Supported titanium dioxide‐based photocatalysts were investigated for the degradation of pharmaceuticals under irradiation with UV−A LEDs. Focus of the presented research was placed on the degradation kinetics under different matrix influences and energy flux densities of UV−A radiation. The chemical parameters, pH, orthophosphate, nitrogen concentration and background organic concentration were investigated. The results were evaluated by time‐resolved measurement of the concentrations and by calculating and plotting the first‐order degradation rate. The results showed clear differences in the rates of degradation of each compound, with diclofenac being the most easily degraded and metoprolol the most resistant. When the influence of energy flux density was examined, a linear relationship between degradation rate and the square root of energy flux density was confirmed. The organic background matrix has a strong influence on the degradation kinetics of the compounds. Nitrogen and orthophosphate slow down the degradation much less than the organic background matrix. Investigating the pH influence, it could be shown that almost no degradation is detected in the basic pH range. The results were illustrated with the help of a radar diagram, which can show all dependencies at a glance.

Antimicrobial resistances (AMR) are ranked among the top ten threats to public health and societal development worldwide. Toilet wastewater contained in domestic wastewater is a significant source of AMR entering the aquatic environment. The current commonly implemented combined sewer systems at times cause overflows during rain events, resulting in the discharge of untreated wastewater into the aquatic environment, thus promoting AMR. In this short research article, we describe an approach to transform combined sewer systems into source separation-modified combined sewer systems that separately treat toilet wastewater. We employ simulations for demonstrating that source separation-modified combined sewer systems reduce the emission of AMR-causing substances by up to 11.5 logarithm levels. Thus, source separation-modified combined sewer systems are amongst the most effective means of combating AMR.

This article studied how wastewater treatment performance of a short rotation forestry system was influenced by the seasonal operational changes under the extreme Mongolian winter conditions. For this reason, two beds planted with Willow (Salix spec.) and Poplar (Populus spec.) trees were operated over a period of two years under two different seasonal conditions: (A) “external winter storage” and (B) “internal winter storage” of pretreated wastewater. For operational condition A, the tree-bed was loaded with wastewater for only 4 summer months. For this operational condition it was considered that the treatment bed was fed with primary treated wastewater, which was stored in a sealed pond during the remaining 8 months. The other Bed B was irrigated throughout the year (12 months) with the same daily loading rate. In winter, the wastewater accumulated as ice in the tree-bed. Bed A, with external winter storage, showed mass removal percentage up to 95%, while the bed with internal winter storage showed mass removal rates up to 86% for pollutants such as COD, BOD₅, TN, and TP. A high yield of biomass was recorded for both beds with slight differences. Based on the results, a design recommendation was developed for full-scale systems of short rotation coppice irrigated with wastewater under various operational conditions, which show these systems to be a viable method for treating wastewater and producing biomass for energy production in Mongolia.

Antimicrobial resistance (AMR) is identified by the World Health Organization (WHO) as one of the top ten threats to public health worldwide. In addition to public health, AMR also poses a major threat to food security and economic development. Current sanitation systems contribute to the emergence and spread of AMR and lack effective AMR mitigation measures. This study assesses source separation of blackwater as a mitigation measure against AMR. A source-separation-modified combined sanitation system with separate collection of blackwater and graywater is conceptually described. Measures taken at the source, such as the separate collection and discharge of material flows, were not considered so far on a load balance basis, i.e., they have not yet been evaluated for their effectiveness. The sanitation system described is compared with a combined system and a separate system regarding AMR emissions by means of simulation. AMR is represented in the simulation model by one proxy parameter each for antibiotics (sulfamethoxazole), antibiotic-resistant bacteria (extended-spectrum beta-lactamase E. Coli), and antibiotic resistance genes (blaTEM). The simulation results suggest that the source-separation-based sanitation system reduces emissions of antibiotic-resistant bacteria and antibiotic resistance genes into the aquatic environment by more than six logarithm steps compared to combined systems. Sulfamethoxazole emissions can be reduced by 75.5% by keeping blackwater separate from graywater and treating it sufficiently. In summary, sanitation systems incorporating source separation are, to date, among the most effective means of preventing the emission of AMR into the aquatic environment.

In this work, the degradation performance for the photocatalytic oxidation of eight micro-pollutants (amisulpride, benzotriazole, candesartan, carbamazepine, diclofenac, gabapentin, methlybenzotriazole, and metoprolol) within real secondary effluent was investigated using three different reactor designs. For all reactor types, the influence of irradiation power on its reaction rate and energetic efficiency was investigated. Flat cell and batch reactor showed almost similar substance specific degradation behavior. Within the immersion rotary body reactor, benzotriazole and methyl-benzotriazole showed a significantly lower degradation affinity. The flat cell reactor achieved the highest mean degradation rate, with half time values ranging from 5 to 64 min with a mean of 18 min, due to its high catalysts surface to hydraulic volume ratio. The EE/O values were calculated for all micro-pollutants as well as the mean degradation rate constant of each experimental step. The lowest substance specific energy per order (EE/O) values of 5 kWh/m³ were measured for benzotriazole within the batch reactor. The batch reactor also reached the lowest mean values (11.8–15.9 kWh/m³) followed by the flat cell reactor (21.0–37.0 kWh/m³) and immersion rotary body reactor (23.9–41.0 kWh/m³). Catalyst arrangement and irradiation power were identified as major influences on the energetic performance of the reactors. Low radiation intensities as well as the use of submerged catalyst arrangement allowed a reduction in energy demand by a factor of 3–4. A treatment according to existing treatment goals of wastewater treatment plants (80% total degradation) was achieved using the batch reactor with a calculated energy demand of 7000 Wh/m³.