scholarly journals The Effect of Gasification Conditions on the Surface Properties of Biochar Produced in a Top-Lit Updraft Gasifier

2020 ◽  
Vol 10 (2) ◽  
pp. 688 ◽  
Author(s):  
Arthur M. James R. ◽  
Wenqiao Yuan ◽  
Duo Wang ◽  
Donghai Wang ◽  
Ajay Kumar
Keyword(s):  
Particle Size ◽  
Moisture Content ◽  
Surface Properties ◽  
Functional Groups ◽  
Cation Exchange Capacity ◽  
Functional Group ◽  
Exchange Capacity ◽  
Low Ph ◽  
Airflow Rate ◽  
Particle Sizes

The effect of airflow rate, biomass moisture content, particle size, and compactness on the surface properties of biochar produced in a top-lit updraft gasifier was investigated. Pine woodchips were studied as the feedstock. The carbonization airflow rates from 8 to 20 L/min were found to produce basic biochars (pH > 7.0) that contained basic functional groups. No acid functional groups were presented when the airflow increased. The surface charge of biochar at varying airflow rates showed that the cation exchange capacity increased with airflow. The increase in biomass moisture content from 10 to 14% caused decrease in the pH from 12 to 7.43, but the smallest or largest particle sizes resulted in low pH; therefore, the carboxylic functional groups increased. Similarly, the biomass compactness exhibited a negative correlation with the pH that reduced with increasing compactness level. Thus, the carboxylic acid functional groups of biochar increased from 0 to 0.016 mmol g−1, and the basic functional group decreased from 0.115 to 0.073 mmol g−1 when biomass compactness force increased from 0 to 3 kg. BET (Brunauer-Emmett-Teller) surface area of biochar was greater at higher airflow and smaller particle size, lower moisture content, and less compactness of the biomass.

scholarly journals Clinoptilolitic Zeolite as an Amendment for Establishment of Creeping Bentgrass on Sandy Media

HortScience ◽  
1991 ◽  
Vol 26 (2) ◽  
pp. 117-119 ◽  
Author(s):  
J.L. NUS ◽  
S.E. Brauen
Keyword(s):  
Particle Size ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Creeping Bentgrass ◽  
Ammonium Nitrogen ◽  
Exchange Capacity ◽  
Particle Sizes ◽  
Agrostis Palustris ◽  
Exchangeable Potassium ◽  
Sphagnum Peat

In a field experiment, clinoptilolitic zeolite was compared to sphagnum peat and sawdust as sand amendments at 5%, 10%, and 209” (v/v) to enhance `Penncross' creeping bentgrass (Agrostis palustris Huds.) establishment and to compare their gravimetric and volumetric cation exchange capacities and their effects on moisture retention and cation exchange capacities of the resultant mixes. In addition, cation exchange capacities and exchangeable K+ and \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document}; were analyzed from clinoptilolitic zeolite of particle sizes ranging from <0.25 mm to >5.0 mm. All amendments, except 10?ZO and 20% sawdust, resulted in superior establishment compared to unamended sand. Peat-amended sand retained significantly more moisture than sawdust- or zeolite-amended sand at –6, –10, –33, and -250 kpa soil matric potentials. Zeolite exhibited a much higher volumetric cation exchange capacity than either sawdust or sphagnum peat. Cation exchange capacity and exchangeable potassium of clinoptilolitic zeolite was greatest when particle size was <0.5 mm; however, little exchangeable ammonium nitrogen was detected.

scholarly journals Bioavailability and leaching of Cd and Pb from contaminated soil amended with different sizes of biochar

2018 ◽  
Vol 5 (11) ◽  
pp. 181328 ◽  
Author(s):  
Alaa Hasan Fahmi ◽  
Abd Wahid Samsuri ◽  
Hamdan Jol ◽  
Daljit Singh
Keyword(s):  
Heavy Metals ◽  
Particle Size ◽  
Contaminated Soil ◽  
Contaminated Soils ◽  
Cation Exchange Capacity ◽  
Application Rate ◽  
Exchange Capacity ◽  
Particle Sizes ◽  
Empty Fruit Bunch ◽  
Treated Soil

