scholarly journals Adsorption of Cr(VI) Ions using Activated Carbon Produced from Indian Water Chestnut (Trapa natans) Peel Powder

2020 ◽  
Vol 32 (4) ◽  
pp. 876-880
Author(s):  
Maninder Singh ◽  
D. P. Tiwari ◽  
Mamta Bhagat
Keyword(s):  
Heavy Metals ◽  
Metal Ions ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Metal Ion ◽  
Ion Concentration ◽  
Solution Ph ◽  
Indian Water ◽  
Trapa Natans

The indiscriminate discharge of heavy metals into water and soil from anthropogenic practices is becoming prominent threat to the environment. Heavy metals like chromium, cadmium, lead, arsenic, nickel etc. are heavily toxic and carcinogenic in nature. This study emphasizes the adequacy of activated water chest nut (Trapa natans) peel powder as a new adsorbent material for removal of chromium(VI) metal ions. Adsorption experiments were performed in batch process. Various process parameters like contact time, temperature, solution pH, dose of adsorbent, metal ion concentration etc. were optimized. The physico-chemical properties of adsorbent material were characterized by FTIR and XRD. The morphology, topology of adsorbent surface was characterized by scanning electron microscopy (SEM) and Brunauer, Emmett and Teller (BET) which revealed a highly porous structure and available specific surface area. The adsorption capacity (maximum) was counted as 59.17 mg/g and specific surface area was found 23.467 m2/g at a pH 7. The adsorption process for Cr(VI) ions was in a good agreement with Langmuir isotherm. The process also followed pseudo second order kinetics. The obtained result shows that activated water chest nut (Trapa natans) peel powder (AWCPP) can be a hopeful low-cost and eco-friendly bio-adsorbent for removal of Cr(VI) metal ions and also better adsorbent than other various reported adsorbents.

scholarly journals PHENOL OXIDATION USING NATURAL ZEOLITE SUPPORTED METAL ION CATALYST

2010 ◽  
Vol 8 (2) ◽  
pp. 215-218
Author(s):  
Sri Wardhani ◽  
Danar Purwonugroho ◽  
Diah Mardiana
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Natural Zeolite ◽  
Metal Ion ◽  
Surface Characteristics ◽  
Ion Concentration ◽  
Rate Of Reaction ◽  
Different Temperatures ◽  
Oxygen Oxidation

Phenol which contained in waste water has to be reduced and it could be done by oxygen oxidation.  In order to increase the rate of reaction it was needed a catalyst. In this research the capability of various catalysts, namely zeolite-Zn(II), zeolite-Cu(II) and zeolite-Co(II)in oxidation of phenol has been investigated. The aim of this research was to study the type of metal ion catalyst towards the percentage of oxidated phenol. The oxidation process were carried out in an aqueous phenol of 100 ppm with oxygen flow rate of 200 mL/min. in the presence of catalysts with 0.2M of initial impregnation concentration. The capabilities of catalysts were performed by calculating the activation energy and it was done at two different temperatures, i.e. 70 and 90 oC. The percentage of oxidated phenol was determinated by measuring its concentration using UV-VIS spectrophotometer. In addition, the impregnated metal was calculated by measuring the ion concentration remains in the filtrate solution and it was determined using Atomic Absorption Spectrophotometer. The results showed that metal ion types affected the catalytic activity. The order of phenol oxidationactivity decreased as Co(II) > Cu(II) > Zn(II). The surface characteristics of catalysts were supported by pore volume and pore diameter i.e 0.009 cm3/g and 16.59 Å for Zn(II) whereas specific surface area was 10.32 m2/g for Zn(II), 0.004 cm3/g and 24.37 Å for Cu(II) whereas specific surface area was 3.57 m2/g for Cu(II), 0.001 cm3/g and 19.63 Å for Co(II) whereas specific surface area was 10.26m2/g for Co(II).   Keywords: phenol,natural zeolite, catalyst, oxidation

scholarly journals Adsorption of pharmaceuticals from aqueous solutions using biochar derived from cotton gin waste and guayule bagasse

Biochar ◽  
2020 ◽  
Author(s):  
Marlene C. Ndoun ◽  
Herschel A. Elliott ◽  
Heather E. Preisendanz ◽  
Clinton F. Williams ◽  
Allan Knopf ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Functional Groups ◽  
Specific Surface Area ◽  
High Surface ◽  
Strong Interactions ◽  
Solution Ph ◽  
Experimental Conditions ◽  
Cotton Gin Waste ◽  
Cotton Gin

