scholarly journals Effects of Pretreatment Methods of Wheat Straw on Adsorption of Cd(II) from Waterlogged Paddy Soil

2019 ◽  
Vol 16 (2) ◽  
pp. 205 ◽  
Author(s):  
Mengjie Wu ◽  
Hongyu Liu ◽  
Chunping Yang
Keyword(s):  
Wheat Straw ◽  
Paddy Soil ◽  
Morphological Changes ◽  
Ethanol Solution ◽  
Acid Oxidation ◽  
Organic Carbon Content ◽  
Microwave Assisted ◽  
Dynamic Variations ◽  
Behavior Study ◽  
Effective Removal

Two types of pretreatment categories, namely microwave-assisted alkalization and microwave-assisted acid oxidation, were used to synthesize novel wheat straw adsorbents for the effective removal of Cd(II) in simulated waterlogged paddy soil. A systematic adsorption behavior study, including adsorption kinetics and adsorption isotherms was conducted. Results showed that wheat straw pretreated by microwave-assisted soaking of NaOH and ethanol solution obtained the highest Cd(II) removal efficiency of 96.4% at a reaction temperature of 25 ℃, pH of 7.0, initial Cd(II) concentration of 50 mg/L, and adsorbent/adsorbate ratio of 10 g/L. Sequential extraction experiment was carried out to analyze the changes of different of Cd(II) in soil, the aim of which was to study the mobility of Cd(II) and then evaluate the toxicity that Cd(II) might bring to plants. A 60-day incubation was performed to investigate the dynamic variations of soil pH and dissolved organic carbon content over incubation time. Characterization analyses revealed the morphological changes of wheat straw adsorbents, which suggested that those pretreatment methods were of significance. This study provided an environmentally friendly way to reuse agricultural wastes and remedy Cd(II) contaminated soil.

Effect of biofertilizer and wheat straw biochar application on nitrous oxide emission and ammonia volatilization from paddy soil

2021 ◽  
Vol 275 ◽  
pp. 116640
Author(s):  
Haijun Sun ◽  
Yu Zhang ◽  
Yiting Yang ◽  
Yudong Chen ◽  
Paramsothy Jeyakumar ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Wheat Straw ◽  
Paddy Soil ◽  
Ammonia Volatilization ◽  
Nitrous Oxide Emission

scholarly journals Self-generated peroxyacetic acid in phosphoric acid plus hydrogen peroxide pretreatment mediated lignocellulose deconstruction and delignification

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Dong Tian ◽  
Yiyi Chen ◽  
Fei Shen ◽  
Maoyuan Luo ◽  
Mei Huang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Acetic Acid ◽  
Synergistic Effect ◽  
Phosphoric Acid ◽  
Wheat Straw ◽  
Lignin Degradation ◽  
Acid Oxidation ◽  
Main Function ◽  
Corn Stalk ◽  
Peroxyacetic Acid

Abstract Background Peroxyacetic acid involved chemical pretreatment is effective in lignocellulose deconstruction and oxidation. However, these peroxyacetic acid are usually artificially added. Our previous work has shown that the newly developed PHP pretreatment (phosphoric acid plus hydrogen peroxide) is promising in lignocellulose biomass fractionation through an aggressive oxidation process, while the information about the synergistic effect between H3PO4 and H2O2 is quite lack, especially whether some strong oxidant intermediates is existed. In this work, we reported the PHP pretreatment system could self-generate peroxyacetic acid oxidant, which mediated the overall lignocellulose deconstruction, and hemicellulose/lignin degradation. Results The PHP pretreatment profile on wheat straw and corn stalk were investigated. The pathways/mechanisms of peroxyacetic acid mediated-PHP pretreatment were elucidated through tracing the structural changes of each component. Results showed that hemicellulose was almost completely solubilized and removed, corresponding to about 87.0% cellulose recovery with high digestibility. Rather high degrees of delignification of 83.5% and 90.0% were achieved for wheat straw and corn stalk, respectively, with the aid of peroxyacetic acid oxidation. A clearly positive correlation was found between the concentration of peroxyacetic acid and the extent of lignocellulose deconstruction. Peroxyacetic acid was mainly self-generated through H2O2 oxidation of acetic acid that was produced from hemicellulose deacetylation and lignin degradation. The self-generated peroxyacetic acid then further contributed to lignocellulose deconstruction and delignification. Conclusions The synergistic effect of H3PO4 and H2O2 in the PHP solvent system could efficiently deconstruct wheat straw and corn stalk lignocellulose through an oxidation-mediated process. The main function of H3PO4 was to deconstruct biomass recalcitrance and degrade hemicellulose through acid hydrolysis, while the function of H2O2 was to facilitate the formation of peroxyacetic acid. Peroxyacetic acid with stronger oxidation ability was generated through the reaction between H2O2 and acetic acid, which was released from xylan and lignin oxidation/degradation. This work elucidated the generation and function of peroxyacetic acid in the PHP pretreatment system, and also provide useful information to tailor peroxide-involved pretreatment routes, especially at acidic conditions. Graphical abstract

