scholarly journals Isolation, Characterization and Application of Humin From Sumatran Peat Soils as Adsorbent for Naphtol Blue Black and Indigosol Blue Dyes

Molekul ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. 67
Author(s):  
Maya Rahmayanti ◽  
Indah Nurhikmah ◽  
Feni Larasati
Keyword(s):  
Kinetics Model ◽  
Cooh Group ◽  
Total Acidity ◽  
Peat Soils ◽  
Quantitative Calculation ◽  
Ftir Characterization ◽  
Optimum Ph ◽  
Carboxylic Groups ◽  
Stretching Vibration ◽  
Ph Conditions

Isolation, characterization and application of humin as adsorbent for naphtol blue black (NBB) and indigosol blue (IB) dyes has been carried out. Humin application in this study aims to obtain the optimum pH conditions and kinetics model for adsorption NBB and IB dyes onto humin. Humin was isolated from peat soils originating from Riau, Sumatra. The isolation method used was the alkaline extraction method and the characterization of humin using FTIR spectrophotometer. The total acidity, carboxylic groups and –OH phenolic groups of humin were determined quantitatively using the acid-base titration method. FTIR characterization indicated the presence of an –OH group which was indicated by the appearance of absorption at a wavelength of 3425.3 cm-1 and a stretching vibration of C=O from the –COOH group at a wavelength of 1705 cm-1. The quantitative calculation of the total acidity value, the content of the carboxylic group and the -OH group phenolics of humin were 508.47 cmol kg-1, 289.42 cmol kg-1 and 219.05 cmol kg-1, respectively. The optimum pH conditions for adsorption NBB and IB onto humin occurred at pH 5 and pH 2, respectively. The adsorption kinetics model of NBB and IB on humin followed the Ho kinetics model.

Coagulation-Direct Filtration of Soft, Low Alkalinity Humic Waters

1999 ◽  
Vol 40 (9) ◽  
pp. 55-62 ◽  
Author(s):  
Bjørnar Eikebrokk
Keyword(s):  
Natural Organic Matter ◽  
Pilot Scale ◽  
Quality Parameters ◽  
Efficient Removal ◽  
Direct Filtration ◽  
Ph Values ◽  
Optimum Ph ◽  
Calcium Sources ◽  
Ph Conditions ◽  
Removal Efficiencies

Optimisation of coagulation-direct filtration processes with respect to efficient removal of humic substances, i.e. natural organic matter (NOM) has gained a lot of focus in many countries over the last years. This paper presents experimental results from pilot scale research studies aimed at optimising the coagulation-direct filtration process applied to soft and humic raw waters with low turbidity and alkalinity levels. Comprehensive tests of 3 types of raw waters with different NOM content, 5 types of coagulants, and 3 calcium sources for the purpose of corrosion control have been conducted. Removal efficiencies with respect to relevant water quality parameters are presented, with typical relationships between raw water NOM content, coagulant dose requirements and pH. Generally, when applying metal-based coagulants, residual metal concentration was the critical parameter regarding minimum coagulant dose requirements. Typical NOM removal efficiencies were in the range of 75-90% and 40-70% with respect to colour and organic carbon, respectively. Optimum pH conditions for the removal of NOM and/or residual metals do not always coincide with that of turbidity. The experiments also showed that poly-aluminium and ferric chlorides might have some benefits over alum in terms of dose requirements and range of optimum pH values, and that chitosan may be used for colour removal with good results.

scholarly journals Urea coated with oxidized charcoal reduces ammonia volatilization

2012 ◽  
Vol 36 (4) ◽  
pp. 1221-1230 ◽  
Author(s):  
Diogo Mendes de Paiva ◽  
Reinaldo Bertola Cantarutti ◽  
Gelton Geraldo Fernandes Guimarães ◽  
Ivo Ribeiro da Silva
Keyword(s):  
Urease Activity ◽  
Eucalyptus Grandis ◽  
Inhibitory Effect ◽  
Ionization Constants ◽  
Total Acidity ◽  
Nh3 Volatilization ◽  
Carboxylic Groups ◽  
Oxidized Carbon ◽  
Acidic Compounds

