scholarly journals Bioadsorption of lead(II) over the pulp of Acrocomia aculeata

2021 ◽  
Vol 46 (4) ◽  
pp. 38-46
Author(s):  
Alexandra Novak ◽  
F�tima Yubero ◽  
Diana Diez-P�rez-N��ez ◽  
Fernando Luis Fertonani ◽  
Brenda Gisselle Da Silva Britez ◽  
...  

The adsorption of lead in aqueous solution onto Acrocomia aculeata pulp was examined. The pulp was characterized in the presence and absence of lead using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG-DTA), and scanning electron microscopy (SEM). Sulfur and oxygen bonds were responsible for adsorbing lead onto the pulp surface. The TG-DTA profile proved that adding sodium azide increases the pulp�s thermal stability until 200 �C. Adsorption data in batch and column systems were analyzed to understand the pulp adsorption compared to other biomaterials. In the batch experiments, the removal efficiency reached a maximum of 91.9% when a solution of 50 ppm of lead was placed in contact with the pulp for 30 min and fit Freundlich isotherm behavior. In the column experiments, the theoretical maximum adsorption capacity was found to be 11.97 mg g�1; more column data is needed to compare column results to other studies. Further studies to improve the pulp adsorption capacity are needed for it to be a competitive biomaterial for water treatment.

1994 ◽  
Vol 30 (9) ◽  
pp. 191-197 ◽  
Author(s):  
R. Leyva Ramos ◽  
A. Juarez Martinez ◽  
R. M. Guerrero Coronado

The adsorption isotherm of chromium (VI) on activated carbon was obtained in a batch adsorber. The experimental adsorption data were fitted reasonably well to the Freundlich isotherm. The effect of pH on the adsorption isotherm was investigated at pH values of 4, 6, 7, 8, 10 and 12. It was found that at pH < 6, Cr(VI) was adsorbed and reduced to Cr(III) by the catalytic action of the carbon and that at pH ≥ 12, Cr(VI) was not adsorbed on activated carbon. Maximum adsorption capacity was observed at pH 6 and the adsorption capacity was diminished about 17 times by increasing the pH from 6 to 10. The pH effect was attributed to the different complexes that Cr(VI) can form in aqueous solution. The adsorption isotherm was also affected by the temperature since the adsorption capacity was increased by raising the temperature from 25 to 40°C. It was concluded that Cr(VI) was adsorbed significantly on activated carbon at pH 6 and that the adsorption capacity was greatly dependent upon pH.


2017 ◽  
Vol 76 (9) ◽  
pp. 2526-2534 ◽  
Author(s):  
Meimei Zhou ◽  
Weizhen Tang ◽  
Pingping Luo ◽  
Jiqiang Lyu ◽  
Aixia Chen ◽  
...  

Abstract Ureido-functionalized mesoporous polyvinyl alcohol/silica composite nanofibre membranes were prepared by electrospinning technology and their application for removal of Pb2+ and Cu2+ from wastewater was discussed. The characteristics of the membranes were investigated by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and N2 adsorption-desorption analysis. Results show that the membranes have long fibrous shapes and worm-like mesoporous micromorphologies. Fourier transform infrared spectroscopy confirmed the membranes were successfully functionalized with ureido groups. Pb2+ and Cu2+ adsorption behavior on the membranes followed a pseudo-second-order nonlinear kinetic model with approximately 30 minutes to equilibrium. Pb2+ adsorption was modelled using a Langmuir isotherm model with maximum adsorption capacity of 26.96 mg g−1. However, Cu2+ adsorption was well described by a Freundlich isotherm model with poor adsorption potential due to the tendency to form chelating complexes with several ureido groups. Notably, the membranes were easily regenerated through acid treatment, and maintained adsorption capacity of 91.87% after five regeneration cycles, showing potential for applications in controlling heavy metals-related pollution and metals reuse.