Biochars have been successfully used to reduce bioavailability and leaching of heavy metals in contaminated soils. The efficiency of biochar to immobilize heavy metals can be increased by reducing the particle size, which can increase the surface area and the cation exchange capacity (CEC). In this study, the empty fruit bunch biochar (EFBB) of oil palm was separated into two particle sizes, namely, fine (F-EFBB < 50 µm) and coarse (C-EFBB > 2 mm), to treat the contaminated soil with Cd and Pb. Results revealed that the addition of C-EFBB and F-EFBB increased the pH, electrical conductivity and CEC of the contaminated soil. The amounts of synthetic rainwater extractable and leachable Cd and Pb significantly decreased with the EFBB application. The lowest extractable and leachable Cd and Pb were observed from 1% F-EFBB-treated soil. The amount of extractable and leachable Cd and Pb decreased with increasing incubation times and leaching cycles. The application of F-EFBB to Cd and Pb-contaminated soil can immobilize the heavy metals more than that of C-EFBB. Therefore, the EFBB can be recommended for the remediation of heavy metal-contaminated soils, and a finer particle size can be applied at a lower application rate than the coarser biochar to achieve these goals.

scholarly journals Effect of Particle Size and Transparent Solar Dryer Cover on the Proximate Analysis of Dried Onion

2021 ◽  
pp. 123-141
Author(s):  
O. O. Oniya ◽  
C. O. Olatunji ◽  
M. I. Olatunji ◽  
K. O. Aremu ◽  
O. A. Adeiza
Keyword(s):  
Particle Size ◽  
Moisture Content ◽  
Proximate Analysis ◽  
Final Moisture Content ◽  
Temperature Cycle ◽  
Airflow Rate ◽  
Particle Sizes ◽  
Drying Temperature ◽  
Solar Dryer ◽  
Effect Of Particle Size

In this work, we investigate effect of particle size and transparent solar dryer cover on the proximate analysis of dried onion. A solar drying unit was developed and constructed for drying the of red onion slices in order to determine the proximate composition of fresh and dried red onion using multi-crop direct solar dryer. Also, the evaluation and effect of particles size and multi-crop transparent solar dryer cover on the proximate analysis of red onion during drying. Consequently, the higher efficiency of the solar collector was obtained at the higher airflow rate. The moisture content of dried onion slices was strongly affected by the thickness of the onion slices and the density of the polyethylene. The final moisture content of dried onion slices ranged from 10.85% to 13.01%, 4.95% to 6.01% ash, 4.69% to 5.26% fibre, 11.17% to 13.09% fat, 6.70% to 5.60% protein and 68.64% to 68.03% carbohydrate for particle sizes of 3 mm, 5 mm and 7 mm dry-basis depending on drying temperature cycle for low density polyethylene cover. While the final moisture content of dried onion slices ranged from 9.85% to 12.01%, 5.96% to 6.01% ash, 3.69% to 4.26% fibre, 13.17% to 12.09% fat, 5.70% to 6.60% protein and 61.64% to 58.03% carbohydrate for particle sizes of 3 mm, 5mm and 7mm dry-basis depending on drying temperature cycle for high density polyethylene cover.

Atrazine mineralisation in New Zealand topsoils and subsoils: influence of edaphic factors and numbers of atrazine-degrading microbes

Soil Research ◽  
1998 ◽  
Vol 36 (4) ◽  
pp. 557 ◽  
Author(s):  
Graham Sparling ◽  
Robert Dragten ◽  
Jackie Aislabie ◽  
Rhonda Fraser
Keyword(s):  
New Zealand ◽  
Moisture Content ◽  
Cation Exchange Capacity ◽  
Surface Soil ◽  
Exchange Capacity ◽  
Most Probable Number ◽  
Edaphic Factors ◽  
Decomposition Rates ◽  
Decomposition Products ◽  
Probable Number

