Two types of cyanobacteria of the genus Arthrospira（commonly known as Spirulina） were tested for biosorption of cerium（III） ions from aqueous solutions. An endemic type（ES） found in the northern Negev desert, Is...Two types of cyanobacteria of the genus Arthrospira（commonly known as Spirulina） were tested for biosorption of cerium（III） ions from aqueous solutions. An endemic type（ES） found in the northern Negev desert, Israel, and a commercial powder（CS） were used in this study. Biosorption was evaluated as a function of p H, contact time, initial metal concentration, number of sorption-desorption cycles, and salt concentration. The optimum p H range for biosorption was found to be 5.0–5.5. The kinetic characteristics of both Spirulina types were found to be highly compatible with a pseudo-second order kinetic model. The adsorption isotherms of both types were found to be well-suited to Langmuir and Freundlich adsorption isotherms. Maximum biosorption uptakes, according to the Langmuir model, were 18.1 and 38.2 mg/g, for ES and CS, respectively. Sodium chloride concentrations of up to 5 g/L had a minor effect on cerium biosorption. Desorption efficiency was found to be greater than 97% with 0.1 mol/L HNO_3 after three sorption-desorption cycles, without significant loss in the biosorption capacity. The results indicated the feasibility of cerium recovery from industrial wastes using Spirulina biomass.展开更多
In order to substitute fossil resources in activated carbon(AC)production,recent efforts have focused on the utilization of renewable raw materials.Regions with important wood industries offer two potentially underest...In order to substitute fossil resources in activated carbon(AC)production,recent efforts have focused on the utilization of renewable raw materials.Regions with important wood industries offer two potentially underestimated resource types:forestry residue biomass(FRB)and waste wood(WW).Although these materials are widely available(approx.130 mio.m3a-1 FRB,approx.50 mio.ta^(-1) WW in the EU),they are mostly valorised through energy production,as they are high in ashes and may be contaminated with organics and heavy metals.In this study,both FRB and WW were treated via one-step pyrolysis for AC production.ZnCl_(2) was applied as activating agent at pyrolysis temperatures varying from 400 to 600℃ and residence times between 1 and 3 h.Overall,76 samples were prepared and characterized thoroughly via elemental analysis,N_(2)/CO_(2) ad/-desorption,thermogravimetric analysis(TGA),scanning electron microscopy(SEM),and infrared spectroscopy(FTIR).The produced carbons showed specific surface areas of up to 1430 m2g1 and a pore size distribution with a micropore share of up to 80%.The presence of oxygen-containing functional groups was confirmed via FTIR.Potential feedstock contamination can be mitigated,as minerals and heavy metals could be leached out(up to-99.15%)by an additional wash step and organic contamination undergoes thermal cracking during pyrolysis.The presented study could be a next step in upcycling considerable waste streams from the wood sector through localised and non-fossil-based AC production.展开更多
The authors regret that there was a mix-up in the illustrations during the approval process.Here is the correct image for Fig.4:The authors would like to apologise for any inconvenience caused.
基金Project supported by PAZY Foundation,Israel(244)
文摘Two types of cyanobacteria of the genus Arthrospira（commonly known as Spirulina） were tested for biosorption of cerium（III） ions from aqueous solutions. An endemic type（ES） found in the northern Negev desert, Israel, and a commercial powder（CS） were used in this study. Biosorption was evaluated as a function of p H, contact time, initial metal concentration, number of sorption-desorption cycles, and salt concentration. The optimum p H range for biosorption was found to be 5.0–5.5. The kinetic characteristics of both Spirulina types were found to be highly compatible with a pseudo-second order kinetic model. The adsorption isotherms of both types were found to be well-suited to Langmuir and Freundlich adsorption isotherms. Maximum biosorption uptakes, according to the Langmuir model, were 18.1 and 38.2 mg/g, for ES and CS, respectively. Sodium chloride concentrations of up to 5 g/L had a minor effect on cerium biosorption. Desorption efficiency was found to be greater than 97% with 0.1 mol/L HNO_3 after three sorption-desorption cycles, without significant loss in the biosorption capacity. The results indicated the feasibility of cerium recovery from industrial wastes using Spirulina biomass.
基金The financial support by the Austrian Federal Ministry for Digital and Economic Affairs and the National Foundation for Research,Technology and Development,the Christian Doppler Research Association as well as the participating companies is gratefully acknowledged.
文摘In order to substitute fossil resources in activated carbon(AC)production,recent efforts have focused on the utilization of renewable raw materials.Regions with important wood industries offer two potentially underestimated resource types:forestry residue biomass(FRB)and waste wood(WW).Although these materials are widely available(approx.130 mio.m3a-1 FRB,approx.50 mio.ta^(-1) WW in the EU),they are mostly valorised through energy production,as they are high in ashes and may be contaminated with organics and heavy metals.In this study,both FRB and WW were treated via one-step pyrolysis for AC production.ZnCl_(2) was applied as activating agent at pyrolysis temperatures varying from 400 to 600℃ and residence times between 1 and 3 h.Overall,76 samples were prepared and characterized thoroughly via elemental analysis,N_(2)/CO_(2) ad/-desorption,thermogravimetric analysis(TGA),scanning electron microscopy(SEM),and infrared spectroscopy(FTIR).The produced carbons showed specific surface areas of up to 1430 m2g1 and a pore size distribution with a micropore share of up to 80%.The presence of oxygen-containing functional groups was confirmed via FTIR.Potential feedstock contamination can be mitigated,as minerals and heavy metals could be leached out(up to-99.15%)by an additional wash step and organic contamination undergoes thermal cracking during pyrolysis.The presented study could be a next step in upcycling considerable waste streams from the wood sector through localised and non-fossil-based AC production.
文摘The authors regret that there was a mix-up in the illustrations during the approval process.Here is the correct image for Fig.4:The authors would like to apologise for any inconvenience caused.
