Preparation, characterization and in vitro anticoagulant activity of corn stover xylan sulfates.

A new anticoagulant agent was prepared by introducing sulfate groups into corn stover xylan through homogeneous reactions. Three organic solvents, N, N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO) and formamide (FA), were adopted as reaction media, with the assistance of LiCl. Structural characterization by FT-IR and CNMR showed that xylan sulfate (XS) could be successfully synthesized with SO∙Pyridine (SO∙Py) complexes sulfation reagent in the three media.

[A rapid method for the determination of hydrogen peroxide concentration].

The present paper reported a spectrophotometry for the determination of hydrogen peroxide concentration. It is based on the reaction between ceric sulfate and hydrogen peroxide in an acidic medium, in which orange tetravalent cerium is converted to colorless trivalent cerium that causeds the change in absorbance. According to the quantitative relationship between ceric sulfate and hydrogen peroxide, the hydrogen peroxide concentration can be calculated.

Use of carboxylated cellulose nanofibrils-filled magnetic chitosan hydrogel beads as adsorbents for Pb(II).

Novel magnetic hydrogel beads (m-CS/PVA/CCNFs), consisting of carboxylated cellulose nanofibrils (CCNFs), amine-functionalized magnetite nanoparticles and poly(vinyl alcohol) (PVA) blended chitosan (CS), were prepared by an instantaneous gelation method. SEM, XRD, and TGA techniques were applied to investigate the structure of the hydrogel materials. The magnetic hydrogels were employed as absorbents for removal of Pb(II) ions from aqueous solutions and the fundamental adsorption behavior was studied.

Superabsorbent nanocomposite hydrogels made of carboxylated cellulose nanofibrils and CMC-g-p(AA-co-AM).

Superabsorbents based on carboxylated cellulose nanofibrils (CCNFs) and carboxymethyl cellulose-g-poly(acrylic acid-co-acrylamide) were synthesized. A series of experiments were performed to evaluate the influence of factors such as CCNFs amount, solution pH, temperature, salt solution type and concentration on the swelling behaviors of the hydrogels. The water uptake of the hydrogels strongly depended on the CCNF content, the swelling capacity in distilled water increased dramatically from 245.

Colloidal stability of negatively charged cellulose nanocrystalline in aqueous systems.

Colloidal stability of negatively charged cellulose nanocrystalline (CNC) in the presence of inorganic and organic electrolytes was investigated by means of dynamic light scattering and atomic force microscopy. CNC could be well dispersed in distilled water due to the electrostatic repulsion among negatively charged sulfate ester groups. Increasing the concentration of inorganic cation ions (Na(+) and Ca(2+)) resulted in CNC aggregation.

[Rapid determination of silicon content in black liquor of straw fibrous material].

The present paper reports a novel method for the determination of silicon content in straw fibrous material black liquor based on alpha-Si--Mo heteropoly acid spectrophotometry. The selected conditions were as follows: detection wavelength 360 nm, pH 4.0, and reaction time 10 min.

Rapid determination of furfural in biomass hydrolysate by full evaporation headspace gas chromatography.

This paper reports a full evaporation (FE) headspace gas chromatographic (HS-GC) method for rapid determination of furfural in the biomass hydrolysate. The data show that a near-complete mass transfer of furfural in the sample from biomass hydrolysate to the vapor phase (headspace) was achieved within 3 min at 105°C when a very small (<40 μL) sample was added to a 20 mL headspace sample vial. The acid-catalyzed furfural decomposition under these conditions was negligible.

Application of statistical design for the optimization of microbial community of synthetic domestic wastewater.

A fractional factorial design (FFD) and a response surface methodology (RSM) were used to optimize the inoculum composition of six strains for treatment of synthetic domestic wastewater. The model predicted the highest overall specific substrate utilization rate (q) of 6.88 g TOC/(d-gVSS).

Chemometrics-assisted spectrophotometry method for the determination of chemical oxygen demand in pulping effluent.

A new method has been developed for the determination of chemical oxygen demand (COD) in pulping effluent using chemometrics-assisted spectrophotometry. Two calibration models were established by inducing UV-visible spectroscopy (model 1) and derivative spectroscopy (model 2), combined with the chemometrics software Smica-P. Correlation coefficients of the two models are 0.

Effect of oxygen availability on the removal efficiency and sludge characteristics during pentachlorophenol (PCP) biodegradation in a coupled granular sludge system.

This study systematically investigated the metabolism of pentachlorophenol (PCP) in batch experiments using coupled sludge granules under various dissolved oxygen concentrations. Results indicated that the oxygen condition in serum bottles has a significant effect on the microorganism metabolism. A greater degree of mineralization of PCP was achieved under oxygen-limited conditions (e.

[Rapid method for determination of furfural and 5-hydroxymethyl furfural in pre-extraction stream of biomass using UV spectroscopy].

The present paper reports a rapid method for the determination of furfural (F) and 5-hydroxymethyl furfural (HMF) in pre-extraction liquors of lignocellulosic biomass based on UV spectroscopy. In a concentrated acetic acid medium, F and HMF have an isosbestic point at 276 nm. It was found that the acidic soluble lignin in the pre-extraction sample is the major interference species in the F and HMF spectroscopic quantification However, only acidic soluble lignins have the absorption at the wavelengths above 325 nm.

