scholarly journals Adsorption-Membrane Hybrid Approach for the Removal of Azithromycin from Water: An Attempt to Minimize Drug Resistance Problem

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1969
Author(s):  
Muhammad Wahab ◽  
Muhammad Zahoor ◽  
Syed Muhammad Salman ◽  
Abdul Waheed Kamran ◽  
Sumaira Naz ◽  
...  

In this study, activated carbon (AC) and magnetic activated carbon (MAC) were prepared from Dalbergia sissoo sawdust for the removal of antibiotic Azithromycin (AZM) from aqueous solution. The effect of initial concentration, contact time, pH, adsorbent dosage, and the temperature were investigated for both the adsorbents. The optimum AZM concentration, contact time, pH and adsorbents dosages were found to be 80 mg/L, 120 min, 6 and 7 (pH, respectively, for AC and MAC), and 0.1 g (for both AC and MAC), respectively. The isothermal data of both sets of experiments correlated well with the Langmuir isotherm model, while the kinetic data with the pseudo-second-order model. The adsorption of AZM on both adsorbents was found to be favorable, which is evident in the values of the thermodynamic parameters (ΔH = −26.506 and −24.149 KJ/mol, ΔS = 91.812 and 81.991 J/mol K, respectively, for AC and MAC). To evaluate the effect of AC and MAC on the membrane parameters, a continuous stirred reactor was connected with ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO) membranes. High % retention and improved permeate flux (around 90%) were obtained for AC/UF, AC/NF AC/RO, MAC/UF, MAC/NF, and MAC/RO treatments. The percent retention of AZM observed for AC/UF, AC/NF AC/RO was higher than MAC/UF, MAC/NF, and for MAC/RO hybrid processes due to greater surface area of AC than MAC.

2011 ◽  
Vol 63 (7) ◽  
pp. 1389-1395 ◽  
Author(s):  
S. Aber ◽  
D. Salari ◽  
B. Ayoubi Feiz

Batch sorption studies using almond shell as an sorbent for the removal of Cu (II) from aqueous solutions, showed that copper removal decreased from 74.9% to 45.6% with increasing its concentration from 10 to 70 ppm. The removal increased with increasing sorbent dose and pH, respectively. Copper removal was obtained equal to 63.7%, 69.6% and 58.6% at 26˚C, 40˚C and 55˚C. The sorption of Cu (II) on almond shell was also optimized by Taguchi method. The optimized conditions were the sorbent mass of 4 g, the ion initial concentration of 10 ppm, pH 7, the temperature of 40˚C and contact time equal to 60 min. The pH and initial Cu (II) concentration with respectively 32.75% and 31.20% contribution had more influence on the removal of Cu (II). The kinetic data fit pseudo-second-order model with correlation coefficients greater than 0.99 and rate constants in the range of 0.26–7.87 g mg−1 min−1.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Muhammad Wahab ◽  
Muhammad Zahoor ◽  
Syed Muhammad Salman ◽  
Sumaira Naz

Abstract In this study two adsorbents (activated carbon; AC and magnetic activated carbon; MCN) were prepared from Dalbergia sissoo sawdust and used as potential adsorbents for the removal of tetracycline (TC) from water. Both the adsorbents were characterized by instrumental techniques like energy dispersive x-ray (EDX), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), x-ray diffraction (XRD), surface area analyzer and thermal gravimetric/Differential thermal analysis (TG/DTA). The effect of antibiotic initial concentration, contact-time, pH, adsorbent-dose, and temperature were evaluated to determine optimum adsorption conditions. The optimum TC concentration for both AC and MCN was 120 mg/L while optimum time of saturation for both adsorbents was 120 min. The optimum pH determined was five while optimum adsorbent dose was 0.1 g. The adsorption isothermal data of both sets of experiments was best explained by Langmuir model. The kinetic data was well explained by pseudo-second order kinetics model. The ΔH° (enthalpy change) and ΔSo (entropy change) were; −14.989 and 25.174 kJ/mol for AC and −11.628 and 51.302 kJ/mol for MCN respectively. The values of Gibbs free energy (ΔG°) calculated for AC were 7.36, −7.99, −7.36, −7.61, and −8.12 kJ/mol while for MCN these were −15.02, −15.53, −16.05, −16.56, and −17.07 kJ/mol corresponding to temperatures; 298, 303, 313, 323, and 333 K. To control fouling in ultra-filtration, nano-filtration, and reverse osmosis membranes caused by TC, and both adsorbents, a continuous stirred reactor was connected in series with membrane pilot plant. The improvement brought about by both adsorbent in parameters like % retention and permeate flux was also evaluated. Comparatively, better improvement was brought about in % retention and permeates flux by MCN.


