Optimization of the extraction process of total flavonoids from Trichosanthis Fructus by Box-Behnken response surface method combined with differential spectrophotometry

Objective:To optimize the extraction process of total flavones in Trichosanthis Fructus(composed of Trichosanthis pericarpium and Trichosanthis semen in certain proportion).Methods:The effects of the mixture ratio of Trichosanthis pericarpium and Trichosanthis semen,ethanol concentration,ultrasonic extraction time and extraction temperature on the extraction rate of total flavonoids in Trichosanthis Fructus were investigated.The extraction process of total flavonoids in Trichosanthis Fructus was optimized by Box-Behnken response surface method combined with differential spectrophotometry.Results:The optimum extraction conditions of total flavonoids in Trichosanthis Fructus were as follows:The mixture ratio of Trichosanthis pericarpium and Trichosanthis semen was 4:6,the ethanol concentration was 70%,the ultrasonic extraction time was 60min and the extraction temperature was 40℃.Conclusion:Box-Behnken response surface method combined with differential spectrophotometry can optimize the extraction process of total flavonoids from Trichosanthis Fructus,which can provide reference for the extraction and application of total flavonoids in Trichosanthis Fructus.

A quick evaluation model for CO_2 flooding and sequestration

CO2 flooding not only triggers an increase in oil production,but also reduces the amount of CO2 released to the atmosphere （by storing it permanently in the formations）.It is one of the best ways to use and store CO2.This paper firstly selects the key factors after analyzing the factors influencing the CO2 storage potential in the formations and oil recovery,and then introduces a series of dimensionless variables to describe reservoir characteristics.All influencing factors with varying values are calculated through a Box-Behnken experimental design.The results are interpreted by a response surface method,and then a quick screening model is obtained to evaluate the oil recovery and CO2 storage potential for an oil reservoir.Based on the evaluation model,sensitivity analysis of each factor is carried out.Finally,research on CO2 sequestration and flooding in a typical reservoir indicates that the evaluation model fits well with the numerical simulation,which proves that the evaluation model can provide criteria for screening attractive candidate reservoirs for CO2 sequestration and flooding.

Study on the Effect of Preparation Parameters of K₂CO₃/Al₂O₃Sorbent on CO₂Capture Capacity at Flue Gas Operating Conditions

In this paper, study on the effect of preparation conditions of K2CO3/Al2O3 sorbent was done. Box-Behnken design was applied to study the influence of four parameters involve initial solution concentration, impregnation time and calcination step temperature and time. A quadratic model was used to correlate the sorbent capture capacity. The model was used to calculate the optimum conditions for preparing sorbent. From the analysis of variance (ANOVA), the most influential factor on each experimental design response was identified. The potassium-based sorbents used in this study were prepared by impregnating K2CO3 on Al2O3 support. The CO2 capture capacity was measured in the presence of H2O in a fixed-bed reactor at CO2 capture temperature of 60°C using breakthrough curves. The optimum sorbent prepared by this method showed CO2 capture capacity of 77.21 mg CO2/g sorbent. It was observed that the experimental values obtained were in good agreement with the values predicted by the model, with relatively small errors between the predicted and the actual values. The results obtained in this study can be used as basic data for study on design and operating condition optimization of CO2 capture process using these sorbents.

Enhancement of the electrocatalytic oxidation of antibiotic wastewater over the conductive black carbon-PbO2 electrode prepared using novel green approach

The secondary pollution caused by modification of an electrode due to doping of harmful materials has long been a big concern.In this study,an environmentally friendly material,conductive carbon black,was adopted for modification of lead dioxide electrode(Pb02).It was observed that the as-prepared conductive carbon black modified electrode(C-PbO2)exhibited an enhanced electrocatalytical performance and more stable structure than a pristine Pb02 electrode,and the removal efficiency of metronidazole(MNZ)and COD by a 1.0%C-Pb02 electrode at optimal conditions was increased by 24.66%and 7.01%,respectively.Results revealed that the electrochemical degradation of MNZ wastewater followed pseudo-first-order kinetics.This intimates that the presence of conductive carbon black could improve the current efficiency,promote the generation of hydroxyl radicals,and accelerate the removal of MNZ through oxidation.In addition,MNZ degradation pathways through a C-Pb02 electrode were proposed based on the identified intermediates.To promote the electrode to treat antibiotic wastewater,optimal experimental conditions were predicted through the Box-Behnken design(BBD)method.The results of this study suggest that a C-Pb02 electrode may represent a promising functional material to pretreat antibiotic wastewaters.

Optimization of Solid-Phase Extraction Conditions for Perfluorooctanoic Acid in Leachate

In order to optimize the solid phase extraction(SPE)conditions of perfluorooctanoic acid(PFOA)in the raw leachate and treated leachate,the effects of activator properties,SPE cartridge,p H value,ionic strength,and eluent properties were studied through single factor experiments.The optimal results of each single factor were obtained.Considering that the concentration of PFOA in the treated leachate is lower than that of the raw leachate,the SPE conditions of the treated leachate have been further optimized.Based on the above single-factor experiment,the main influencing factors were screened out as the volume of activator,ionic strength,and volume of eluent,and the three-factor threelevel response surface methodology(RSM)was optimized.The optimum SPE conditions of PFOA from treated landfill leachate were as follows:Activation of weak anion exchange(WAX)cartridge with 10 mL methanol,dosage of 600 mg KCl,6 m L 1%ammonia methanol eluted PFOA,the theory recovery rate is over95.67%.It has been verified that the error between the predicted value and the actual extraction recovery is small and has good repeatability.