The Rapid Small Scale Column Test (RSSCT) was developed to predict the adsorbtion of organic compounds in activated carbon adsorbers. In the RSSCT, a small column, which is loaded with an adsorbent ground to small practicle sizes, is used to simulate the performance of a pilot or full scale system. Due to the similarity of mass transfer processes and hydrodynamic characteristics between the small, pilot and full-scale columns, the breakthrough curves are expected to be similar. Due to its small size, the RSSCT requires a fraction of the time and water volume compared to pilot column testing. Recently the RSSCT has been used successfully in simulating the performance of metal-oxide based arsenic adsorbers. The adsorptive-filtration column was scaled down to mimic the performance of continuous flow, full and pilot scale arsenic treatment systems using the RSSCT approach. This paper investigates the application of the RSSCT method for assessing arsenic removal by unconventional adsorptive media such as waste materials.

Processes in the aquatic environment have been intensively explored in recent years, especially sorption processes. In this study, the sorption behavior of benzothiazole (BT) and 2-methylthiobenzothiazole (MTBT) was investigated, on geosorbents with different contents of organic carbon (OC). For both geosorbents and selected organic compounds, nonlinear isotherms were obtained. BT had the greatest degree of nonlinearity on the geosorbent with a higher content of OC, whereas the greatest degree of nonlinearity for MTBT was obtained on the geosorbent with lower OC content. From a comparison of logKoc for selected concentrations, it can be concluded that the geosorbent with the higher OC content has a higher affinity for the sorption of selected compounds.

This study investigates removal efficiency of arsenic species from water on natural and modified sorbent materials. Selective removal of As(III) and As(V) from water was carried out with pure natural materials: bentonite, sepiolite, limonite, pyrolusite and zeolite. Materials most commonly used in water treatment, quartz sand and granular active carbon, were modified by iron coating in order to increase its sorption capacity. For the purpose of comparison, commercial material, granular ferry hydroxide (Everzit As), was investigated under the same conditions. The investigations were performed in batch experiments following the standard experimental methodology. Of all the tested natural materials zeolite exhibited significant sorption capacity: 100 microgram As(III, V)/g. Iron coating increased materials sorption capacity for at least 80%. Iron coated sand and iron coated activated carbon exhibited 340 and 430 microgram As(V)/g respectively.

Anionic clays (layered double hydroxides) comprise positively charged layers with at least two different metal cations, octahedrally coordinated by hydroxyl groups. The positive charges of layered double hydroxides are counterbalanced by interlayer anions. The interlayer anions and water, which fill the interlayer space, are often labile. Therefore, anionic clays exhibit anion exchange capacity (AEC). Anionic clays which have a high surface area and a high anion exchange capacity, are potential adsorbents for anionic contanimants, such as the oxyanion of chrome. The adsorption study of chromium (VI) from aqueous solutions by natural cationic clay mineral (kaolinite, montmorillonite, etc.) was not given much attention, perhaps due to the fact cationic clays have negatively charged layers and clay mineral surface shows no affinity for oxyanion of chrome.