scholarly journals Mono-disperse PdO nanoparticles prepared via microwave-assisted thermo-hydrolyzation with unexpectedly high activity for formic acid oxidation

2020 ◽  
Vol 329 ◽  
pp. 135166 ◽  
Author(s):  
Zuopeng Li ◽  
Jili Song ◽  
Dong-Chan Lee ◽  
Ali Abdelhafiz ◽  
Zhuojie Xiao ◽  
...  
Keyword(s):  
Formic Acid ◽  
High Activity ◽  
Formic Acid Oxidation ◽  
Acid Oxidation ◽  
Microwave Assisted

Microwave assisted liquefaction of wheat straw alkali lignin for the production of monophenolic compounds

2015 ◽  
Vol 24 (1) ◽  
pp. 72-76 ◽  
Author(s):  
Xinping Ouyang ◽  
Guodian Zhu ◽  
Xiangzhen Huang ◽  
Xueqing Qiu
Keyword(s):  
Wheat Straw ◽  
Alkali Lignin ◽  
Microwave Assisted

Microporous activated carbon from pinewood and wheat straw by microwave-assisted KOH treatment for the adsorption of toluene and acetone vapors

RSC Advances ◽  
2015 ◽  
Vol 5 (45) ◽  
pp. 36051-36058 ◽  
Author(s):  
Haiyan Mao ◽  
Dingguo Zhou ◽  
Zaher Hashisho ◽  
Sunguo Wang ◽  
Heng Chen ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Wheat Straw ◽  
Size Distribution ◽  
Microwave Assisted ◽  
Mass Ratios

Pore size distribution of raw char, pinewood char activated with KOH/char mass ratios 0.5, 1.5 and 3.0 was explored.

scholarly journals Microwave-assisted combustion to produce benzene polycarboxylic acids as molecular markers for biochar identification and quantification

Biochar ◽  
2021 ◽  
Author(s):  
Bruno Glaser ◽  
Marie Guenther ◽  
Heike Maennicke ◽  
Tobias Bromm
Keyword(s):  
High Pressure ◽  
Molecular Markers ◽  
Nitric Acid ◽  
Soil Samples ◽  
Acid Oxidation ◽  
Microwave Assisted ◽  
Polycarboxylic Acids ◽  
Digestion Technique ◽  
Nitric Acid Oxidation ◽  
Identification And Quantification

AbstractBiochar is a promising carbon dioxide removal (CDR) technology for climate change mitigation. Current procedures for its determination are lengthy, labor-intensive, and difficult to conduct. Benzene polycarboxylic acids (BPCA) are the most promising molecular markers for identification and quantification of biochar and its quality as they specifically represent the stable polyaromatic backbone of biochar. Therefore, using the BPCA method, its stability and, thus, its C sequestration potential could be used for CDR accounting. The current BPCA method relies on a specific high-pressure digestion apparatus, which is not available around the world. Therefore, the aims of the present work were (i) to compare the conventional high-pressure nitric acid oxidation with a microwave-assisted digestion technique and optimize the oxidation conditions in such a way that previous results are comparable with future ones, and (ii) to significantly reduce the digestion time of soil samples of 8 h and to develop a suitable routine method that produces comparable and reproducible results. For this purpose, soil and control sample series were prepared for different temperature–time-program. Obtained results were compared with the values of the conventional method both for individual samples and for the whole dataset separately. To ensure the representativeness of the results, in addition to various soil samples with different properties, we included two reference materials into our data set, one without biochar (wheat flour) and a biochar sample. Our results showed that conventional nitric acid oxidation in the BPCA determination at 170 °C and 8 h can be substituted by digestion in a microwave reaction system (CEM Mars6) at 190 °C and 1 h. Our results further showed that this condition needs to be strictly matched, because, otherwise, over- or underestimation of biochar quantity and/or quality will be the consequence. The goal of a less time-consuming BPCA extraction from soil samples was achieved by reducing the extraction time from 8 to 1 h using the microwave-assisted method. However, one disadvantage of the new method is that five times more sample material and chemicals are needed for further BPCA analysis, compared to the original method.

