scholarly journals STUDY ON ADSORPTION OF Cd(II) BY CHITOSAN-ALUMINA

2010 ◽  
Vol 6 (3) ◽  
pp. 238-244 ◽  
Author(s):  
Darjito Darjito ◽  
Danar Purwonugroho ◽  
Siti Nasirotun Nisa
Keyword(s):  
Adsorption Capacity ◽  
Aqueous Phase ◽  
Functional Group ◽  
Adsorption Process ◽  
Ph Optimum ◽  
Optimum Ph ◽  
Before And After ◽  
Infrared Spectrophotometer ◽  
Agitation Time

One techniques to reduce the concentration of heavy metal Cd(II) in aqueous solution is adsorption by chitosan. To modify the surface textures and expose the active binding sites, composite biosorbent has been prepared by coating chitosan onto alumina. The aims of this research were to identify the functional group of chitosan-alumina, to characterize adsorption of Cd(II) by using chitosan-alumina adsorbent including optimum pH, optimum agitation time, and to determine the adsorption capacity of the adsorbent. The functional group of chitosan-alumina was identified by infrared spectrophotometer. Determination of the optimum condition was carried out at 40 ppm Cd(II), 125 rpm and 0,1 g adsorbent. Calculation of adsorpted Cd(II) based on its concentration in aqueous phase before and after adsorption process. The concentrations of Cd(II) in aqueous phase after adsorption process  were determined by using Atomic Absorption Spectroscopy (AAS). Identified functional groups of chitosan-alumina were -OH (3466.39 cm-1), -NH amine (1625.15 cm-1), C=O (1703.30 cm-1), and Al-O (1302.07 cm-1). The optimum pH was reached at pH 7, optimum agitation time at 15 minutes, and adsorption capacity of chitosan-alumina was 15.35 ± 0.05 mg/g.   Keywords: adsorption, chitosan-alumina, characterization of adsorption

scholarly journals Pemanfaatan Biomassa Serbuk Gergaji Sebagai Penyerap Logam Timbal

2017 ◽  
Vol 5 (4) ◽  
pp. 166
Author(s):  
Dey Intan ◽  
Irwan Said ◽  
Paulus Hengky Abram
Keyword(s):  
Heavy Metal ◽  
Adsorption Capacity ◽  
Adsorption Process ◽  
Ph Optimum ◽  
Optimum Weight ◽  
Optimum Ph ◽  
High Level

Lead (Pb) is one kind of heavy metal that has high level of toxicity. One way to reduce the level of Pb is by adsorption using cellulose and lignin of sawdust. The aim of this study is to determine the optimum pH, the optimum weight and to determine the adsorption capacity of sawdust when it absorbs Pb in solution of Pb(NO3)2. The adsorption process is carried out by using the various pH of 3, 4, 5, 6, 7, and 8 with a weight of 100 mg, and then the various weight of 100, 200, 300, 400, and 500 mg with the pH optimum. The analysis of Pb content in the solution was conducted by Spectro-direct. The analysis result shows the determination of pH occured at pH 7, Pb absorbed is 14.89 mg/g, and the percentage of Pb absorbed was 96.97%. For the determination of 400 mg of the adsorbent weight of Pb absorbed was 3,83 mg/g, the adsorption percentage of Pb was 99.98%, and the optimum adsorption for optimum weight was 0.15 mg Pb/mg sawdust.

Sorption of Bisphenol A in Aqueous Solutions on Irradiated and as-Grown Multiwalled Carbon Nanotubes

2018 ◽  
Vol 69 (5) ◽  
pp. 1233-1239
Author(s):  
Raluca Madalina Senin ◽  
Ion Ion ◽  
Ovidiu Oprea ◽  
Rusandica Stoica ◽  
Rodica Ganea ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Bisphenol A ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Multiwalled Carbon Nanotubes ◽  
Adsorption Process ◽  
Sorption Process ◽  
Multiwalled Carbon ◽  
Before And After ◽  
Kinetic Sorption

In this study, non-irradiated and weathered multiwalled carbon nanotubes (MWCNTs) obtained through irradiation, were studied as adsorbents for BPA, both nanomaterials being characterized before and after the adsorption process. The objectives of our investigation were to compare the characteristics of non-irradiated and irradiated MWCNTs, to evaluate the adsorption capacity of BPA by pristine and irradiated MWCNTs and to determine the variation of the kinetic, sorption and thermodynamic parameters during sorption process using both sorbents.

scholarly journals Immobilization of Isolated Lipase From Moldy Copra(Aspergillus Oryzae)

