In the last decade a growing interest was observed in low-cost adsorbents for heavy metal ions. Clinoptilolite is a mineral sorbent extracted in Poland that is used to remove heavy metal ions from diluted solutions. The experiments in this study were carried out in a laboratory column for multicomponent water solutions of heavy metal ions, i.e. Cu(II), Zn(II) and Ni(II). A mathematical model to calculate the metals' concentration of water solution at the column outlet and the concentration of adsorbed substances in the adsorbent was proposed. It enables determination of breakthrough curves for different process conditions and column dimensions. The model of process dynamics in the column took into account the specificity of sorption described by the Elovich equation (for chemical sorption and ion exchange). Identification of the column dynamics consisted in finding model coefficients β, KE and Deff and comparing the calculated values with experimental data. Searching for coefficients which identify the column operation can involve the use of optimisation methods to find the area of feasible solutions in order to obtain a global extremum. For that purpose our own procedure of genetic algorithm is applied in the study.
The subject of this work was the investigation of zeolite as a sorbent of toxic gases. In Nizny Hrabovec in the Slovak republic, two layers of zeolite with the active component clinoptilolite can be found. The study presented here investigated the ability of this natural zeolite to reduce polycyclic aromatic hydrocarbons (PAH) and NO emissions from engine exhaust. Exhaust gases from combustion engines include toxic components such as carbon monoxide, nitrogen oxides and hydrocarbons. Polycyclic aromatic hydrocarbons (PAH) are a component of hydrocarbons causing harmful influence on life forms. The experiments focused on the potential reduction of these toxic gases based on the sorption and catalytic properties of natural zeolite. Also observed was the influence of chemical adjustment including incorporation of certain metal elements. Chemical analysis by mutually independent technologies served to observe the sorption of PAH with carcinogenic properties on the natural zeolite tested. The experiments showed that chemical modification improved the sorption and catalytic properties of natural zeolite. The PAH were analysed in an extract of the contaminated, thermally-activated natural zeolite and modified zeolite after washing with ammonium chloride, cobalt chloride and copper sulphate. The study also presents results of NO measurements obtained by testing the filter-sorptive automobile system.