Abstract Biochars produced from cotton gin waste (CG) and guayule bagasse (GB) were characterized and explored as potential adsorbents for the removal of pharmaceuticals (sulfapyridine-SPY, docusate-DCT and erythromycin-ETM) from aqueous solution. An increase in biochar pyrolysis temperature from 350 οC to 700 οC led to an increase in pH, specific surface area, and surface hydrophobicity. The electronegative surface of all tested biochars indicated that non-Coulombic mechanisms were involved in adsorption of the anionic or uncharged pharmaceuticals under experimental conditions. The adsorption capacities of Sulfapyridine (SPY), Docusate (DCT) and Erythromycin (ETM) on biochar were influenced by the contact time and solution pH, as well as biochar specific surface area and functional groups. Adsorption of these pharmaceutical compounds was dominated by a complex interplay of three mechanisms: hydrophobic partitioning, hydrogen bonding and π–π electron donor–acceptor (EDA) interactions. Despite weaker π–π EDA interactions, reduced hydrophobicity of SPY− and increased electrostatic repulsion between anionic SPY− and the electronegative CG biochar surface at higher pH, the adsorption of SPY unexpectedly increased from 40% to 70% with an increase in pH from 7 to 10. Under alkaline conditions, adsorption was dominated by the formation of strong negative charge-assisted H-bonding between the sulfonamide moiety of SPY and surface carboxylic groups. There seemed to be no appreciable and consistent differences in the extent of DCT and ETM adsorption as the pH changed. Results suggest the CG and GB biochars could act as effective adsorbents for the removal of pharmaceuticals from reclaimed water prior to irrigation. High surface area biochars with physico-chemical properties (e.g., presence of functional groups, high cation and anion exchange capacities) conducive to strong interactions with polar-nonpolar functionality of pharmaceuticals could be used to achieve significant contaminant removal from water. Graphic Abstract

Bi2WO6 Nanoparticles Prepared by Combustion Synthesis with Different Fuels and their Photocatalytic Activity

2014 ◽  
Vol 604 ◽  
pp. 93-101
Author(s):  
Maris Kodols ◽  
Sabine Didrihsone ◽  
Janis Grabis
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Citric Acid ◽  
Ethylene Glycol ◽  
Specific Surface ◽  
Crystallite Size ◽  
Combustion Synthesis ◽  
Surface Area ◽  
Specific Surface Area ◽  
Solution Ph

The influence of glycine, glycerine, ethylene glycol and citric acid fuel and their ratio to NO3- on formation and dispersity of Bi2WO6 nanoparticles prepared by combustion synthesis has been studied. The pure crystalline Bi2WO6 with specific surface area 24,8 m2/g and crystallite size of 28 nm was obtained by using glycerine as fuel at its ratio to NO3- of 0,67. The photocatalytic activity of the prepared Bi2WO6 in degradation of methylene blue depended on its specific surface area of samples and solution pH.

scholarly journals Preparation of phosphorus-doped boron nitride and its adsorption of heavy metals from flue gas

2020 ◽  
Vol 7 (8) ◽  
pp. 200079
Author(s):  
Yanlong Li ◽  
Hongxi Li ◽  
Rundong Li ◽  
Xin Su ◽  
Shengqiang Shen
Keyword(s):  
Heavy Metals ◽  
Boron Nitride ◽  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Flue Gas ◽  
Maximum Adsorption Capacity ◽  
Addition Rate ◽  
Phosphorus Doped

Boron nitride, also known as white graphene, has attracted extensive attention in the fields of adsorption, catalysis and hydrogen storage due to its excellent chemical properties. In this study, a phosphorus-doped boron nitride (P-BN) material was successfully prepared using red phosphorus as a dopant for the preparation of porous boron nitride precursors. The phosphorus content in the P-BN was adjusted based on the addition rate of phosphorus. The specific surface area of P-BN first increased and then decreased with increasing addition rate of phosphorus. The maximum specific surface area was 837.8 m 2 g −1 when the phosphorus addition rate was 0.50. The P-BN prepared in the experiments was used as an adsorbent, and its adsorption capacity for heavy metals from flue gas was investigated. In particular, P-BN presented a stronger adsorption selectivity for zinc compared with other heavy metals, and its adsorption capacity for zinc was 5–38 times higher than for other heavy metals. The maximum adsorption capacity of P-BN for zinc and copper in a single heavy metal atmosphere was 69.45 and 53.80 mg g −1 , respectively.

