scholarly journals A Study of the Adsorption and Removal of Sb(III) from Aqueous Solution by Fe(III) Modified Proteus cibarius with Mechanistic Insights Using Response Surface Methodology

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 933
Author(s):  
Xiaojian Li ◽  
Renjian Deng ◽  
Zhie Tang ◽  
Saijun Zhou ◽  
Xing Zeng ◽  
...  

Environmental pollution caused by excessive Sb(III) in the water environment is a global issue. We investigated the effect of processing parameters, their interaction and mechanistic details for the removal of Sb(III) using an iron salt-modified biosorbent (Fe(III)-modified Proteus cibarius (FMPAs)). Our study evaluated the optimisation of the adsorption time, adsorbent dose, pH, temperature and the initial concentration of Sb(III). We use response surface methodology to optimize this process, determining optimal processing conditions and the adsorption mechanism evaluated based on isotherm model and adsorption kinetics. The results showed that—(1) the optimal conditions for the adsorption of Sb(III) by FMPAs were an adsorption time of 2.2 h, adsorbent dose of 3430 mg/L, at pH 6.0 and temperature 44.0 °C. For the optimum initial concentration of Sb(III) 27.70 mg/L, the removal efficiency of Sb(III) reached 97.60%. (2) The adsorption process for Sb(III) removal by FMPAs conforms to the Langmuir adsorption isotherm model, and its maximum adsorption capacity (qmax) is as high as 30.612 mg/g. A pseudo-first-order kinetic model provided the best fit to the adsorption process, classified as single layer adsorption and chemisorption mechanism. (3) The adsorption of Sb(III) takes place via the hydroxyl group in Fe–O–OH and EPS–Polyose–O–Fe(OH)2, which forms a new complex Fe–O–Sb and X≡Fe–OH. The study showed that FMPAs have higher adsorption capacity for Sb(III) than other previously studied sorbents and with low environmental impact, it has a great potential as a green adsorbent for Sb(III) in water.

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3150
Author(s):  
Mengwei Xu ◽  
Chao Huang ◽  
Jing Lu ◽  
Zihan Wu ◽  
Xianxin Zhu ◽  
...  

Magnetic MXene composite Fe3O4@Ti3C2 was successfully prepared and employed as 17α-ethinylestradiol (EE2) adsorbent from water solution. The response surface methodology was employed to investigate the interactive effects of adsorption parameters (adsorption time, pH of the solution, initial concentration, and the adsorbent dose) and optimize these parameters for obtaining maximum adsorption efficiency of EE2. The significance of independent variables and their interactions were tested by the analysis of variance (ANOVA) and t-test statistics. Optimization of the process variables for maximum adsorption of EE2 by Fe3O4@Ti3C2 was performed using the quadratic model. The model predicted maximum adsorption of 97.08% under the optimum conditions of the independent variables (adsorption time 6.7 h, pH of the solution 6.4, initial EE2 concentration 0.98 mg L−1, and the adsorbent dose 88.9 mg L−1) was very close to the experimental value (95.34%). pH showed the highest level of significance with the percent contribution (63.86%) as compared to other factors. The interactive influences of pH and initial concentration on EE2 adsorption efficiency were significant (p < 0.05). The goodness of fit of the model was checked by the coefficient of determination (R2) between the experimental and predicted values of the response variable. The response surface methodology successfully reflects the impact of various factors and optimized the process variables for EE2 adsorption. The kinetic adsorption data for EE2 fitted well with a pseudo-second-order model, while the equilibrium data followed Langmuir isotherms. Thermodynamic analysis indicated that the adsorption was a spontaneous and endothermic process. Therefore, Fe3O4@Ti3C2 composite present the outstanding capacity to be employed in the remediation of EE2 contaminated wastewaters.


Author(s):  
Nnaemeka John Okorocha ◽  
J. Josphine Okoji ◽  
Charles Osuji

The potential of almond leaves powder, (ALP) for the removal of Crystal violet (CV) and Congo red (CR) dyes from aqueous solution was investigated. The adsorbent (ALP) was characterized by FTIR and SEM analysis. Batch adsorption studies were conducted and various parameters such as contact time, adsorbent dosage, initial dye concentration, pH and temperature were studied to observe their effects in the dyes adsorption process. The optimum conditions for the adsorption of CV and CR dyes onto the adsorbent (ALP) was found to be: contact time (100mins), pH (10.0), temperature (343K) for an initial CV dye concentration of 50mg/L using adsorbent dose of 1.0g and contact time (100mins), pH (2.0), temperature (333K) for an initial CR dye concentration of 50mg/L using adsorbent dose 1.0g respectively. The experimental equilibrium adsorption data fitted best and well to the Freundlich isotherm model for both CV and CR dyes adsorption. The maximum adsorption capacity of ALP was found to be 22.96mg/g and 7.77mg/g for the adsorption of CV and CR dyes respectively. The kinetic data conformed to the pseudo-second-order kinetic model. Thermodynamic quantities such as Gibbs free energy (ΔG0), enthalpy (ΔH0) and entropy (ΔS0) were evaluated and the negative values of ΔG0obtained for both dyes indicate the spontaneous nature of the adsorption process while the positive values of ΔH0and ΔS0obtained indicated the endothermic nature and increased randomness during the adsorption process respectively for the adsorption of CV and CR onto ALP. Based on the results obtained such as good adsorption capacity, rapid kinetics, and its low cost, ALP appears to be a promising adsorbent material for the removal of CV and CR dye stuff from aqueous media.


Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2554
Author(s):  
Panlong Dong ◽  
Hailin Liu ◽  
Shengrui Xu ◽  
Changpo Chen ◽  
Suling Feng ◽  
...  

To remove the pollutant methylene blue (MB) from water, a sheet-like skeleton carbon derived from shaddock peels (SPACs) was prepared by NaOH activation followed by a calcination procedure under nitrogen protection in this study. Characterization results demonstrated that the as-prepared SPACs displayed a hierarchically porous structure assembled with a thin sheet-like carbon layer, and the surface area of SPAC-8 (activated by 8 g NaOH) was up to 782.2 m2/g. The as-prepared carbon material presented an ultra-fast and efficient adsorption capacity towards MB due to its macro-mesoporous structure, high surface area, and abundant functional groups. SPAC-8 showed ultrafast and efficient removal capacity for MB dye. Adsorption equilibrium was reached within 1 min with a removal efficiency of 99.6% at an initial concentration of 100 mg/g under batch adsorption model conditions. The maximum adsorption capacity for MB was up to 432.5 mg/g. A pseudo-second-order kinetic model and a Langmuir isotherm model described the adsorption process well, which suggested that adsorption rate depended on chemisorption and the adsorption process was controlled by a monolayer adsorption, respectively. Furthermore, column adsorption experiments showed that 96.58% of MB was removed after passing through a SPAC-8 packed column with a flow rate of 20 mL/min, initial concentration of 50 mg/L, and adsorbent dosage of 5 mg. The as-prepared adsorbent displays potential value in practical applications for dye removal due to its ultrafast and efficient adsorption capacity.


2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Ferda Gönen ◽  
Esra Köylü

The adsorptive removal of Telon Blue AGLF (TB AGLF) from aqueous solution using sunflower pulp was studied. The effects of pH, adsorbent dose, temperature, and initial dye concentration on the adsorption capacity and the removal % of TB AGLF were investigated. Experimental results showed that sunflower pulp was excellent agroindustrial adsorbent with maximum dye removal efficiency of 97.22% for a very short time (under conditions of 100 mg L−1initial dye concentration, pH = 3,T=50°C, and 1 g L−1of adsorbent dose). The binary effects of initial dye concentration and temperature on the adsorption properties of sunflower pulp were analysed by RSM and two model equations for predicting adsorption capacity and dye removal % of pulp because arbitrarily chosen initial dye concentration and temperature were developed by using response surface methodology (RSM). Experimental values of the adsorption capacity and dye removal % were in good agreement with the predicted values by the improved models. Adsorption experiments and kinetic regression results indicated that the experimental data were well defined with pseudo-second-order kinetic model.


Author(s):  
Nor Zida Rosly ◽  
Abdul Halim Abdullah ◽  
Mazliana Ahmad Kamarudin ◽  
Siti Efliza Ashari ◽  
Shahrul Ainliah Alang Ahmad

Lead sulphide (PbS) modified with calix[6]arene was synthesised as an alternative and regenerative adsorbent for the adsorption of methylene blue (MB) dye. The prepared calix[6]arene-modified PbS was characterised via Fourier-transform infrared spectroscopy, field emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The response surface methodology (RSM) based on the central composite design (CCD) was employed to identify the most significant factors, such as the initial concentration, adsorbent dosage, pH, and temperature, and to optimise the effects of the factors on the adsorptive efficiency as its response. The optimised initial concentration, adsorbent dosage, pH, and temperature were 20.00 mg/L initial concentration, 44.00 mg calix[6]arene-modified PbS, pH 6, and a temperature of 31.00 °C. A good correlation between the values and well-fitted model was observed. The adsorption performance was evaluated based on the percentage removal of MB dye from the water system. The adsorption isotherm best fit the Langmuir isotherm model, and the adsorption rate was followed by a pseudo-second-order kinetic model, a single layer chemical adsorption with a maximum adsorption capacity (qmax) of 5.495 mg/g.


2014 ◽  
Vol 529 ◽  
pp. 22-25 ◽  
Author(s):  
Li Wei Xie ◽  
Ze Long Xu ◽  
Yan Hua Huang ◽  
Shuang Cao ◽  
Zong Qiang Zhu ◽  
...  

