The dynamic adsorption characteristics of phenol by granular activated carbon

Kinetics analysis of zinc sorption in fixed bed column using a strongly basic anionic exchange resin

The aim of this study was to examine the capacity of anionic resins to remove zinc as zinc chloride complexes in fixed bed. The applicability of the kinetics models and the characteristics of the bed (sorption capacity, breakthrough curve, depth of the adsorption zone) were taken into account. The influence of the process parameters, such as resin quantity (bed height) and zinc initial concentration, on the removal process was also considered. The obtained results (Amberlite IRA410) were analyzed using sorption kinetic models such as Thomas, Adam-Bohart, and Clark, by linear regression analysis. Similarly, the concept of the mass transfer zone was applied in order to properly design the fixed bed adsorption process. By comparing various resins, the following series was depicted based on sorption capacities: Amberlite IRA410>Purolite A103S>Purolite NRW700>Purolite A400MBOH. The experimental data were in good agreement with the Clark model, while for the other models, lower correlation coefficients were obtained under the same experimental conditions. The MTZ height and rate of movement increased with increasing initial concentration.

Removal of radioisotopes in solution and bactericidal/bacteriostatic sterilising power in activated carbon and metal silver filters

Activated carbon filters play an important role in water filtration and purification from contaminants of different origin. Their limit consists in bacterial proliferation, which may occur only during prolonged periods of non-use and in their ability to remove radioactive contaminants present in waste water from Industry or Nuclear Medicine departments. In this work we tested a commercially available activated carbon filter for water purification enriched with silver plated parts incubating in static condition at room temperature different micro organisms (Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis, Staphylococcus aureus, Aspergillum niger), up to 78 days. The microbial growth was in general more inhibited in the presence of metal silver into the activated carbon in respect to filters with the activated carbon alone: >4log inhibition of bacterial proliferation after 78 days of incubation the presence of silver vs. 2log without silver. When the filters were incubated empty of carbon, the sterilizing power of silver was confirmed further. The activated carbon filters proved also their ability in removing from water the principal radioisotopes used for residues liquid medical and research purposes ((131)I, (99m)Tc, (201)Tl, (67)Ga). These results contribute useful data for the use of the silver-enriched carbon filters in water filtration both for daily use at home, and professional use in a Nuclear Medicine laboratory.