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It is widely accepted that partial nitrification by ANAMMOX has the potential to become one of the key processes in wastewater treatment. However, large greenhouse gas emissions have been panobserved in many cases. A novel mesh separated reactor, developed to allow continuous operation of deammonification at smaller scale without external biomass selection, was compared to a conventional single-chamber deammonification sequencing batch reactor (SBR), where both were equally-sized pilot-scale reactors. The mesh reactor consisted of an aerated and an anoxic zone separated by a mesh. The resulting differences in the structure of the microbial community were detected by next-generation sequencing. When both systems were operated in a sequencing batch mode, both systems had comparable nitrous oxide emission factors in the range of 4% to 5% of the influent nitrogen load. A significant decrease was observed after switching from sequencing batch mode to continuous operation.

A new approach to perform partial nitritation-anammox in a single tank was investigated. The tank incorporated a mesh (opening size 1.0 × 1.2 mm) as permeable barrier to create two distinct reaction zones (aerated and anoxic). The study reports on the operation and optimization of a 13 L laboratory scale reactor to treat sludge reject water with an NH 4 -N concentration of ∼750 mg·L -1 . Performance throughout 250 days at increasing nitrogen loading rates is presented. The maximum loading rate applied was 1.5 kg NH 4 -N·m -3 ·d -1 at a hydraulic retention time of 12 h. Typical composition of the effluent was ∼50 mg·L -1 NH 4 -N; <5-10 mg·L -1 NO 2 -N and ∼60 mg·L -1 NO 3 -N. The corresponding average N removal rates were 85% for total nitrogen and 90% for NH 4 -N, respectively. Process control was very simple. It comprised only regulation of the aeration rate to maintain a pre-set pH (7.1) in the nitritation zone. Performance data clearly indicate that the investigated reactor configuration offers distinct advantages over currently installed processes. It demonstrated high robustness without the need for sophisticated process control. Apparently, the use of a permeable mesh to establish different reaction conditions in a single reactor provides new features of high potential.

In Austria, 1,840 wastewater treatment plants (WWTPs) with design size >50 population equivalent (PE) serve about 95% of the population. The remaining 5% of the population live in single houses and small settlements that require on site and decentralized wastewater treatment technologies. There is no common database on small WWTPs with design size <50 PE; thus data had to be collected from the Austrian federal states and compiled in a database. The total number of small WWTPs in Austria is about 28,700 comprising 1,300 WWTPs with design size 51-500 PE and 27,400 with design size <50 PE, respectively. The total number of treatment wetlands implemented in Austria is 5,450. Due to legal requirements (nitrification), only vertical flow wetlands are implemented in Austria. From the 5,450 treatment wetlands, about 100 are of design size larger than 50 PE and about 2,800 treatment wetlands have a design size of 5-10 PE. The peak of wetland implementation was in the years 2007-2011 with 2,200 implemented systems in 5 years. Since about 2000, about 30-40% of the new implemented small WWTPs are treatment wetlands.

The ATV-A-131 guideline and the design approach published in 'Wastewater Engineering, Treatment and Reuse (WE)' are widely used for the design of activated sludge plants. They are both based on simplified steady-state assumptions tailored to the boundary conditions of temperate climates. Using design guidelines beyond the designated temperature range may lead to inappropriate results. The objectives of this paper are (1) to summarise temperature relevant differences between ATV-A-131 and WE; (2) to show the related design components; and (3) to demonstrate a procedure for design parameter adaptation for a full-scale activated sludge plant located in a warm climate region. To gain steady-state data required for wastewater treatment plant (WWTP) design according to ATV-A-131 and WE, full-scale plant data were acquired for a period of 6 months as a basis for analyses and adaptation. Mass balances were calculated for the verification of the measurements and for analysing excess sludge production. The two approaches showed relevant temperature related differences. WE default application resulted in lower deviation in the mass balance results for excess sludge production. However, with the adaptation of the heterotrophic decay rates for both approaches and the inert organic and mineral solids fraction additionally for ATV-A-131, a good fit to the observed excess sludge production could be achieved.

Planning, construction and operation of onsite wastewater treatment systems at mountain refuges is a challenge. Energy supply, costly transport, limited water resources, unfavourable climate and load variations are only some of the problems that have to be faced. Additionally, legal regulations are different between and even within countries of the Alps. To ensure sustainability, integrated management of the alpine infrastructure management is needed. The energy and water supply and the wastewater and waste disposal systems and the cross-relations between them were analysed for 100 mountain refuges. Wastewater treatment is a main part of the overall 'mountain refuge' system. The data survey and first analyses showed the complex interaction of the wastewater treatment with the other infrastructure. Main criteria for reliable and efficient operation are training, technical support, user friendly control and a relatively simple system set up. Wastewater temperature, alkalinity consumption and high peak loads have to be considered in the planning process. The availability of power in terms of duration and connexion is decisive for the choice of the system. Further, frequency fluctuations may lead to damages to the installed aerators. The type of water source and the type of sanitary equipment influence the wastewater quantity and quality. Biosolids are treated and disposed separately or together with primary or secondary sludge from wastewater treatment dependent on the legal requirements., (IWA Publishing 2008.)

When using dynamic simulation for fine tuning of the design of activated sludge (AS) plants diurnal variations of influent data are required. For this application usually only data from the design process and no measured data are available. In this paper a simple method to generate diurnal variations of wastewater flow and concentrations is described. The aim is to generate realistic influent data in terms of flow, concentrations and TKN/COD ratios and not to predict the influent of the AS plant in detail. The work has been prepared within the framework of HSG-Sim (Hochschulgruppe Simulation, http://www.hsgsim.org), a group of researchers from Germany, Austria, Luxembourg, Poland, the Netherlands and Switzerland., ((c) IWA Publishing 2008.)

Cytostatic agents are applied in cancer therapy and subsequently excreted into hospital wastewater. As these substances are known to be carcinogenic, mutagenic and toxic for reproduction, they should be removed from wastewater at their source of origin. In this study the fate and effects of the cancerostatic platinum compounds (CPC) cisplatin, carboplatin, oxaliplatin, 5-fluorouracil (5-FU) and the anthracyclines doxorubicin, daunorubicin and epirubicin were investigated in hospital wastewater. Wastewater from the in-patient treatment ward of a hospital in Vienna was collected and monitored for the occurrence of the selected drugs. A calculation model was established to spot the correlation between administered dosage and measured concentrations. To investigate the fate of the selected substances during wastewater treatment, the oncologic wastewater was treated in a pilot membrane bioreactor system (MBR) and in downstream advanced wastewater treatment processes (adsorption to activated carbon and UV-treatment). Genotoxic effects of the oncologic wastewater were assessed before and after wastewater treatment followed by a risk assessment. Monitoring concentrations of the selected cytostatics in the oncologic wastewater were in line with calculated concentrations. Due to different mechanisms (adsorption, biodegradation) in the MBR-system 5 - FU and the anthracyclines were removed < LOD, whereas CPC were removed by 60%. In parallel, genotoxic effects could be reduced significantly by the MBR-system. The risk for humans, the aquatic and terrestrial environment by hospital wastewater containing cytostatic drugs was classified as small in a preliminary risk assessment.