Enhancing biodegradation of wastewater by microbial consortia with fractional factorial design.

Batch experiments were conducted on the degradation of synthetic and municipal wastewater by six different strains, i.e., Agrobacterium sp.

Novel preparation and characterization of cellulose microparticles functionalized in ionic liquids.

Ionic liquid (IL)-reconstituted acrylic acid (AA)-functionalized cellulose microparticles were successfully prepared by a water-in-oil suspension technique preliminary modification with AA in homogeneous condition. Cellulose was fully dissolved in 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) IL, and subsequently was grafted homogeneously with AA and N,N'-methylenebisacrylamide (N,N'-MBA) initiated with ammonium persulfate. The grafted cellulose was spheroidized using white silicone oil as the dispersion medium and Span 80 as a dispersant and then reconstituted from [Bmim]Cl.

Rapid determination of ethanol in fermentation liquor by full evaporation headspace gas chromatography.

This paper reports a full evaporation (FE) headspace gas chromatographic (GC) method for rapid determination of ethanol in fermentation liquor. The data show that ethanol in the fermentation liquor was transferred to the vapor phase (headspace) almost completely within 3 min at a temperature of 105 degrees C when a very small volume (< 50 microL) of sample was directly added to a sealed headspace sample vial (20 mL). The ethanol in the vapor phase was then measured by headspace GC using a flame ionization detector.

Kinetic modeling of formic acid pulping of bagasse.

Organic solvent or organosolv pulping processes are alternatives to soda or kraft pulping to delignify lignocellulosic materials for the production of paper pulp. Formic acid, a typical organosolv system, has been presently examined under atmospheric pressure to pulp bagasse fibers. It was shown that efficient bagasse pulping was achieved when the formic acid concentration was limited to 90% (v/v).

Determination of oxalate in black liquor by headspace gas chromatography.

This study demonstrated a headspace gas chromatographic method (HS-GC) for the determination of oxalate content in black liquor (alkaline aqueous solution of inorganic chemicals and dissolved wood species from the alkaline pulping of wood). The method described in this paper is based on the reaction between oxalic and manganese dioxide in an acidic medium, in which oxalic acid is converted to carbon dioxide that is measured with a GC using a thermal conductivity detector. The challenge in developing this method was ensuring complete conversion of oxalic acid while minimizing the contribution of side reactions between carbohydrates, lignin and manganese dioxide to the carbon dioxide measured.

Rapid determination of methanol in black liquors by full evaporation headspace gas chromatography.

This paper reported a full evaporation headspace gas chromatographic (GC) technique for determination of methanol content in black liquors (pulping spent liquor). In this method, a very small volume (10-20 microL) of liquor sample is introduced into a headspace sample vial (20 mL) and heated up to a temperature of 105 degrees C. A near-complete mass transfer of methanol from the liquid phase to vapor phase (headspace), i.

Simultaneous anaerobic-aerobic biodegradation of halogenated phenolic compound under oxygen-limited conditions.

The successful application of co-immobilized aerobic-anaerobic biomass under limited aeration in wastewater treatment systems would eliminate the problems associated with the intermediates mono-chlorophenol (MCP) and di-chlorophenol(DCP) accumulations. With low initial pentachlorophenol (PCP) concentration, all PCP could be completely removed under oxygen-limited strict anaerobic conditions, and the removal efficiencies with different initial headspace oxygen percentage (IHOP) were not obviously different from each other. While at high initial PCP concentration, under strictly anaerobic conditions PCP and their intermediates were clearly higher than that under other conditions, and produced obvious accumulation, the highest PCP reduction was achieved by the system receiving 30 IHOP, oxygen-limited system also exhibited lower residual TOC concentration and lower concentration of metabolic intermediates MCP and DCP.

Adsorption/desorption behavior between a novel amphoteric granular lignin adsorbent and reactive red K-3B in aqueous solutions.

A novel amphoteric granular lignin adsorbent (AGLA) was prepared using magnesium lignosulfonate as a raw material which was provided by a straw sulfite pulp mill in Guangdong Province, China. A reactive dye (red K-3B) was used as an adsorbate to investigate the adsorption behavior by static and mobile ways. The removal of reactive red K-3B was found to be initially pH and concentration dependent.

Coupled anaerobic/aerobic biodegradation of 2,4,6 trichlorophenol.

Degradation of 2,4,6-trichlorophenol (TCP) with co-immobilizing anaerobic granular sludge and isolated aerobic bacterial species was studied in coupled anaerobic/aerobic integrated reactors. The synergism of aerobes and anaerobes within co-immobilized granule might facilitate degrading the TCP and exchange of anaerobic metabolites 4-CP, which promoted system organic removal efficiency and recovered from organic shock-loads more quickly. The biomass specific activities experiment further confirmed that strict anaerobes be not affected over the course of this experiment by the presence of an oxic environment, aerobic activity predominated in the outer co-immobilized granule layers, while the interior was characterized by anaerobic activity.

Study on the treatment of the sulfite pulp CEH bleaching effluents with the coagulation-anaerobic acidification-aeration package reactor.

The coagulation-anaerobic acidification-aeration package reactor was designed for the treatment of pulp CEH bleaching effluents, the efficiencies in CODcr, BOD(5), AOX and toxicity removal achieved were 88.1%, 81.0%, 98.