Environment friendly emerging techniques for the treatment of waste biomass: a focus on microwave and ultrasonication processes.

In the recent past, an increasing interest is mostly observed in using microwave and ultrasonic irradiation to aid the biological conversion of waste materials into value-added products. This study is focused on various individual impacts of microwaves and ultrasonic waves for the treatment of biomass before the synthesis of value-added products. Following, a comprehensive review of the mechanisms governing microwaves and ultrasonication as the treatment methods, their effects on biomass disruption, solubilization of organic matter, modification of the crystalline structure, enzymatic hydrolysis and production of reducing sugars was performed. However, based on the lab-scale experiments evaluated, microwaves and ultrasonication were studied to be economically and energetically ineffective despite their beneficial effects on the waste biomass. This article reviews some of the difficulties associated with using microwaves and ultrasonic irradiation for the efficient processing of waste biomasses and identified some potential directions for future study.

Recent Developments of Silk-Based Scaffolds for Tissue Engineering and Regenerative Medicine Applications: A Special Focus on the Advancement of 3D Printing.

Regenerative medicine has received potential attention around the globe, with improving cell performances, one of the necessary ideas for the advancements of regenerative medicine. It is crucial to enhance cell performances in the physiological system for drug release studies because the variation in cell environments between in vitro and in vivo develops a loop in drug estimation. On the other hand, tissue engineering is a potential path to integrate cells with scaffold biomaterials and produce growth factors to regenerate organs. Scaffold biomaterials are a prototype for tissue production and perform vital functions in tissue engineering. Silk fibroin is a natural fibrous polymer with significant usage in regenerative medicine because of the growing interest in leftovers for silk biomaterials in tissue engineering. Among various natural biopolymer-based biomaterials, silk fibroin-based biomaterials have attracted significant attention due to their outstanding mechanical properties, biocompatibility, hemocompatibility, and biodegradability for regenerative medicine and scaffold applications. This review article focused on highlighting the recent advancements of 3D printing in silk fibroin scaffold technologies for regenerative medicine and tissue engineering.

Multivariate regression and artificial neural network modelling of sugar yields from acid pretreatment and enzymatic hydrolysis of lignocellulosic biomass.

Reducing sugar generation from lignocellulosic biomass (LCB) is closely linked with biomass characteristics, pretreatment and enzymatic hydrolysis conditions. In this study curated experimental data from literature was used to develop multivariate regression and artificial neural network (ANN) model considering nine predictors (i.e., cellulose, hemicellulose, lignin content, cellulose-lignin ratio, acid concentration, temperature, time, pretreatment severity, and enzyme concentration). Selected reduced polynomial model (R2: 0.891, Adj. R2: 0.849) suggests positive influence of acid and enzyme, while negative influence of treatment severity, temperature and time on reducing sugar generation. Genetic algorithm-optimized ANN model offered excellent fitness for LCB hydrolysis on training (R2: 0.997), validation (R2: 0.984), and test sets (R2: 0.967). Sensitivity analysis of the ANN predictors suggests lignin and to some extent hemicellulose contents can be inhibitory. Though polynomial models can have simple interpretation, use of optimized ANN offers better predictability in dataset with diverse biomass compositions.

Sugarcane bagasse into value-added products: a review.

Strategic valorization of readily available sugarcane bagasse (SB) is very important for waste management and sustainable biorefinery. Conventional SB pretreatment methods are ineffective to meet the requirement for industrial adaptation. Several past studies have highlighted different pretreatment procedures which are lacking environmentally benign characteristics and effective SB bioconversion. This article provides an in-depth review of a variety of environmentally acceptable thermochemical and biological pretreatment techniques for SB. Advancements in the conversion processes such as pyrolysis, liquefaction, gasification, cogeneration, lignin conversion, and cellulose conversion via fermentation processes are critically reviewed for the formation of an extensive array of industrially relevant products such as biofuels, bioelectricity, bioplastics, bio adsorbents, and organic acids. This article would provide comprehensive insights into several crucial aspects of thermochemical and biological conversion processes, including systematic perceptions and scientific developments for value-added products from SB valorization. Moreover, it would lead to determining efficient pretreatment and/or conversion processes for sustainable development of industrial-scale sugarcane-based biorefinery.

Understanding the management of household food waste and its engineering for sustainable valorization- A state-of-the-art review.

Increased urbanization and industrialization accelerated demand for energy, large-scale waste output, and negative environmental consequences. Therefore, the implementation of an effective solid-waste-management (SWM) policy for the handling of food waste is of great importance. The global food waste generation is estimated at about 1.6 gigatons/yr which attributes to an economic revenue of 750 billion USD. It can be converted into high-value enzymes, surfactants, Poly-hydroxybutyrate, biofuels, etc. However, the heterogeneous composition of food with high organic load and varying moisture content makes their transformation into value-added products difficult. This review aims to bring forth the possibilities and repercussions of food waste management. The socio-economic challenges related to SWM are comprehensively discussed particularly in terms of environmental concern. The engineering aspect in the collection, storage, and biotransformation of food waste into useful value-added products such as biofuels, advanced biomaterials, bioactive compounds, and platform chemicals are critically reviewed for efficient food waste management.

Bimetallic p-ZnO/n-CuO nanocomposite synthesized using Aegle marmelos leaf extract exhibits excellent visible-light-driven photocatalytic removal of 4-nitroaniline and methyl orange.

In the current study, the photocatalytic activity of bimetallic ZnO-CuO hetero-nanocomposite was evaluated and compared with the monometallic ZnO and CuO nanoparticles using 4-nitroaniline (4-NA) and methyl orange (MO). Bimetallic ZnO-CuO hetero-nanocomposite, ZnO, and CuO nanostructure were synthesized utilizing leaf extract of Aegle marmelos and characterized by transmission electron microscopy, X-ray diffraction, and XPS. Benefiting from the p-n heterostructures formation, bimetallic ZnO-CuO hetero-nanocomposite exhibits an excellent photocatalytic activity against 4-NA as well as MO compared to pure ZnO and CuO. In particular, bimetallic ZnO-CuO hetero-nanocomposite expressed the highest photocatalytic activity by reducing 90% of 4-NA in 20 min and by degrading 96% of MO in 10 min, whereas 65% reduction of 4-NA in 30 min and 93% degradation of MO in 45 min was exhibited by CuO and 48% reduction of 4-NA in 30 min and 98% degradation of MO in 50 min was exhibited by ZnO. Moreover, bimetallic ZnO-CuO hetero-nanocomposite maintains excellent photocatalytic activity even after five cycles indicating its stability as photocatalyst and reusability. Based on the experimental findings, bimetallic ZnO-CuO hetero-nanocomposite could be used as a photocatalyst for wastewater treatment with excellent regeneration efficiency.