Dekonta (Czechia)

The feasibility of using advanced oxidation processes (AOPs) for abatement of ammonia from livestock buildings was examined in a series of pilot plant experiments. In this study, all the experiments were conducted in a two-step unit containing a dry photolytic reactor (UV185/UV254/O3) and a photochemical scrubber (UV254/H2O2). The unit efficiency was tested for two initial ammonia concentrations (20 and 35 ppmv) and three different air flows (150, 300 and 450 m3·h−1). While the first step removes mainly organic pollutants that are often present together with ammonia in the air and ammonia only partially, the second step removes around 90% of ammonia emissions even at the highest flow rate of 450 m3·h−1. Absorbed ammonia in the aqueous phase can be effectively removed without adjusting the pH (i.e. without the addition of other additives) using UV and ozone. Complete removal of ammonia was achieved after 15 h of irradiation. In order to assess the price efficiency of the suggested technology and to be able to compare it with other methods the figures-of-merit were determined. The price needed for lowering ammonia emission by one order of magnitude is 0.002 € per cubic meter of treated air at the highest flow rate of 450 m3·h−1 and for initial ammonia concentrations of 20 ppmv. These findings demonstrate that AOPs are a promising method for ammonia abatement from livestock buildings which are rarely using any waste air treatment method.

Agriculture is being negatively affected by the decrease in precipitation that has been observed over the last few years. Even in the Czech Republic, farmers are being urged to irrigate their fields despite the fact that sources of water for irrigation are rapidly being depleted. This problem might be partially solved via the reuse of treated wastewater in certain agricultural sectors. However, the public perception of the reuse of wastewater remains negative primarily due to unknown risks to the environment and public health. To overcome this barrier, a semi-operated irrigation field was established at Kostelec nad Ohří in the Central Bohemian region of the Czech Republic and planted with common garden crops such as tomatoes (Lycopersicon esculentum), potatoes (Solanum tuberosum) and lettuces (Lactuca sativa L.) irrigated with two different water sources, i.e., treated wastewater from a local nature-based treatment system, a hybrid constructed wetland (HCW), and local fresh water from well. The HCW was put into operation in 2017 and was reconstructed in 2018 and includes both horizontal and vertical flow beds; the trial irrigation field was added in the same year. The reconstruction of the facility significantly enhanced the removal efficiency with respect to all monitored parameters, e.g., biochemical oxygen demand (BOD5), chemical oxygen demand (COD), N–NH4+, total N and the suspended solids (TSS), except for total P. The HCW also ensured the significant removal of several observed pathogenic microorganisms (E. coli, intestinal enterococci and thermotolerant coliforms). During the 2018 and 2019 growing seasons, we observed the significantly enhanced growth of the crops irrigated with wastewater from the HCW due to the fertilizing effect. The risks associated with the contamination of crops irrigated with treated water are not negligible and it is necessary to pay sufficient attention to them, especially when introducing irrigation with wastewater into practice.

A modular electrocoagulation unit, supported by Ca(OH)2 addition to treated water, was operated in the vicinity of a Natura 2000 site for the removal of Cr6+ or Ni2+ from contaminated groundwater. The process was performed at a constant flow rate of 350 L/h. Day 0 concentrations of Cr6+ and Ni2+ started at 91.6 mg/L for Ni2+ and 43 mg/L for Cr and during testing, were decreased by 15%–25%. Residual concentrations of Crtot. and Ni2+ below the required limits of 0.5 mg/L for Crtot. and 0.8 mg/L for Ni2+ can be achieved with the electrocoagulation unit and total removal efficiencies often exceeded 98%. The overall economic assessment showed its feasible application for removal of Cr6+ and Ni2+ on sites with requirements of high environmental protection standards. The polluted area was about 150 × 150 m (22,500 m2), and it contained approximately 78,750 m3 of water contaminated with Cr6+ and Ni2+ (over 41 and 91 mg/L, respectively). The modular arrangement might allow a scaling up. The process’ output could be thus increased according to the number of EC modules in operation.

The treatment of domestic wastewater using constructed wetlands (CWs) is common in the Czech Republic; however, the treatment of agro-industrial wastewater is still at the beginning of its application. A hybrid CW consisting of two horizontal filters (HF1 and HF2), one vertical filter (VF), and three stabilization ponds (SP1–SP3) was put into operation in 2012 in Chramce, Usti region, Czech Republic. The hybrid system treats mixed household and agro-industrial wastewater mainly from sheep farms and wine and fruit juice production factories. The filters are planted with Phragmites australis, Phalaris arundinacea, Iris pseudacorus, Iris sibirica, Glyceria maxima, and Lythrum salicaria. In a fed-batch operation, the inflow values vary on the basis of wine processing seasons. In high season, it reaches 17,012 mg L−1 of chemical oxygen demand (COD), 1806 mg L−1 of biochemical oxygen demand (BOD5), and 43,723 mg L−1 of total suspended solids (TSS) on average. Despite such high inlet concentrations, the removal efficiency (RE) for the three selected parameters reached up to 99% for all the parameters. In this work, the removal of four pharmaceuticals (diclofenac, ibuprofen, ketoprofen, and naproxen) in the hybrid system was studied as well. The CW performed high RE for all of the four pharmaceuticals when the RE of diclofenac, ibuprofen, ketoprofen, and naproxen was 81.1%, 93.2%, 96.7%, and 78.3%, respectively.

Detailed investigation of soil and sediment pollution is a crucial aspect of remediation. Direct-push methods (direct sensing tools) represent a powerful tool for characterization of the contaminated site. One of these methods is Membrane Interface Probe suitable for detection of volatile organic compounds in soils.

Non-steroidal anti-inflammatory drugs (NSAIDs) belong to the group of remedies with the largest global sales volume. They are broadly used for the treatment of a wide range of non-specific symptoms accompanying a number of diseases. Many of them also belong to OTC (over-the-counter) distributed drugs, thus, they are easily available for broad masses of the world's population. The aforementioned properties, together with low production costs, high content per dose, and relatively high proportions of non-metabolized drugs in human excretions have made several NSAIDs water pollutants of the highest importance. The most important drug of the NSAID group on a global scale is the oldest industrially produced remedy, aspirin (acetylsalicylic acid), which has been substituted by ibuprofen in recent times due to its lower side effects. In the Czech Republic, ibuprofen has the largest sales volume of all NSAIDs and is the second best-selling drug on the Czech market. Naproxen and ketoprofen are other widely used NSAIDs in human medicine together with halogenated compounds such as diclofenac and indomethacin.