scholarly journals Efficient and Fast Removal of Oils from Water Surfaces via Highly Oleophilic Polyurethane Composites

Toxics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 186
Author(s):  
Antonio De Nino ◽  
Fabrizio Olivito ◽  
Vincenzo Algieri ◽  
Paola Costanzo ◽  
Antonio Jiritano ◽  
...  

In this study we evaluated the oil adsorption capacity of an aliphatic polyurethane foam (PU 1) and two of its composites, produced through surface coating using microparticles of silica (PU-Si 2) and activated carbon (PU-ac 3). The oil adsorption capacity in diesel was improved up to 36% using the composite with silica and up to 50% using the composite with activated carbon with respect to the initial PU 1. Excellent performances were retained in gasoline and motor oil. The adsorption was complete after a few seconds. The process follows a monolayer adsorption fitted by the Langmuir isotherm, with a maximum adsorption capacity of 29.50 g/g of diesel for the composite with activated carbon (PU-ac 3). These materials were proved to be highly oleophilic for oil removal from fresh water and sea water samples. Regeneration and reuse can be repeated up to 50 times by centrifugation, without a significant loss in adsorption capacity.

2012 ◽  
Vol 161 ◽  
pp. 162-166 ◽  
Author(s):  
Xiao Lan SONG ◽  
Ying Zhang ◽  
Cheng Yin Yan ◽  
Wen Juan Jiang ◽  
Hong Jiang Xie

The adsorption performance of mercury ion onto activated carbon prepared from rice husk with NaOH was carried out at initial concentration of 100 mg/L. The activated carbon obtained at 800 °C possessed the outstanding specific surface area of 2786 m2/g. And the results showed that the maximum adsorption capacity of Hg2+ was recorded as 342.0 mg/g due to abundant micropores of 1.076 nm. In addition, the adsorption data were well explained by the Langmuir model with the monolayer adsorption capacity of 555.6 mg/g.


2012 ◽  
Vol 164 ◽  
pp. 297-301 ◽  
Author(s):  
Wei Fang Dong ◽  
Li Hua Zang ◽  
Qing Chao Gong ◽  
Cun Cun Chen ◽  
Cai Hong Zheng ◽  
...  

Low cost carbonaceous materials were evaluated for their ability to remove phenol from wastewater. The effects of adsorbents dosage, contact time and maximum adsorption capacity were investigated for granular activated carbon, powdered activated carbon, petroleum coke and multi-walled carbon nanotube (MWNT). Equilibrium studies were conducted in 50mg/L initial phenol concentration, solution pH of 5 and at temperature of 23°C. The results showed the adsorption process was fast and it reached equilibrium in 3 h. Petroleum coke and MWNT had poor adsorption which could reach the removal efficiency of phenol with 43.18% and 36.64% respectively. The granular activated carbon possessed good adsorption ability to phenol with 96.40% at the optimum dosage 5g and optimum time 90min.The powdered activated carbon was an effective adsorbent with a maximum adsorption capacity of 42.32 mg/g.


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.


2007 ◽  
Vol 561-565 ◽  
pp. 1719-1722 ◽  
Author(s):  
Chiravoot Pechyen ◽  
Duangdao Aht-Ong ◽  
Duangduen Atong ◽  
Viboon Sricharoenchaikul

Char derived from pyrolysis of physic nut waste at 400-800°C was used for the preparation of activated carbon by chemical impregnation of phosphoric acid and potassium hydroxide. The original char exhibited the BET surface area in the range of 120-250 m2·g-1. The surface area increased to 480 and 532 m2·g-1 when activated with H3PO4 and KOH, respectively. Equilibrium adsorption data was found to be best represented by the Langmuir isotherm with maximum monolayer adsorption capacity of 560.13 mg·g-1 at 30°C. The adsorption capacity of the physic nut residue activated carbon was comparable to commercial activated carbon.


