When the activated carbon adsorbs impurities in water, adsorption and desorption phenomena will occur at the same time, when the adsorption and desorption are in equilibrium, it is called adsorption equilibrium, at this time, the concentration of the solute between the activated carbon and water has a certain distribution of the ratio, describing the relationship between the adsorption capacity qe and the concentration of the solution in adsorption equilibrium, C, commonly used in Fruendlich adsorption isothermal formula to express.
Operation method
adsorption
Principle
When the activated carbon adsorption of impurities in water, adsorption and desorption phenomenon will occur at the same time, when the adsorption and desorption is in equilibrium, called adsorption equilibrium, when the concentration of solutes between the activated carbon and water has a certain distribution of the ratio of describing the adsorption capacity qe and the adsorption of equilibrium when the concentration of the solution C is commonly used in the Fruendlich adsorption isothermal formula to express: qe=kC1/n where: qe --adsorption capacity, mg/g; k - coefficient related to adsorption specific surface area and temperature; n - coefficient related to temperature n＞1; C --Adsorption equilibrium solution concentration, mg / L. This is an empirical formula, usually graphical method to find the k, n value, the method is to take the logarithm of the above equation into a linear relationship: lgqe = lgmc / c 0 = lg k +n1 lg c where: C0 - the original concentration of adsorbed substances in water, mg / g; k - with the adsorption of specific surface area, temperature-related coefficients; n - temperature-related coefficients n > 1; C -original concentration of adsorbed substances in water, mg/L; C - equilibrium concentration of adsorbed substances, mg/L; m - activated carbon dosage, g/L. Move I. Experimental apparatus and drugs Caveat 1. A negative value of qe indicates that the activated carbon is adsorbing solvents, and the activated carbon or water sample should be replaced. For more product details, please visit Aladdin Scientific website.
Oscillator, pH meter, COD tester, thermometer, 250 mL stoppered triangular flask, triangular flask, funnel, filter paper, activated carbon.
II. Experimental steps
1. Measurement of raw water
The CODcr, pH and temperature of the raw water were measured by taking 100 mL of water samples and recorded in the table.
2. 0.10, 0.20, 0.30, 0.40, 0.50 g of powdered activated carbon were added to 5 stoppered triangular vials, 150 mL of water was added, and the samples were put into an oscillator for 30 min, the water samples were taken out, and the samples were filtered into the triangular vials.
3. Determination of CODcr value of treated water samples. Follow the instructions.
III. Treatment of experimental results
1. Data processing
2. The Fruendlich adsorption isotherm was plotted with lgC as the horizontal coordinate and lg(C0-C)/m as the vertical coordinate, and the values of K and n were obtained from the adsorption isotherm to derive the Fruendlich adsorption isotherm equation.