The assessment of the coke wastewater treatment efficacy in rotating biological contractor.

Coke wastewater is known to be relatively difficult for biological treatment. Nonetheless, biofilm-based systems seem to be promising tool for such treatment. That is why a rotating biological contactor (RBC) system focused on the Anammox process was used in this study. The experiment was divided into two parts with synthetic and then real wastewater. It was proven that it is possible to treat coke wastewater with RBC but such a procedure requires a very long start-up period for the nitritation (190 days), as well as for the Anammox process, where stable nitrogen removal over 70% was achieved after 400 days of experiment. Interestingly, it was possible at a relatively low (20.2 ± 2.2 °C) temperature. The polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) based monitoring of the bacterial community showed that its biodiversity decreased when the real wastewater was treated and it was composed mainly of GC-rich genotypes, probably because of the modeling influence of this wastewater and the genotypes specialization.

Biological nitrogen removal from landfill leachate by deammonification assisted by heterotrophic denitrification in a rotating biological contactor (RBC).

Due to negative environmental effects of nitrogen discharge to recipients and increasingly stringent effluent standards, effective nitrogen removal is necessity. Biological methods are the simplest and cheapest way to treat wastewater; however, it may become an extremely expensive option when high influent nitrogen concentrations are measured and there is a lack of biodegradable organic carbon. Therefore, there is a great need to find new solutions and improve existing technologies. The deammonification is an excellent example of such a new process that requires considerably low amounts of organic carbon and oxygen in comparison to conventional nitrification/denitrification. The main objective of presented research was to investigate an Anammox process accompanied with autotrophic nitrification and heterotrophic denitrification in one rotating biological contactor (RBC). During the research period, it was possible to carry out the Anammox process in low temperature below 20 'C. Additionally, it was found that the process is insensitive to high nitrite concentration in the reactor, up to 100 g NO2-N m(-3), resulting only in a temporary decrease in removal rates. Furthermore, analysis of data indicated that the Stover-Kincannon model can be used for the description of ammonium and nitrite removal processes.

Nitrification of ammonia nitrogen high concentration in membrane assisted bioreactor.

Use of the membrane-assisted bioreactors (MBR) in wastewater treatment can bring a lot of advantages. Usually COD removal achieves level 90% and nitrification of ammonia nitrogen concentrations typical for municipal wastewater performs without any disturbances, what was confirmed by large number of experiments. However, inhibition of nitrification of the high ammonia nitrogen concentration was noticed. In this study, the performance of ammonia-rich wastewater nitrification in membrane-assisted bioreactor (MBR) was examined. With SRT of 40, 32, 24 and 16 days any nitrification inhibition effect wasn't noticed. Ammonia nitrogen removal was around 98% and full nitrification was observed. At the sludge age equal to 12 d the first stage of nitrification was full, but the second stage of nitrification was incomplete. The variation in number and presence of the higher organisms were noticed at the all examined sludge ages. With SRT of 40, 32, 24 and 16 days the free ciliates were prominent organisms. At the sludge age of 12 days the domination of flagellates was observed The kinetic constants of the high-ammonia wastewater nitrification were calculated The average value of Vmax at the sludge age 12, 16 and 24 days was constant (4.7 mg NH4(+)-N/g MLSS h, 4.8 mg NH4(+)-N/g MLSS h and 4.8 mg NH4(+)-N/g MLSS, respectively), but the value of Km rose, when the sludge age increased (6.8 mg NH4(+)-N/L for 12 days, 11.3 mg NH4(+)-N/L for 16 days, 21.6 mg NH4(+)-N/L for 24 days). At the sludge age 32 and 40 days the increase of Vmax was observed (7.2 mg NH4(+)-N/g MLSS h and 12.5 mg NH4(+)-N/g MLSS h, respectively) and, also, changes of Km (6.8 mg NH4(+)-N/L and 44 mg NH4(+)-N/L, respectively. Concerning the second stage of nitrification value of Vmax decreased with the increase of the sludge age and the average Km varied from 20.3 to 31.3 mg NO2(-)-N/L.