1997 ◽  
Vol 35 (7) ◽  
pp. 205-211 ◽  
Author(s):  
R. Leyva-Ramos ◽  
J. R. Rangel-Mendez ◽  
J. Mendoza-Barron ◽  
L. Fuentes-Rubio ◽  
R. M. Guerrero-Coronado

The adsorption isotherm of cadmium on activated carbon was measured in a batch adsorber. Effects of temperature and solution pH on the adsorption isotherm were investigated by determining the adsorption isotherm at temperatures of 10, 25, and 40°C and at initial pH values from 2 to 8. Langmuir isotherm better fitted the experimental data since the average percent deviation was lower than with the Freundlich isotherm It was noticed that the amount of Cd2+ adsorbed was reduced about 3 times by increasing the temperature from 10 to 40°C. It was found that Cd2+ was not adsorbed on activated carbon at pH of 2 or lower and that Cd2+ was precipitated out as Cd(OH)2 at pH values above 9. Maximum adsorption capacity was observed at pH of 8 and the adsorption capacity was decreased about 12 times by reducing the initial pH from 8 to 3. According to the cadmium speciation diagram the predominant species below pH of 8 is Cd2+. Thus, cadmium was adsorbed on the activated carbon surface as Cd2+. It was concluded that the adsorption capacity is a strong function of pH and temperature.


2021 ◽  
Author(s):  
Mingyue Piao ◽  
Hongxue Du ◽  
Yuwei Sun ◽  
Honghui Teng

Abstract Hybrid hydrogel was synthesized by immobilizing TiO2 in polyethylene glycol diacrylate (TiO2@PEGDA) as an efficient adsorbent with photocatalysis property for bisphenol A (BPA) elimination. TiO2@PEGDA exhibited spherical and rough structure with limited crystallinity and abundant functional groups. The contact angle was 61.96°, indicating that TiO2@PEGDA is hydrophilic. The swelling capacity of TiO2@PEGDA (9.0%) was decreased compared with pristine PEGDA (15.6%). Adsorption results demonstrated that the maximum adsorption capacity of TiO2@PEGDA (101.4 mg/g) for BPA was slightly higher than pristine PEGDA (97.68 mg/g). The adsorption capacity was independent with pH at pH < 8.0, and decreased obviously when the value of pH was higher than 8.0. The adsorption behavior was fitted well with the pseudo-second-order kinetic and the Freundlich isotherm model. Both ΔG0 and ΔH0 were negative, indicating that BPA adsorbed on TiO2@PEGDA was an exothermic and spontaneous process. Regeneration study was performed by photocatalysis, and the adsorption capacity was 85.6% compared with the initial capacity after four cycles of illumination, indicating that TiO2@PEGDA could be recycled without significant loss of adsorption capacity. Consequently, TiO2@PEGDA can serve as an eco-friendly and promising material for efficiently adsorbing BPA with self-clean property.


2017 ◽  
Vol 6 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Farida Hanum ◽  
Rikardo Jgst Gultom ◽  
Maradona Simanjuntak

Durian is a kind of tropical fruits which can grow well in Indonesia. Durian is containing 60-75% shell. Durian shell could be a potential alternative to activated carbon because it contains 57.42% carbon. The aim of this research is to know the effect of contact time and  stirring speed to activated carbon adsorption capacity from durian shell with KOH and NaOH as activators. FTIR (Fourier Transform Infra Red) analysis showed the activation process effects on  absorption intensity  wavelength region and resulted in formation of C = C aromatic tape, so that the nature of the charcoal becomes more polar compared with the initial condition. Analysis using spectrophotometer UV-Vis to determine  absorbance and  final concentration of each variation of contact time and stirring speed. The results showed that the maximum adsorption capacity obtained by activation of KOH and NaOH on stirring speed of 150 rpm and a contact time of 90 minutes is equal to 3.92 mg / g and 3.8 mg / g respectively. The maximum surface area obtained by activation of KOH and NaOH during the stirring speed 130 rpm and a contact time of 120 minutes is equal to 1785.263 m2 / g and 1730.332 m2 / g respectively. The maximum surface area obtained from this research has met the standards of commercial activated carbon surface area was between 800-1800 m2/ g. Modeling pseudo second order presents a more representative adsorption data, a second order equation is based on the assumption that adsorption step is chemosorption.


