scholarly journals Sorption of Arsenic(III) from wastewater using Prosopis spicigera L. wood (PsLw) carbon-polyaniline composite

2021 ◽  
Vol 13 (4) ◽  
pp. 1283-1293
Author(s):  
Ramasubbu Dhana Ramalakshmi ◽  
Mahalingam Murugan ◽  
Vincent Jeyabal

Water contamination by toxic heavy metal ions causes a serious public health problem for humans. The present work reports the development of a new adsorbent of PsLw carbon-polyaniline composite by direct oxidation polymerisation of aniline with PsLw carbon for the removal of arsenic (As).  The structure and morphologies of the adsorbent were characterised by Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM). The ability of the adsorbent for the removal of As(III) was estimated by batch and kinetic studies. The optimum adsorption behaviour of the adsorbent was measured at pH=6.0. The equilibrium process was found to be in good agreement with Langmuir adsorption isotherm and the maximum adsorption capacity was 98.8 mg/g for an initial concentration of 60 mg/L at 30 °C. The kinetic study followed pseudo-second-order kinetics. Thermodynamic parameters predict the spontaneous, feasible and exothermic nature of adsorption. Column operation was carried out to remove As(III) bulk and column data obeys the Thomas model. The results indicated that PsLw carbon-polyaniline composite can be employed as an efficient adsorbent than polyaniline for removal of As(III) from wastewater.

2010 ◽  
Vol 171-172 ◽  
pp. 15-18
Author(s):  
Zeng Quan Ji ◽  
Tian Hai Wang ◽  
Kai Hong Luo ◽  
Yao Qing Wang

An extracellular biopolymer (PFC02) produced by Pseudomonas alcaligenes was used as an alternative biosorbent to remove toxic Cd(II) metallic ions from aqueous solutions. The effect of experimental parameters such as pH, Cd(II) initial concentration and contact time on the adsorption was studied. It was found that pH played a major role in the adsorption process, the optimum pH for the removal of Cd(II) was 6.0. The FTIR spectra showed carboxyl, hydroxyl and amino groups of the PFC02 were involved in chemical interaction with the Cd(II) ions. Equilibrium studies showed that Cd(II) adsorption data followed Langmuir model. The maximum adsorption capacity (qmax) for Cd(II) ions was estimated to be 93.55 mg/g. The kinetic studies showed that the kinetic rates were best fitted to the pseudo-second-order model. The study suggestted that the novel extracellular biopolymer biosorbent have potential applications for removing Cd(II) from wastewater.


Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 218 ◽  
Author(s):  
Alfred Mensah ◽  
Pengfei Lv ◽  
Christopher Narh ◽  
Jieyu Huang ◽  
Di Wang ◽  
...  

In this study, a novel green adsorbent material prepared by the esterification of bacterial cellulose (BC) and graphene oxide (GO), richly containing hydroxyl, alkyl, and carboxylate groups was characterised by FTIR (Fourier Transform infrared spectroscopy), XRD (X-ray diffraction), SEM (Scanning electron microscopy) and TGA (Thermo-graphimetric analysis). The specific surface area (SSA) and pore size distribution (PSD) analysis of materials were also analysed. Batch experiments–adsorption studies confirmed the material to have a very high Pb2+ removal efficiency of over 90% at pH 6–8. Kinetic studies showed that the uptake of metal ions was rapid with equilibrium attained after 30 min and fitted well with the pseudo-second-order rate model (PSO). Isotherm results with a maximum adsorption capacity (Qmax) of 303.03 mg/g were well described by Langmuir’s model compared to Freundlich. Desorption and re-adsorption experiments realised that both adsorbent and adsorbates could be over 90–95% efficiently recovered and reused using 0.1 M HNO3 and 0.1 M HCl.


2009 ◽  
Vol 610-613 ◽  
pp. 65-68 ◽  
Author(s):  
Xue Gang Luo ◽  
Feng Liu ◽  
Xiao Yan Lin

Konjac glucomannan (KGM) was converted into water insoluble konjac glucomannan (WIKGM) by treating with NaOH through completely deacetylated reaction. Adsorption study was carried out for the adsorption of Pb2+ from aqueous solution using water insoluble konjac glucomannan. The influences of pH, contact time, temperature and initial Pb2+ concentration on the absorbent were studied. Results of kinetic data showed that the Pb2+ adsorption rate was fast and good correlation coefficients were obtained for the pseudo second-order kinetic model. The equilibrium process was described well by the Langmuir isotherm model with maximum adsorption capacity of 9.18 mg/g on WIKGM at 25°C.


