Osmosis

This thesis investigates the technical problems associated with large-scale stand-alone wind powered desalination employing a short-term energy store, particularly the complexities associated with the intermittent operation of the desalination plant. To achieve this, a non-linear, time domain system model of an existing wind powered desalination plant has been developed using the propriety code Simulink. Two desalination techniques have been considered: reverse osmosis and electrodialysis, due firstly to their relatively low specific energy consumption, and secondly, their efficient coupling to a wind turbine generator. As a way of reducing power mismatch, optimising water production, and above all reducing the switching rates of the desalination units, operation of the reverse osmosis and electrodialysis units under variable power conditions is suggested. Little information is available on plant performance under such conditions. A mathematical model has therefore been developed to...

Biofilm formation on reverse osmosis (RO) systems represents a drawback in the application of this technology by different industries, including oil refineries. In RO systems the feed water maybe a source of microbial contamination and thus contributes for the formation of biofilm and consequent biofouling. In this study the planktonic culturable bacterial community was characterized from a feed water of a RO system and their capacities were evaluated to form biofilm in vitro. Bacterial motility and biofilm control were also analysed using phages. As results, diverse Protobacteria, Actinobacteria and Bacteroidetes were identified. Alphaproteobacteria was the predominant group and Brevundimonas, Pseudomonas and Mycobacterium the most abundant genera. Among the 30 isolates, 11 showed at least one type of motility and 11 were classified as good biofilm formers. Additionally, the influence of non-specific bacteriophage in the bacterial biofilms formed in vitro was investigated by action...

The central concepts of biology, which are both diffusion and osmosis, can be found in both
cellular and organ levels. The diffusion is marked as a “net movement of matter” and is present virtually in
all chemical processes in a living organism. Whereas the osmosis is a diffusion of water in a semipermeable
membrane and plays in important roles in functions. For the students to acknowledge the differences of both
terms when conducted in an experiment. This laboratory report shows the consequences of various solutions
when a semipermeable material was soaked in a particular solution. Moreover, the gathered data concluded
that the hypertonic solution makes the specimen shrink while the hypotonic solution yields to cellular
swelling — making the tonicity of the material be visible to the reader. The data gathered from the diffusion
of betadine drop from three different water temperature indicated that the hot water could diffuse the
betadine drop more rapidly than in cold and plain tap water. The eggs coming from a hypertonic and were
submerged into a hypotonic solution made both eggs to swell and gain weight, from a baseline weight of 90
g (1st egg) and 85 g (2nd egg) to the final weight of 125 g (1st egg) and 115 g (2nd egg) after the 75-minutes
mark. The carrot slices also differ in the tightness of the string attached on both slices as a result of being
submerged in an isotonic and hypertonic solution separately. Furthermore, the objectives of this laboratory
report were answered, and the knowledge gained from the conducted experiments were understood by the
student. This laboratory report also included the documented photos of the three experimentation in which
can be found in the methodology

Living organisms have a cell membrane that is selectively permeable. This means that some materials can pass through the membrane while others cannot. One way that materials can pass through the membrane is by passive transport. Passive transport does not require the cell to use energy in order to move materials through the membrane along the concentration gradient. Passive transport mechanisms in cells include diffusion, osmosis, facilitated diffusion, and filtration. Diffusion is the movement of solute molecules from an area where they are highly concentrated to an area where they are not concentrated. An example of diffusion (figure 1) is when a sugar cube is placed in water. Figure 1 Diffusion of sugar in water A special type of diffusion is osmosis. Osmosis is the diffusion of water move through a cell membrane. Water just like solute molecules, will move through a cell membrane from an area of high water concentration to an area of lower water concentration. Cells need to have an extracellular environment that has a solute concentration that is the same as their cytoplasm. If the solute concentration of the extracellular fluid and the cytoplasm are the same then the two fluids are described as being isotonic to each other. There is no net movement of water in or out of the cell. If the two fluid environments are not isotonic to each other, then the terms hypotonic and hypertonic are used to describe each of the fluid environments compared to each other. The solution that has the greatest amount of solute is hypertonic and the solution with the least amount of solute is considered hypotonic. When a cell is placed in a solution that is hypertonic to the cell's cytoplasm and the solute molecules cannot pass through the membrane, then water flows out of the cell. Osmosis has occurred; water is flowing out of the cell with the higher water concentration to the lower water concentration of the extracellular fluid. The opposite occurs when a cell is placed in a solution that is hypotonic to the cells cytoplasm and the solute cannot pass through the cell membrane. Osmosis now occurs as water moves along its concentration gradient into the cell

