Papers by Author: Yan Chen

Abstract: In this paper, the activated sludge from liquor-making factory was domesticated by adding the Yellow water to simulate wastewater, and the well-treated activated sludge was used to deal with the wastewater from liquor-making factory. The results show that: compared with the activity of activated sludge with appropriated addition of the Yellow water or not, the activated sludge, which was acclimated with the Yellow water, can increase the capability of activated sludge in dealing with wastewater. Through 16-hour cycle reaction system with the well treated activated sludge, COD of liquor wastewater was decreased to 95mg/L, and at the same time Polyhydroxybutyrate can accumulate about 33.2% of DCW.

Abstract: To extract PHAs which produced by Bacillus cereus, three methods were used in this article, such as chloroform extraction, chloroform-hypochlorite dispersion extraction and hypochlorite-surfactant extraction. Also the thermal processing performance of the materials was examined. The results showed that chloroform-hypochlorite dispersion extraction was the optimum method. The PHAs isolated had the molecular weight 5.0×10⁵ and the extraction rate was up to 72.4%. The thermal property of these materials was studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The result showed that the materials extracted by three methods were all of good thermal processing performance. The processing temperature was forecasted as 220°C.

Abstract: Effects of parameters including pH value, temperature, absorbent dosage, initial ion concentration, and absorbed time, on the removal efficiency of Ag⁺ from aqueous solution were investigated through single factor experiment. Vinasse before and after adsorption were characterized by IR. The maximum removal efficiency of Ag⁺ on vinasse is 97%. The equilibrium sorption is well demonstrated by Freundlich isotherm model.

Abstract: Waste beer yeast was utilized as adsorbent to remove Th⁴⁺ from simulated radioactive wastewater. Effects of various parameters including pH value, temperature, absorbent dosage, and absorption time on adsorption of Th⁴⁺ by waste beer yeast were studied. Beer yeast before and after adsorption was characterized by IR and SEM. The results show that the removal efficiency could be reached 95% at the optimized conditions. The adsorption kinetics was described well by the pseudo second-order equation.

Abstract: Warner-Bratzler shear force (WBSF), area force versus time (AF-T), and cooking loss rate (CLR) are used to evaluate the improvement of tenderness in pork. Kiwi protease concentration, temperature, pH and time are investigated in detail. The results show that kiwi protease processing conditions have great impact on the tenderness of pork. Pork is tendered in kiwi thiol protease with the concentration of 0.001% at 50 °C for 2 h. The initial pH value of the tenderization solution is 5.5.

Abstract: The paper studied the effect of kiwifruit protease on tenderization of pork and related characterization has been made, the result indicates that pork marinate with kiwifruit protease may lead the degradation of collagen protein and the change of the myofibril fragmentation index (MFI), particle size, viscosity, Warner-Bratzler shear force, area force versus time (Area F-T) as well as microstructure characteristics. Because of the inconvenience of characterization of MFI and soluble collagen, viscosity, particle size analysis, shear force and area F-T can fast and accurate characteristic the changes of tenderizer of pork after marination with kiwifruit protease.

Abstract: Distillers' grains (DG) has high cellulose contents and is suitable for conversion to reducing sugar under dilute acid conditions. The effects of the hydrolysis conditions, including acid concentration, solid to liquid ratio, reaction temperature and time, were discussed, as well as the changes of microstructure and groups after hydrolysis. The conversion rate of reducing sugar could reach 25.07% (g/100g DG) when the hydrolysis conditions are as follows: the concentration of sulphuric acid is 5% (wt), the temperature is 120 °C, the ratio of sulphuric acid solution volume (mL) to weight of DG (g) is 30:1 and the reaction time is 10 h.

Abstract: The influences of processing parameters on the tensile strength (TS) of KGM/CaCO₃ composite films (KCaCF) were investigated through orthogonal experiment method. Calcium carbonate and KCaCF were characterized, respectively, by XRD, laser diffraction particle size analyzer, zeta potential analyzer and SEM. The results showed that micron-sized calcite CaCO₃ crystals with-16.4 mv of Zeta potential were synthesized. Calcium carbonate dispersion was blended with KGM to fabricate KCaCF. The mass of CaCO₃, KGM and swelling time affected TS of composite films differently, but didnt reach the significant level (p>0.05). The optimal preparation process for KCaCF is that 5.0% (wt) of KGM powder is added into the dispersion with 2.0% (wt) of CaCO₃, swelling for 1.0 hour at 50 °C and pH 8.0 and then poured onto plate and dried at 50 °C for 15 h.

Abstract: The influences of preparing conditions on mechanical properties of the white mud (WM) / Konjac glucomannan (KGM) composite film (MKG) were investigated by orthogonal experiments. Zeta potential analysis and DSC were used to characterize the properties of WM and MKG. The results show that the mechanical properties of MKG films can be enhanced through proper modification. Optimized processing parameters of MKG film are described as following: the ratio of KGM, WM, benzoic acid, sodium dodecyl benzene sulfonate(LAS) and stearic acid was 100:14:2:0.24:0.14. 1.00 (wt) % of KGM powder was swelled in deionized water with WM modified by stearic acid, benzoic acid and LAS, stirred for 1.5 hour at 60°C and then paved on plate and dried at 40°C for 15 h to form the MKG film.

Abstract: Konjac Glucomannan (KGM) was modified by maleic anhydride (MA). The influences of processing parameters on the mechanical properties of KGM films were investigated through orthogonal experiments. The results showed that the effects of pH, temperature and time of KGM swelling on tensile strength and folding endurance of modified KGM membranes were insignificant (FF0.01). Folding endurance and tensile strength of KGM membranes could be improved by proper addition of MA. The optimum conditions of KGM modification were that the mixture of KGM and MA was swelling at pH 4.0 and 60°C for 2 h, and then cast on a flat and dried at 50°C to give modified KGM membranes.