2011 ◽  
Vol 8 (2) ◽  
pp. 896-902
Author(s):  
Seniwati Dali ◽  
A. B. D. Rauf Patong ◽  
M. Noor Jalaluddin ◽  
Pirman ◽  
Baharuddin Hamzah
Keyword(s):  
Thermal Stability ◽  
Aspergillus Oryzae ◽  
Immobilized Lipase ◽  
Optimum Temperature ◽  
Adsorption Method ◽  
Ph Optimum ◽  
Optimum Ph ◽  
Recovery Technique ◽  
Free Lipase

Enzyme immobilization is a recovery technique that has been studied in several years, using support as a media to help enzyme dissolutions to the reaction substrate. Immobilization method used in this study was adsorption method, using specific lipase fromAspergillus oryzae. Lipase was partially purified from the culture supernatant ofAspergillus oryzae. Enzyme was immobilized by adsorbed on silica gel. Studies on free and immobilized lipase systems for determination of optimum pH, optimum temperature, thermal stability and reusability were carried out. The results showed that free lipase had optimum pH 8,2 and optimum temperature 35 °C while the immobilized lipase had optimum 8,2 and optimum temperature 45 °C. The thermal stability of the immobilized lipase, relative to that of the free lipase, was markedly increased. The immobilized lipase can be reused for at least six times.

scholarly journals Removal of triphenylmethane dye from aqueous solutions through an adsorption process over waste materials

2020 ◽  
Vol 10 (4) ◽  
pp. 5772-5779
Keyword(s):  
Adsorption Isotherm ◽  
Adsorption Capacity ◽  
Dye Removal ◽  
Functional Group ◽  
Adsorption Process ◽  
Removal Rate ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Pseudo Second Order ◽  
Best Fit

Water pollution is the most significant issue due to rapid growing industrial development especially textile dye industry. Therefore, the adsorption process experiment was conducted to determine the removal ability of the adsorbent chosen. The removal rate and adsorption capacity of Phenol red and Cresol were analyzed by using eggshell adsorbent in the adsorption process. The experiment was conducted with parameters of initial concentration, dosage, pH and contact time. Results indicated that the removal rate achieved more than 90% and the adsorption capacity exceeded more than 5 mg/g. The functional group before adsorption process eggshell adsorbent and after adsorption process eggshell adsorbent was analyzed by using FTIR (Fourier Transform Infrared Spectroscopy). The study of adsorption isotherm and kinetics model was carried out to identify the efficiency of the eggshell adsorbent reacting with the dye solution. The adsorption isotherm that applied in this research was Langmuir isotherm, Jovanovic isotherm and Freundlich isotherm. Moreover, Pseudo-first-order and Pseudo-second-order chosen were conducted to determine the kinetic studies. In short, eggshell adsorbent is highly effective on dye removal through adsorption capacity. The functional group of the eggshell adsorbent was found such as alcohols, phenol, alkanes, carbonyls, ester, saturated aliphatic, aldehydes, aromatics, 2°amines and phosphorus. For kinetics study, Freundlich isotherm was analyzed as the best fit isotherm model as it achieved the highest R2 value which is closed to 1 and Pseudo-second-order was analyzed as the best fit kinetic model in this experiment. Therefore, eggshell adsorbent is highly effective in dye removal.

scholarly journals Understanding the physicochemical properties of Zn–Fe LDH nanostructure as sorbent material for removing of anionic and cationic dyes mixture

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rehab K. Mahmoud ◽  
Mohamed Taha ◽  
Amal Zaher ◽  
Rafat M. Amin
Keyword(s):  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Adsorption Process ◽  
Dye Adsorption ◽  
Chemical Properties ◽  
Cationic Dyes ◽  
Anionic Dyes ◽  
Visible Radiation ◽  
X Ray ◽  
Before And After

AbstractIn our work, the removal of cationic and anionic dyes from water was estimated both experimentally and computationally. We check the selectivity of the adsorbent, Zn–Fe layered double hydroxide (LDH) toward three dyes. The physical and chemical properties of the synthesis adsorbent before and after the adsorption process were investigated using X-ray photoelectron spectroscopy, energy dispersive X-ray, X-ray diffraction, FT-IR, HRTEM, and FESEM analysis, particle size, zeta potential, optical and electric properties were estimated. The effect of pH on the adsorption process was estimated. The chemical stability was investigated at pH 4. Monte Carlo simulations were achieved to understand the mechanism of the adsorption process and calculate the adsorption energies. Single dye adsorption tests revealed that Zn–Fe LDH effectively takes up anionic methyl orange (MO) more than the cationic dyes methylene blue (MB) and malachite green (MG). From MO/MB/MG mixture experiments, LDH selectively adsorbed in the following order: MO > MB > MG. The adsorption capacity of a single dye solution was 230.68, 133.29, and 57.34 mg/g for MO, MB, and MG, respectively; for the ternary solution, the adsorption capacity was 217.97, 93.122, and 49.57 mg/g for MO, MB, and MG, respectively. Zn–Fe LDH was also used as a photocatalyst, giving 92.2% and 84.7% degradation at concentrations of 10 and 20 mg/L, respectively. For visible radiation, the Zn–Fe LDH showed no activity.