2016 ◽  
Vol 20 (2) ◽  
pp. 77 ◽  
Author(s):  
. Priyadi ◽  
. Iskandar ◽  
. Suwardi ◽  
Rino Rakhmata Mukti

It is generally known that zeolite has potential for heavy metal adsorption. The  objectives of this study were to synthesize and characterize zeolite ZSM-5 and to figure out the adsorption capacity of zeolite ZSM-5 for heavy metals of Cu2+, Pb2+ and Cd2+. Characterization of zeolite ZSM-5 included some variables i.e. crystal structure (XRD), morphology (SEM), specific surface area and total pore volume (N2 physisorption). Adsorption capacity of zeolite ZSM-5 was analysed using a batch system with heavy metals of Cu2+, Pb2+ and Cd2+ in various concentrations (50, 100, 150, 200 and 250 ppm) with contact times 30, 60, 90, 120 and 250 minutes. Adsorption data was calculated by Langmuir and Freundlich isotherm. The results showed that the maximum adsorption capacity of zeolite ZSM-5 against heavy metals of Pb2+, Cu2+, and Cd2+, were 74.07, 69.93 and 60.24 mg g-1, respectively. These indicated that synthetic zeolite ZSM-5 had potential to adsorb heavy metals. The results also suggested that the adsorption capacity was affected by the pore size of zeolite, negative charge of zeolite, diameter of hydrated and electronegative ion.


2011 ◽  
Vol 391-392 ◽  
pp. 773-777 ◽  
Author(s):  
Ya Ling Huang ◽  
Ru Lin Fu ◽  
Zhen Kun Huang ◽  
Xian Su Cheng

A spherical amine modified lignin-base adsorbent had been prepared (L-BAA) by condensation polymerization of lignin with epoxy chloropropane and diamines. The modified products were characterized by FTIR spectra and scanning electron microscopy. Few researches on adsorbing Pb (II) of high concentration from aqueous had been reported. The spherical lignin-base adsorbent was used to adsorb Pb (II) of high concentration from aqueous solution. The effect of shaking time, pH value and temperature on adsorption had been investigated in the study. It was indicated that the adsorption was dependent on pH and temperature of Pb (II) aqueous solution. The maximum adsorption capacity was 151.0 mg/g at follow condition: pH value was 4.00 and temperature was 35°C. The adsorption capacity was better than other reported adsorbents.


2013 ◽  
Vol 750-752 ◽  
pp. 1919-1923 ◽  
Author(s):  
Guo Xian Zhou ◽  
Ming Wei Yuan ◽  
Lin Jiang ◽  
Ming Long Yuan ◽  
Hong Li Li

The laponite-poly (L-lactide) composite films are prepared by the method of solution blending with polylactide (PLA) and laponite. The result shows that the homogeneous and smooth composite film is prepared with 1, 4-dioxane. Thermogravimetry analysis (TG) and tensile strength studies demonstrate that the thermal stability and tensile strength are improved with the laponite added. The scanning electron microscopy (SEM) measurement indicates that the pores of composite films get uniform and network structure is more and more compact with compared to pure PLA film. The present study reveals that the laponite as a complexing agent can improve the mechanical properties and thermal stability of PLA.


2010 ◽  
Vol 5 (1) ◽  
Author(s):  
Hülya Karaca ◽  
Turgay Tay ◽  
Merih Kıvanç

The biosorption of lead ions (Pb2+) onto lyophilized fungus Aspergillus niveus was investigated in aqueous solutions in a batch system with respect to pH, contact time and initial concentration of the ions at 30 °C. The maximum adsorption capacity of lyophilized A. niveus was found to be 92.6 mg g−1 at pH 5.1 and the biosorption equilibrium was established about in 30 min. The adsorption capacity obtained is one of the highest value among those reported in the literature. The kinetic data were analyzed using the pseudo-first-order kinetic, pseudo-second-order kinetic, and intraparticle diffusion equations. Kinetic parameters, such as rate constants, equilibrium adsorption capacities, and related correlation coefficients for the kinetic models were calculated and discussed. It was found that the adsorption of lead ions onto lyophilized A. niveus biomass fit the pseudo-second-order kinetic model well. The Langmuir and Freundlich isotherm parameters for the lead ion adsorption were applied and the Langmuir model agreed better with the adsorption of lead ions onto lyophilized A. niveus.


