of microorganisms and retards their ability to reproduce” (USEPA, N.D.). One of the popular disinfection methods in water treatment is the Ultraviolet (UV) disinfection. The ultraviolet (UV) disinfection is a physical disinfection of water. This paper would provide a broadly definition of UV disinfection and its purpose in water treatment. Also, this paper will provide the advantages and disadvantages of using the advance technology over the common technology in water treatment.

Membrane-based pervaporation processes have been intensively studied for separation of organic mixtures and dehydration of aqueous/organic solutions

Fouling in FO membrane is physically reversible process that decreases the need for chemical cleaning compared to reverse osmosis (RO) membrane [7, 8].

The groundwater source is from GoldCentury gold mine, whereby excess groundwater is pumped out of mine at a maximum volumetric flow rate of 477L/s. It contains contaminants such as volatile organic compounds (VOCs), heavy metal impurities, sulphates, bicarbonates, microorganisms, dissolved minerals and objectionable gases, but focuses on the removal of dissolved inorganic contaminants such as calcium and iron. The most prevalent dissolved minerals which are Calcium and Magnesium, also known as hardness, can be removed by precipitation, requiring softening steps. The purification system designed is based more on efficiency over cost effectiveness. The purpose of treating the groundwater in this assignment, is to purify it to drinking standards to hydrate mineworkers underground during heated, intense mine-work operations, and for operating certain equipment and tools.

Without treatment waste water from both municipal and industrial sources would have a significant impact on the environment, to protect the water environment the waste water must first be appropriately treated and processed. Water comes from many various sources and therefore the pollutants found in the water include a wide array of chemicals and pathogens, that all come with different physical chemistries (Rao, Senthilkumar, et al., 2016, p. 2). Eutrophication is the process in which waters experience excessive inputs of nutrients, namely nitrogen and phosphorus from wastewater discharges. Waste water treatment does focus on reducing the levels of nitrogen and phosphorus present in their effluent, as these contribute to nutrient loading in the environment. The combinations of tertiary treatments needed depends on the uses of the water the effluent is discharged into and how sensitive this area is deemed. The municipal waste water treatment process does vary slightly depending on many factors but it is essentially a three stage treatment process (Anand, 2011). The primary treatment stage objectives are to remove organic and inorganic solids through sedimentation and the skimming of materials floating on the surface of the effluent. During the primary treatment some organic nitrogen and organic phosphorus that are associated with solids can be removed (Food and Agriculture Organizations of the United Nations, 1992). Secondary treatment involves bacterial decomposition of both

Continuous growth in population of the world has led to rapid increase in demand and competition for water. Also, Canada is one of the highest water users per capita in the world(Government of Canada). Therefore, removal of contaminates from water that threat the quality and integrity of water resources is an important issue and demands vast researches to be conducted in this field.

There are seven components to a biosand filter design. These are; the lid, diffuser, sand layer, outlet tube, filter body, gravel layer and the separated gravel layer (Cawst, 2009). All of these components all contribute to the purification of water. The purpose of the lid is to protect the water from any external contamination. The diffuser is a plastic sheet with holes drilled into it and protects the biolayer while the water is being poured in (CDC, 2014). This is achieved through slowing down the rate of the water. The third component is the sand layer and this removes any suspended solids within the water. This is able to occur through the use of mechanical trapping and the solids being trapped in between the grains of sand (Cawst, 2009). The separating gravel layer is purely placed in the filter to support the sand layer on top while the drainage gravel layer’s purpose is to support the flow of water into the outlet tube. The use of bigger rocks is used for this drainage layer to prevent smaller rocks accessing this outlet tube (Cawst, 2009). The outlet tube brings the water from the bottom of the

The disposal of untreated wastewater coming from the industries into the water bodies will pollute the water bodies because of its high concentrations. So, the wastewater produced from the industry should be treated properly to meet the permissible limits given by central and state pollution control boards. Therefore it is necessary to treat the wastewater properly with the help of an appropriate treatment plant. However, the treatment plant even though properly planned may not work satisfactory because of several reasons. Hence, it is essential to evaluate the treatment plant considering individual treatment unit in the entire treatment flow. In the present work emphasis has been given to the study of the performance of treatment facilities because of its importance in the conventional treatment of wastewater. Hence, the literature review related to the evaluation of the entire treatment process along with biological treatment process particularly suspended growth process Activated Sludge Process (ASP), attached growth process Trickling Filter (TF) and a combination of the both suspended and attached growth process Hybrid Reactor (HR) is presented in the following sections of this chapter.