2014 ◽  
Vol 1043 ◽  
pp. 219-223 ◽  
Author(s):  
Noor Shawal Nasri ◽  
Jibril Mohammed ◽  
Muhammad Abbas Ahmad Zaini ◽  
Usman Dadum Hamza ◽  
Husna Mohd. Zain ◽  
...  

Concern about environmental protection has increased over the years and the presence of volatile organic compounds (VOCs) in water poses a threat to the environment. In this study, coconut shell activated carbon (PHAC) was produced by potassium hydroxide activation via microwave for benzene and toluene removal. Equilibrium data were fitted to Langmuir, Freundlich and Tempkin isotherms with all the models having R2 > 0.94. The equilibrium data were best fitted by Langmuir isotherm, with maximum adsorption capacity of 212 and 238mg/g for benzene and toluene, respectively. The equilibrium parameter (RL) falls between 0 and 1 confirming the favourability of the Langmuir model. Pseudo-second-order kinetic model best fitted the kinetic data. The PHAC produced can be used to remediate water polluted by VOCs.


2016 ◽  
Vol 42 (2) ◽  
pp. 3-11 ◽  
Author(s):  
Gabriela Ciobanu ◽  
Simona Barna ◽  
Maria Harja

AbstractIn the present study the adsorption of Reactive Blue 19 dye on the hydroxyapatite (HAp) nanopowders was investigated. The batch adsorption experiments were performed by monitoring the adsorbent dosage, contact time, dye solution concentration, pH and temperature. At pH 3 and 20°C, high dye removal rates of about 95.58% and 86.95% for the uncalcined and calcined nanohydroxyapatites, respectively, were obtained. The kinetic studies indicated the dye adsorption onto nanohydroxyapatite samples to follow a pseudo-second order model. The Langmuir isotherm was found to be the best to represent the equilibrium with experimental data. The maximum adsorption capacity of uncalcined and calcined nanohydroxyapatite samples has been found to be 90.09 mg/g and 74.97 mg/g, respectively.


Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 962
Author(s):  
Kuo-Yu Chen ◽  
Wei-Yu Zeng

Poly-γ-glutamate/apatite (PGA-AP) nanoparticles were prepared by chemical coprecipitation method in the presence of various concentrations of poly-γ-glutamate (γ-PGA). Powder X-ray diffraction pattern and energy-dispersive spectroscopy revealed that the main crystal phase of PGA-AP was hydroxyapatite. The immobilization of γ-PGA on PGA-AP was confirmed by Fourier transform infrared spectroscopy and the relative amount of γ-PGA incorporation into PGA-AP was determined by thermal gravimetric analysis. Dynamic light scattering measurements indicated that the particle size of PGA-AP nanoparticles increased remarkably with the decrease of γ-PGA content. The adsorption of aqueous Cu(II) onto the PGA-AP nanoparticles was investigated in batch experiments with varying contact time, solution pH and temperature. Results illustrated that the adsorption of Cu(II) was very rapid during the initial adsorption period. The adsorption capacity of PGA-AP nanoparticles for Cu(II) was increased with the increase in the γ-PGA content, solution pH and temperature. At a pH of 6 and 60 °C, a higher equilibrium adsorption capacity of about 74.80 mg/g was obtained. The kinetic studies indicated that Cu(II) adsorption onto PGA-AP nanoparticles obeyed well the pseudo-second order model. The Langmuir isotherm model was fitted well to the adsorption equilibrium data. The results indicated that the adsorption behavior of PGA-AP nanoparticles for Cu(II) was mainly a monolayer chemical adsorption process. The maximum adsorption capacity of PGA-AP nanoparticles was estimated to be 78.99 mg/g.


Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2559 ◽  
Author(s):  
Bogdan Adrian Militaru ◽  
Rodica Pode ◽  
Lavinia Lupa ◽  
Winfried Schmidt ◽  
Agnes Tekle-Röttering ◽  
...  

