Osmosis kit with U-tube apparatus and methods of using thereof

A method for determining osmotic rate, or the rate of osmosis, using a U-tube apparatus comprising a U-tube having two arms separated by a forward osmosis membrane, comprising steps of:

• (a) preparing solutions of unmodified glycerin-in-water with known glycerin concentration by adjusting volume ratio of glycerin to water;
• wherein a table is provided listing volume of unmodified glycerin and volume of water for varying concentrations of glycerin-in-water solutions;
• (b) filling one arm of the U-tube with water as a feed solution and filling the other arm of the U-tube with glycerin-in-water as the draw solution for osmosis to occur with water flowing from its arm into the glycerin-in-water arm;
• (c) with same glycerin-in-water solution in its arm of the U-tube, replacing water with pure or undiluted glycerin in the other arm of the U-tube for osmosis to occur in the opposite direction with water flowing from the glycerin-in-water arm into the pure or undiluted glycerin arm;
• (d) performing slower osmosis experiments wherein osmosis is allowed to occur for more than 180 minutes, filling both arms of the U-tube to same liquid level height and measuring the difference in liquid level heights between the two arms as a function of time;
• (e) performing faster osmosis experiment wherein osmosis is allowed to occur up to 180 minutes, using an open lid with narrow tube inserted in draw solution arm of the U-tube inserted, filling draw solution arm of the U-tube completely and allowing liquid to enter the narrow tube as osmosis occurs, and measuring the rise in liquid level inside the narrow tube as a function of time;
• (f) performing the steps (d) and (e) at room temperature, inside a refrigerator, or inside an oven wherein osmosis occurs at different temperatures;
• (g) recording and plotting the difference in liquid level heights between the two arms of the U-tube as a function of time to determine the osmotic rate as performed in step (d) and recording and plotting the rise in liquid level height inside the narrow tube as a function of time to determine the osmotic rate as performed in step (e).