Urea is the most consumed nitrogen fertilizer in the world. However, its agronomic and economic efficiency is reduced by the volatilization of NH3, which can reach 78 % of the applied nitrogen. The coating of urea granules with acidic compounds obtained by charcoal oxidation has the potential to reduce the volatilization, due to the acidic character, the high buffering capacity and CEC. This work aimed to evaluate the effect of HNO3-oxidized carbon on the control of NH3 volatilization. These compounds were obtained by oxidation of Eucalyptus grandis charcoal, produced at charring temperatures of 350 and 450 ºC, with 4.5 mol L-1 HNO3. The charcoal was oxidized by solubilization in acidic or alkaline medium, similar to the procedure of soil organic matter fractionation (CHox350 and CHox450). CHox was characterized by C, H, O, N contents and their respective atomic relations, by the ratio E4 (absorbance 465 nm) by E6 (absorbance 665 nm), and by active acidity and total acidity (CEC). The inhibitory effect of CHox on the urease activity of Canavalia ensiformis was assessed in vitro. The NH3 volatilization from urea was evaluated with and without coating of oxidized charcoal (U-CHox350 or U-CHox450) in a closed system with continuous air flow. The pH of both CHox was near 2.0, but the total acidity of CHox350 was higher, 72 % of which was attributed to carboxylic groups. The variation in the ionization constants of CHox350 was also greater. The low E4/E6 ratios characterize the high stability of the compounds in CHox. CHox did not inhibit the urease activity in vitro, although the maximum volatilization peak from U-CHox450 and U-CHox350 occurred 24 h after that observed for uncoated urea. The lowest volatilization rate was observed for U-CHox350 as well as a 43 % lower total amount of NH3 volatilized than from uncoated urea.

scholarly journals Plasma Treatment of Polymer Powder as an Effective Tool to Functionalize Polymers: Case Study Application on an Amphiphilic Polyurethane

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2109 ◽  
Author(s):  
Rossella Laurano ◽  
Monica Boffito ◽  
Alessandro Torchio ◽  
Claudio Cassino ◽  
Valeria Chiono ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Gas Flow ◽  
Polymer Degradation ◽  
Water Soluble ◽  
Cooh Group ◽  
Water Soluble Polymer ◽  
Acid Vapor ◽  
Custom Made ◽  
Carboxylic Groups ◽  
Ar Gas

Plasma treatment is a widely applied, easy, fast, and highly reproducible surface modification technique. In this work powder plasma treatment was exploited to expose carboxylic groups along the backbone of a water soluble polymer. Specifically, a custom-made amphiphilic poly(ether urethane) containing Poloxamer® 407 blocks (Mw = 54,000 Da) was first synthesized and its powders were plasma treated in the presence of Acrylic Acid vapor. To maximize –COOH group exposure while preventing polymer degradation, different Ar gas flow rates (i.e., 10, 30, and 50 sccm) were investigated. Upon gas flow increase, significant polymer degradation was observed, with a 35% molecular weight reduction at 50 sccm Ar flow rate. On the other hand, the highest number of exposed carboxylic groups (5.3 × 1018 ± 5.5 × 1017 units/gpolymer) was obtained by setting gas flow at 10 sccm. Hence, a gas flow of 10 sccm turned out to be the best set-up to maximize –COOH exposure while preventing degradation phenomena. Additionally, upon plasma treatment, no detrimental effects were observed in the thermoresponsiveness of polymer aqueous solutions, which was ensured by Poloxamer® 407 blocks. Therefore, the newly developed technology here applied on an amphiphilic poly(ether urethane) could pave the way to the tailored design of a plethora of different multifunctional hydrogels.

scholarly journals Sifat Fisik, Kimia dan FTIR Spektrofotometri Gambut Hidrofobik Kalimantan Tengah

2013 ◽  
Vol 14 (2) ◽  
pp. 159-166
Author(s):  
Sri Nuryani Hidayah Utami ◽  
Azwar Maas ◽  
Bostang Radjagukguk ◽  
Benito Heru Purwanto
Keyword(s):  
Soil Moisture ◽  
Chemical Analysis ◽  
Moisture Content ◽  
Physical Properties ◽  
Soil Moisture Content ◽  
Ftir Spectra ◽  
Water Repellent ◽  
Total Acidity ◽  
Peat Soils ◽  
Oven Drying

Peat soils naturally have hydrophilic or waterloving character with highly capable of exchanging the cations and cycling the nutrients from the vegetations. This water-loving character is altered to water-repellent character in hydrophobic peat soils. This research was aimed toobserve deeply the functional bunch carrier of hydrophobic and hydrophilic peat soils as shown by FTIR spectra in relation with inherent chemical and physical properties of the soils. Five peat soils consisted of two native andartificial hydrophobic peat soils and one sample of hydrophilic peat soils were studied. Artificial hydrophobic peat soils were yielded by oven-drying the native hydrophobic peat soils at 50 oC for 10 hours. FTIR spectra can distinguish the functional bunch carrier of hydrophobic and hydrophilic peat soils. FTIR spectra of hydrophobic peat soils showed degradation of hydrophilic bunch carrier (OH and COOH) and increase of the hydrophobic bunch carrier (tying aromatic from esther and ether). Chemical analysis of the hydrophobic peat soils also indicated the decrease of OH and COOH content, decrease of CEC , soil total acidity and soil moisture content.

