Wood Chemistry, Fundamentals and Applications, Second Edition, examines the basic principles of wood chemistry and its potential applications to pulping and papermaking, wood and wood waste utilization, pulping by-products for production of chemicals and energy, and biomass conversion.

Wood chemistry: fundamentals and applications.

Non-wood lignocellulosic biomass is abundantly available, low cost, easy to process and consists of a short growth and harvest period; therefore, it is introduced as a potential feedstock biomass for bioethanol production. Common non-wood lignocellulosic biomasses are categorised into agricultural residues, native and non-wood plant fibres. The potential of non-wood lignocellulosic biomass as a resource for cellulosic ethanol production are determined and, analyzed in the context of their chemical composition, fibre production yield, total cellulose availability as well as the enzymatic saccharification efficiency after pretreatment. Based on the obtained data, agricultural residues show significant advantages in all contexts over other non-wood lignocellulosic biomasses. Moreover, pretreatment plays an important role in enhancing the enzymatic accessibility and hydrolysability of non-wood biomass. This review found that various pretreatments could be applied to enhance the enzymatic hydrolysability of different biomasses; however the major factors that vary the effectiveness of particular pretreatment on improving of different biomass hydrolysability have not been clearly highlighted. In addition, even though enzymatic saccharification of pretreated biomass is mainly highlighted in most of the cellulosic ethanol studies to evaluate the improvement of biomass hydrolysability, this data is unable to show the total glucose that obtained from the untreated biomass directly. In this study, the importance of total glucose yield is emphasized and it is calculated from various research data by multiplying the solid recovery yield by the enzymatic saccharification yield of the pretreated biomass, as it presents the percentage of the total glucose that could be converted directly from the original biomass. This work verifies that besides enzymatic saccharification yield, the solid recovery yield is also one of the major factors to be identified in cellulosic ethanol study.

The world availability of non-wood lignocellulosic biomass for the production of cellulosic ethanol and potential pretreatments for the enhancement of enzymatic saccharification

A review on the environment-friendly emerging techniques for pretreatment of lignocellulosic biomass: Mechanistic insight and advancements

Microplastics have been widely reported to contaminate aquatic environments, particularly impacting marine organisms, but little is known of microplastic contamination of the soil environment. This study compared the distribution of microplastics in forest, urban, and agricultural soils, investigating the reasons for differences in abundance associated with land use. We analyzed distribution and abundance of microplastics in 100 soils, representing different land use types that include forest, urban (traffic and residence), and agriculture the environs of Yeoju City. Sampling plots were located on a systematic grid with 2.5 km × 2.5km spacing. Topsoil (0–5 cm) was collected with a hand auger and samples were pretreated by drying, density separation using ZnCl2 solution, organic matter digestion, and decompression filtration. Abundance of microplastics was measured by counting using a digital stereo microscope; microplastics were grouped by shapes (fragment, film, fiber, and sphere) and color (black, red, green, blue, yellow, white, and transparent). Fourier-transform infrared spectroscopy (FT-IR) analysis was used to identify polymer type of the microplastics. Soils of Yeoju contained an average 700 pieces·kg−1 of microplastics, but this greatly varied with land use types. Roadside soils had more microplastics (1108 pieces kg−1), mostly black styrene-butadiene rubber (SBR) fragments associated with tire dust. Unexpectedly, the largest amount of microplastics was detected not from urban soils but from an upland soil (3440 pieces kg−1). The mean abundance of microplastics in agricultural soil was 664 pieces kg−1, varying with farming types; the highest abundance was at orchard sites, followed by upland, greenhouse, and then paddy field sites. Polyethylene (PE) and polypropylene (PP) were identified from microplastics sampled at upland, greenhouse, and orchard sites, while SBR-derived microplastics were found more widely in all farmland soils, implicating that mulching film usage and farm machinery. Soil microplastic contamination is significant and widespread in urban and agricultural soils of Yeoju, but differs in form and distribution, according to the locality of traffic and farming. Atmospheric fallout to forest soils is quantified and found to be significantly impacted by microplastics. The use of mulching film as a source of PE and PP presents particular concern in terms of the effects of microplastic contamination on soil quality, health, and functionality in agroecosystems.