scholarly journals Zeolite Synthesis from Brazilian Coal Fly Ash for Removal of Zn2+ and Cd2+ from Water

2011 ◽  
Vol 356-360 ◽  
pp. 1900-1908 ◽  
Author(s):  
Juliana De Carvalho Izidoro ◽  
Denise Alves Fungaro ◽  
Shao Bin Wang
Keyword(s):  
Fly Ash ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Metal Ion ◽  
Raw Materials ◽  
Coal Fly Ash ◽  
Mineralogical Composition ◽  
Batch Process ◽  
Metal Ion Removal

A Brazilian fly ash sample (CM1) was used to synthesize zeolites by hydrothermal treatment. Products and raw materials were characterized in terms of real density (Helium Pycnometry), specific surface area (BET method), morphological analysis (SEM), chemical composition (XRF) and mineralogical composition (XRD). The zeolites (ZM1) from fly ash were used for metal ion removal from water. Results indicated that hydroxy-sodalite zeolite could be synthesized from fly ash sample. The zeolite presented higher specific surface area and lower SiO2/Al2O3ratio than the ash precursor. The adsorption showed that cadmium is more preferentially adsorbed on ZM1 than zinc. The adsorption equilibrium time for both Zn2+and Cd2+was 20 hours in a batch process. The adsorption isotherms were better fitted by the Langmuir model and the highest percentages of removal using ZM1 were obtained at pH 6 and 5 and doses of 15 and 18 g L-1for Zn2+and Cd2+, respectively. Thermodynamic studies indicated that adsorption of Zn2+and Cd2+by ZM1 was a spontaneous, endothermic process and presented an increase of disorder at the interface solid/solution.

Electrosorptive Deionization Based on Activated Carbon Capacitor Prepared from Bamboo Char

2011 ◽  
Vol 233-235 ◽  
pp. 378-381
Author(s):  
Ling Zhang ◽  
Dan Zuo ◽  
Su Li Guo ◽  
Zhong Cao ◽  
Jun Liu ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Metal Ions ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Tap Water ◽  
High Specific Surface Area ◽  
Carbon Electrodes ◽  
Carbon Electrode ◽  
Direct Voltage

A kind of bamboo char with high specific surface area has been studied as the absorption material of the activated carbon electrodes, and the electrosorptive deionization ability of the as-obtained electrodes for elimination of metal ions in tap water has been examined under certain direct voltage. The effects of the distance between the elect rode plates, and the numbers of the electrode plates have been investigated in detail. The results show that the electrodes exhibit the optimal deionization ability over 2 cm of distance between the electrode plates and 4 couples of the elect rode plates. The reverse wash treatment indicates that the activated carbon electrodes can be cycle used. The efficiency order of the electrosorptive deionization of different metal ions on the activated carbon electrode has been summarized as follows: Pb2+＞Cu2+＞Cr3+＞Cd2+.

scholarly journals Optimisation and Modelling of Pb (II) and Cu (II) Biosorption onto Red Algae (Gracilaria changii) by Using Response Surface Methodology

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2325 ◽  
Author(s):  
Mubeen Isam ◽  
Lavania Baloo ◽  
Shamsul Rahman Mohamed Kutty ◽  
Saba Yavari
Keyword(s):  
Response Surface Methodology ◽  
Metal Ions ◽  
Response Surface ◽  
Metal Ion ◽  
Ion Concentration ◽  
Solution Ph ◽  
Gracilaria Changii ◽  
Red Macroalgae ◽  
Removal Of Metal ◽  
Removal Of Metal Ions

The removal of Pb (II) and Cu (II) ions by using marine red macroalgae (Gracilaria changii) as a biosorbent material was evaluated through the batch equilibrium technique. The effect of solution pH on the removal of metal ions was investigated within the range of 2–7. The response surface methodology (RSM) technique involving central composite design (CCD) was utilised to optimise the three main sorption parameters, namely initial metal ion concentration, contact time, and biosorbent dosage, to achieve maximum ion removal. The models’ adequacy of response was verified by ANOVA. The optimum conditions for removal of Pb (II) and Cu (II) were as follows: pH values of 4.5 and 5, initial concentrations of 40 mg/L, contact times of 115 and 45 min, and biosorbent dosage of 1 g/L, at which the maximum removal percentages were 96.3% and 44.77%, respectively. The results of the adsorption isotherm study showed that the data fitted well with the Langmuir’s model for Pb (II) and Cu (II). The results of the adsorption kinetic study showed that the data fitted well with the pseudo-second order model for Pb (II) and Cu (II). In conclusion, red alga biomass exhibits great potential as an efficient low-cost sorbent for removal of metal ions.

