Preparation and characterization of sorbents from food waste

2017 ◽  
Vol 6 (3) ◽  
Author(s):  
Barbora Grycova ◽  
Adrian Pryszcz ◽  
Pavel Lestinsky ◽  
Katerina Chamradova
Keyword(s):  
Mass Balance ◽  
Surface Area ◽  
Food Waste ◽  
Chromatographic Analysis ◽  
Potassium Hydroxide ◽  
Laboratory Apparatus ◽  
Microwave Pyrolysis ◽  
Conventional Pyrolysis ◽  
Bet Theory

AbstractWaste coffee was treated by pyrolysis in the conventional laboratory apparatus at 800°C. Afterwards, a mass balance of the final yields, gas chromatographic analysis and assessment of solid and liquid residues were done. The selected waste material was also subjected to microwave pyrolysis in terms of adsorbents preparation. The solid residues were further activated with potassium hydroxide. Final characterization of prepared sorbents was made by sorption of nitrogen at 77 K. Activated sorbents had much better sorption properties. The surface area according to Brunauer-Emmett-Teller (BET) theory of activated material (from conventional pyrolysis) was measured 1794 m

scholarly journals Conversion of automotive paint sludge to activated carbon via microwave pyrolysis technique for supercapacitor application

2020 ◽  
Vol 3 (1) ◽  
pp. 35
Author(s):  
Siti Shawalliah Idris ◽  
Muhammad Nasrul Bojy ◽  
Zakiuddin Januri
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Power Supply ◽  
Pore Volume ◽  
Potassium Hydroxide ◽  
Microwave Pyrolysis ◽  
Supercapacitor Application ◽  
Paint Sludge ◽  
The Impact ◽  
Radiation Time

Conversion of waste to wealth has been one of the ways to reduce the volume of industrial waste to disposal site, hence reducing the impact to the environment. In this work, paint sludge from an automotive industry (APS) was converted into activated carbon through chemical activation (potassium hydroxide (KOH)) using microwave pyrolysis technique. The effect of power and radiation time on the produced activated carbon were investigated and characterised (carbon content, surface area, and pore volume) to identify the possibility of application as a supercapacitor. Potassium hydroxide activation of the APS char via microwave pyrolysis has shown that power level and radiation time has influenced the yield of the APS activated carbon. A longer radiation time and higher power supply has produced activated carbon having higher carbon contents, lower impurities, higher surface area and higher pore volume. Thus, the APS activated carbon obtained via microwave pyrolysis at power supply 1000 W and 45 minutes radiation time had produced the highest surface area and total pore volume of 434.3 m2/g and 0.2901 cm3/g, respectively. However, the produced activated carbon is not suitable for the supercapacitor application as the minimum surface area requirement must be more than 1000 m2/g. The pore size of the activated APS char produced in this study was in the range of mesopores size which was also considered very poor for supercapacitor application. The outcome of this research has shown that the produced activated carbon could otherwise be used for other application than a supercapacitor.

scholarly journals Glacier changes in the Pascua-Lama region, Chilean Andes (29° S): recent mass balance and 50 yr surface area variations

2011 ◽  
Vol 5 (4) ◽  
pp. 1029-1041 ◽  
Author(s):  
A. Rabatel ◽  
H. Castebrunet ◽  
V. Favier ◽  
L. Nicholson ◽  
C. Kinnard
Keyword(s):  
Mass Balance ◽  
Surface Area ◽  
Monitoring Program ◽  
High Elevation ◽  
Aerial Photographs ◽  
Late 20Th Century ◽  
Surface Mass ◽  
Glacier Changes ◽  
Chilean Andes

Abstract. Since 2003, a monitoring program has been conducted on several glaciers and glacierets in the Pascua-Lama region of the Chilean Andes (29° S/70° W; 5000 m a.s.l.), permitting the study of glaciological processes on ice bodies in a subtropical, arid, high-elevation area where no measurements were previously available. In this paper we present: (1) six years of glaciological surface mass balance measurements from four ice bodies in the area, including a discussion of the nature of the studied glaciers and glacierets and characterization of the importance of winter mass balance to annual mass balance variability; and (2) changes in surface area of twenty ice bodies in the region since 1955, reconstructed from aerial photographs and satellite images, which shows that the total glaciated surface area reduced by ~29% between 1955 and 2007, and that the rate of surface area shrinkage increased in the late 20th century. Based on these datasets we present a first interpretation of glacier changes in relation with climatic parameters at both local and regional scales.

