scholarly journals Assessment of By-Product from Botryosphaeria rhodina MAMB-05 as an Effective Biosorbent of Pb(II)

Molecules ◽  
2019 ◽  
Vol 24 (18) ◽  
pp. 3306 ◽  
Author(s):  
Antonio J. Muñoz ◽  
Francisco Espínola ◽  
Encarnación Ruiz ◽  
Aneli M. Barbosa-Dekker ◽  
Robert F. H. Dekker ◽  
...  

In this work, two types of biomass preparations (VMSM and M3) from the filamentous fungus Botryosphaeria rhodina MAMB-05, which were previously used in a process of production of β-glucan, were assessed as biosorbents of lead. The operating conditions, optimized through response surface methodology and experimental design, were shown to be pH 5.29 and a biosorbent dose of 0.23 g/L for the VMSM biomass type; and pH 5.06 and a dose of biosorbent of 0.60 g/L for the M3 biomass type, at a constant temperature of 27 °C. Fourier transform-infrared spectroscopy analyzed the presence of functional groups on the biomass surface. In addition to give an extra value to the by-product biomass, the VMSM-type from B. rhodina MAMB-05 showed an excellent lead biosorption capacity (qm) with a value of 403.4 mg/g for the Langmuir model, comparing favorably with literature results, while the M3 subtype biomass showed a value of 96.05 mg/g.

Membranes ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 70
Author(s):  
Jasir Jawad ◽  
Alaa H. Hawari ◽  
Syed Javaid Zaidi

The forward osmosis (FO) process is an emerging technology that has been considered as an alternative to desalination due to its low energy consumption and less severe reversible fouling. Artificial neural networks (ANNs) and response surface methodology (RSM) have become popular for the modeling and optimization of membrane processes. RSM requires the data on a specific experimental design whereas ANN does not. In this work, a combined ANN-RSM approach is presented to predict and optimize the membrane flux for the FO process. The ANN model, developed based on an experimental study, is used to predict the membrane flux for the experimental design in order to create the RSM model for optimization. A Box–Behnken design (BBD) is used to develop a response surface design where the ANN model evaluates the responses. The input variables were osmotic pressure difference, feed solution (FS) velocity, draw solution (DS) velocity, FS temperature, and DS temperature. The R2 obtained for the developed ANN and RSM model are 0.98036 and 0.9408, respectively. The weights of the ANN model and the response surface plots were used to optimize and study the influence of the operating conditions on the membrane flux.


Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1230 ◽  
Author(s):  
Wen Yu ◽  
Jian-Hao Huang ◽  
Chung-Sung Tan

In this study, the cyclic oligomers in the highly chemically resistant polyester polybutylene terephthalate (PBT) were effectively removed using a compressed CO2 antisolvent technique in which 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) was used as the solvent. In addition to the oligomers, tetrahydrofuran was completely removed because of its low molecular weight and liquid state. The effects of the operating variables, including temperature, pressure, and the PBT concentration in HFIP, on the degree of removal of the oligomers were systematically studied using experimental design and the response surface methodology. The most appropriate operating conditions for the purification of PBT were 8.3 MPa and 23.4 °C when using 4.5 wt % PBT in HFIP. Under these conditions, the cyclic trimers and dimers could be removed by up to 81.4% and 95.7%, respectively, in a very short operating time.


Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3320
Author(s):  
Imtiaz Ali ◽  
Maqsood Ahmad ◽  
Tarek Ganat

Drilling mud’s rheological characteristics, such as plastic viscosity and yield point, are adversely affected with an inappropriate mud formulation. Native starch is one of the most important components in water-based mud because it improves the rheological and filtration characteristics of the mud. The native starch stability under various temperature and exposure time regimes is an important concern for utilizing starch in oil and gas drilling operations. In this work, tapioca starch was modified using carboxymethylation for the first time in order to improve its performance in non-damaging water-based muds. The modified starch was characterized by Fourier-transform infrared spectroscopy and X-ray diffraction. The thermal stability was tested using thermal gravimetric analysis. Various mud blends were formulated based on the experimental design using response surface methodology (RSM) to investigate their performance at various temperature conditions. Thirty experimental runs were carried out based on the selected factors and responses considering the optimal (custom) design, and the results were analyzed through ANOVA. The Fourier-transform infrared spectroscopy and X-ray diffraction results confirmed the carboxymethylation of starch. The TGA analysis revealed strong thermal stability after modification. Additionally, the Power law model (PLM) described the obtained rheological data for the selected formulations, resulting in determination coefficients of more than 0.95. Furthermore, the examined samples showed a reduction in the flow behavior index from 0.30 to 0.21 and an increase in the consistency index from 5.6 to 15.1. Optimization and confirmation results revealed the adequacy of the generated empirical models for both plastic viscosity and yield point. The obtained consistency index values provided a direct relationship with the modified starch concentration, indicating an improvement in the cutting carrying capacity of mud. Based on the current literature survey, the studied formulation has not been reported in the literature.


RSC Advances ◽  
2016 ◽  
Vol 6 (54) ◽  
pp. 48329-48335 ◽  
Author(s):  
Heng-Zhi Duan ◽  
Hong-Yan Zeng ◽  
Hua-Miao Xiao ◽  
Chao-Rong Chen ◽  
Gao-Fei Xiao ◽  
...  

SO42− intercalated Mg–Al hydrotalcite (S-LDH) was prepared under microwave irradiation and characterized by powder X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM).


2014 ◽  
Vol 926-930 ◽  
pp. 383-386
Author(s):  
Yan Xiong Yang

In this paper, Zn-hydroxyapatite/chitosan composite was synthesized via a co-precipitation method. Fourier Transform infrared spectroscopy (FTIR) and X-ray analyzer (EDXA) were used to investigate the microstructure of composite. Then, it was used for removal of Co ions from synthetic aqueous solution. The results indicated that the prepared Zn-hydroxyapatite/chitosan was successful prepared and the adsorption pattern fitted well with Langmuir model.


2015 ◽  
Vol 50 (2) ◽  
pp. 109-122 ◽  
Author(s):  
Gholamreza Tolian ◽  
Seyed Ali Jafari ◽  
Saeid Zarei

In the present paper, the biosorption capacity of an indigenous seaweed Enteromorpha sp. was assessed and compared for nickel(II) and cadmium(II) removal from aqueous solution. Response surface methodology based on Box–Behnken design was employed to achieve the optimum removal conditions as well as investigating the effects of some independent variables on the process performance. It was found that the maximum nickel(II) removal achieved was 87.16% under optimum conditions of pH 4.79, biomass concentration of 1,000 mg/L, contact time 70 min and temperature of 25 °C. For cadmium the optimum conditions were defined as pH 4.88, biomass concentration of 1,000 mg/L, contact time 50 min and temperature fixed at 65 °C which resulted in a maximum 75.16% removal. Equilibrium isotherm studies revealed that Freundlich and Langmuir models were more successful for describing nickel(II) and cadmium(II) biosorption data, respectively. The maximum sorption capacities of biomass, qmax, for nickel(II) and cadmium(II) were predicted as 250 and 167 mg/g, respectively, by the Langmuir model. The results suggest Enteromorpha seaweed as an eco-friendly and suitable biosorbent for nickel(II) and cadmium(II) removal from aqueous solutions.


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