Incineration of sewage sludge produces every year huge amounts of sewage sludge ash. Due to its porosity and composition, sewage sludge ash can be used as an adsorbent for heavy metal ions removal. The present paper discusses the efficiency and feasibility of its use as an adsorbent for Pb (II) and Cu (II) removal in single and binary systems. Sewage sludge ash dosage, pH influence, equilibrium and kinetic studies were examined. The results show that sewage sludge ash is an effective and environmentally friendly adsorbent. The maximum adsorption capacity was 25.0 mg/g for Pb (II) and 7.5 mg/g for Cu (II). The presence of the competitive metal led to lower adsorption rate. The study concludes that sewage sludge ash is a promising adsorbent for Pb (II) and Cu (II) removal from wastewater presenting both economic and environmental benefits.


2018 ◽  
Vol 43 (6) ◽  
pp. 623-631 ◽  
Author(s):  
Reza Mahini ◽  
Hossein Esmaeili ◽  
Rauf Foroutan

Abstract Objective The presence of dyes in the water is toxic and harmful to human body so, it must be removed from the water. In the present study, the removal of methyl violet (MV) from aqueous solutions using brown algae “Padina sanctae-crucis” was investigated. Materials and methods The rate of adsorption was investigated under various parameters such as contact time (5–200), pH (2–11), dye concentration (10–60 mg/L), amount of adsorbent (0.25–5 g/L) and temperature (25–45°C). Results The maximum adsorption was achieved in 10 mg/L, pH=8 and adsorbent dose 2 g/L and 80 min contact time for removal of MV from aqueous solutions. Kinetic studies showed that the pseudo second-order model describes adsorbent kinetic behavior better. Besides, experimental data have been modeled using Langmuir and Freundlich isotherms and the results showed that both models are proper to describe adsorption isotherm behavior. In addition, the equilibrium study shows that the adsorption was physical and favorable. Moreover, a thermodynamic study revealed that the adsorption process is exothermic and spontaneously in nature. Furthermore, Maximum adsorption capacity using adsorbent was 10.02 mg/g. Conclusions It could be concluded that the P. sanctae-crucis biomass is a good adsorbent for removing MV dyes from aqueous solutions.


2014 ◽  
Vol 1046 ◽  
pp. 34-38
Author(s):  
Shan Yu ◽  
Chang Hai Li ◽  
Dong Mei Jia

The hydroxyl alumina impregnated weakly basic resin composite (D301Al) successfully prepared through incorporation of hydroxyl alumina into the D301 resin for 2-naphthalenesulfonic acid (2-NSA) removal from aqueous solution. The structure of D301Al was examined using scanning electron microscopy and Fourier transform infrared spectroscopy. The adsorption behaviors of 2-NSA on D301Al were investigated by static adsorption experiments. Effects of pH of solution, temperature and contact time were determined. The results indicated D301Al reached the maximum adsorption capacity to 2-NSA with pH 2.4. Nonlinear regression was used to estimate of Langmuir and Freundlich model parameters. And the Langmuir model can give a satisfactory fit of the experimental equilibrium data. The kinetic studies indicated that the adsorption of D301Al for 2-NSA can establish adsorption equilibrium at 8 h. The pseudo-first-order and pseudo-second-order rate models could characterize the kinetic data of 2-NSA adsorption on D301Al.


2020 ◽  

<p>Abstract: Water is the main factor of movement and transport of pesticides and contamination of water by these pollutants is one of the most important challenges due to their widespread use and increased concentrations. Moreover, these compounds are on the U.S.EPA Priority Pollutant list because of the potential of accumulation and the property of damaging effects. In this study, multiwalled carbon nanotube-based magnetic nanoparticles were synthesized and used as an affective adsorbent for carbaryl pesticide. The properties of the synthesized Fe3O4@MWCNTs were characterized by TEM images and XRD analysis. The obtained data were studied by isotherm and kinetic models. Carbaryl adsorbed onto the synthesized adsorbent was compatible with the Langmuir isotherm (R2 =0.993). The maximum adsorption capacity (qmax) of the pesticide onto the Fe3O4-MWCNTs was obtained at 68.2 mg/g. The kinetic studies of the reactions showed that the adsorption process followed the pseudo-second order model with R2 ≥0.99 for all initial carbaryl concentrations. The adsorbent was extracted by magnet reused several times (six rounds) with a reasonable efficiency. The Fe3O4-MWCNTs have great potential for adsorption of carbaryl from water and wastewater due to high efficiency, easy separation and reusability.</p>


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