The usage of the low-cost catalysts for methylene blue removal from wastewater was investigated. Heterogeneous Fenton-like process consists of the use of a hydrogen peroxide solution, and an iron-rich catalyst, red mud and black nickel mud were used for that purpose. The factors such as the catalyst dose and the hydrogen peroxide solution volume were monitored. The results of experiments showed that the degradation of methylene blue dye in Fenton-like oxidation process using selected catalysts can be described by a pseudo-second-order kinetic model. The highest dye removal efficiency (87.15 %) was achieved using the black nickel mud catalyst after 30 minutes of reaction.

This article discusses the use of alternative inexpensive adsorbents – wastes from the metal production - red mud (RM) and black nickel mud (BNM) and their sorption efficiency in 3,5-dichlorophenol removal. Chlorophenols are organic compounds consisting of a benzene ring, OH groups and chlorine atoms. The effects of adsorbent dose, contact time, and temperature on sorption process were monitored. The results showed that the optimal conditions to achieve the highest sorption efficiency of 3,5-dichlorophenol were reached with the use of black nickel mud at the amount (2.0 g), sorption time (1 hour) and at increased temperature (45 °C). The sorption efficiency under these conditions was 87.99 %. With increasing sorption time, the sorption efficiency decreased and desorption occurred. The same behaviour was observed using red mud of the same amount (2.0 g) at the same temperature (45 °C); however, after 1 hour, sorption efficiency was slightly reduced (85.16 %) compared to black nickel mud. Anyway, both of used materials are suitable for the use as alternative sorbents of 3,5-dichlorophenol under suitable conditions.

This article deals with pharmaceutical compounds as micropollutants in anaerobic digestion of sludge from waste water treatment plant (WWTP). Part of the work included the research into presence of pharmaceuticals in different types of waters. Description of anaerobic fermentation process is also important in terms of optimal conditions. The practical aim of the investigation was preparation of a model of anaerobic fermentation of sewage sludge, where influence of pharmaceuticals on mesophilic anaerobic digestion was monitored. Wash out of micropollutants from sludge in big semicontinuous anaerobic reactors was running since October 2013. The resulting non-adapted sludge from mesophilic reactor was used since March 2014 for pharmaceuticals tests in half-a-litre glass bottles with a septum cap. The compounds of interest were diclofenac, tramadol, ibuprofen, carbamazepine and amoxicillin and their concentration in the tested sludge was 10 μg/L and 500 μg/L. The results showed that pharmaceuticals have different influence on the amount of produced biogas even if they are from the same therapeutic group. In the low concentration, the inhibition was present for diclofenac, carbamazepine and amoxicillin, at the high concentration, while diclofenac showed almost no influence. Other compounds caused a stimulative effect on the process. The mixture of all pharmaceuticals of interest in low concentration was stimulative at first, while it was inhibotory since mid-time of the test.