This study focuses on the synthesis of nanocomposites named CCA and CZA that were prepared by the incorporation of cellulose(CL)in the Ca/Al and Zn/Al layered double hydroxide(LDH),respectively.These materials were th...This study focuses on the synthesis of nanocomposites named CCA and CZA that were prepared by the incorporation of cellulose(CL)in the Ca/Al and Zn/Al layered double hydroxide(LDH),respectively.These materials were then used for the uptake of As(Ⅲ)and As(V)from aqueous medium.Characterization of both nanocomposites(CCA and CZA)was done using FTIR and Raman analysis to identify the functional groups,N2 adsorption-desorption isotherms to determine the specific surface area and pore geometry and XPS analysis to obtain the surface atomic composition.Some other characters were investigated using simultaneous TGA and DTA and elemental chemical analysis(CHNS/O).The crystallinity of the prepared nanocomposites was displayed by XRD patterns.Furthermore,the sheet-like structure of the LDHs and the irregularity of surface morphology with porous structure were observed by TEM and SEM microphotographs.Optimization of maximum adsorption capacity was adjusted using different parameters including pH,contact time and adsorbent dosage.The pseudo-second-order model was in good fitting with kinetics results.The adsorption isotherm results showed that CZA exhibits better adsorption capacity for As(Ⅲ)than CCA and the Langmuir isotherm model described the data well for both nanocomposites.Thermodynamic studies illustrated the endothermic nature of CCA and exothermic nature on CZA,as well as the fact that the adsorption process is spontaneous.A real water sample collected from well located in Gabes(Tunisia),has also been treated.The obtained experimental results were confirmed that these sorbents are efficient for the treatment of hazardous toxic species such as.展开更多
Waste generation from food manufacturing facilities poses a serious hazard like environmental degradation, water pollution, and land pollution due to its high nutrient composition. Specifically, solid waste(powder) di...Waste generation from food manufacturing facilities poses a serious hazard like environmental degradation, water pollution, and land pollution due to its high nutrient composition. Specifically, solid waste(powder) disposal requires additional energy sources in terms of scientific treatment, structured collection, and disposal packaging according to the safety regulation. Thus, this research discusses the viewpoint of integrating food processing waste as an organic carbon source with BG-11 medium for Chlorella vulgaris(FSP-E) growth. The food processing waste powders investigated in this study were obtained from milk, and biscuit manufacturing facilities. The culture medium was modified by combining both BG-11 and food processing waste powders to identify the optimal algal growth and biochemical content.Compared to the microalgae grown in BG-11 alone(IBG), the combination of biscuit waste and IBG produced higher biomass concentration(44%), with increased lipid(11%), protein(20%), and carbohydrate(57%) contents. Chlorella vulgaris was able to uptake nutrients from the culture medium with combination of food processing waste and IBG thus enhancing its growth. The results obtained also indicate that an integrated culture system using food processing waste and synthetic sources can generate energy out of waste by improving the bio-composition of the microalgae biomass.展开更多
Simulating the detailed movement of a rising bubble can be challenging, especially when it comes to bubble path instabilities. A solution based on the Euler Lagrange (EL) approach is presented, where the bubbles show ...Simulating the detailed movement of a rising bubble can be challenging, especially when it comes to bubble path instabilities. A solution based on the Euler Lagrange (EL) approach is presented, where the bubbles show oscillating shape and/or instable paths while computational cost are at a far lower level than in DNS. The model calculates direction, shape and rotation of the bubbles. A lateral force based on rotation and direction is modeled to finally create typical instable path lines. This is embedded in an EL simulation, which can resolve bubble size distribution, mass transfer and chemical reactions. A parameter study was used to choose appropriate model constants for a mean bubble size of 3 mm. To ensure realistic solution, validation against experimental data of single rising bubbles and bubble swarms are presented. References with 2D and also 3D analysis are taken into account to compare simulative data in terms of typical geometrical parameters and average field values.展开更多