Electrical and optical properties of well-dispersed MWCNTs/PVA nanocomposites under different pH conditions

2018 ◽  
Vol 32 (4) ◽  
pp. 442-453 ◽  
Author(s):  
Emad AM Farrag ◽  
Rami A Abdel-Rahem ◽  
SS Ibrahim ◽  
Ayman S Ayesh
Keyword(s):  
Room Temperature ◽  
Ph Value ◽  
Poly Vinyl Alcohol ◽  
Electrical And Optical Properties ◽  
Multiwalled Carbon ◽  
Casting Technique ◽  
Ph Values ◽  
Current Voltage ◽  
Optimum Ph ◽  
Ph Conditions

Series of polymer nanocomposites films consisting of pretreated multiwalled carbon nanotubes (PT-MWCNTs) and poly (vinyl alcohol) (PVA) were prepared at room temperature. The MWCNTs were initially pretreated with 1.0 M sulfuric acid (PT-MWCNTs) and then allowed to disperse in aqueous solutions at different pH values (2–14). It was found that the dispersion of the PT-MWCNTs is a pH dependent. The best PT-MWCNTs dispersion was obtained at pH = 10. Films of PT-MWCNTs/PVA, at this optimum pH-value, were then prepared by casting technique at different PT-MWCNTs weight fractions. The resulted PT-MWCNTs/PVA films were characterized through the direct visualization, Fourier transform infrared, and morphology test. Besides, current–voltage and direct current electrical conductivity for PT-MWCNTs/PVA nanocomposites at 60°C showed that the conductivity mechanism was ohmic and the percolation threshold was around 0.8 wt% PT-MWCNTs. Optical results showed that PT-MWCNTs are homogeneously distributed in the neat PVA and optical gap is significantly decreased from 4.40 to 2.96 eV.

scholarly journals BIOSORPTION OF Cr(III) ION ON ALGAE Eucheuma spinosum BIOMASSA

2010 ◽  
Vol 8 (1) ◽  
pp. 78-82 ◽  
Author(s):  
I Wayan Sudiarta ◽  
Ni Putu Diantariani
Keyword(s):  
Contact Time ◽  
Interaction Mechanism ◽  
Electrostatic Attraction ◽  
Total Acidity ◽  
Biosorption Capacity ◽  
Optimum Ph

Studies on biosorption and desorption of Cr(III) on algae (Eucheuma spinosum) adsorbent have been carried out. These studies included determination of biosorbent acidity, optimum pH, contact time of biosorption, isoterm and biosorption capacity, and mechanisms of interaction between Cr(III) and algae (E. spinosum) biosorben. Mechanisms of interaction were evaluated by sequential desorption of Cr(III) on algae biosorben by using aquadest, 1 M HCl and 0.05 M Na2EDTA. The result showed that the total acidity of algae biosorbent was 4.15 ± 0.33 mmol/g, the optimum pH was 3, and the optimum contact time was 20 min. Biosorption capacity of algae (E. spinosum) toward chromium (III) was 57.33 mg/g. The highest desorption of Cr(III) achieved when 1 M HCl was used, i.e. 51,01%, wheareas desorptions using aquadest and 0.05 M Na2EDTA were relatively low, i.e. 2.07% and 2.38% respectively. This result indicates that the main interaction mechanism of Cr(III) on algae was electrostatic attraction.   Keywords : Biosorption, Cr(III), Eucheuma Spinosum

scholarly journals Bioleaching of Gold from Silicate Ore by Macrococcus caseolyticus and Acinetobacter calcoaceticus: Effect of Medium, Amino Acids and Growth Supernatant

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 580
Author(s):  
Kanjana Kudpeng ◽  
Parinda Thayanukul ◽  
Paitip Thiravetyan
Keyword(s):  
Amino Acids ◽  
High Performance ◽  
Acinetobacter Calcoaceticus ◽  
Gold Leaching ◽  
Term Operation ◽  
Carboxylic Groups ◽  
Amine Groups ◽  
Ph Conditions ◽  
The Fourier Transform