2020 ◽  
Vol 21 (1) ◽  
pp. 125-130
Author(s):  
Nyoman Sumawijaya ◽  
Asep Mulyono ◽  
Anna Fadliah Rusydi

ABSTRACTThe leather tanning industry in Sukaregang, Garut Regency, produces liquid waste containing Chromium and is discharged directly into the Ciwalen River without a waste treatment process. The content of Cr6+ as metal ions in the waste can also contaminating groundwater. The movement of Cr6+ will pass through the soil media before entering to the groundwater wells. The capability of the soil to adsorb the contaminant will reduce the impact on groundwater. The purpose of this study was to determine the ability of the soil in adsorbing and inhibiting the movement of Cr6+ into groundwater. The study was carried out at Sukaregang, Garut Regency and conducting adsorption experiments with a batch system. The analysis was carried out using the Langmuir and Freundlich isotherm model. The experimental results showed that Cr6+ adsorbed ranged from 38% to 57% of the initial concentration. The results from Langmuir Isotherm were: the distribution coefficient (Kads) was 0.45 L/mg and the maximum adsorption capacity (qm) was 2.44 mg/100g sorbent with R2 = 0.959 and Freundlich Isotherm was: qm was 2,86 mg/100g sorbent and Kads was 0,35 L/mg with R2 = 0,860. This large adsorption capacity is caused by soil texture and soil organic content. The soil in Sukaregang tanning industries has a high adsorption capacity towards Cr6+ contaminants.Keywords: adsorption, chromium, Cr6+, contaminant, volcanic soil, GarutABSTRAKIndustri penyamakan kulit di wilayah Sukaregang, Kabupaten Garut, menghasilkan limbah cair yang mengandung Kromium dan dibuang ke Sungai Ciwalen tanpa proses pengolahan limbah. Kandungan ion logam Cr6+ pada limbah dapat mencemari air tanah. Pergerakan ion logam Cr6+ akan melalui media tanah sebelum memasuki sumur-sumur penduduk. Beberapa jenis tanah mempunyai kemampuan untuk mengadsorpsi ion pencemar sehingga tidak semua limbah yang meresap ke dalam tanah mencemari air tanah. Tujuan dari penelitian ini adalah untuk mengetahui peranan tanah dalam menghambat pergerakan ion logam Cr6+ ke dalam air tanah. Penelitian dilaksanakan dengan pengambilan sampel tanah di daerah Sukaregang, Garut, dan melakukan percobaan adsorpsi dengan sistem batch. Sementara analisis dilakukan dengan menggunakan model isotherm Langmuir dan Freundlich. Hasil percobaan menunjukkan konsentrasi Cr6+ yang teradsorpsi berkisar 38 – 57 % dari konsentrasi awal. Kads sebesar 0,45 L/mg dan qm sebesar 2,44 mg/100g tanah dengan nilai R2 = 0,959 menggunakan isoterm Langmuir dan isoterm Freundlich memberikan nilai qm sebesar 2,86 mg/100 g sorbent dan Kads sebesar 0,35 L/mg dengan R2 = 0,860. Tingginya daya adsorpsi ini disebabkan oleh tekstur tanah dan kandungan bahan organik. Tanah di wilayah penelitian memiliki daya adsorpsi yang besar terhadap kontaminan Cr6+.Kata kunci: adsorpsi, kromium, Cr6+, kontaminan, tanah vulkanik, Garut


2017 ◽  
Vol 54 (1) ◽  
pp. 41-44 ◽  
Author(s):  
Maria Adina Vulcan ◽  
Celina Damian ◽  
Paul Octavian Stanescu ◽  
Eugeniu Vasile ◽  
Razvan Petre ◽  
...  