Plastic contamination of forest, urban, and agricultural soils: a case study of Yeoju City in the Republic of Korea

Plastic is a very useful material and presents numerous advantages in the daily life of individuals and society. However, plastics are accumulating in the environment and due to their low biodegradability rate, this problem will persist for centuries. Until recently, oceans were treated as places to dispose of litter, thus the persistent substances are causing serious pollution issues. Plastic and microplastic waste has a negative environmental, social and economic impact, e.g. causing injury/death to marine organisms and entering the food chain, which leads to health problems. The development of solutions and methods to mitigate marine (micro)plastic pollution is in high demand. There is a knowledge gap in this field, reason why research on this thematic is increasing. Recent studies reported the biodegradation of some types of polymers using different bacteria, biofilm forming bacteria, bacterial consortia, and fungi. Biodegradation is influenced by several factors, from the type of microorganism to the type of polymers, their physicochemical properties and the environment conditions (e.g. temperature, pH, UV radiation). Currently, green environmentally friendly alternatives to plastic made from renewable feedstocks are starting to enter the market. This review covers the period from 1964 to April 2020 and comprehensively gathers investigation on marine plastic and microplastic pollution, negative consequences of plastic use, bioplastic production and lists the most useful methods for plastic degradation and recycling valorization, including degradation mediated by microorganisms (biodegradation) and the methods used to detect and analyze the biodegradation.

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Marine Environmental Plastic Pollution: Mitigation by Microorganism Degradation and Recycling Valorization

Pretreatment is an important step in the conversion of biomass to bioethanol. In this study microwave-assisted oxalic acid (MOA) pretreatment was chosen to pretreat oil palm empty fruit bunch (OPEFB) to enhance enzymatic saccharification of the biomass. The objective of this study was to determine an optimum pretreatment condition for reducing sugar production, which could be further fermented by yeast to produce ethanol. Preliminary study was conducted to determine the range of duration of heating and temperature that will be used in the optimization by using response surface methodology (RSM). Central composite design (CCD) was used with three independent variables (duration of heating, temperature and acid concentration). Reducing sugar yield per initial biomass was used as a response variable. Preliminary study, that was conducted at 160, 170, 180, 190, and 200 °C for 5, 7.5, 10, 12.5, and 15 min, shows that pretreatment at temperature of 170–190 °C for 5–10 min produced higher reducing sugars than other conditions. Optimization using RSM shows that the optimum condition of MOA pretreatment of OPEFB was at 190 °C for 3 min with 1.1% oxalic acid, which resulted in as much as 34.60% reducing sugars after enzymatic saccharification. The pretreated OPEFB was then characterized and compared with untreated OPEFB. MOA pretreatment successfully removed 50.57% of lignin and 76.56% of hemicellulose from the OPEFB that were confirmed by a decrease or disappearance of the absorption bands of functional groups at 1339–1650 cm−1 and 1735 cm−1, respectively.

Optimization of Microwave-Assisted Oxalic Acid Pretreatment of Oil Palm Empty Fruit Bunch for Production of Fermentable Sugars

The influence of sulfuric acid concentration in aqueous glycerol during microwave pretreatment on the chemical content and morphological characteristics changes of pretreated EFB were investigated. After pretreatment, the pulp was further subjected to enzymatic hydrolysis. The micro-morphology and crystallinity of original and pretreated EFB were observed by scanning electron microscopy (SEM) and X-ray diffraction. Lignin content of pretreated EFB was determined, while hydrolysate after enzymatic hydrolysis was also analyzed the reducing sugar content. These results indicated that microwave assisted acid pretreatment of EFB caused weight loss. Evaluation on effect of varying acid concentration and residence times results 1 % acid concentration for 12.5 min as the best pretreatment condition. Under the best pretreatment condition, lignin removal was about 59.16 % with the reducing sugar yield per original EFB was 25.09 or 55.85 % per pretreated EFB. The acid–glycerol catalyst successfully improved reducing sugar yield compared to both untreated and biological pretreated samples. SEM images revealed that the pretreated of EFB surface changed noticeably and the increase of crystallinity degree of pretreated EFB indicated a great effect on amorphous region to crystalline region. The addition glycerol in reaction mixture both acid and alkaline has synergistic effect to increase reducing sugar yield. Much volume of glycerol in mixture has great effect to improve enzymatic hydrolysis performance than that of acid ones. The highest reducing sugar yield is produced as much as 98 % when EFB irradiated using glycerol–acid ratio of 1:2 for 12.5 min at 1 % acid concentration. The addition glycerol of 2 fold can increase 3.9 fold reducing sugar yield in the best pretreatment condition. Microwave assisted acid pretreatment in aqueous glycerol was an effective way to increase reducing sugar yield of EFB by lignin removal and fiber disruption.