The aims of this work were to study the gold leaching by the isolated bacteria from silicate ore. Three strains were isolated and identified as Macrococcus caseolyticus, Acinetobacter calcoaceticus, and Bacillus sp. MBEA40. However, only M. caseolyticus and A. calcoaceticus were capable of gold bioleaching. In order to examine only the effect of microorganisms involved in the gold bioleaching process, minimal medium and ethanol mineral salt medium without amino acids were used for culturing M. caseolyticus and A. calcoaceticus, respectively. The result showed that the growth supernatant (in the absence of microorganisms) of both strains might be more suitable to leaching gold from ore than leaching by microorganisms (in the presence of microorganisms) directly. This might be due to the fact that there is no interference of gold absorption and metal toxicity in microorganisms in the long-term operation. The result also confirmed that amino acids/peptides/proteins produced by microorganisms might be involved in gold bioleaching, as shown in the high-performance liquid chromatography (HPLC) results. The Fourier transform infrared spectroscopy (FTIR) study also found that amine groups and carboxylic groups played important roles in gold bioleaching by M. caseolyticus and A. calcoaceticus. In addition, the bioleaching process had significantly higher gold leaching than mixed pure amino acids due to the growth supernatant containing mixed amino acids/peptides/proteins and other compounds. Therefore, the growth supernatant of M. caseolyticus and A. calcoaceticus can be applied in gold bioleaching under neutral pH conditions, which is considered to be a safe, not corrosive, and environmentally friendly leaching process. This study is also needed further study in order to increase the percentage of gold bioleaching and decrease times.

scholarly journals Characteristics of a Microcystin-Degrading Bacterium under Alkaline Environmental Conditions

2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Kunihiro Okano ◽  
Kazuya Shimizu ◽  
Yukio Kawauchi ◽  
Hideaki Maseda ◽  
Motoo Utsumi ◽  
...  
Keyword(s):  
Water Bloom ◽  
Rrna Gene ◽  
Degrading Bacterium ◽  
Degrading Bacteria ◽  
Optimum Ph ◽  
Degradation Activity ◽  
Ph Conditions ◽  
Toxic Blooms ◽  
The 16S Rrna Gene ◽  
Water Blooms

The pH of the water associated with toxic blooms of cyanobacteria is typically in the alkaline range; however, previously only microcystin-degrading bacteria growing in neutral pH conditions have been isolated. Therefore, we sought to isolate and characterize an alkali-tolerant microcystin-degrading bacterium from a water bloom using microcystin-LR. Analysis of the 16S rRNA gene sequence revealed that the isolated bacterium belonged to the genusSphingopyxis, and the strain was named C-1.Sphingopyxissp. C-1 can grow; at pH 11.0; however, the optimum pH for growth was pH 7.0. The microcystin degradation activity of the bacterium was the greatest between pH 6.52 and pH 8.45 but was also detected at pH 10.0. ThemlrAhomolog encoding the microcystin-degrading enzyme in the C-1 strain was conserved. We concluded that alkali-tolerant microcystin-degrading bacterium played a key role in triggering the rapid degradation of microcystin, leading to the disappearance of toxic water blooms in aquatic environments.

scholarly journals Pectin methylesterase activity determined by different methods and thermal inactivation of exogenous pme in mango juice

2011 ◽  
Vol 35 (5) ◽  
pp. 987-994 ◽  
Author(s):  
Samantha Lemke Gonzalez ◽  
Regina Cristina Aparecida Lima ◽  
Eliana Beleski Borba Carneiro ◽  
Mareci Mendes de Almeida ◽  
Neiva Deliberali Rosso
Keyword(s):  
Methyl Ester ◽  
Thermal Inactivation ◽  
Alcohol Oxidase ◽  
Pectin Methylesterase ◽  
Bromophenol Blue ◽  
Vis Spectroscopy ◽  
Optimum Ph ◽  
Carboxylic Groups ◽  
Mango Juice

Pectin methylesterase (PME) hydrolyzes methyl ester groups in pectin chains to form carboxylic groups, releasing methanol and H3O+. The aim of this study was to determine PME activity in samples of pectinases by UV-VIS spectroscopy, to measure the acid and methanol produced in the reaction of pectin with pectinase and to verify the thermal inactivation of exogenous PME in mango juice. The activity of PME in samples of pectinase was determined by potentiometry, UV-VIS spectroscopy, and by the action of alcohol oxidase. The reaction showed greater activity at pH 4.0 to 4.5 and at a temperature of 45° C. PME activity determined by UV-VIS spectroscopy with bromophenol blue indicator showed a good correlation with the activity determined by potentiometry and with alcohol oxidase. The results showed that bromophenol blue indicators can be used to determine PME activity in samples of pectinases where the optimum pH is located in the acidic range. The thermal inactivation of exogenous PME in mango juice occurred at 75° C for 20 min of exposure.

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