2019 ◽  
Vol 41 (1) ◽  
pp. 62-62
Author(s):  
Farida Bouremmad Farida Bouremmad ◽  
Abdennour Bouchair Abdennour Bouchair ◽  
Sorour Semsari Parapari Sorour Semsari Parapari ◽  
Shalima Shawuti and Mehmet Ali Gulgun Shalima Shawuti and Mehmet Ali Gulgun

Biosorbents can be an alternative to activated carbon. They are derived from agricultural by-products or aquatic biomass. They are low cost and they may have comparable performances to those of activated carbon. The present study focuses on the characterization of the Corallina Elongata (CE) alga and its adsorption performance for Methylene Blue (MB), this alga is found in abundance at the Mediterranean coast of the city of Jijel in eastern Algeria. The dried alga was characterized using various characterization techniques such as DTA, TG, FTIR, XRD, SEM and EDX, which showed that the material consists essentially of a calcite containing magnesium. Batch adsorption studies were carried out and the effect of experimental parameters Such as pH, initial dye concentration, temperature, adsorbent dose and contact time, on the adsorption of MB was studied. The kinetic experimental data were found to conform to the pseudo-second-order model with good correlation and equilibrium data were best fitted to The Langmuir model, with a maximum adsorption capacity of 34.4 mg/g. The adsorption isotherms at various temperatures allowed the determination of certain thermodynamic parameters (ΔG, ΔH and ΔS). Finally, the adsorption results showed a good affinity between CE and MB with a high adsorption capacity.


2021 ◽  
Vol 324 ◽  
pp. 125-130
Author(s):  
Wara Dyah Pita Rengga ◽  
Bayu Triwibowo ◽  
Jovian Triyana Putra ◽  
Ardi Nugroho ◽  
Sri Kadarwati ◽  
...  

Cooking oil saturation due to frequent use for frying will result in a higher fatty acid content. Activated carbon made from the banana peel (Musa acuminata) with micro-mesoporous specifications can absorb free fatty acids. Banana peels are pyrolyzed into charcoal then activated alkaline at a temperature of 650°C. Then the activated carbon is washed and mashed to obtain activated carbon powder as an adsorbent by batch. FTIR carried out adsorption analysis on cooking oil to reduce carboxylic acid in used cooking oil. The regeneration process is carried out using surfactants to save on the use of necessary materials so that they need to be recycled. The experimental results based on isothermic equilibrium show that the Freundlich model can describe the adsorption process well at 28°C with a maximum adsorption capacity of 10 mg/g. The lifespan of activated carbon can only be extended once regeneration, reaching an adsorption capacity of 65% of fresh activated carbon's ability.


2019 ◽  
Vol 79 (3) ◽  
pp. 466-479 ◽  
Author(s):  
Fatemeh Mojoudi ◽  
Amir Hossein Hamidian ◽  
Yu Zhang ◽  
Min Yang

Abstract Novel porous nanocomposite (AC/NC/TGO) was successfully synthesized through the composition of activated carbon, nanoclay and graphene oxide as a Pb(II) adsorbent for the treatment of contaminated aqueous environment. The physicochemical properties and morphology of AC/NC/TGO were examined by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and nitrogen adsorption-desorption techniques. Results showed Pb(II) adsorption on the AC/NC/TGO was rapid in the first 20 min and reached equilibrium in 40 min. Kinetic studies showed significant fit to the pseudo second order kinetic model (R2 ≥ 0.9965) giving an equilibrium rate constant (K2) of 0.0017 g mg−1 min−1 for Pb(II) loaded. The experimental adsorption data were better fitted with the Langmuir isotherm model than with the Freundlich isotherm model. Prepared nanocomposite exhibited high values of Brunauer–Emmett–Teller (BET) surface area of 1,296 m2 g−1 and total pore volume of 1.01 cm3 g−1. Maximum adsorption capacity (Qmax = 208 mg g−1) and a relatively high adsorption rate was achieved at pH 5.0 using an adsorbent dose of 0.5 g L−1 and an initial lead concentration of 50 mg L−1. High adsorption capacity, reusability, fast kinetics and simple synthesis method indicate that prepared nanocomposite can be suggested as a high-performance adsorbent for Pb(II) removal from polluted water.


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