Vol 38, No 4 (2016)

Modification of a homogenous anion–exchange MA-100 membrane by chlorosulfonic acid is accompanied by grafting of negatively charged–SO₃^– groups and a substantial increase of hydrophilicity. The method of differential scanning calorimetry indicated that the mass fraction of free and bound water increases nearly twice. The porous structure of the modified membrane becomes more developed at the expense of an increase of the volume of micropores. The membrane acquires resistance to poisoning by large organic anions.

The kinetics of photodegradation of alizarin green (AG) in an acoustic fluidized bed was investigated using Degussa P25 catalyst and N-doped TiO₂ catalyst, respectively. The effects of initial concentration of AG, catalyst amount, initial pH value and liquid flow rate on the photodegradation rates were the main goal of present study. The degradation rate increased with increasing amount of photocatalyst, pH value and liquid flow rate, reached a maximum and then decreased. The degradation rate decreased with increasing initial concentration. According to the Langmuir–Hinshelwood model, the disappearance of the AG followed pseudo-first-order kinetics. Experimental results showed that AG can be degraded effectively by Degussa P25 catalyst and N-doped TiO₂ catalyst in an acoustic fluidized bed reactor. N-doped TiO₂ catalyst has high and significant photocatalytic activity and in comparison with Degussa P25 catalyst was photocatalyst.

The technology of liquid extraction treatment of wastewaters of the paint and varnish production facility using a three-stage spray extractor has been developed for the removal of butylglycol, phenyl isopropanol, acetic acid, and acetylacetone using isopropyl ether as an extractant. A mathematical model of extraction is presented that takes into account the hydrodynamics of countercurrent liquid flows, the mass transfer and mass exchange of liquid phases for each component. The differential cell model is applied to determine optimal parameters of the process, calculate basic dimensions of the spray extractor, and propose a three-stage process flowsheet with the minimum consumption of extractant at the ratio 1: 15 in relation to wastewater.

In this study, the bioaugmentation of a sequencing batch reactor (SBR) for the treatment of reject water from wastewater treatment plant was evaluated. For the bioaugmentation step a product containing an enrichment of microorganisms from the Archaea domain was used to enhance the performance of the reactor for treating reject water. The experiment was carried out in two parallel lab-scale sequencing batch reactors. The first one (SBR A) was bioaugmented with a suspension of microorganisms from the Archaea domain, while the second reactor (SBR B) was not bioaugmented. The results here presented show that the SBR technology could sustain efficient NH₄⁺–N and chemical oxyden demand removal rates and can be applied for the treatment of reject water. Moreover, the addition of microorganisms belonging to the Archaea domain improved the SBR overall operation, especially when the loading in the influent was increased. Administering Archaea to the reactor had also a positive effect on ammonia oxidation as well as on the nitrite removal.