Removal of antimonite[Sb(Ⅲ)]from the aquatic environment and reducing its biotoxicity is urgently needed to safeguard environmental and human health.Herein,crawfish shell-derived biochars(CSB),pyrolyzed at 350,500,an...Removal of antimonite[Sb(Ⅲ)]from the aquatic environment and reducing its biotoxicity is urgently needed to safeguard environmental and human health.Herein,crawfish shell-derived biochars(CSB),pyrolyzed at 350,500,and 650℃,were used to remediate Sb(Ⅲ)in aqueous solutions.The adsorption data best fitted to the pseudo-second-order kinetic and Langmuir isotherm models.Biochar produced at 350℃(CSB350)showed the highest adsorption capacity(27.7 mg g^(−1)),and the maximum 78%oxidative conversion of Sb(Ⅲ)to Sb(V).The adsorption results complemented with infrared(FTIR),X-ray photoelectron(XPS),and near-edge X-ray absorption fine structure(NEXAFS)spectroscopy analyses indicated that the adsorption of Sb(Ⅲ)on CSB involved electrostatic interaction,surface complexation with oxygen-containing functional groups(C=O,O=C-O),π-πcoordination with aromatic C=C and C-H groups,and H-bonding with-OH group.Density functional theory calculations verified that surface complexation was the most dominant adsorption mechanism,whilstπ-πcoordination and H-bonding played a secondary role.Furthermore,electron spin resonance(ESR)and mediated electrochemical reduction/oxidation(MER/MEO)analyses confirmed that Sb(Ⅲ)oxidation at the biochar surface was governed by persistent free radicals(PFRs)(•O_(2)^(−)and•OH)and the electron donating/accepting capacity(EDC/EAC)of biochar.The abundance of preferable surface functional groups,high concentration of PFRs,and high EDC conferred CSB350 the property of an optimal adsorbent/oxidant for Sb(Ⅲ)removal from water.The encouraging results of this study call for future trials to apply suitable biochar for removing Sb(Ⅲ)from wastewater at pilot scale and optimize the process.展开更多
文摘This study focuses on the synthesis of nanocomposites named CCA and CZA that were prepared by the incorporation of cellulose(CL)in the Ca/Al and Zn/Al layered double hydroxide(LDH),respectively.These materials were then used for the uptake of As(Ⅲ)and As(V)from aqueous medium.Characterization of both nanocomposites(CCA and CZA)was done using FTIR and Raman analysis to identify the functional groups,N2 adsorption-desorption isotherms to determine the specific surface area and pore geometry and XPS analysis to obtain the surface atomic composition.Some other characters were investigated using simultaneous TGA and DTA and elemental chemical analysis(CHNS/O).The crystallinity of the prepared nanocomposites was displayed by XRD patterns.Furthermore,the sheet-like structure of the LDHs and the irregularity of surface morphology with porous structure were observed by TEM and SEM microphotographs.Optimization of maximum adsorption capacity was adjusted using different parameters including pH,contact time and adsorbent dosage.The pseudo-second-order model was in good fitting with kinetics results.The adsorption isotherm results showed that CZA exhibits better adsorption capacity for As(Ⅲ)than CCA and the Langmuir isotherm model described the data well for both nanocomposites.Thermodynamic studies illustrated the endothermic nature of CCA and exothermic nature on CZA,as well as the fact that the adsorption process is spontaneous.A real water sample collected from well located in Gabes(Tunisia),has also been treated.The obtained experimental results were confirmed that these sorbents are efficient for the treatment of hazardous toxic species such as.