2018 ◽  
Vol 18 (44) ◽  
pp. 52-61 ◽  
Author(s):  
Tseveendorj E ◽  
Enkhdul T ◽  
S Lin ◽  
Dorj D ◽  
Oyungerel Sh ◽  
...  

Due to its toxicity causing serious health problems, persistence in the environment and non-biodegradability, lead (Pb) is considered as one of the most harmful metals on earth. In this study, dried aquatic plants as sorbents including Nymphoides peltata (NP), Typha laxmannii (TL), and Eichhornia crassipes (EC) were examined and compared to discover the best biosorption for Pb. The effect of physical and chemical parameters including pH (2.0–5.5), sorbent dosage (1–5 g/l), metal concentration (20–100 mg/l), and contact time (~240 min) were investigated to determine the optimal condition for Pb(II) biosorption. As a result, the optimum pH, sorbent dosage, and contact time were 5.0, 1 g/l, and 120 minutes, respectively. Pb2+ biosorption data were found to follow the Langmuir isotherm model while the kinetic biosorption data followed pseudo-second-order model. The maximum biosorption capacity from Langmuir model was calculated as 63.3, 82.9, and 51.9 mg/g for EC, NP, and TL, respectively. All the results showed that biosorption efficiencies of Pb(II) by different biosorbents were in following order NP>EC>TL.


2013 ◽  
Vol 448-453 ◽  
pp. 134-138
Author(s):  
Si Jia Liu ◽  
Ran Xu

Chitosan/Poly (vinyl alcohol) (CS/PVA) composite nanofibrous membranes with diameter between 150-350 nm have been fabricated by electrospinning. The effect of contact time, temperature, pH and concentration of triclosan on the adsorption capacity of the membranes were investigated. The equilibrium adsorption capacity of triclosan on CS/PVA nanofibrous membranes was 61.61 mg/g. The favorable pH for triclosan adsorption was pH 6. After five regeneration cycles, the removal rate of triclosan maintained above 67%. The adsorption of triclosan on the membranes fitted both Freundlich and Langmuir isotherm model. Its adsorption kinetics followed a pseudo-second-order model.


2020 ◽  
Vol 16 (7) ◽  
pp. 880-892
Author(s):  
Şerife Parlayıcı ◽  
Kübra Tuna Sezer ◽  
Erol Pehlivan

Background: In this work, Cr (VI) adsorption on nano-ZrO2๏TiO2 impregnated orange wood sawdust (Zr๏Ti/OWS) and nano-ZrO2๏TiO2 impregnated peach stone shell (Zr๏Ti/PSS) was investigated by applying different adsorption parameters such as Cr (VI) concentrations, contact time, adsorbent dose, and pH for all adsorbents. Methods: The adsorbents were characterized by SEM and FT-IR. The equilibrium status was achieved after 120 min of contact time and optimum pH value around 2 were determined for Cr (VI) adsorption. Adsorption data in the equilibrium is well-assembled by the Langmuir model during the adsorption process. Results: Langmuir isotherm model showed a maximum adsorption value of OWS: 21.65 mg/g and Zr๏Ti/OWS: 27.25 mg/g. The same isotherm displayed a maximum adsorption value of PSS: 17.64 mg/g, and Zr๏Ti/PSS: 31.15 mg/g. Pseudo-second-order kinetic models (R2=0.99) were found to be the best models for describing the Cr (VI) adsorption reactions. Conclusıon: Thermodynamic parameters such as changes in ΔG°, ΔH°, and ΔS° have been estimated, and the process was found to be spontaneous.


Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1437
Author(s):  
Chih Ming Ma ◽  
Bo-Yuan Yang ◽  
Gui-Bing Hong

Hydrogel beads based on the husk of agarwood fruit (HAF)/sodium alginate (SA), and based on the HAF/chitosan (CS) were developed for the removal of the dyes, crystal violet (CV) and reactive blue 4 (RB4), in aqueous solutions, respectively. The effects of the initial pH (2–10) of the dye solution, the adsorbent dosage (0.5–3.5 g/L), and contact time (0–540 min) were investigated in a batch system. The dynamic adsorption behavior of CV and RB4 can be represented well by the pseudo-second-order model and pseudo-first-order model, respectively. In addition, the adsorption isotherm data can be explained by the Langmuir isotherm model. Both hydrogel beads have acceptable adsorption selectivity and reusability for the study of selective adsorption and regeneration. Based on the effectiveness, selectivity, and reusability of these hydrogel beads, they can be treated as potential adsorbents for the removal of dyes in aqueous solutions.