Determination of Plasminogen by Means of a Chroniogenic Peptide Substrate

1975 ◽  
Author(s):  
P. Friberger ◽  
G. Axelsson ◽  
K. Korsan-Bengtsen
Keyword(s):  
Ionic Strength ◽  
Linear Relationship ◽  
Reaction Rate ◽  
High Rate ◽  
Chromogenic Substrate ◽  
Peptide Substrate ◽  
Ph Optimum ◽  
Optimum Ph ◽  
Slight Inhibition

Plasmin splits the chromogenic substrate B2-Phe-Val-Arg-pNA (S-2160, Bofors) at a relatively high rate. Standard plasmin in glycerol obtained from Nat. Inst, for Biol. Stand, and Contr., London, was tested in a system with Tris buffer of varying pH and ionic strength. The pH optimum for the reaction was found to be 7.4. Variations in ionic strength between 0.05–0.1 had insignificant influence but at higher ionic strength there was a slight inhibition. A linear relationship was found between plasmin and AOD/min. At optimum pH and a final substrate concentration of 0.2 mM 0.1 CTA unit corresponds to approximately 0.10 nkat. Purified plasminogen (AB Kabi, Stockholm, Sweden) in the concentrations 0.02–0.2 CU/ml was activated optimally with streptokinase (Kabikinase® ) in the concentrations 500–2000 IU/ml. Higher concentration gave inhibition. The activity of streptokinase activated plasminogen increased with a decreasing ionic strength. A linear relationship was found between streptokinase activated plasminogen and AOD/min. Approximately 3,000 Plong/units per ml of urokinase was needed to obtain the same activation as with optimal streptokinase concentration. The method has been used for determination of plasminogen in plasma. With final dilution of plasma in the range 1/20–1/200 activated by streptokinase (2000 IU/ml) in a system of pH 8.2, I = 0.05, a linear relationship was found between plasma dilution and AOD/min. The reproducibility in a series of tests is good (variation coefficient < 3%) and with insignificant interference by inhibitors. The determinations were easily carried out in a simple spectrometer (405 nm) and in an automatic reaction rate analyzer (LKB 8600, 410 nm).

Adsorption of Cu(II) and Zn(II) Ions by Solidified Landfilled Sludge and its Pyrolyzed Produce

2014 ◽  
Vol 955-959 ◽  
pp. 2629-2634 ◽  
Author(s):  
Wu Yao ◽  
Wei Qin Zhu ◽  
Yin Na Zhan ◽  
Yang Wu
Keyword(s):  
Surface Roughness ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Functional Group ◽  
Adsorption Process ◽  
Langmuir Equation ◽  
Ftir Analysis ◽  
Aromatic Rings ◽  
Adsorption Capacities ◽  
Hydroxy Aldehydes

In this study, using solidified landfilled sludge (SLS) and its pyrolyzed produce (PSLS) as adsorbents, adsorption characteristics of Cu2+and Zn2+onto SLS and PSLS was investigated. These results revealed that PSLS had more irregular pores and its surface roughness increased, and the surface area of PSLS was twice than that of SLS. Adsorption studies showed that adsorption capacity of Cu2+and Zn2+increased with the increasing dosage of adsorbents, and the adsorption process of Cu2+and Zn2+onto SLS or PSLS could be divided into the first rapid step and the second slower step. Based on Langmuir equation, the maximum limiting adsorption capacities of Cu2+and Zn2+onto PSLS was much higher that onto SLS. Moreover, FTIR analysis showed that the adsorption of Cu2+and Zn2+on SLS depended on active functional group such as hydroxy aldehydes while that relied on the groups such as C=C bond of aromatic rings, Si-O-Si or Si-O-C structures for PSLS.

scholarly journals Penentuan Kapasitas Adsorpsi Selulosa Terhadap Rhodamin B dalam Sistem Dinamis

2017 ◽  
Vol 2 (1) ◽  
pp. 23
Author(s):  
Asnawati Asnawati
Keyword(s):  
Adsorption Capacity ◽  
Flow Rate ◽  
Rhodamine B ◽  
Dynamic Method ◽  
Breakthrough Curves ◽  
Column Diameter ◽  
Ph Optimum ◽  
Model Equations ◽  
Rhodamin B

