83,583 research outputs found
A review of agricultural waste activated carbon and effect on adsorption parameters
Activated carbon is widely used in industrial wastewater treatment operation because of the effectiveness in removing the dye. As the conventional activated carbon on market nowadays is expensive, lots of research was done on agricultural materials to replace the activated carbon. Sugarcane bagasse is listed as one of the agricultural material alternatives. This review compiles the characterisation of sugarcane bagasse and several agricultural wastes-based activated carbon including proximate analysis, ultimate analysis, and activated carbon surface characteristic used to remove dye in textile wastewater. Nevertheless, the adsorption parameters are the main focus as it affecting the removal of dye. The expansion review regarding activated carbon performance implies that dye removal efficiency depends on the amount of adsorbent dosage, contact time, pH solution, dye concentration applied during the adsorption process. This review shows the need of thoughtful information on adsorption parameters with an expanded list of various types of agricultural-based activated carbon and various dye removal
Preparation and characterization of activated carbon from palm kernel shell
In Malaysia, the production of activated carbons is still coconut-based although Malaysia has long shifted from coconut into palm oil plantation. Huge amount of waste Palm Kernel Shells (PKS) are being generated and disposed off into the landfill with little known of their usage on large scale. In this study, the potential of production of activated carbon from raw palm kernel shells are studied. Activated carbon was prepared from raw palm kernel shells using chemical activation with potassium hydroxide (KOH) as an activating agent. The effects of different process parameters: KOH concentration, activation temperature and time on physicochemical properties of the prepared activated carbon were investigated. The activated carbon was analyzed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier Transform Infrared (FTIR) spectroscopy, proximate analysis and methylene blue adsorption study. FTIR analysis indicates that raw palm kernel shell has successfully been converted into activated carbon. SEM photograph revealed that prepared activated carbons have numerous burn-off pores with extensive surface area for adsorption. Activated carbon sample prepared at 700 ºC and 1 hour activation with 30 wt % KOH impregnation showed greatest extend of methylene blue removal of 6.932 mg/g equivalent to 69.324 %RE with largest specific surface area of 21.137 x 10-3 km2kg-1 have been reported. This study shows that palm kernel shells can be used as a good source for the production of activated carbon
Evaluation of Activated Carbon as a Reactive Cap Sorbent for Sequestration of PCBs in Presence of Humic Acid
This study investigated the interferences caused by high humic acid concentrations on the adsorption of coplanar and noncoplanar polychlorinated biphenyls (PCBs) on coconut shell activated carbon. In particular, the research focuses on the application of activated carbon as a reactive cap for contaminated sediment sites, a possible intervention to reduce contaminant flux through pore water, and to organisms in aquatic environments. Kinetic and equilibrium studies were conducted using activated carbon as a sorbent for individual PCB congeners including BZ 1, 52, 77, 153, and 169, respectively, in the presence and absence of humic acid. Results showed that preloading of activated carbon with humic acid significantly reduced the adsorption affinity for all selected PCB congeners. Experiments conducted without preloading of activated carbon demonstrated that desorption upon subsequent spiking with humic acid (simulating long-term exposure to pore water that contains high humic acid concentrations) was not found to be statistically significant, and varied with coplanarity of PCBs. Results provide important information for the design of reactive caps in sediments where high concentrations of dissolved organic carbon are found, and highlight the importance of considering site conditions when designing effective reactive caps
Integrated process for production of surfactin Part 1: Adsorption rate of pure surfactin onto activated carbon
The work reported in this paper is aimed at studying the adsorption of surfactin from aqueous solution onto activated carbon. Among the factors,agitation rate, activated carbon particle-size, pH, temperature, initial adsorbate concentration, adsorbent amount and ionic strength of the solution were studied. Both adsorption equilibrium and kinetics showed that activated carbon acted as a suitable adsorbent for surfactin recovery. Two
mechanisms represented by different kinetic models were examined, namely, the intraparticle diffusion one and the one involving chemisorption accompanied by surface coverage (conforming to the Elovich concept)
Modification of Rice Husk-Based Activated Carbon using Sodium Lauryl Sulfat (SLS) for Lead (Pb) Ions Removal
A rice husk-based active carbon modified using SLS surfactant showed an increase on Pb ionic metal removal with the efficiency of 99.96%. Activated carbon is commonly applied as adsorben in waste water treatment, in particularly, waste water containing heavy metals and dye molecules. Even though it is commonly used, the adsorption efficiency of activated carbon to the heavy metal waste is still low. Therefore, in the present work, carbon from rice husk was modified using surfactant which further it is called surfactant modified active carbon (SMAC). Firstly, rice husk-based carbon was activated using 40% H3PO4 for 2,
6, 10, 14, 15 and 16 hours. The activated carbon was then modified by contacting it into SLS in different concentration 10, 20, 30, 40, 50, 60 and 70 ppm for 5 hours. Finally, the SMAC was then applied to remove Pb ionic metal. Moreover, several characterisation techniques were performed including FTIR, SEM, UV-Vis and AAS.
