The aim of this work is to investigate the ability of an adsorbent of a clay mineral composite to remove and recover gold and silver ions from wastewater.The composite was prepared by mixing phosphogypsum(PG),obtained...The aim of this work is to investigate the ability of an adsorbent of a clay mineral composite to remove and recover gold and silver ions from wastewater.The composite was prepared by mixing phosphogypsum(PG),obtained from an industrial waste,and a natural clay mineral.The materials were characterized before and after use in adsorption by several techniques.Batch adsorption experiments were carried out,and the effects of the contact time and the pH and temperature of solution on the removal processes were investigated.The optimum pH for the adsorption was found to be 4.The adsorption of these metal ions reached equilibrium after 2 h of contact.The pseudo-first-and the pseudo-second-order kinetic models,as well as the Freundlich and the Langmuir isotherm equations,were considered to describe the adsorption results.The maximum adsorbed amount of 85 mg·g^-1 Ag(I)and 108.3 mg·g?1 Au(III)was found.The recovery of the adsorbed gold and silver ions from the adsorbent was also analyzed.Strong acids appeared to be the best desorption agents to recover gold and silver ions.The use of aqua regia gave regeneration rates close to 95.3%and 94.3%for Ag(I)and Au(III),respectively.Finally,the removal of gold and silver ions from an industrial wastewater was tested in batch experiments,and percentage recoveries of 76.5%and 79.9%for Ag(I)and Au(III),respectively,were obtained.To carry out the industrial application of the proposed methodology,an economic viability study is required.展开更多
In this study, a new composite ceramic material using a red clay matrix with different amount of clinker from the cement industry has been developed. The aim is to valorize some natural resources such as red clay and ...In this study, a new composite ceramic material using a red clay matrix with different amount of clinker from the cement industry has been developed. The aim is to valorize some natural resources such as red clay and sub-products from the cement industry as clinker in order to develop new materials for industrial and/or catalytic uses. Raw materials were grounded in order to reduce the particle size and obtain a homogeneous slip. The samples were mixed and compressed into pellets and undergo a heat treatment up to 1100℃. Geotechnical characterization has been carried out. Firing proprieties (shrinkage, water absorption, and mechanical resistance to the inflection) were measured. The composition of the ceramic material was investigated by X-ray diffraction, XRF, SEM and EDS methods. The incorporation of clinker in the ceramic composite material up to 50 wt% exhibits good behaviors (physical and mechanical proprieties) and can be used as a ceramic product.展开更多
基金Santander Bank for funding through the Research Intensification Program
文摘The aim of this work is to investigate the ability of an adsorbent of a clay mineral composite to remove and recover gold and silver ions from wastewater.The composite was prepared by mixing phosphogypsum(PG),obtained from an industrial waste,and a natural clay mineral.The materials were characterized before and after use in adsorption by several techniques.Batch adsorption experiments were carried out,and the effects of the contact time and the pH and temperature of solution on the removal processes were investigated.The optimum pH for the adsorption was found to be 4.The adsorption of these metal ions reached equilibrium after 2 h of contact.The pseudo-first-and the pseudo-second-order kinetic models,as well as the Freundlich and the Langmuir isotherm equations,were considered to describe the adsorption results.The maximum adsorbed amount of 85 mg·g^-1 Ag(I)and 108.3 mg·g?1 Au(III)was found.The recovery of the adsorbed gold and silver ions from the adsorbent was also analyzed.Strong acids appeared to be the best desorption agents to recover gold and silver ions.The use of aqua regia gave regeneration rates close to 95.3%and 94.3%for Ag(I)and Au(III),respectively.Finally,the removal of gold and silver ions from an industrial wastewater was tested in batch experiments,and percentage recoveries of 76.5%and 79.9%for Ag(I)and Au(III),respectively,were obtained.To carry out the industrial application of the proposed methodology,an economic viability study is required.
文摘In this study, a new composite ceramic material using a red clay matrix with different amount of clinker from the cement industry has been developed. The aim is to valorize some natural resources such as red clay and sub-products from the cement industry as clinker in order to develop new materials for industrial and/or catalytic uses. Raw materials were grounded in order to reduce the particle size and obtain a homogeneous slip. The samples were mixed and compressed into pellets and undergo a heat treatment up to 1100℃. Geotechnical characterization has been carried out. Firing proprieties (shrinkage, water absorption, and mechanical resistance to the inflection) were measured. The composition of the ceramic material was investigated by X-ray diffraction, XRF, SEM and EDS methods. The incorporation of clinker in the ceramic composite material up to 50 wt% exhibits good behaviors (physical and mechanical proprieties) and can be used as a ceramic product.
