ABSTRACT
How to propel an efficient exploitation of waste streams is a pivotal tache for the long-range augment of hydrothermal biomass valorization. A facile approach was proposed to simultaneously produce carbon dots (CDs), fermentable sugar, and cellulose enzymatic lignin from agricultural straw with the aid of ionic liquid (IL, 1-aminoethyl-3-methylimidazolium nitrate, [C2NH2MIm][NO3]) catalyzed hydrothermal treatment. The graphite N-doped CDs with bright-blue fluorescence, which was mainly derived from the incorporation of hemicellulose (e.g. xylooligosaccharides), lignin and [C2NH2MIm][NO3], exhibited an average-diameter of 8.14 nm. The exfoliation of amorphous parts and robust fibers was formed to improve cellulose digestibility from 14.7 to 81.6%. The efficient recovery and checkup of lignin pave a way for its potential depolymerization into arenes. This protocol offers a significant benefit for large-scale hydrothermal biorefinery where reduction of process waste is a prime concern, and leads to high-value products (i.e., CDs and lignin) that also fosters the feasibility of bioethanol.
ABSTRACT
To achieve high electrochemical surface area (ECSA) and avoid carbon support and binder in the anode catalyst of direct ethanol fuel cell, herein, we design freestanding core-shell nickel@palladium-nickel nanowire arrays (Ni@Pd-Ni NAs) without carbon support and binder for high-efficiency ethanol electro-oxidation. Bare Ni nanowire arrays (Ni NAs) are first prepared using the facile template-assistant electrodeposition method. Subsequently, the Ni@Pd-Ni NAs are formed using one-step solution-based alloying reaction. The optimized Ni@Pd-Ni NA electrode with a high ECSA of 64.4 m2 g-1Pd exhibits excellent electrochemical performance (peak current density: 622 A g-1Pd) and cycling stability for ethanol electro-oxidation. The facilely obtained yet high-efficiency core-shell Ni@Pd-Ni NA electrode is a promising electrocatalyst, which can be utilized for oxygen reduction reaction, urea, hydrazine hydrate, and hydrogen peroxide electro-oxidation, not limited to the ethanol electro-oxidation.
ABSTRACT
Quinoline and its derivatives are widely considered to be environmental pollutants. In this study, the biodegradation characteristics and bioaugmentation potential for a novel strain were described. The strain, named Q2, which could utilize quinoline as the sole carbon, nitrogen and energy source, was isolated and identified as a Bacillus sp. The optimum temperature, initial pH and shaker rotary speed for quinoline degradation were 30°C, pH 8-10 and 100-200 rpm, respectively. During the biodegradation process, the quinoline-N was released as ammonium and the culture broth became yellow, pink and brown in turn, which indicated that several intermediates were generated. GC/MS analysis showed that 2(1H)-quinolinone and 8-hydroxycoumarin were produced. Furthermore, the bioaugmentation of Q2 into the sludge consortium, which was taken from refinery wastewater treatment plant, to degrade quinoline was investigated. The results showed that it could coexist with the other microbes and the remarkably enhanced quinoline biodegradation ability was achieved.