基金supported by the Fundamental Research Grant Scheme, Malaysia (No. FRGS/1/2019/STG05/UNIM/02/2)My PAIR-PHCHibiscus Grant (No. My PAIR/1/2020/STG05/UNIM/1)supported by the National Natural Science Foundation of China (No. 41876124)。
文摘Waste generation from food manufacturing facilities poses a serious hazard like environmental degradation, water pollution, and land pollution due to its high nutrient composition. Specifically, solid waste(powder) disposal requires additional energy sources in terms of scientific treatment, structured collection, and disposal packaging according to the safety regulation. Thus, this research discusses the viewpoint of integrating food processing waste as an organic carbon source with BG-11 medium for Chlorella vulgaris(FSP-E) growth. The food processing waste powders investigated in this study were obtained from milk, and biscuit manufacturing facilities. The culture medium was modified by combining both BG-11 and food processing waste powders to identify the optimal algal growth and biochemical content.Compared to the microalgae grown in BG-11 alone(IBG), the combination of biscuit waste and IBG produced higher biomass concentration(44%), with increased lipid(11%), protein(20%), and carbohydrate(57%) contents. Chlorella vulgaris was able to uptake nutrients from the culture medium with combination of food processing waste and IBG thus enhancing its growth. The results obtained also indicate that an integrated culture system using food processing waste and synthetic sources can generate energy out of waste by improving the bio-composition of the microalgae biomass.
基金Funding by the Deutsche Forschungsgemeinschaft(DFG)within the RTG GrK 1932“Stochastic Models for Innovations in the Engineering Sciences”,project area P1
文摘Simulating the detailed movement of a rising bubble can be challenging, especially when it comes to bubble path instabilities. A solution based on the Euler Lagrange (EL) approach is presented, where the bubbles show oscillating shape and/or instable paths while computational cost are at a far lower level than in DNS. The model calculates direction, shape and rotation of the bubbles. A lateral force based on rotation and direction is modeled to finally create typical instable path lines. This is embedded in an EL simulation, which can resolve bubble size distribution, mass transfer and chemical reactions. A parameter study was used to choose appropriate model constants for a mean bubble size of 3 mm. To ensure realistic solution, validation against experimental data of single rising bubbles and bubble swarms are presented. References with 2D and also 3D analysis are taken into account to compare simulative data in terms of typical geometrical parameters and average field values.
基金the National Key Research and Development Program of China(2020YFC1807704)the National Natural Science Foundation of China(21876027)the Science and Technology Innovation Project of Foshan,China(1920001000083).
文摘Removal of antimonite[Sb(Ⅲ)]from the aquatic environment and reducing its biotoxicity is urgently needed to safeguard environmental and human health.Herein,crawfish shell-derived biochars(CSB),pyrolyzed at 350,500,and 650℃,were used to remediate Sb(Ⅲ)in aqueous solutions.The adsorption data best fitted to the pseudo-second-order kinetic and Langmuir isotherm models.Biochar produced at 350℃(CSB350)showed the highest adsorption capacity(27.7 mg g^(−1)),and the maximum 78%oxidative conversion of Sb(Ⅲ)to Sb(V).The adsorption results complemented with infrared(FTIR),X-ray photoelectron(XPS),and near-edge X-ray absorption fine structure(NEXAFS)spectroscopy analyses indicated that the adsorption of Sb(Ⅲ)on CSB involved electrostatic interaction,surface complexation with oxygen-containing functional groups(C=O,O=C-O),π-πcoordination with aromatic C=C and C-H groups,and H-bonding with-OH group.Density functional theory calculations verified that surface complexation was the most dominant adsorption mechanism,whilstπ-πcoordination and H-bonding played a secondary role.Furthermore,electron spin resonance(ESR)and mediated electrochemical reduction/oxidation(MER/MEO)analyses confirmed that Sb(Ⅲ)oxidation at the biochar surface was governed by persistent free radicals(PFRs)(•O_(2)^(−)and•OH)and the electron donating/accepting capacity(EDC/EAC)of biochar.The abundance of preferable surface functional groups,high concentration of PFRs,and high EDC conferred CSB350 the property of an optimal adsorbent/oxidant for Sb(Ⅲ)removal from water.The encouraging results of this study call for future trials to apply suitable biochar for removing Sb(Ⅲ)from wastewater at pilot scale and optimize the process.