2013 ◽  
Vol 684 ◽  
pp. 194-197
Author(s):  
Yi Ke Li ◽  
Bing Lu Zhao ◽  
Wei Xiao ◽  
Run Ping Han ◽  
Yan Qiang Li

The effect of contact time and the determination of the kinetic parameters of adsorption of methyl orange (MO) from aqueous solution onto Iron-Oxide-Coated-Zeolite (IOCZ) powder are important in understanding the adsorption mechanism. The effect of contact time on adsorption quantity was studied at different initial concentration and temperature, respectively. The pseudo-second-order model was adopted to fit the experimental data using non-linear regressive analysis and it was used to predict the adsorption behavior. The results showed that the process of adsorption MO was endothermic and chemisorption. The pore diffusion was not significant.


Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1401 ◽  
Author(s):  
Ricardo Coimbra ◽  
Carla Escapa ◽  
Nadyr Vázquez ◽  
Guillermo Noriega-Hevia ◽  
Marta Otero

In the present work, the adsorptive removal of diclofenac from water by biosorption onto non-living microalgae biomass was assessed. Kinetic and equilibrium experiments were carried out using biomass of two different microalgae strains, namely Synechocystis sp. and Scenedesmus sp. Also, for comparison purposes, a commercial activated carbon was used under identical experimental conditions. The kinetics of the diclofenac adsorption fitted the pseudo-second order equation, and the corresponding kinetic constants indicating that adsorption was faster onto microalgae biomass than onto the activated carbon. Regarding the equilibrium results, which mostly fitted the Langmuir isotherm model, these pointed to significant differences between the adsorbent materials. The Langmuir maximum capacity (Qmax) of the activated carbon (232 mg∙g−1) was higher than that of Scenedesmus sp. (28 mg∙g−1) and of Synechocystis sp. (20 mg∙g−1). In any case, the Qmax values determined here were within the values published in the recent scientific literature on the utilization of different adsorbents for the removal of diclofenac from water. Still, Synechocystis sp. showed the largest KL fitted values, which points to the affinity of this strain for diclofenac at relative low equilibrium concentrations in solution. Overall, the results obtained point to the possible utilization of microalgae biomass waste in the treatment of water, namely for the adsorption of pharmaceuticals.


2012 ◽  
Vol 66 (8) ◽  
pp. 1699-1707 ◽  
Author(s):  
A. K. Giri ◽  
R. K. Patel ◽  
P. C. Mishra

In this work, the biosorption of As(V) from aqueous solutions by living cells of Bacillus cereus has been reported. The batch biosorption experiments were conducted with respect to biosorbent dosage 0.5 to 15 g/L, pH 2 to 9, contact time 5 to 90 min, initial concentration 1 to 10 mg/L and temperature 10 to 40 °C. The maximum biosorption capacity of B. cereus for As(V) was found to be 30.04 at pH 7.0, at optimum conditions of contact time of 30 min, biomass dosage of 6 g/L, and temperature of 30 ± 2 °C. Biosorption data were fitted to linearly transformed Langmuir isotherms with R2 (correlation coefficient) >0.99. Bacillus cereus cell surface was characterized using AFM and FTIR. The metal ions were desorbed from B. cereus using both 1 M HCl and 1 M HNO3. The pseudo-second-order model was successfully applied to predict the rate constant of biosorption.


2017 ◽  
Vol 82 (4) ◽  
pp. 449-463 ◽  
Author(s):  
Sanja Marinovic ◽  
Marija Ajdukovic ◽  
Natasa Jovic-Jovicic ◽  
Tihana Mudrinic ◽  
Bojana Nedic-Vasiljevic ◽  
...  

Bentonites from three different deposits (Wyoming, TX, USA and Bogovina, Serbia) with similar cation exchange capacities were sodium enriched and tested as adsorbents for Sr2+ in aqueous solutions. X-Ray diffraction analysis confirmed successful Na-exchange. The textural properties of the bentonite samples were determined using low-temperature the nitrogen physisorption method. Significant differences in the textural properties between the different sodium enriched bentonites were found. Adsorption was investigated with respect to adsorbent dosage, pH, contact time and the initial concentration of Sr2+. The adsorption capacity increased with pH. In the pH range from 4.0?8.5, the amount of adsorbed Sr2+ was almost constant but 2?3 times smaller than at pH ?11. Further experiments were performed at the unadjusted pH since extreme alkaline conditions are environmentally hostile and inapplicable in real systems. The adsorption capacity of all the investigated adsorbents toward Sr2+ was similar under the investigated conditions, regardless of significant differences in the specific surface areas. It was shown and confirmed by the Dubinin?Radushkevich model that the cation exchange mechanism was the dominant mechanism of Sr2+ adsorption. Their developed microporous structures contributed to the Sr2+ adsorption process. The adsorption kinetics obeyed the pseudo-second-order model. The isotherm data were best fitted with the Langmuir isotherm model.


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