Practical course Technical Engineering WaterNgoc Dieu Huynh, Alexander Timm ADSORPTION INTRODUCTION Due to the increasing use of medical substances like pharmaceuticals and pesticides, residues of these substances can be found in surface water and ground water. For drinking water medical residues have to be removed, what can be done by adsorption processes. Adsorption materials are highly porous materials like zeolithe and activated carbon. Organic pollutants can be adsorbed to the surface. Activated carbon can be produced by the pyrolysis of plant derived materials like coconut shells, fruit stones, coal, peat and wood. Primary activated carbon was used at the beginning of the 20 th century for removal of odour from drinking water. For the effective application of the activated carbon, it is important to know the material´s properties like adsorption equilibrium and kinetics for different contaminants. the relationship between absorbance and concentration of DCF was defined by calibration curve development. with the amount of DFC adsorbed increasing markedly within the first 10 minutes and having little changes afterwards.41 DFC (g)/PAC (kg) after 30 minutes. Adsorption kinetics When using PAC JACOBI MG.Practical course Technical Engineering Water Ngoc Dieu Huynh. the DFC was strongly adsorbed in 5 first minutes and reached highest adsorbed concentration of 304. Alexander Timm RESULTS 1. This pattern is also observed for PAC NORIT-SA-UF. adsorption rate moderately decreased in the next 20 minutes. Calibration curve development In order to determine the concentration of Diclofenac (DFC) by UV-vis. Calibration curve of Diclofenac at wavelength of 276nm 2. Following this peak. at which DCF effectively adsorbs the UV light the most. the correlation coefficient (R2 =0. Figure 1.99) exhibits strong linear relationship of absorbance and concentration. Figure 1 shows absorbance of DCF in concentration range of 0 to 5 mg/L at wavelength of 276nm. It can be seen clearly from figure 1. It can be seen that in the next 60 minutes. . there was little change in the amount DFC adsorbed. Adsorption of DCF by two kinds of activated carbon during 90 minutes reaction time 3. Alexander Timm Noticeably. Adsorption isotherm with solid-phase concentration q against liquid-phase concentration C . This supports the conclusion from figure 2 that PAC JACOBI MG removed DCF from solution more effectively than NORIT-SA-UF. It can be seen clearly DCF adsorbed by PAC JACOBI MG was much higher than by NORIT-SA-UF. Figure 2. the adsorption capacity of PAC JACOBI MF was nearly as twice as that of NORIT-SA-UF (Figure 2).Practical course Technical Engineering Water Ngoc Dieu Huynh. Adsorption isotherm Figure 3 presented adsorption isotherm with solid-phase concentration q against liquid-phase concentration c. Figure 3. there is the significantly different amount of DFC absorbed by two branches of activated carbon. Freudlich linear regression for JACOBI PAC MG Figure 5. Alexander Timm Freudlich equation Figure 4.Practical course Technical Engineering Water Ngoc Dieu Huynh. Freudlich linear regression for NORIT –SA-UF Langmuir equation . Langmuir linear regression for JACOBI PAC MG Figure 7. Langmuir linear regression for NORIT-SA-UF . Alexander Timm Figure 6.Practical course Technical Engineering Water Ngoc Dieu Huynh. Alexander Timm Figure 8.Practical course Technical Engineering Water Ngoc Dieu Huynh. Langmuir linear regression for JACOBI PAC MG . 660 3. JACOBI PAC MG ISOTHERM DATA Carbon Concentration of Extinction Dosage DFC remaining at 276 nm (mg/L) (mg/L) (C) 0 0.38 .Practical course Technical Engineering Water Ngoc Dieu Huynh.13 317.000 0.133 6 0.32 n KF 6.819 4.877 1.UF qm KL 434.728 4 0.461 2.554 3.449 DFC DFC removed/ removed Unit weight of (mg/L) 0.78 2. Langmuir linear regression for NORIT SA-UF Table 1.00 438.156 PAC (g/kg) (Q) 0.10 -6.35 359. Langmuir and Freudlich constant Langmuir constant (c/q = 1/(qm* KL) + c/ qm ) Freudlich constant (log q = log K + 1/n * log C) PAC JACOBI NORIT-SA.93 207.428 2.595 2 0.42 365. Alexander Timm Figure 9.87 Table 1.51 -1.87 151. 