Algae-silica hybrid materials for biosorption purposes were prepared using sol-gel technology. The resulting biological ceramics (biocers) ought to combine the mechanical stability and porosity of the silicate matrix ...Algae-silica hybrid materials for biosorption purposes were prepared using sol-gel technology. The resulting biological ceramics (biocers) ought to combine the mechanical stability and porosity of the silicate matrix with the algae’s capability for the biosorption for heavy metals. The structure, mechanical properties, and sorption capability of such algae-silicate materials were investigated. Comparative equilibrium sorption ex-periments were performed batchwise with 13 different microalgae and macroalgae powders, and the corre-sponding algae biocers using waters loaded with either concentrations of nickel below 3mg/L or a mixture of different heavy metals (Cr, Ni, Cu, Pb). The algae biocers showed good mechanical stability up to an algae content of 30-50% and a total porosity of 40-60%. The silica matrix itself was involved in the sorption of metals. The metal binding capability of embedded macroalgae biomass was unaffected by immobilisation in the silica matrix. In contrast, for waters with nickel or different heavy metals, reduced sorption capability was shown by embedded microalgae.展开更多
Discharging wastewater containing heavy metals of Cu, Pb, Zn and Cd into water bodies can cause toxicity in plants and aquatic animals and some of them will be unable to survive except algae. Wastewater treatment meth...Discharging wastewater containing heavy metals of Cu, Pb, Zn and Cd into water bodies can cause toxicity in plants and aquatic animals and some of them will be unable to survive except algae. Wastewater treatment method to remove heavy metal contaminants includes chemical precipitation, ion exchange, membrane, filtration, adsorption using activated carbon. However, these methods are either expensive or have other disadvantages such as high energy consumption and inefficiencies when existing heavy metals are at trace concentration. Biosorption using algae biomass can be an alternative method to eliminate heavy metals. The objective of the project is to investigate the capability of Marine Algae (MA) and Freshwater Algae (FA) bi-omass in adsorbing heavy metals of Cu, Pb, Zn and Cd from water medium using synthetic water and industrial water. MA and FA were obtained from the eastern coast of Pulau Ubin and local fish farm respectively. After being fully washed with deionised water, dried in a furnace for 105°C, they are grinded to pass 1 mm2 of siever. MA and FA were characterised using FTIR to determine their functional groups. An industrial water was collected from industrial discharge from metal fac-tories in northern side of Singapore. Effect of adsorption time, adsorbent concentra-tion, and pH were studied. The result showed that FA and MA had a higher capability in adsorbing a total metal of about 40 ppm level from an industrial water, or 4 times than synthetic water concentration, at the same adsorbent dosage of 50 mg. In con-clusion, the presence of various functional groups, hydroxyl, carboxylic and amine groups, in all MA and FA samples had enabled the algae biomass to adsorb heavy metals of Cu, Pb, Cd and Zn from synthetic and industrial water. Due to their bio-sorptive properties and fast adsorption capability, algae could be a potential method for cleaning up surface water or post-treatment of wastewater and minimise the cost of eutrophication.展开更多
Heavy metal pollution from industrial wastewater is a worldwide environmental issue. Biosorption of heavy metals by using biosorbents derived from various types of biomass has been shown to be effective for the uptake...Heavy metal pollution from industrial wastewater is a worldwide environmental issue. Biosorption of heavy metals by using biosorbents derived from various types of biomass has been shown to be effective for the uptake of heavy metal ions. In this study, biosorbents derived from the biomass of a group of marine macroalgae were used for the removal and recovery of heavy metal ions from aqueous solutions. Results indicated that the biosorbents have high uptake capacities and affinities for a number of heavy metal ions. The uptake capacities of the biosorbents were in the range of 1.0 to 1.5mmol·g-1 for divalent heavy metal ions. The kinetics of the uptake process was fast and the process can be used in both batch and fixed-bed operations. It appears that the biosorption process by using biosorbents from marine macroalgae can be an efficient and cost effective technology for the treatment of heavy metal containing wastewater.展开更多
1 INTRODUCTIONBiosorption of heavy metals using biosorbents derived from suitable biomass is a new tech-nology for the removal and recovery of heavy metals from industrial waste waters.The ad-vantages of the biosorpti...1 INTRODUCTIONBiosorption of heavy metals using biosorbents derived from suitable biomass is a new tech-nology for the removal and recovery of heavy metals from industrial waste waters.The ad-vantages of the biosorption technology include rapid reduction of dissolved heavy metal ionsconcentration to 10<sup>-6</sup>and 10<sup>-9</sup>levels,use of inexpensive and non-hazardous biosorbents,useof existing adsorption process equipment and therefore low operating costs,high uptake ca-pacity and specificity for selective heavy metal removals,and low interference from展开更多
