scholarly journals Composites Based on Natural Polymers and Microbial Biomass for Biosorption of Brilliant Red HE-3B Reactive Dye from Aqueous Solutions

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4314
Author(s):  
Daniela Suteu ◽  
Alexandra Cristina Blaga ◽  
Ramona Cimpoesu ◽  
Adrian Cătălin Puiţel ◽  
Ramona-Elena Tataru-Farmus

Natural polymers have proven to be extremely interesting matrices for the immobilization of microbial biomasses, via various mechanisms, in order to bring them into a form easier to handle—the form of composites. This article aimed to study composites based on a residual microbial biomass immobilized in sodium alginate via an encapsulation technique as materials with adsorbent properties. Thus, this study focused on the residual biomass resulting from beer production (Saccharomyces pastorianus yeast, separated after the biosynthesis process by centrifugation and dried at 80 °C)—an important source of valuable compounds, used either as a raw material or for transformation into final products with added value. Thus, the biosorptive potential of this type of composite was tested—presenting in the form of spherical microcapsules 900 and 1500 μm in diameter—in a biosorption process applied to aqueous solutions containing the reactive dye Brilliant Red HE-3B (16.88–174.08 mg/L), studied in a batch system. The preparation and characterization of the obtained polymeric composites (pHPZC, SEM, EDS and FTIR spectra) and an analysis of different equilibrium isotherms (Langmuir, Freundlich and Dubinin-Radushkevich—D–R) were investigated in order to estimate the quantitative characteristic parameters of the biosorption process, its thermal effects, and its possible mechanisms of action. The modelling of the experimental data led to the conclusion that the studied biosorption process took place after reaching the Langmuir isotherm (LI), and that the main mechanism was possibly physical, being spontaneous and probably exothermic according to the values obtained for the free energy of biosorption (E = 8.45–13.608 kJ/mol, from the DR equation), as well as the negative values for the Gibbs free energy and the enthalpy of biosorption (ΔH0 = −87.795 kJ/mol). The results obtained lead to the conclusion that encapsulation of this residual microbial biomass in sodium alginate leads to an easier-to-handle form of biomass, thus being an efficient biosorbent for static or dynamic operating systems for effluents containing moderate concentrations of reactive organic dyes.

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4810
Author(s):  
Lăcrămioara Rusu ◽  
Cristina-Gabriela Grigoraș ◽  
Elena Mirela Suceveanu ◽  
Andrei-Ionuț Simion ◽  
Andreea Veronica Dediu Botezatu ◽  
...  

Pharmaceuticals and dyes are a very important part of the nonbiodegradable or hard biodegradable substances present in wastewater. Microorganisms are already known to be effective biosorbents, but the use of free microbial cells involves difficulties in their separation from effluents and limits their application in wastewater treatment. Thus, this study aimed to develop biosorbents by immobilizing Saccharomyces cerevisiae, Saccharomyces pastorianus and Saccharomyces pastorianus residual biomass on natural polymers (alginate and chitosan) and to evaluate the biosorptive potential for removal of pharmaceuticals and dyes from water. Six types of biosorbents were synthesized and characterized by Scanning Electron Microscopy and Fourier Transform Infrared Spectroscopy techniques and their biosorptive capacities for three drugs (cephalexin, rifampicin, ethacridine lactate) and two dyes (orange II and indigo carmine) were evaluated. The obtained results show that the removal efficiency depends on the polymer type used for the immobilization. In case of alginate the removal efficiency is between 40.05% and 96.41% for drugs and between 27.83% and 58.29% for dyes, while in the case of chitosan it is between 40.83% and 77.92% for drugs and between 17.17% and 44.77% for dyes. In general, the synthesized biosorbents proved to be promising for the removal of drugs and dyes from aqueous solutions.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Ghadah M. Al-Senani ◽  
Foziah F. Al-Fawzan

Wild herbs (Origanum (OR) and Lavandula (LV)) were used as environment-friendly adsorbents in this study. The adsorbents were used for adsorption of Cu and Ba from water. The adsorption of heavy metals onto OR and LV was dependent on particle size, dose, and solution pH. The diameter of adsorbent particles was less than 282.8 nm. The adsorption follows second-order kinetics. Langmuir and Freundlich models have been applied to describe the equilibrium data, and the thermodynamic parameters, the Gibbs free energy, ∆G°, enthalpy, ∆H°, and entropy, ∆S°, have been determined. The positive value of ∆H° suggests that the adsorption of heavy metals by the wild herbs is endothermic. The negative values of ∆G° at all the studied temperatures indicate that the adsorption is a spontaneous process. It can be concluded that OR and LV are promising adsorbents for the removal of heavy metals from aqueous solutions over a range of concentrations.


2019 ◽  
Vol 25 (4) ◽  
pp. 341-351
Author(s):  
Aleksandar Zdravkovic ◽  
Novica Stankovic ◽  
Nebojsa Ristic ◽  
Goran Petkovic

The aim of this study was to determine adsorptive properties of acid activated bentonite clay for the removal of Direct Red 173 (DR 173) and Reactive Red 22 (RR 22) dyes from aqueous solutions. Raw and modified clay were characterized by the following methods: Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRPD), and scanning electron microscopy (SEM). The efficiency of activated clay adsorption was investigated depending on process parameters: the adsorbent dose, pH, temperature, initial dye concentration, and contact time. Experimental data were analyzed by Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm as well as kinetic models of pseudo-first order, pseudo-second order and intra-particle diffusion. The process of dye adsorption was best described by Langmuir, Temkin, and Dubinin-Radushkevich isotherm (R2 > 0.97). Pseudo-second order model (R2 > 0.99) had the highest correlation with the obtained kinetic results. The positive value of ?H? indicated that adsorption of dyes by activated bentonite clay is endothermic process. The activated bentonite exhibited good regenerative ability in the 0.1 M NaOH solution. Maximum adsorption capacities of acid activated bentonite clay at 25?C for DR 173 and RR 22 dyes were 356.65 and 109.58 ?mol g-1, respectively.


2018 ◽  
Vol 22 (1) ◽  
pp. 116-123
Author(s):  
Yuliya Polkovnikova ◽  
Kseniya Korynova ◽  
Amila Jeewantha Halahakoon

2018 ◽  
Vol 38 (s1) ◽  
pp. S205-S213 ◽  
Author(s):  
Reza Shokoohi ◽  
Zahra Torkshavand ◽  
Mohammad Molla Mahmoudi ◽  
Abbas Moradi Behgoo ◽  
Effat Ghaedrahmati ◽  
...  

2021 ◽  
Author(s):  
Xiao Zhang ◽  
Zhiyue Li ◽  
Taoyi Zhang ◽  
Jing Chen ◽  
Wenxi Ji ◽  
...  

A novel zeolitic imidazolate framework-8 (ZIF-8) alginate composite hydrogel material (PVA/SA@ZIF-8) is alginate composite bead which was fabricated by grafting ZIF-8 on the surface of the sodium alginate hydrogel beads...


2017 ◽  
Vol 19 (36) ◽  
pp. 24678-24688 ◽  
Author(s):  
Yixing Chen ◽  
Halil I. Okur ◽  
Chungwen Liang ◽  
Sylvie Roke

Specific ion effects in aqueous solutions are investigated at the molecular, nanoscopic and macroscopic levels.


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