893 4.749 4.29 166.573 2.10 258.93 193.640 1.508 2.89 .95 DFC DFC removed/ removed Unit weight of (mg/L) 0.33 167.01 159.00 193.287 10 0.328 1.000 0. Alexander Timm 8 10 12 14 16 18 0.247 0.026 2.483 2.75 185.070 0.014 1.93 164.464 0.222 Table 2.181 0.742 12 0.319 1.848 18 0.131 4.219 4 0.36 178.154 3.819 4. NORIT –SA-UF ISOTHERM DATA Carbon Concentration of Extinction Dosage DFC remaining at 276 nm (mg/L) (mg/L) (C) 0 0.595 2 0.396 0.703 3.767 3.113 0.271 1.351 0.608 3.965 6 0.373 322.58 3.164 1.086 0.006 2.853 2.581 3.431 8 0.44 172.440 1.20 278.022 PAC (g/kg) (Q) 0.609 14 0.518 3.Practical course Technical Engineering Water Ngoc Dieu Huynh.16 242.44 293.61 315.457 2.701 0.107 16 0.366 2. extinction measured and DFC concentration is very strong. The second stage the adsorption rate remained nearly the same due to limited availability of reactive surface. Therefore.Practical course Technical Engineering Water Ngoc Dieu Huynh. The isotherms indicated that PAC JACOBI MG removed DFC better than PAC NORIT-SA-UF. the differences between two PAC used could be because of the difference in size of the carbon particles. this shows the correlation between the two variables. In kinetic experiment. The first stage is observed with strong adsorption rate due to high surface area of fresh materials. . the regression equation well represents the set of data. having much higher solid-phase concentration. Therefore. activated carbon surface is saturated and 90 minutes could be sufficient for adsorption equilibrium. The coefficient of determination R2 is very close to 1. Alexander Timm DISCUSSION DFC is able to absorb the light of 276 nm resulting in the specific extinction according to its different concentration. there are two stages of AFC by activated carbon. The calibration is essential for determination of DFC concentration corresponding to a certain range of wavelength. In addition. it could be concluded after about 90 minute reaction. The value of coefficient of determination showed that Freudlich isotherm was not the suitable for description of DFC adsorption using NORIT-SA-UF. Therefore. different activated carbon works differently on kind of substances depending upon its characteristics which eventually influence on the effect of removal process. Jyoti Mittal. comparing to that for NORIT –SA. including organic pollutants. with KL (an indicator for adsorption capacity) being higher for JACOBI PAC MG system.pollutants. 2006 . especially surface area and the pore size of carbon because the adsorption capacity is proportional to surface area and correct pore size is necessary to facilitate adsorption process (providing adsorption sites for specific substances). The difference in removal efficiency is derived mainly from the carbon characteristics.Essen 2013 Freundlich and Langmuir adsorption isotherms and kinetics for the removal of Tartrazine from aqueous solutions using hen feathers. Journal of Hazardous Materials 146 (2007) 243–248.Practical course Technical Engineering Water Ngoc Dieu Huynh. the adsorption isotherm test need to be conducted to chose the appropriate carbon for the best efficient. Alexander Timm The Langmuir equation could be the better description for adsorption using NORIT-SA-UF activated carbon because the coefficient of determination for its is high enough while its for Freudlich equation is so weak. CONCLUSION Power activated carbon is capable of removal impurities in water.8701 and 0. Adsorption. Alok Mittal.UF. University of Duisburg. 2857 respectively. being 0. micro. Lisha Kurup. REFERENCES Script “Technical Engineering Water”. It can be seen that using JACOBI PAC MG for removal of DFC is better NORIT –SA.UF (Table 1). However. Practical course Technical Engineering Water Ngoc Dieu Huynh. Alexander Timm Measuring adsorptive capacity of powder activated carbon. Norit Americas Inc .