Reverse osmosis membrane technology has developed over the past 40 years to a 44% share in world desalting production capacity, and an 80% share in the total number of desalination plants installed worldwide. The use of membrane desalination has increased as materials have improved and costs have decreased. Today, reverse osmosis membranes are the leading technology for new desalination installations, and they are applied to a variety of salt water resources using tailored pretreatment and membrane system design. Two distinct branches of reverse osmosis desalination have emerged: seawater reverse osmosis and brackish water reverse osmosis. Differences between the two water sources, including foulants, salinity, waste brine (concentrate) disposal options, and plant location, have created significant differences in process development, implementation, and key technical problems. Pretreatment options are similar for both types of reverse osmosis and depend on the specific components of the water source. Both brackish water and seawater reverse osmosis (RO) will continue to be used worldwide; new technology in energy recovery and renewable energy, as well as innovative plant design, will allow greater use of desalination for inland and rural communities, while providing more affordable water for large coastal cities. A wide variety of research and general information on RO desalination is available; however, a direct comparison of seawater and brackish water RO systems is necessary to highlight similarities and differences in process development. This article brings to light key parameters of an RO process and process modifications due to feed water characteristics.

Global water shortages due to droughts and population growth have created increasing interest in water reuse and recycling and, concomitantly, development of effective water treatment processes. Pressured membrane processes, in particular reverse osmosis, have been adopted in water treatment industries and utilities despite the relatively high operational cost and energy consumption. However, emerging contaminants are present in reverse osmosis concentrate in higher concentrations than in the feed water, and have created challenges for treatment of the concentrate. Further, standards and guidelines for assessment and treatment of newly identified contaminants are currently lacking. Research is needed regarding the treatment and disposal of emerging contaminants of concern in reverse osmosis concentrate, in order to develop cost-effective methods for minimizing potential impacts on public health and the environment. This paper reviews treatment options for concentrate from membrane p...

Hewan dalam rangka memenuhi kebutuhannya akan energy (ATP) menyelenggarakan berbagai reaksi metabolisme, akan tetapi tidak hanya menghasilkan ATP dan zat-zat yang bermanfaat lainnya melainkan juga menghasilkan zat sisa, yang tidak digunakan lagi didalam tubuh, dan harus dikeluarkan melalui sistem yang disebut dengan sistem ekskresi atau sistem pengeluaran untuk menjaga konsep homeostatis dalam tubuh.

This review focuses on the present status of forward osmosis (FO) niches in two main areas: seawater desalination and wastewater reuse. Specific applications for desalination and impaired-quality water treatment and reuse are described, as well as the benefits, advantages, challenges, costs and knowledge gaps on FO hybrid systems are discussed. FO can play a role as a bridge to integrate upstream and downstream water treatment processes, to reduce the energy consumption of the entire desalination or water recovery and reuse processes, thus achieving a sustainable solution for the water-energy nexus. FO hybrid membrane systems showed to have advantages over traditional membrane process like high pressure reverse osmosis and nanofiltration for desalination and wastewater treatment: (i) chemical storage and feed water systems may be reduced for capital, operational and maintenance cost, (ii) water quality is improved, (iii) reduced process piping costs, (iv) more flexible treatment uni...

Kami mengadakan penelitian untuk lebih mengetahui dan membuktikan kebenaran teori tersebut. Di dalam penelitian ini, kita akan mengamati proses osmosis yang terjadi pada mawar putih. Kami memilih mawar putih karena hasil proses osmosis akan terlihat lebih mudah.

I. Tujuan
Mengamati proses osmosis dan faktor-faktor yang memengaruhi osmosis.
II. Alat dan Bahan
Alat:
• Pelubang gabus
• Neraca
• Gelas kimia
• Penggaris
• Pisau silet
Bahan:
• Kentang
• Larutan gula 0%
• Larutan gula 5%
• Larutan gula 30%
III. Cara Kerja
1. Dengan menggunakan pelubang gabus buatlah 4 buah silinder umbi kentang segar sepanjang ± 5 cm.
2. Letakkan keempat silinder umbi kentang di atas rapat satu sama lain, selanjutnya dengan menggunakan pisau tajam potonglah ujung-ujungnya hingga memperoleh empat buah silinder umbi kentang yang sama besar.
3. Timbanglah tiap silinder umbi kentang itu setepat mungkin dan catatlah hasilnya dalam tabel.
4. Lakukanlah terhadap silinder umbi kentang itu seperti berikut :
• Silinder 1 direnddam dalam air
• Silinder 2 direndam dalam laurtan gula 5%
• Silinder 3 direndam dalam larutan gula 30%
• Silinder 4 dibiarkan berada di udara
5. Biarkan silinder umbi batang dalam keadaan demikian selama satu atau dua hari.
6. Timbanglah lagi tiap silinder umbi kentang itu dan catatlah hasilnya dalam tabel.
7. Peganglah tiap silinder umbi batang dengan jari dan catat hasil pengamatan anda dalam tabel.