Heavy metal pollution is one of the most important environmental problems today.Biosorption is an innovative tech-nology that employs biological materials to accumulate heavy metals from waste water through metabolic ...Heavy metal pollution is one of the most important environmental problems today.Biosorption is an innovative tech-nology that employs biological materials to accumulate heavy metals from waste water through metabolic process or physicochemi-cal pathways of uptake.Even though several physical and chemical methods are available for removal of heavy metals,currently many biological materials such as bacteria,algae,yeasts and fungi have been widely used due to their good performance,low cost and large quantity of availability.The aim of the present study is to explore the biosorption of toxic heavy metals,Cr(VI),Cr(III),Pb(II) and Cd(II) by algal biomass obtained from algae Sargassum wightii(brown) and Caulerpa racemosa(green).Biosorption of algal biomass was found to be biomass concentration-and pH-dependent,while the maximal biosorption was found at pH 5.0 and with the metal concentration of 100 mg L-1.S.wightii showed the maximal metal biosorption at the biomass concentration of 25 g L-1,followed by C.racemosa with the maximal biosorption at 30 g L-1.S.wightii showed 78% biosorption of Cr(VI),Cr(III),Pb(II) and Cd(II) ions.C.racemosa exhibited 85% biosorption of Cd(II) and Cr(VI),and 50% biosorption of Cr(III) and Pb(II).The results of our study suggest that seaweed biomass can be used efficiently展开更多
The present study investigates the biosorption of cadmium ions from aqueous solution onto unmodified, ultrasound and microwave treated cells of Saccharomyces cerevisiae. FTIR analysis was conducted to characterize the...The present study investigates the biosorption of cadmium ions from aqueous solution onto unmodified, ultrasound and microwave treated cells of Saccharomyces cerevisiae. FTIR analysis was conducted to characterize the biosorbent. Equilibrium and kinetic studies of unmodified RBW (residual brewery waste) cell yeast and DSM 1333 (pure strain) were conducted by considering the effect of initial cadmium ions concentration. Results showed that the ultrasound and microwave treatments decrease the heavy metal uptake compared with the unmodified biomass. Langmuir and Freundlich isotherm models on both unmodified yeast cell types were used to analyze the equilibrium data. It was found that the Langmuir isotherm and pseudo-second-order kinetics models describe better the cadmium ions removal process.展开更多
文摘Algae-silica hybrid materials for biosorption purposes were prepared using sol-gel technology. The resulting biological ceramics (biocers) ought to combine the mechanical stability and porosity of the silicate matrix with the algae’s capability for the biosorption for heavy metals. The structure, mechanical properties, and sorption capability of such algae-silicate materials were investigated. Comparative equilibrium sorption ex-periments were performed batchwise with 13 different microalgae and macroalgae powders, and the corre-sponding algae biocers using waters loaded with either concentrations of nickel below 3mg/L or a mixture of different heavy metals (Cr, Ni, Cu, Pb). The algae biocers showed good mechanical stability up to an algae content of 30-50% and a total porosity of 40-60%. The silica matrix itself was involved in the sorption of metals. The metal binding capability of embedded macroalgae biomass was unaffected by immobilisation in the silica matrix. In contrast, for waters with nickel or different heavy metals, reduced sorption capability was shown by embedded microalgae.
文摘Discharging wastewater containing heavy metals of Cu, Pb, Zn and Cd into water bodies can cause toxicity in plants and aquatic animals and some of them will be unable to survive except algae. Wastewater treatment method to remove heavy metal contaminants includes chemical precipitation, ion exchange, membrane, filtration, adsorption using activated carbon. However, these methods are either expensive or have other disadvantages such as high energy consumption and inefficiencies when existing heavy metals are at trace concentration. Biosorption using algae biomass can be an alternative method to eliminate heavy metals. The objective of the project is to investigate the capability of Marine Algae (MA) and Freshwater Algae (FA) bi-omass in adsorbing heavy metals of Cu, Pb, Zn and Cd from water medium using synthetic water and industrial water. MA and FA were obtained from the eastern coast of Pulau Ubin and local fish farm respectively. After being fully washed with deionised water, dried in a furnace for 105°C, they are grinded to pass 1 mm2 of siever. MA and FA were characterised using FTIR to determine their functional groups. An industrial water was collected from industrial discharge from metal fac-tories in northern side of Singapore. Effect of adsorption time, adsorbent concentra-tion, and pH were studied. The result showed that FA and MA had a higher capability in adsorbing a total metal of about 40 ppm level from an industrial water, or 4 times than synthetic water concentration, at the same adsorbent dosage of 50 mg. In con-clusion, the presence of various functional groups, hydroxyl, carboxylic and amine groups, in all MA and FA samples had enabled the algae biomass to adsorb heavy metals of Cu, Pb, Cd and Zn from synthetic and industrial water. Due to their bio-sorptive properties and fast adsorption capability, algae could be a potential method for cleaning up surface water or post-treatment of wastewater and minimise the cost of eutrophication.