Adsorption of ammonia nitrogen from aqueous solution onto the bagasse adsorbent has been investigated to evaluate the effects of Adsorbent dose, initial NH4+-N concentration, and pH on the removal systematically. With increasing initial concentration, the amount of ammonia nitrogen sorbed onto the adsorbent increased until it gradually decreased due to the initial concentration exceed 50 mg·L-1, and the maximum adsorption capacity was observed for the sample to be 1.31 mg·g-1 at the initial concentration of 30 mg·L-1, and the corresponding removal rates decreased from 94.01 to 3.89%, with increase in initial concentration from 5 to 100 mg·L-1. Adsorption capacities decreased from 6.04 to 0.49 mg·g-1 with increasing adsorbent dose from 0.1 to 1.5g. What’s more, under alkaline condition, the removal efficiency of ammonia nitrogen from aqueous solution onto the samples were superior to that under acidity and neutrality condition.


Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 652 ◽  
Author(s):  
Wang ◽  
Zhao ◽  
Wang ◽  
Zhang ◽  
Zhang

The selective recovery of gold from wastewater is necessary because it is widely used in various fields. In this study, a new polymeric adsorbent (TP-AFC) was prepared by modifying polyaniline with trimethyl phosphate for the selective recovery of gold from wastewater. Bath experiments were carried out to explore the adsorption capacity and mechanism. The optimum pH of adsorption is 4. The adsorption equilibrium is reached at 840 min. The maximum adsorption capacity is 881 mg/g and the adsorption was a spontaneous endothermic process. The adsorption process fitted well with pseudo second-order kinetic and the Langmuir-models. The single-layer chemisorption governed the adsorption process. In addition, the application in wastewater indicated that the interfering ions had no effect on the adsorption of gold ions. TP-AFC has good selectivity. The interaction mechanism was mainly ion exchange and complexation. In general, TP-AFC was successfully prepared and has an excellent future in practical application.


2020 ◽  
Vol 39 (03) ◽  
Author(s):  
VO THANH CONG ◽  
DO QUY DIEM ◽  
NGUYEN VAN SON

Wastewater treatment is one of the urgent and important issues in environmental protection. Nowadays, many methods to treat wastewater in industry were found to which adsorption applied as an effective method. Among possible adsorbents, bone char appeared to be of important application especially for heavy metals. In this study, we are applied char bone char sample as an adsorbent at optimal condition on previous investigation to adsorb arsenic ion (type of As5+ ion) contained in wastewater. The detail in experimental performance, the initial concentration, capacity adsorption, and adsorption time at optimal condition of arsenic ion solution were examined. The results of arsenic adsorption process were found that the optimization of initial concentration to be As5 sample with adsorption capacity of 0.124 mg arsenic ion/g bone char at time of 60 minute. In addition, the optimal adsorption time on As5 sample was also determined as 90 minutes with capacity adsorption of 0.02 mg arsenic ion/ g bone char. The positive research results of the adsorption on bone char have pointed out a possible application of bone char as an adsorbent in future.


BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 3991-4006
Author(s):  
Zhixin Gu ◽  
Sijia Zhang ◽  
Chuanqing Zhu ◽  
Lijuan Wang

A biosorbent was prepared from the cellulose fibers found in rice straw through cationic modification. The effects of the dosage, pH, contact time, and initial concentration of lemon yellow dye were explored. The static adsorption results showed that cationic modification drastically improved the adsorption capacity of straw cellulose fiber. The maximum equilibrium adsorption capacity value was 137.6 mg/g and the highest removal reached 99%. The pseudo-second-order kinetic model was a good fit for the adsorption process, together with the Langmuir isotherm model. The adsorption reaction was spontaneous, and the adsorption process was an exothermic reaction, which was shown by the thermodynamic model. As the adsorption time became longer, the effluent concentration became larger until reaching equilibrium. The time was 420 min. After desorption using a dilute NaOH solution, the maximum adsorption capacity was still 36.1 mg/g and the maximum removal still reached 36.2%. The parameters calculated from the Yoon-Nelson model have a good fit with the experimental data. In short, cationic straw cellulose fiber is an effective and easy to prepare biosorbent. This work offers a new method for dye wastewater purification and solves the effective utilization of rice straw resources.


Gels ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 225
Author(s):  
Katarina Antić ◽  
Antonije Onjia ◽  
Dana Vasiljević-Radović ◽  
Zlate Veličković ◽  
Simonida Lj. Tomić

The adsorption of Ni2+ ions from water solutions by using hydrogels based on 2-hydroxyethyl acrylate (HEA) and itaconic acid (IA) was studied. Hydrogel synthesis was optimized with response surface methodology (RSM). The hydrogel with the best adsorption capacity towards Ni2+ ions was chosen for further experiments. The hydrogel was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis before and after the adsorption of Ni2+ ions. Batch equilibrium experiments were conducted to investigate the influence of solution pH, hydrogel weight, ionic strength, adsorption time, temperature and initial concentration of nickel ions on the adsorption. Time-dependent adsorption fitted the best to the pseudo-second-order kinetic model. A thermodynamic study revealed that the adsorption was an exothermic and non-spontaneous process. Five isotherm models were studied, and the best fit was obtained with the Redlich–Peterson model. Consecutive adsorption/desorption studies indicated that the HEA/IA hydrogel can be efficiently used as a sorbent for the removal of Ni2+ ions from the water solution. This study develops a potential adsorbent for the effective removal of trace nickel ions.


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