scholarly journals Synthesis of PANI@ZnO Hybrid Material and Evaluations in Adsorption of Congo Red and Methylene Blue Dyes: Structural Characterization and Adsorption Performance

Author(s):  
I. Toumi ◽  
H. Djelad ◽  
F. Chouli ◽  
A. Benyoucef
2017 ◽  
Vol 727 ◽  
pp. 853-858 ◽  
Author(s):  
Han Bing Zhang ◽  
Ning Hua Chen ◽  
Zhang Fa Tong ◽  
Qi Feng Liu ◽  
Yan Kui Tang ◽  
...  

Both bentonite and CaCO3 are cheap and abundant superior regional non-metal ores in Guangxi province, so it is very meaningful to jointly exploit bentonite and CaCO3 for real applications. In this study, bentonite modified with CaCO3 (CCB) was prepared and its adsorption performance of Congo Red (CR) and Methylene Blue (MB) was evaluated by investigating the adsorption influencing effects of initial pH, SDBS and phosphate. Adsorption isotherms and adsorption kinetics models were also fitted to analysis the corresponding kinetic characteristics of CCB. The results show that CCB exhibited superior adsorption performance with the respective > 90% MB and CR removal within the initial pH range 2 ~ 10. To a certain extent, MB removal efficiencies by CCB can be increased with the addition of SDBS. On the other hand, CR adsorption on CCB was inhibited slightly in presence of SDBS. But as a whole, removal efficiencies of MB and CR by CCB were kept constant when SDBS co-existed. MB and CR adsorption on CCB decreased to some extent because of competitive adsorption effect when phosphate co-existed. It also demonstrated that CCB can remove phosphate at the same time with dyes. Adsorption models including adsorption isotherms adsorption kinetics indicated that MB and CR adsorption on CCB was a monolayer process, and the adsorption rate depended on both adsorbent and adsorbate. In summary, CCB is a promising adsorbent for dyes removal with many advantages such as simple preparation technology, excellent adsorption performance for anionic and cationic dyes, broad fitting pH range and SDBS resistance. Besides, it can remove dyes together with phosphate at the same time. Therefore, this study is very useful for the dyeing wastewater treatment and exploiting the resources of bentonite and CaCO3.


Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1917
Author(s):  
Guangpu Zhang ◽  
Rong Wo ◽  
Zhe Sun ◽  
Gazi Hao ◽  
Guigao Liu ◽  
...  

A magnetic metal−organic frameworks adsorbent (Fe3O4@MIL-53(Al)) was prepared by a typical solvothermal method for the removal of bisphenol A (BPA), tetracycline (TC), congo red (CR), and methylene blue (MB). The prepared Fe3O4@MIL-53(Al) composite adsorbent was well characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), and fourier transform infrared spectrometer (FTIR). The influence of adsorbent quantity, adsorption time, pH and ionic strength on the adsorption of the mentioned pollutants were also studied by a UV/Vis spectrophotometer. The adsorption capacities were found to be 160.9 mg/g for BPA, 47.8 mg/g for TC, 234.4 mg/g for CR, 70.8 mg/g for MB, respectively, which is superior to the other reported adsorbents. The adsorption of BPA, TC, and CR were well-fitted by the Langmuir adsorption isotherm model, while MB followed the Freundlich model, while the adsorption kinetics data of all pollutants followed the pseudo-second-order kinetic models. The thermodynamic values, including the enthalpy change (ΔH°), the Gibbs free energy change (ΔG°), and entropy change (ΔS°), showed that the adsorption processes were spontaneous and exothermic entropy-reduction process for BPA, but spontaneous and endothermic entropy-increasing processes for the others. The Fe3O4@MIL-53(Al) was also found to be easily separated after external magnetic field, can be a potential candidate for future water treatment.


Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 384
Author(s):  
Ahmed Labena ◽  
Ahmed E. Abdelhamid ◽  
Abeer S. Amin ◽  
Shimaa Husien ◽  
Liqaa Hamid ◽  
...  