基金Supported in part by the Australian Research Council (Small Grant Scheme) and a Royal Thai Government Scholarship.
文摘Heavy metal pollution from industrial wastewater is a worldwide environmental issue. Biosorption of heavy metals by using biosorbents derived from various types of biomass has been shown to be effective for the uptake of heavy metal ions. In this study, biosorbents derived from the biomass of a group of marine macroalgae were used for the removal and recovery of heavy metal ions from aqueous solutions. Results indicated that the biosorbents have high uptake capacities and affinities for a number of heavy metal ions. The uptake capacities of the biosorbents were in the range of 1.0 to 1.5mmol·g-1 for divalent heavy metal ions. The kinetics of the uptake process was fast and the process can be used in both batch and fixed-bed operations. It appears that the biosorption process by using biosorbents from marine macroalgae can be an efficient and cost effective technology for the treatment of heavy metal containing wastewater.
文摘1 INTRODUCTIONBiosorption of heavy metals using biosorbents derived from suitable biomass is a new tech-nology for the removal and recovery of heavy metals from industrial waste waters.The ad-vantages of the biosorption technology include rapid reduction of dissolved heavy metal ionsconcentration to 10<sup>-6</sup>and 10<sup>-9</sup>levels,use of inexpensive and non-hazardous biosorbents,useof existing adsorption process equipment and therefore low operating costs,high uptake ca-pacity and specificity for selective heavy metal removals,and low interference from
文摘Heavy metal pollution is one of the most important environmental problems today.Biosorption is an innovative tech-nology that employs biological materials to accumulate heavy metals from waste water through metabolic process or physicochemi-cal pathways of uptake.Even though several physical and chemical methods are available for removal of heavy metals,currently many biological materials such as bacteria,algae,yeasts and fungi have been widely used due to their good performance,low cost and large quantity of availability.The aim of the present study is to explore the biosorption of toxic heavy metals,Cr(VI),Cr(III),Pb(II) and Cd(II) by algal biomass obtained from algae Sargassum wightii(brown) and Caulerpa racemosa(green).Biosorption of algal biomass was found to be biomass concentration-and pH-dependent,while the maximal biosorption was found at pH 5.0 and with the metal concentration of 100 mg L-1.S.wightii showed the maximal metal biosorption at the biomass concentration of 25 g L-1,followed by C.racemosa with the maximal biosorption at 30 g L-1.S.wightii showed 78% biosorption of Cr(VI),Cr(III),Pb(II) and Cd(II) ions.C.racemosa exhibited 85% biosorption of Cd(II) and Cr(VI),and 50% biosorption of Cr(III) and Pb(II).The results of our study suggest that seaweed biomass can be used efficiently
基金This work was made possible by the financial support of the Sectoral Operational Programme for Human Re-sources Development 2007-2013,co-financed by the Eu-ropean Social Fund,under the project POSDRU/107/1.5/S/76841 with the title“Modern Doctoral Studies:Internationalization and Interdisciplinary”.
文摘The present study investigates the biosorption of cadmium ions from aqueous solution onto unmodified, ultrasound and microwave treated cells of Saccharomyces cerevisiae. FTIR analysis was conducted to characterize the biosorbent. Equilibrium and kinetic studies of unmodified RBW (residual brewery waste) cell yeast and DSM 1333 (pure strain) were conducted by considering the effect of initial cadmium ions concentration. Results showed that the ultrasound and microwave treatments decrease the heavy metal uptake compared with the unmodified biomass. Langmuir and Freundlich isotherm models on both unmodified yeast cell types were used to analyze the equilibrium data. It was found that the Langmuir isotherm and pseudo-second-order kinetics models describe better the cadmium ions removal process.