AbstrakPenelitian ini bertujuan untuk menentukan kapasitas adsorpsi selulosa, massa optimum dan pH optimum. Kapasitas adsorbsi ditentukan dengan sistem dinamis dengan kecepatan 1 mL/12 menit melalui kolom, diameter 8 mm mengandung selulosa. Metoda ini dibuat dengan menvariasikan massa adsorbent dan pH Rhodamine B. kapasitas adsorpsi selulosa ditentukan dengan menggunakan persamaan Thomas. kurva Breakthrough digunakan untuk mengetahui keefektifan kolom dalam mengadsorpsi Massa adsorben divariasikan sebesar 0,1; 0,2; dan 0,3 gram serta pH larutan influen divariasikan pada pH 5, 6 dan 7. Massa adsorben dan pH larutan influen dengan kapasitas adsorpsi paling optimum adalah massa 0,3 gram dan pH 7. Kapasitas adsorpsi selulosa terhadap Rhodamin B sebesar 5, 94 mg/g. Kata kunci: Adsorpsi, Rhodamin B, selulosa, sistem dinamis AbstractThis study is to determine the adsorption capacity of the cellulose to Rhodamine,  the mass optimum and pH optimum. Cellulose adsorption capacity is determined in a dynamic method with a flow rate of 1 mL/12 minutes through the column, diameter of 8 mm, containing cellulose. This method was made variations of the mass of adsorbent and the pH of the influent Rhodamine B solution. Determination of the adsorption capacity of cellulose in this study used the model equations Thomas. Breakthrough curves were used to determine the effectiveness of the column in which cellulose adsorb.  Mass adsorbent and the pH of the influent with the highest adsorption capacity is mass of 0.3 grams and pH 7. The adsorption capacity of cellulose to Rhodamine B is 5,94 mg/g Keywords: Adsorption, Rhodamine B, cellulose, dynamic system

scholarly journals A simple and reliable method for determination of optimum pH in coupled enzyme assays

BioTechniques ◽  
2020 ◽  
Vol 68 (4) ◽  
pp. 200-203
Author(s):  
Lee Bowman ◽  
Rachael Motamed ◽  
Paul Lee ◽  
Kadijah Aleem ◽  
Astha S Berawala ◽  
...  
Keyword(s):  
Lactate Dehydrogenase ◽  
Pyruvate Kinase ◽  
Enzyme Assay ◽  
Reliable Method ◽  
Enzyme Assays ◽  
Ph Optimum ◽  
Optimum Ph

Determination of the optimum pH in a coupled enzyme assay poses significant challenges because altering the pH of the reaction mixture can affect the performance of both enzymes. Here, we demonstrate a simple and reliable method to determine the pH optimum for pyruvate kinase using the pyruvate kinase/lactate dehydrogenase coupled enzyme assay. This simple and reliable method can be broadly adapted to determine the pH optimum for various enzymes that are assayed using a coupled enzyme assay.

scholarly journals Pembuatan Kitosan dari Cangkang Udang sebagai Adsorben Emas (Au)

2017 ◽  
Vol 5 (2) ◽  
pp. 48
Author(s):  
Indra Jaya ◽  
Joni Syaputra ◽  
Dwi Sabda Budi Prasetya ◽  
Dwi Pangga
Keyword(s):  
Acetic Acid ◽  
Moisture Content ◽  
Adsorption Capacity ◽  
Metal Ion ◽  
Glacial Acetic Acid ◽  
Functional Group ◽  
Shrimp Shell ◽  
Before And After ◽  
White Colour ◽  
Chitin Powder

[Title: Making Chitosan From Shrimp Cup As Gold (Au) Adsorben]. This study aims to make chitosan from shrimp shell as golden adsorbent. Stages of chitosan preparation include demineralization stage using 1,5M HCL, deproteination stage using 3.5% NaOH to obtain chitin powder, then followed by chitin deacetylation stage using 60% NaOH to produce an anime that is chitosan. Subsequently, the chitosan obtained was characterized, analyzed functional group with FTIR and determined its adsorption capacity against Au metal ion, Au content in the sample before and after adsorption was measured using AAS. The results showed chitosan characterization as follows: rendeman 45.83%, have powder texture, white colour, odourless, have moisture content 1.55%, perfectly soluble in glacial acetic acid 2% and purple positive with ninhydrin solution showed chitin has turned into chitosan. Based on calculations from the results of the resulting chitosan FTIR data has a degree of deacetylation 71.17%. From the result of analysis by using AAS that chitosan obtained able to adsorb Au metal from concentration 8.55 ppm decrease until 5,09 ppm with adsorption percentage equal to 40.46%.

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