Adsorption characteristics of potentially toxic metals in single- and multi-metal forms onto ferronickel slag were evaluated. Competitive sorption of metals by ferronickel slag has never been reported previously. The maximum adsorption capacities of toxic metals on ferronickel were in the order of Cd (10.2 mg g−1) > Cu (8.4 mg g−1) > Zn (4.4 mg g−1) in the single-metal adsorption isotherm and Cu (6.1 mg g−1) >> Cd (2.3 mg g−1) > Zn (0.3 mg g−1) in the multi-metal adsorption isotherm. In comparison with single-metal adsorption isotherm, the reduction rates of maximum toxic metal adsorption capacity in the multi-metal adsorption isotherm were in the following order of Zn (93%) > Cd (78%) >> Cu (27%). The Freundlich isotherm provides a slightly better fit than the Langmuir isotherm equation using ferronickel slag for potentially toxic metal adsorption. Multi-metal adsorption behaviors differed from single-metal adsorption due to competition, based on data obtained from Freundlich and Langmuir adsorption models and three-dimensional simulation. Especially, Cd and Zn were easily exchanged and substituted by Cu during multi-metal adsorption. Further competitive adsorption studies are necessary in order to accurately estimate adsorption capacity of ferronickel slag for potentially toxic metals in natural environments.
Life Among The Heavy Metals
Authors in scientific and applied works interpret the meaning of the concept "heavy metals" in different ways. Today, they include more than 40 chemical elements with an atomic mass of more than 50 atomic units. An important role in the determination of heavy metals is played by the following conditions: their high toxicity in relatively low concentrations, and the ability to bioaccumulation. Specialists on environmental protection among the heavy metals have identified a priority group. It includes cadmium,...
New ways for Metal Recycling
REWAVE XRF 3-way-sorting in innovative “Free-Fall”-design Recycling of metal and aluminium knows no limits because it can be remelted as scrap indefinitely. Metals, however have to be separated from non-metallic impurities, and different metals have to be sorted in pure fractions to be used as secondary raw materials substituting primary resources. Especially when it comes to aluminium a lot of energy can be saved when remelting scrap aluminium. By using secondary raw materials in the production of...
Cadmium ion adsorption by amine-modified activated carbon
Cadmium (Cd) is one of the most toxic metals found in water and sediments. In the effort to develop an effective adsorbent for aqueous Cd removal, activated carbon (AC) was modified with an amino-terminated organosilicon (3-aminopropyltrimethoxysilane, APS). Response surface methodology was used to optimize selected operational parameters of adsorption of aqueous Cd by considering a central composite design with three input variables, temperature of the mixture solution, the contact time and feed ratio (APS/AC),...
The binding of metal ions to molecularly-imprinted polymers
Imprinting polymerization is a flexible method to make resins specific for different compounds. Imprinting polymerization involves the polymerization of the resin in the presence of a template, here cadmium ions or arsenate. The template is then removed by washing, leaving specific binding sites in the resin. In water treatment, the removal of toxic metal ions is difficult due to the limited affinity of these ions to ion exchange resins. Imprinting polymerization of ion-exchange resins is used to develop resins...
Removal of lead(II) and nickel(II) ions from aqueous solution via Bermuda grass biomass
Adsorption of lead(II) and nickel(II) ions from aqueous solutions was investigated by Bermuda grass biomass. The adsorption process was studied as a function of pH, initial metal concentration, temperature and time. The experimental data obtained were investigated via Langmuir, Freundlich and Temkin isotherms. The kinetic data were examined by pseudo-second-order and intraparticle diffusion models. The biomass was shown to be highly efficient in the removal of lead and nickel ions with the removal of 99% and 54%...