The mineralisation of 14C-ring-labelled atrazine to 14CO2 was measured in 3 contrasting New Zealand soils under controlled conditions of temperature and moisture. The numbers of atrazine-degrading organisms were measured by a most probable number technique. Decomposition rates were slow, with a maximum of 41% of atrazine being mineralised over 263 days. Mineralisation was generally very low in subsoils and was much reduced by low moisture content. However, one subsoil from 60–90 cm depth had unusually high numbers of atrazine-degrading microbes and showed mineralisation greater than or equivalent to the surface soil. Mineralisation was approximately doubled by a 10°C rise in temperature over the range 16–28°C. In general, the rate of atrazine mineralisation over 7–96 days could be predicted from the number of atrazine-degrading microbes and the cation exchange capacity of the soil (R2 = 0·86). A large amount (54–77%) of 14C remained in the soil as non-extractable residues after 263 days, but only trace amounts of the added atrazine or the decomposition products de-ethyl atrazine and de-isopropyl atrazine were detected by extraction in organic solvent.

scholarly journals The Influence of the Gold Particle Size on the Catalytic Oxidation of 5-(Hydroxymethyl)furfural

Catalysts ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 342 ◽  
Author(s):  
Oliver Schade ◽  
Paolo Dolcet ◽  
Alexei Nefedov ◽  
Xiaohui Huang ◽  
Erisa Saraçi ◽  
...  
Keyword(s):  
Particle Size ◽  
Functional Groups ◽  
Chemical Reduction ◽  
Large Fraction ◽  
Particle Sizes ◽  
Mean Particle Size ◽  
Hydroxymethyl Furfural ◽  
Highly Active ◽  
Surface Steps ◽  
Aldehyde Oxidation

For the production of chemicals from biomass, new selective processes are required. The selective oxidation of 5-(Hydroxymethyl)furfural (HMF), a promising platform molecule in fine chemistry, to 2,5-furandicarboxylic acid (FDCA) is considered a promising approach and requires the oxidation of two functional groups. In this study, Au/ZrO2 catalysts with different mean particle sizes were prepared by a chemical reduction method using tetrakis(hydroxymethyl)phosphonium chloride (THPC) and tested in HMF oxidation. The catalyst with the smallest mean particle size (2.1 nm) and the narrowest particle size distribution was highly active in the oxidation of the aldehyde moiety of HMF, but less active in alcohol oxidation. On the other hand, increased activity in FDCA synthesis up to 92% yield was observed over catalysts with a larger mean particle size (2.7 nm), which had a large fraction of small and some larger particles. A decreasing FDCA yield over the catalyst with the largest mean particle size (2.9 nm) indicates that the oxidation of both functional groups require different particle sizes and hint at the presence of an optimal particle size for both oxidation steps. The activity of Au particles seems to be influenced by surface steps and H bonding strength, the latter particularly in aldehyde oxidation. Therefore, the presence of both small and some larger Au particles seem to give catalysts with the highest catalytic activity.

INFLUENCE OF CLAY MINERALS ON MICROORGANISMS: III. EFFECT OF PARTICLE SIZE, CATION EXCHANGE CAPACITY, AND SURFACE AREA ON BACTERIA

1966 ◽  
Vol 12 (6) ◽  
pp. 1235-1246 ◽  
Author(s):  
G. Stotzky
Keyword(s):  
Particle Size ◽  
Cation Exchange ◽  
Surface Area ◽  
Clay Minerals ◽  
Cation Exchange Capacity ◽  
Physicochemical Characteristics ◽  
Exchange Capacity ◽  
Bacterial Respiration ◽  
Effect Of Particle Size ◽  
Stimulation Of

The stimulation of bacterial respiration by clay minerals was related to certain physicochemical characteristics of clays. Respiration increased with an increase in the cation exchange capacity and surface area of the particles. The importance of surface area, however, could not be unequivocally established, as some of the methods used to determine this characteristic on certain clay species were questionable. Particle size did not appear to be a critical characteristic. The implications of the cation exchange capacity of clay minerals in the activity, ecology, and population dynamics of microorganisms in nature are discussed.

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