This paper deals with the synthesis of polyurea and its use as polymer matrix for nanocomposites reinforced with multi-walled carbon nanotubes (MWCNT). Two types of materials were obtained during this research, the first cathegory uses the polyurea as matrix and the second one uses a mixture between epoxy resin and polyurea. The nanocomposites were characterized by Thermogravimetric Analysis (TGA), Dynamic Mechanical Analysis (DMA), Scanning Electron Microscopy (SEM) and Tensile Tests .The elastomeric features of nanocomposites were highlighted by the results which showed low value of Tg. Also higher thermal stability with ~40oC compared with commercial products (M20) were observed, but lower mechanical properties compared to neat polyurea.


SAINTIFIK ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 104-115
Author(s):  
Agusriyadin Agusriyadin

Penelitian ini bertujuan untuk menguji kemampuan AK dan AKPM dalam mengadsorpsi ion Cu (II), pengaruh parameter adsorpsi dan mekanisme adsorpsi. AK dan AKP Madsorben dibuat dari residu ampas kelapa. Adsorben dikarakterisasi dengan FTIR, SEM dan EDS. Pengaruh parameter adsorpsi seperti pH awal, dosis adsorben, waktu kontak dan konsentrasi ion Cu (II) awal diperiksa untuk menentukan kondisi optimum serapan tembaga (II). Ion Cu (II) yang teradsorpsi diukur berdasarkan pada konsentrasi Ion Cu (II) sebelum dan sesudah adsorpsi menggunakan metode AAS. Hasil karakterisasi menunjukkan bahwa struktur pori dan gugus fungsi tersedia pada permukaan adsorben. Menurut percobaan efek pH, kapasitas adsorpsi maksimum dicapai pada pH 7. Waktu kontak optimal dan konsentrasi tembaga awal (II) ditemukan masing-masing pada 120 menit dan 100 mg L-1. Data eksperimental sesuai dengan model kinetik orde dua orde dua, dan Langmuir isoterm adsorpsi yang diperoleh paling sesuai dengan data adsorpsi. Kapasitas adsorpsi maksimum adsorben ditemukan menjadi 4,73 dan 6,46 mg g-1 pada kondisi optimal. The results of characterization showed that the pore structure and the functional groups were available on adsorbent surface. According to the pH effect experiments, the maximum adsorption capacity was achieved at pH 7. Optimum contact time and initial copper(II) concentration were found at 120 min and 100 mg L-1, respectively. The experimental data were comply with the pseudo-second-order kinetic model, and Langmuir adsorption isotherm obtained best fitted the adsorption data. The maximum adsorption capacity of the adsorbents was found to be 4.73 and 6.46 mg g-1 at optimum conditions.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Dhiraj Dutta ◽  
Jyoti Prasad Borah ◽  
Amrit Puzari

Results of investigation on adsorption of Mn2+ from aqueous solution by manganese oxide-coated hollow polymethylmethacrylate microspheres (MHPM) are reported here. This is the first report on Mn-coated hollow polymer as a substitute for widely used materials like green sand or MN-coated sand. Hollow polymethylmethacrylate (HPM) was prepared by using a literature procedure. Manganese oxide (MnO) was coated on the surface of HPM (MHPM) by using the electroless plating technique. The HPM and MHPM were characterized by using optical microscopy (OM), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Optical and scanning micrographs were used to monitor the surface properties of the coated layer which revealed the presence of MnO on the surface of HPM. TGA showed the presence of 4-5% of MnO in MHPM. Adsorption isotherm studies were carried out as a function of pH, initial ion concentration, and contact time, to determine the adsorption efficiency for removal of Mn2+ from contaminated water by the synthesized MHPM. The isotherm results showed that the maximum adsorption capacity of MnO-coated HPM to remove manganese contaminants from water is 8.373 mg/g. The obtained R 2 values of Langmuir isotherm and Freundlich isotherm models were 1 and 0.87, respectively. Therefore, R 2 magnitude confirmed that the Langmuir model is best suited for Mn2+ adsorption by a monolayer of MHPM adsorbent. The material developed shows higher adsorption capacity even at a higher concentration of solute ions, which is not usually observed with similar materials of this kind. Overall findings indicate that MHPM is a very potential lightweight adsorbent for removal of Mn2+ from the aqueous solution because of its low density and high surface area.


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