Various models and mechanisms for the solvent and solute transport mechanism through reverse osmosis membrane have been developed and proposed by a number of investigators and researchers. The flow of solvent through the membrane is defined in terms of flux as: The solvent flux of the permeate depends on the hydraulic pressure applied across the membrane, minus the difference in the osmotic pressure of the solutions of the feed and permeate side of the membrane which is written as.
While the solute flux depends on the concentration gradient as: The membrane rejection is defined as the difference between the feed concentration and permeate concentration as:
From the solvent and solute flux Equations.
…show more content…
The osmotic pressure coefficient must be determined for different solutions. It has been determined by various researchers and investigators to be less than unity and slightly increases with increasing solution concentration if the solute is not known or it is complex, we have to use mass concentration instead of molar concentration. For convenience: this model assumed to be at a constant temperature and is incorporated with the other constant Y which simplifies osmotic pressure to solute concentration coefficient. The value of Y was assumed t-o be constant over the operating range of the solute concentration. In corporation of osmotic pressure equation into the expression for the solute flux Eq. yields:
Combining the above equations. we
This lab uses a lake simulation to study how the addition of nutrients and toxins can affect the lake, its inhabitants and the surrounding area. There is a strong focus on the addition of Phosphorous and added toxins because both are key elements in growth in lakes. The Virtual lake includes these five simulated species; green algae, cyanobacteria, bosmina, daphnia, and trout. There are two types of phytoplankton in the lake model, green algae and cyanobacteria. Green algae are a very diverse group that are photosynthetic, aquatic, plant like organisms that have a very simple reproductive structure.
RESTING MEMBRANE POTENTIAL When the neuron is not sending a signal at rest the membrane potential called as resting membrane potential. In this stage, permeability of K+ much greater than Na+ When a neuron is at rest, the inside of the neuron is negative relative to the outside. Although the concentrations of the different ions endeavor to balance out on both sides of the membrane, they cannot because the cell membrane sanctions only some ions to pass through channels (ion channels). At rest, potassium ions (K+) can cross through the membrane facilely. Additionally at rest, chloride ions (Cl-) and sodium ions (Na+) have a more arduous time crossing.
Part A: Osmosis practical task Aim: To observe the effects of osmosis in rhubarb cells. Hypothesis: Water will be extracted out of the cells in the salt solution causing the cells to look different to the cells in the freshwater solution. Materials: Rhubarb Distilled water in a dropping bottle Salt solution in a dropping bottle Microscope, slides, and coverslips Forceps and razor blades or scalpel Paper Towel Method: Clean and dry a slide and coverslip.
Exploration Title: Effect of Temperature on rate of Osmosis Submitted By: Abdulkarim Kamal Date Submitted: October 19th 2015 Subject: Biology HL Teacher: Mr. Nick Aim: This is an investigation to determine the relation between temperature of a solution (sucrose) and the rate of osmosis Scientific Context: Osmosis is defined a passive transport process in which a fluid diffuses across a semi-permeable membrane, from an area of high solute concentration to an area of low solute concentration and vice-versa. There are various factors that could potentially influence the rate of osmosis; these factors include volume, concentration, and temperature. If all external factors that may interfere with rate of osmosis are controlled, the results will show equal amounts of fluid on both sides of the barrier (membrane); this is known as an “isotonic” state.
Dept of Mechanical and Biomedical Engineering CFD Lab BME402 Student Name Student ID Number: AASHRAY JHA 17232641 Class ME (BIO-MEDICAL Assignment Number & Title: 1 Submission Date: 8th OCTOBER 2017 Academic Integrity and Plagiarism Plagiarism is the act of copying, including or directly quoting from, the work of another without adequate acknowledgement. All work submitted by students for assessment purposes is accepted on the understanding that it is their own work and written in their own words except where explicitly referenced using the correct format. For example, you must NOT copy information, ideas, portions of text, figures, designs, CAD drawings, computer programs, etc.
Essay 13: How does the brain sense osmolality and regulate water balance? Before answering this question, it is necessary to understand the meaning of the term osmolality as well as its implications for human physiology. In chemistry, the osmolality of a solution is defined as the number of moles of solute (e.g. salt or sugar) per kilogram of solvent. When the solvent in question is water, osmolality is practically the same as the more familiar unit osmolarity, which is defined as moles of solute per liter of solvent. Since 1 liter of water has a mass of approximately 1 kilogram, the two values are virtually the same.
