Tananaev Institute of Chemistry – Subdivision of the Federal Research Centre “Kola Science Centre of the Russian Academy of Sciences” (ICT KSC RAS), Apatity, Murmanskaya Oblast’, Russia
Dr. Natalia Mudruk
Tananaev Institute of Chemistry – Subdivision of the Federal Research Centre “Kola Science Centre of the Russian Academy of Sciences” (ICT KSC RAS), Apatity, Murmanskaya Oblast’, Russia
The treatment of heavy metal-contaminated wastewater is an important action to reduce The negative impacts of industrial wastes on water bodies. This work focuses on The application of a low-cost titanium (IV) phosphate sorbent of TiO(OH)H2PO42H2O chemical composition toward lead and zinc ions depending on their concentration and The temperature of The solution. The kinetic studies showed that The values of The rate of intraparticle diffusion and The effective diffusion coefficients for Zn2+ were considerably higher than those for Pb2+. To explain The difference between The sorption kinetics rates for Pb2+ and Zn2+, The effective radius and dehydration degree of The adsorbed ions were calculated. The sorbent capability of The lead and zinc ion removal and its excellent efficiency in The presence of a high concentration of calcium ions were demonstrated using simulated mine water. Due to The fast kinetics and The high exchange capacity of titanium phosphate toward divalent ions, this sorbent can be considered as a promising material for The concentration and immobilization of heavy metals into The phosphate matrix.
1 November 2019 in Journal of the Taiwan Institute of Chemical Engineers
Individual titanium and calcium–magnesium phosphates are widely known as effective sorbents. The sorption processes on these phosphates are based on different mechanisms. The sorption efficiency towards different cations depends on the phase composition of the sorbent. Composite materials with various ratio Ti:(Ca+Mg) have been synthesized. The sorption properties of samples obtained towards Cs+, Sr2+, Co2+, Cd2+, Zn2+, Cu2+, and Pb2+ have been studied to establish the effect of sorbent composition on metal removal. The adsorption isotherms have been analyzed using the Langmuir, Freundlich, and Redlich–Peterson models. The composition of sorbents has no effect on the level of removal of readily hydrolyzable Pb2+ and Cu2+ cations. Removal of lead occurs preferentially via the precipitation of metal phosphates and hydroxides. Copper precipitates as hydroxide in case of a high share of Ca-Mg phosphates in the composite sorbent. The removal of cesium proceeds according to the ion exchange mechanism only. For Cd2+, Co2+, Sr2+, and Zn2+ cations, the sorption efficiency on the composite materials synthesized is found to increase with the increase in titanium phosphate’s share in the sample. All composite sorbents synthesized demonstrated a considerable increase in the level of purification of solutions studied compared with individual Ti and Ca-Mg phosphates due to the synergism of the components.