Synthesis and Characterization of Green Porous Carbons with Large Surface Area by Two Step Chemical Activation with KOH

2014 ◽  
Vol 67 (4) ◽  
Author(s):  
Noor Shawal Nasri ◽  
Mohammed Jibril ◽  
Muhammad Abbas Ahmad Zaini ◽  
Rahmat Mohsin ◽  
Hamza Usman Dadum ◽  
...  
Keyword(s):  
Surface Area ◽  
Porous Carbon ◽  
Pore Volume ◽  
Potassium Hydroxide ◽  
Chemical Activation ◽  
Bet Surface Area ◽  
Porous Carbons ◽  
Precursor Material ◽  
Proximate And Ultimate Analysis

Porous carbons were synthesized from coconut shell using chemical activation by potassium hydroxide (KOH). N2 adsorption isotherm analysis for BET surface area and pore volume of the synthesized porous carbon were carried out. The Langmuir surface area, BET surface area and pore volume are 1646 m2/g, 1353 m2/g and 0.6 cm3/g, respectively. From the FTIR analysis, hydroxyls, alkenes, carbonyls and aromatics functional groups were identified. The proximate and ultimate analysis shows high percentage of carbon and less ash content which indicates a good precursor material for porous carbon. The carbonization temperature and time were also varied to observe their effect on the yield of char, with carbonization at 7000C for 2 h having highest yield of 32%.

Microwave Pyrolysis of Emulsified Ceramic Precursor Ocompounds

1994 ◽  
Vol 347 ◽  
Author(s):  
M. Willert-Porada ◽  
S. Dennhöfer ◽  
D. Hachmeister
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Calcination Temperature ◽  
Processing Route ◽  
Nanosized Powders ◽  
Pyrolysis Products ◽  
Microwave Pyrolysis ◽  
Grain Sizes ◽  
Conventional Pyrolysis ◽  
Metalorganic Compounds

ABSTRACTApplication of paraffin as a MW-transparent matrix for microwave pyrolysis of metalorganic compounds enables synthesis of large quantities of nanosized powders with excellent storability and packing behavior. Fully crystalline, nanosized t-ZrO2 powders with specific surface area > 200 m 2 g -1 are obtained from Zr-alcoholate, and alumina powders with > 500 m2g-1 from Al-alcoholates. Some differences exist between microwave pyrolysis and conventional pyrolysis of such mixtures. Powders from microwave pyrolysis transform at lower calcination temperature to α-A12O3 and exhibit after calcination a more homogeneous morphology as compared to powders from conventional pyrolysis. Furthermore, a different composition of the volatile pyrolysis products is found. t-ZrO2 powder from the microwave processing route exhibits an increased stability towards transformation to monoclinic ZrO2 as well as smaller initial grain sizes than a conventionally synthesized powder.

Development and Characterization of Amine-Clay Hybrid Adsorbents for CO2 Capture

2016 ◽  
Vol 1133 ◽  
pp. 547-551 ◽  
Author(s):  
Ali E.I. Elkhalifah ◽  
Mohammad Azmi Bustam ◽  
Azmi Mohd Shariff ◽  
Sami Ullah ◽  
Nadia Riaz ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Surface Area ◽  
Surface Properties ◽  
Molar Mass ◽  
Adsorption Ability ◽  
Stepwise Increase ◽  
Inverse Effect ◽  
Bet Method ◽  
Sodium Form

The present work aims at a better understanding of the influences of the intercalated mono-, di- and triethanolamines on the characteristics and CO2 adsorption ability of sodium form of bentonite (Na-bentonite). The results revealed that the molar mass of intercalated amines significantly influenced the structural and surface properties as well as the CO2 adsorption capacity of Na-bentonite. In this respect, a stepwise increase in the d-spacing of Na-bentonite with the molar mass of amine was recorded by XRD technique. However, an inverse effect of the molar mass of amine on the surface area was confirmed by BET method. CO2 adsorption experiments on amine-bentonite hybrid adsorbents showed that the CO2 adsorption capacity inversly related to the molar mass of amine at 25 ͦC and 101 kPa. Accordingly, Na-bentonite modified by monoethanolammonium cations adsorbed as high as 0.475 mmol CO2/g compared to 0.148 and 0.087 mmol CO2/g for that one treated with di- and triethanolammonium cations, respectively.

scholarly journals Preparation and Characterization of the Sulfur-Impregnated Natural Zeolite Clinoptilolite for Hg(II) Removal from Aqueous Solutions

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 217
Author(s):  
Marin Ugrina ◽  
Martin Gaberšek ◽  
Aleksandra Daković ◽  
Ivona Nuić
Keyword(s):  
Chemical Modification ◽  
Aqueous Solutions ◽  
Specific Surface ◽  
Surface Area ◽  
Natural Zeolite ◽  
Contact Time ◽  
Liquid Ratio ◽  
X Ray ◽  
Solid Liquid