Osmosis Lab Report Research Question: How does the change in the concentration of a sucrose solution affect the process of osmosis in a potato cell by measuring its mass? Background information: 1 Osmosis is the process by which a liquid passes through a semi-permeable membrane, moving from an area with a high concentration of water to a low concentration of water. There are various factors that affect osmosis such as: concentration, surface area and temperature. The concentration of solutions can affect the rate of osmosis, as there is more difference in the concentration of the solutions, which means osmosis, will take place quicker. Surface area could affect osmosis based on the ease by which molecules can get through the semi-permeable
The effects of alcohol on Biological Membranes. Introduction In this experiment it will be analysed the damage alcohols can have on biological membranes. Membranes are made up of lipids and proteins. Membranes usually help maintain the balance in a cell as it holds all the cellular materials.
The purpose of this experiment is to analyze the P content in a wastewater sample and to test the efficiency of 2 different methods for P removal from wastewater. To analyze the P content in a wastewater sample, standard P solution is made and calibration curve is generated and phosphate concentration in wastewater is determined by using calibration curve that is generated. To determine the concentration of P, vanadomolybdophosphoric acid spectrophotometric method is used. The predominating form of phosphate is dependent on pH. H₃PO₄ ⇌ H₂PO₄⁻ + H⁺ pKₐ=2.12 H₂PO₄⁻ ⇌ HPO₄²⁻ + H⁺ pKₐ=7.25 HPO₄²⁻ ⇌ PO₄³⁻ + H⁺ pKₐ=12.7
The phenomenon of freezing point depression has many practical uses. The radiator fluid in an automobile is a mixture of water and ethylene glycol (antifreeze). As a result of freezing point depression, radiators do not freeze in winter (unless it is extremely cold, e.g. −30 to −40 °C (−22 to −40 °F)). Road salting takes advantage of this effect to lower the freezing point of the ice it is placed on. Lowering the freezing point allows the street ice to melt at lower temperatures, preventing the accumulation of dangerous, slippery ice.
Membrane separation technologies are among the most promising processes in water purification regarding their low energy consumptions. Membrane distillation (MD) is a thermally driven separation process in which liquid feed is evaporated at the feed/membrane interface and is transported through a hydrophobic microporous membrane[1–4]. The hydrophobic character of the membrane allows only volatile components to enter the pores. The differences of the vapour pressures across the membrane is the driving force of the process[5,6].
Introduction: In this lab, of water in a hydrate, or a substance whose crystalline structure is bound to water molecules by weak bonds, is determined by heating up a small sample of it. By heating, the water of hydration, or bound water, is removed, leaving only what is called an anhydrous compound. Based on the percent water in the hydrate, it can be classified as one of three types: BaCl2O ⋅ 2H20, with a percent water of about 14.57%, CuSO4
Title: Diffusion & Osmosis Purpose: The purpose of this experiment was to test the tonicity of the different solutions. Background: Diffusion and osmosis are both processes that occur within the plasma membrane. Diffusion is the process by which molecules intermingle as a result of kinetic energy. Osmosis is the movement of water across a semi-permeable membrane. Tonicity is also related to osmosis.
Joshua Miller 12/18/17 Fermentation Lab report Introduction The term fermentation refers to the chemical breakdown of a substance by bacteria, yeasts, or other microorganisms, typically involving effervescence and the giving off of heat (wikipedia). Sugars are converted to ethyl alcohol when fermentation happens. In this experiment we determined if yeast cells undergo fermentation when placed in a closed flask with no oxygen. Glucose and yeast are mixed together in a closed flask and allowed to incubate for about one hour.
Biology Design Practical Joshua Edwards What are effects of the volume of a potato and the amount of weight it loses when placed in salt solution? Introduction This design practical uses a potato’s surface area to volume ratio to see what affects it has on osmosis in different concentrations. Osmosis is the movement of water molecules through a cell membrane into an area of a higher solute concentration. The movement goes the way of the solvent with more solute because the lower solute concentration is drifting through balancing the ratio of solute per solvent (En.wikipedia.org, 2018).