Biosorption is a bioremediation approach for the removal of harmful dyes from industrial effluents using biological materials. This study investigated Methylene blue (M. blue) and Congo red (C. red) biosorption from model aqueous solutions by two marine macro-algae, Ulva fasciata and Sargassum dentifolium, incorporated within acrylic fiber waste to form composite membranes, Acrylic fiber-U. fasciata (AF-U) and Acrylic fiber-S. dentifolium (AF-S), respectively. The adsorption process was designed to more easily achieve the 3R process, i.e., removal, recovery, and reuse. The process of optimization was implemented through one factor at a time (OFAT) experiments, followed by a factorial design experiment to achieve the highest dye removal efficiency. Furthermore, isotherm and kinetics studies were undertaken to determine the reaction nature. FT-IR and SEM analyses were performed to investigate the properties of the membrane. The AF-U membrane showed a significant dye removal efficiency, of 88.9% for 100 ppm M. blue conc. and 79.6% for 50 ppm C. red conc. after 240 min sorption time. AF-S recorded a sorption capacity of 82.1% for 100 ppm M. blue conc. after 30 min sorption time and 85% for 100 ppm C. red conc. after 240 min contact time. The membranes were successfully applied in the 3Rs process, in which it was found that the membranes could be used for five cycles of the removal process with stable efficiency.


2017 ◽  
Vol 11 (5) ◽  
pp. 538-545 ◽  
Author(s):  
Mahmoud Nasrollahzadeh ◽  
S. Mohammad Sajadi ◽  
Mehdi Maham ◽  
Hamid Reza Dasmeh

2019 ◽  
Vol 7 (2) ◽  
pp. 240-246
Author(s):  
Kaur Harpreet ◽  
Kaur Harpreet ◽  
Vandana Kamboj ◽  
Vandana Kamboj

Water is the most crucial thing to mankind and so its contamination by various agencies is posing a threat to the natural balance. So, in the present work, the efficiency of various adsorbents derived from plant waste, to remove different dyes from aqueous solution was evaluated. Parameters for study were contact time, concentration and pH. Various combinations of plant ashes were used for the study. It was found that adsorbent prepared from the combination of orange peels, pomegranate and banana peels ashes, exhibited good adsorption capacity for methylene blue, congo red and crystal violet. All these dyes were completely removed from the aqueous solution while methyl orange was not removed. Congo red was removed completely within 40 min of contact with the adsorbent while methyl orange took 3 hrs to be removed to the extent of 48% only. The adsorption coefficient of congo red was found to be 2.33 while value for methylene blue and crystal violet was 1 and 1.66 respectively. The characterization of adsorbent was done by Scanning Electron Microscopy and IR spectroscopy. SEM image revealed the surface of adsorbent to be made of differential pores. From the results it became evident that the low-cost adsorbent could be used as a replacement for costly traditional methods of removing colorants from water.


2018 ◽  
Vol 83 (1) ◽  
pp. 107-120 ◽  
Author(s):  
Zdravka Velkova ◽  
Gergana Kirova ◽  
Margarita Stoytcheva ◽  
Velizar Gochev

Pretreated waste Streptomyces fradiae biomass was utilized as an eco-friendly sorbent for Congo Red (CR) and Methylene Blue (MB) removal from aqueous solutions. The biosorbent was characterized by Fourier transform infrared spectroscopy. Batch experiments were conducted to study the effect of pH, biosorbent dosage, initial concentration of adsorbates, contact time and temperature on the biosorption of the two dyes. The equilibrium adsorption data were analysed using Freundlich and Langmuir models. Both models fitted well the experimental data. The maximum biosorption capacity of the pretreated Streptomyces fradiae biomass was 46.64 mg g-1 for CR and 59.63 mg g-1 for MB, at a pH 6.0, with the contact time of 120 min, the biosorbent dosage of 2 g dm-3 and the temperature of 298 K. Lagergren and Ho kinetic models were used to analyse the kinetic data obtained from different batch experiments. The biosorption of both dyes followed better the pseudo-second order kinetic model. The calculated values for ?G, ?S, and ?H indicated that the biosorption of CR and MB onto the waste pretreated biomass was feasible, spontaneous, and exothermic in the selected temperature range and conditions.


Sign in / Sign up

Export Citation Format

Share Document