Keywords: activated carbon, surfactant-modified active carbon, adsorption, rice hus
Urea Coating with Activated Carbon Enriched by Microbial Indigenous Can Reduce Endrin Concentration
Endrin residues are still remain in the land field these compounds are no longer used by farmers and have been banned by the government. This residue can stay in the soil longer and persistant. Microbial enrichment is expected to accelerate the degradation of pesticide residues. Microbes stretcher are Bacillus substillis, Heliothrix oregonensis, Catenococcus thiocycli, and Achoromobacter sp obtained from the preliminary research results from soil isolation of idegenus in LIPI Cibinong Microbiology Laboratory. Soil for the planting medium obtained from the village of Karawang, Regency Cilamaya Wetan, Cilamaya District. The experiment was conducted in the field by using lysimeter at the Experiment Jakenan station from July 2013 to December 2013. The objective of the research is to obtain technology of activated carbon-coated urea and biochar which enriched microbial indegenus. The experiment was used randomized block design (RAK) with 3 replications. Plant used are rice. Insecticide residue analysis was carried out in the laboratory in Bogor Balingtan using gas chromatography (GC), with the SNI method 06-6991.1-2004. The purpose of this study knowing the capabilities of urea coating with activated carbon enrichment microbia in reducing the concentration of residues endrin. Results of research urea coated activated carbon from coconut shell are enriched with microbes on paddy field can lower pesticide residues of endrin respectively to 33.6%. This is presumably due to the role of microbes degrading effective as activated carbon as the preferred home. Enrichmentwith microbial indegenuscan improve theeffectivenessof ureacoating biochar andureacoatingactivated carbon coconut shell todecrease concentration endrin
Rapid removal of phenol from aqueous solutions by AC_Fe3O4 nano-composite: Kinetics and equilibrium studies
Background and purpose: Phenol and its derivatives are used as raw material in many chemical, pharmaceutical and petrochemical industries. It is classified as priority pollutant, due to its high toxicity. In this study, the magnetic activated carbon nano-composite was used for quick removal of phenol. Materials and methods: The activated carbon was modified by magnetic nano-particles. Then physical properties of the adsorbent were investigated using BET, XRD and SEM. Afterwards, adsorption behavior of phenol onto the adsorbent was studied considering various parameters such as: pH, phenol concentration, contact time and adsorbent dosage. Also, the isotherms and adsorption kinetics model was studied. Results: BET analysis showed 10.25% decrease in the specific area of activated carbon after being amended by the Fe3O4 nano-particles. SEM and XRD confirmed the presence of Fe3O4 nanoparticles on the activated carbon. Optimum absorption points in this process were pH=8, contact time of 15 min and adsorbent dose 2 g/L. The Longmuir isotherm and pseudo-second-order kinetics were fitted to the data. The maximum adsorption capacity of phenol on AC_Fe3O4 was 84.033 mg/g. Conclusion: Creating magnetic properties on the activated carbon which has a high adsorption capacity of phenol could result in quick separation of phenol from aqueous solutions. Also, this adsorbent could be widely applied since it is inexpensive and simple to use. © 2015, Mazandaran University of Medical Sciences. All rights reserved
Application of Activated Carbon Mixed Matrix Membrane for Oxygen Purification
This study is performed primarily to investigate the effect of activated carbon on oxygen separation performance of polyethersulfone mixed matrix membrane. In this study, polyethersulfone (PES)-activated carbon (AC) mixed matrix membranes were fabricated using dry/wet technique. This study investigates the effect of polyethersulfone concentration and activated carbon loading on the performance of mixed matrix membrane in terms of permeability and selectivity of O2/N2 gas separation. The fabricated flat sheet mixed matrix membranes were characterized using permeation test, Field Emission Scanning Electron Microscopy (FESEM) analysis and Differential Scanning Calorimetry (DSC). It was found that the activated carbon loading affected the gas separation performance of mixed matrix membrane. PES- 1wt% AC membrane yielded 3.75 of O2/N2 selectivity, however 5 wt% of AC can produced 5 O2/N2 selectivit
Low frequency sound propagation in activated carbon
Activated carbon can adsorb and desorb gas molecules onto and off its surface. Research has examined
whether this sorption affects low frequency sound waves, with pressures typical of audible
sound, interacting with granular activated carbon. Impedance tube measurements were undertaken
examining the resonant frequencies of Helmholtz resonators with different backing materials. It
was found that the addition of activated carbon increased the compliance of the backing volume.
The effect was observed up to the highest frequency measured (500 Hz), but was most significant at
lower frequencies (at higher frequencies another phenomenon can explain the behavior). An apparatus
was constructed to measure the effective porosity of the activated carbon as well as the number
of moles adsorbed at sound pressures between 104 and 118 dB and low frequencies between 20
and 55 Hz. Whilst the results were consistent with adsorption affecting sound propagation, other
phenomena cannot be ruled out. Measurements of sorption isotherms showed that additional energy
losses can be caused by water vapor condensing onto and then evaporating from the surface of the
material. However, the excess absorption measured for low frequency sound waves is primarily
caused by decreases in surface reactance rather than changes in surface resistance
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Imaging the atomic structure of activated carbon
The precise atomic structure of activated carbon is unknown, despite its huge commercial importance in the purification of air and water. Diffraction methods have been extensively applied to the study of microporous carbons, but cannot provide an unequivocal identification of their structure. Here we show that the structure of a commercial activated carbon can be imaged directly using aberration-corrected transmission electron microscopy. Images are presented both of the as-produced carbon and of the carbon following heat treatment at 2000 degrees C. In the 2000 degrees C carbon clear evidence is found for the presence of pentagonal rings, suggesting that the carbons have a fullerene-related structure. Such a structure would help to explain the properties of activated carbon, and would also have important implications for the modelling of adsorption on microporous carbons
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