Sulfur-impregnated zeolite has been obtained from the natural zeolite clinoptilolite by chemical modification with Na2S at 150 °C. The purpose of zeolite impregnation was to enhance the sorption of Hg(II) from aqueous solutions. Chemical analysis, acid and basic properties determined by Bohem’s method, chemical behavior at different pHo values, zeta potential, cation-exchange capacity (CEC), specific surface area, X-ray powder diffraction (XRPD), scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), as well as thermogravimetry with derivative thermogravimetry (TG-DTG) were used for detailed comparative mineralogical and physico-chemical characterization of natural and sulfur-impregnated zeolites. Results revealed that the surface of the natural zeolite was successfully impregnated with sulfur species in the form of FeS and CaS. Chemical modification caused an increase in basicity and the net negative surface charge due to an increase in oxygen-containing functional groups as well as a decrease in specific surface area and crystallinity due to the formation of sulfur-containing clusters at the zeolite surface. The sorption of Hg(II) species onto the sulfur-impregnated zeolite was affected by the pH, solid/liquid ratio, initial Hg(II) concentration, and contact time. The optimal sorption conditions were determined as pH 2, a solid/liquid ratio of 10 g/L, and a contact time of 800 min. The maximum obtained sorption capacity of the sulfur-impregnated zeolite toward Hg(II) was 1.02 mmol/g. The sorption mechanism of Hg(II) onto the sulfur-impregnated zeolite involves electrostatic attraction, ion exchange, and surface complexation, accompanied by co-precipitation of Hg(II) in the form of HgS. It was found that sulfur-impregnation enhanced the sorption of Hg(II) by 3.6 times compared to the natural zeolite. The leaching test indicated the retention of Hg(II) in the zeolite structure over a wide pH range, making this sulfur-impregnated sorbent a promising material for the remediation of a mercury-polluted environment.

scholarly journals The Efficacy of Whole Oyster Shells for Removing Copper, Zinc, Chromium, and Cadmium Heavy Metal Ions from Stormwater

2021 ◽  
Vol 13 (8) ◽  
pp. 4184
Author(s):  
Zhiying Xu ◽  
Caterina Valeo ◽  
Angus Chu ◽  
Yao Zhao
Keyword(s):  
Surface Area ◽  
Hexavalent Chromium ◽  
Removal Efficiency ◽  
Exposure Time ◽  
Food Waste ◽  
Positive Relationship ◽  
Copper Ions ◽  
Zinc Ions ◽  
Cadmium Ions ◽  
Initial Concentration

This research investigates the use of a common food waste product for removing four different types of metals typically found in stormwater. Whole, unprocessed oyster shells are explored for use in stormwater management infrastructure that addresses water quality concerns. The role of the shells’ surface area, exposure time, and the solution’s initial concentration on the removal efficiency were examined. Beaker scale experimental results demonstrated very good efficiency by the oyster shells for removing copper ions (80–95%), cadmium ions (50–90%), and zinc ions (30–80%) but the shells were not as effective in removing hexavalent chromium (20–60%). There was a positive relationship between initial concentration and removal efficiency for copper and zinc ions, a negative relationship for hexavalent chromium, and no relationship was found for cadmium ions. There was also a positive relationship between surface area and removal efficiency, and exposure time and removal efficiency. However, after a certain exposure time, the increase in removal efficiency was negligible and desorption was occasionally observed. A mid-scale experiment to mimic real-world conditions was conducted in which continuous inflow based on a 6-h design storm was applied to 2.7 kg of whole, unprocessed oyster shells. The shells provided an 86% and an 84% removal efficiency of cadmium and copper ions, respectively, in one day of hydraulic retention time. No removal was observed for hexavalent chromium, and zinc ion removal was only observed after initial leaching. This work has significant implications for sustainable stormwater infrastructure design using a material commonly found in municipal food waste.

scholarly journals A Rubisco-binding protein is required for normal pyrenoid number and starch sheath morphology inChlamydomonas reinhardtii

2019 ◽  
Vol 116 (37) ◽  
pp. 18445-18454 ◽  
Author(s):  
Alan K. Itakura ◽  
Kher Xing Chan ◽  
Nicky Atkinson ◽  
Leif Pallesen ◽  
Lianyong Wang ◽  
...  
Keyword(s):  
Surface Area ◽  
Structure And Function ◽  
Binding Motif ◽  
Starch Granules ◽  
Wild Type ◽  
Bisphosphate Carboxylase ◽  
Biophysical Mechanism ◽  
Mechanism Function ◽  
And Function

A phase-separated, liquid-like organelle called the pyrenoid mediates CO2fixation in the chloroplasts of nearly all eukaryotic algae. While most algae have 1 pyrenoid per chloroplast, here we describe a mutant in the model algaChlamydomonasthat has on average 10 pyrenoids per chloroplast. Characterization of the mutant leads us to propose a model where multiple pyrenoids are favored by an increase in the surface area of the starch sheath that surrounds and binds to the liquid-like pyrenoid matrix. We find that the mutant’s phenotypes are due to disruption of a gene, which we call StArch Granules Abnormal 1 (SAGA1) because starch sheath granules, or plates, in mutants lacking SAGA1 are more elongated and thinner than those of wild type. SAGA1 contains a starch binding motif, suggesting that it may directly regulate starch sheath morphology. SAGA1 localizes to multiple puncta and streaks in the pyrenoid and physically interacts with the small and large subunits of the carbon-fixing enzyme Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase), a major component of the liquid-like pyrenoid matrix. Our findings suggest a biophysical mechanism by which starch sheath morphology affects pyrenoid number and CO2-concentrating mechanism function, advancing our understanding of the structure and function of this biogeochemically important organelle. More broadly, we propose that the number of phase-separated organelles can be regulated by imposing constraints on their surface area.

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