Sintesis katalis NiMo untuk hydrotreating coker nafta

2018 ◽  
Vol 5 (1) ◽  
pp. 365
Author(s):  
Hidayah Dwi Lestari ◽  
S Subagjo ◽  
IGBN Makertihartha
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Catalyst Activity ◽  
Catalyst Characterization ◽  
Impregnation Method ◽  
Solution Ph ◽  
Ammonium Heptamolybdate ◽  
Catalyst Synthesis ◽  
Nimo Catalyst

NiMo catalyst synthesis aimed to make catalyst based on nickel molybdenum Ni(4%-wt) Mo(20%­ wt)γ-Al2O3 by using ammonium heptamolybdate as source of Mo and nickel nitrate as source of Ni, and γ-Al2O3  as a support.  The catalysts are prepared by sequential-dry impregnation method. The preparation parameters that studied are characteristic of support, the ammonium heptamolybdate solution pH, volume of impregnation solution, and stages impregnation of ammonium heptamolybdate solution. The preparation parameter affected the Mo distribution to the support. The inhomogeneous Mo distribution produced MoO crystal in the catalyst. The characterization of catalyst consists of N2 adsorption, XRD, SEM EDAX, and XRF. The results of catalyst characterization are specific surface area, crustallinity of catalyst, deposition metal in pore of support, and catalyst compositions. The NiMo catalyst activity is tested by using coker naphtha feed. The result of activity test is compared with commercial catalyst to know how the performance of catalyst. The composition of NiMo 15 catalyst is 19.43%-b MoO3 dan 2.61%-b NiO. NiMo catalyst with composition 20%-wt Mo and 4%-wt Ni needs support with specific surface area larger than 212 m2/g cat, to get more homogenous Mo distribution. The ammonium heptamolybdate solution pH that is good to use in impregnation to get a homogenous Mo distribution is less or same as 5.Keywords: Hydrotreating, Nimo/γ-Al2O3, ImpregnationAbstrakSintesis katalis NiMo dilakukan untuk membuat katalis hydrotreating dengan komposisi 20%-b MoO3 4%-b NiO/γAl2O3. Sumber Mo dan Ni yang digunakan berasal dari amonium heptamolibdat dan nikel nitrat dengan penyangga γAl2O3.  Preparasi katalis dilakukan dengan menggunakan metode impregnasi kering bertahap. Parameter preparasi yang dipelajari adalah karakteristik penyangga, pH larutan amonium heptamolibdat, volum larutan impregnasi, dan tahapan impregnasi larutan amonium heptamolibdat. Parameter preparasi tersebut mempengaruhi distribusi Mo pada penyangga. Distribusi Mo yang tidak merata akan menghasilkan kristal MoO3 di dalam katalis. Katalis NiMo dikarakterisasi dengan menggunakan analisa adsorpsi N2 difraksi sinar X, SEM EDAX, dan XRF. Hasil karakterisasi katalis berupa luas permukaan spesifik, kristalinitas katalis, gambaran deposisi logam pada pori penyangga, dan komposisi katalis. Katalis NiMo diuji aktivitasnya dengan menggunakan umpan coker nafta. Hasil uji aktivitas dibandingkan dengan katalis komersial untuk mengetahui kinerja dari katalis tersebut. Katalis NiMo 15 memiliki komposisi 19,43%-b MoO3 dan 2,61%-b NiO. Luas permukaan spesifik penyangga yang dibutuhkan untuk membuat katalis NiMo dengan komposisi 20%-b Mo03 dan 4%-b NiO adalah lebih besar dari 212 m2/g kat, agar didapatkan distribusi Mo yang lebih merata. pH larutan amonium heptamolibdat yang baik untuk digunakan dalam impregnasi agar didapatkan distribusi Mo yang merata adalah ≤ 5.Kata Kunci: Hydrotreating, Nimo/ γAl2O3, lmpregnasi

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