Microwave Assisted Acid Pretreatment of Oil Palm Empty Fruit Bunches (EFB) to Enhance Its Fermentable Sugar Production

Decolorization of synthetic dyes by laccase produced from newly isolated Trametes hirsuta EDN084 under in-vitro condition was investigated in this study. Partial purification was conducted using ultrafiltration Amicon 10K at 5000 x g for 20 min. Laccase (0.1 U/mL) could decolorize 50% remazol brilliant blue R (RBBR), 47% reactive blue 4 (RBlue4), 51% acid blue 129 (AB129), 21% acid blue 25 (AB25), 40% acid blue 113 (AB113), 11% acid orange 7 (AO7), 2% reactive black 5 (RBlack5), 2% reactive red 120 (RR120), and 85% direct blue 71 (DBlue71) for 4 h. In order to improve the decolorization, the addition of violuric acid (VA), 2, 2, 6, 6-tetramethylpiperidine 1-oxyl (TEMPO), and 1-hydroxybenzotriazole (HBT) were individually assayed. The result showed that decolorization was improved significantly (2 to 30-fold) after the addition of 1 mM VA. This study suggests that mediator VA is suitable for the enhanced decolorization of synthetic dyes by laccase from T. hirsuta EDN084.

https://iopscience.iop.org/article/10.1088/1755-1315/374/1/012005/pdf

Decolorization of synthetic textile dyes by laccase from newly isolated Trametes hirsuta EDN084 mediated by violuric acid

Immobilization of laccase from Trametes hirsuta EDN 082 in light expanded clay aggregate for decolorization of Remazol Brilliant Blue R dye

Developing an effective pretreatment for the conversion of lignocellulosic biomass to ethanol is an important effort in reducing the cost of this process. Microwave-assisted pretreatment is considered a green technology that can effectively break down lignocellulosic structures. The objective of this study was to investigate the most effective temperature for microwave-assisted oxalic acid pretreatment regarding the structural characteristic changes of oil palm empty fruit bunches (OPEFB) fibers. The fibers were subjected to microwave-assisted oxalic acid pretreatment at 160–200 °C with 2.5 minutes heating time and a liquid to solid ratio of 10. The effectiveness of the pretreatment was determined based on its delignification selectivity, morphological characteristics, and functional group changes. Microwave irradiation of OPEFB fibers at 180 oC was effective in increasing the cellulose content by 24%. This pretreatment resulted in 1.82 delignification selectivity. More than 50% of the hemicellulose of the OPEFB was removed after this treatment, which was confirmed by a decrease of the absorption bands of functional groups at 1732 cm -1 . The increase of pretreatment temperature disrupted the morphological structure of the OPEFB and removed its hemicellulose but did not change its functional groups and lignin content.

Sita Heris Anita

Papers

Optimization of Microwave-Assisted Oxalic Acid Pretreatment of Oil Palm Empty Fruit Bunch for Production of Fermentable Sugars

Microwave Assisted Acid Pretreatment of Oil Palm Empty Fruit Bunches (EFB) to Enhance Its Fermentable Sugar Production

Decolorization of synthetic textile dyes by laccase from newly isolated Trametes hirsuta EDN084 mediated by violuric acid

Immobilization of laccase from Trametes hirsuta EDN 082 in light expanded clay aggregate for decolorization of Remazol Brilliant Blue R dye

Disruption of Oil Palm Empty Fruit Bunches by Microwave-assisted Oxalic Acid Pretreatment