scholarly journals Extraction and Chemical Characterization of Humic Acid from Nitric Acid Treated Lignite and Bituminous Coal Samples

2021 ◽  
Vol 13 (16) ◽  
pp. 8969
Author(s):  
Noureen Fatima ◽  
Asif Jamal ◽  
Zaixing Huang ◽  
Rabia Liaquat ◽  
Bashir Ahamad ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Humic Acid ◽  
Bituminous Coal ◽  
Morphological Changes ◽  
Chemical Characterization ◽  
Green Energy ◽  
High Rank ◽  
Low Rank ◽  
Acid Oxidation ◽  
Chemical Pretreatment

Currently, conversion of coal into alternative fuel and non-fuel valuable products is in demand and growing interest. In the present study, humic acid was extracted from two different ranks of coal, i.e., low rank and high rank (lignite and bituminous), through chemical pretreatment by nitric acid. Samples of lignite and bituminous coal were subjected to nitric acid oxidation followed by extraction using KOH and NaOH gravimetric technique. The chemical pretreatment of both types of coal led to enhanced yield of humic acid from 21.15% to 57.8% for lignite low-rank coal and 11.6% to 49.6% bituminous high rank coal. The derived humic acid from native coal and nitric acid treated coal was analyzed using elemental analysis, E4/E6 ratio of absorbance at 465 nm and 665 nm using UV-Visible spectrophotometry and Fourier transformed infrared spectroscopy FTIR. The chemical characteristics of coal treated with nitric acid have shown increased molecular weight and improved aromaticity with more oxygen and nitrogen and lower C, H, and sulphur content. The E4/E6 ratio of nitric acid-treated low and high ranks of coal were high. The FTIR spectroscopic data of nitric acid-treated lignite coal indicates an intensive peak of carboxyl group at 2981.84 cm, while bituminous coal was shown in cooperation of N-H group at 2923.04 cm. SEM was performed to detect the morphological changes that happen after producing humic acid from HNO3 treatment and native coal. The humic acid produced from HNO3 treated coal had shown clear morphological changes and some deformations on the surface. SEM-EDS detected the major elements, such as nitrogen, in treated humic acid that were absent in raw coal humic acid. Hence, the produced humic acid through HNO3 oxidation showed a more significant number of humic materials with improved efficiency as compared to native coal. This obtained humic acid can be made bioactive for agriculture purposes, i.e., for soil enrichment and improvement in growth conditions of plants and development of green energy solution.

scholarly journals Study of the Mechanics and Micro-Structure of Wheat Straw Returned to Soil in Relation to Different Tillage Methods

Agronomy ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 894
Author(s):  
Yanpeng Wang ◽  
Adnan Abbas ◽  
Xiaochan Wang ◽  
Sijun Yang ◽  
Morice R. O. Odhiambo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Wheat Straw ◽  
Decomposition Rate ◽  
Morphological Changes ◽  
Micro Structure ◽  
Dynamic Changes ◽  
Straw Decomposition ◽  
Nylon Mesh ◽  
Mesh Bag ◽  
Tillage Methods

A field experiment was conducted to study the effects of different tillage methods, and their interaction on the dynamic changes of straw decomposition rate, mechanical properties, and micro-structure of the stalk. A nylon mesh bag technique was used. An obvious change was observed in the decomposition rate of straw, and its mechanical, and micro-structural properties. The decomposition rate of straw was increased in all tillage treatments. Specifically, it increased consistently in conventional and dry rotary tillage, and sharply in wet rotary tillage. Furthermore, for all tillage, the mechanical properties like shear and bending strengths decreased sharply while compressive strength first decreased linearly and then increased, whereas the micro-structure of wheat straw showed a fluctuating trend, i.e., it changed neither regularly nor consistently over time. Moreover, the micro-structure of the stalk explained the morphological changes to the straw that returned to the field, which may impact the mechanical properties. However, these changes could not explain the degradation trend of straw directly. The findings of the study could be used as a theoretical reference for the design of tillage and harvesting machinery keeping in view soil solidification and compaction dynamics.

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