Research Articles

This study investigated the efficiency of peanut hull (PBC), bush branch (BBC), Spartina alterniflora (SBC), and rape straw (RBC) in removing 2,4-dichlorophen (2,4-DCP) from an aqueous solution. The 2,4-DCP removal efficiency of the four kinds of biochars (BCs) increased in the order BBC > PBC > SBC > RBC. The adsorption process was affected by the pH, contact time, temperature, BC’s particle size, and dosage. Based on the results of Fourier transform infrared spectrometry (FTIR) and scanning electron microscope (SEM), the adsorption mechanism of 2,4-DCP was associated with the functional groups and the microtissue and structure of BCs. Furthermore, the organic components of the BCs played an essential role during the adsorption process of the 2,4-DCP. The remediation of organic pollutants by BCs is a complicated process that is characterized by the physical-chemical reaction between the two components (organic pollutants and BCs).

Sweet sorghum juice (SSJ) is considered a good carbon source for biorefinery due to its low price and high fermentable-sugar content. In this study, 2,3-butanediol (2,3-BD) production from SSJ by Serratia marcescens H30 was investigated. First, the medium compositions including the contents of SSJ, nitrogen source, and mineral salts were optimized in conical flasks using a single factor and orthogonal design method. Under the optimal conditions, the 2,3-BD concentration reached up to 33.40 g/L. Then the optimized medium was used to perform fermentative experiments in a 5-L bioreactor. In batch experiments, the effects of various agitation speeds on 2,3-BD production were compared. Based on batch process results, an efficient two-stage fermentative control strategy was developed, where the agitation speed was maintained at 300 rpm in the first 12 h and subsequently switched to 200 rpm. About 43.32 g/L 2,3-BD was obtained by using this strategy. Finally, fed-batch fermentation was conducted through feeding the concentrated SSJ and a maximum 2,3-BD concentration of 109.44 g/L with the productivity of 1.40 g/L·h; a yield of 83.02% was achieved. The results showed that SSJ could be used as an economical substrate for efficient 2,3-BD production by S. marcescens H30.

To gain a better understanding of the effect of the interactions between two biomass components (cellulose-lignin and xylan-lignin) on lignin-derived phenolic products, two analysis methods are introduced. With 3:1, 2:1, and 1:1 ratios of cellulose and lignin, and xylan and lignin, the mixtures were subjected to fast pyrolysis, which was carried out in a fixed-bed tubular furnace at 450 to 600 °C. The phenolic content in the bio-oils was analyzed by gas chromatography-mass spectrometry. The product distributions showed that cellulose, xylan, and lignin were the main contributors to the mass of biomass bio-oil, gas, and char, respectively. The char yields decreased and the bio-oil and gas yields increased in the presences of cellulose and xylan. Comparative analyses of both the phenol content and peak area of the two methods suggest that in the case of cellulose and lignin co-pyrolysis, the formation of three kinds of phenolic products is promoted. The strength of this positive effect increased with increasing lignin content. However, the production of hydroxyphenols is promoted, while the productions of guaiacols and syringols are inhibited by the effect of xylan, which creates a different interaction between xylan and lignin.

A new kind of thermoplastic elastomer nanocomposite reinforced with cellulose nanofibers has been reported. The aim of this investigation was to study the interaction and dispersion of cellulose nanofibers into the Pebax matrix. These copolymers are considered as polyether-b-amide thermoplastic elastomers. They are from renewable resources, and their hydrophilic character allows them to interact with nanocellulose. The interaction and reinforcement effect of nanocellulose at 3 levels of nanocellulose, (1%, 3%, and 5%), were examined by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and other mechanical tests. The results achieved from these tests indicated appropriate effects of cellulose nanofibers for the strong interaction and close contact with the polyamide phase of the Pebax polymer via strong hydrogen bonding.

The swelling of natural porous materials, including bleached pulp, as represented by mathematical descriptions, is influenced by a variety of different operating factors. The formerly used Generalised Hygroscopicity Model leads to either a disproportion between a model and a limit value of the sorption capacity or to noticeable deviation in the early swelling phase. Alternatively, the so-called Simple Bounded Growth model solely depends on the maximum sorption capacity, ignoring the physical properties that affect the fibre swelling rate. This research shows that the combination of the two models best describes the swelling process of bleached pulp – a rapid swelling phase and a slower swelling phase. The combined model was found to be useful in characterizing the well-known hornification process.