Aeration tank settling and real time control as a tool to improve the hydraulic capacity and treatment efficiency during wet weather: results from 7 years' full-scale operational data.

This paper investigates the aeration tank settling (ATS) operation in combination with real time control (RTC) as a tool for increasing the hydraulic capacity and improving the treatment efficiency of a wastewater treatment plant (WWTP) during wet weather flows. Results from 7 years' full-scale operational data at the Avedøre WWTP, Denmark, show that ATS operation in combination with RTC increases the hydraulic capacity of the treatment plant with up to 150 and 67% of the design capacity during winter and summer respectively. Compared to the conventional wet weather operation, the ATS in combination with RTC operation resulted in lower effluent concentrations for total phosphate (40-50%), suspended solids (30-60%) and chemical oxygen demand (30-50%), whereas no significant effect was observed on total nitrogen. Apart from the reduced effluent concentrations, the RTC resulted in economic savings in the form of reduced costs for electricity and green taxes. However, in very few cases the ATS operation in combination with RTC was not able to handle design capacity, and some overflows occurred at flows below the design capacity. The frequency of these overflows may increase in the future due to increased rain intensity resulting in shorter prediction time available for ATS.

Telonemia, a new protist phylum with affinity to chromist lineages.

Recent molecular investigations of marine samples taken from different environments, including tropical, temperate and polar areas, as well as deep thermal vents, have revealed an unexpectedly high diversity of protists, some of them forming deep-branching clades within important lineages, such as the alveolates and heterokonts. Using the same approach on coastal samples, we have identified a novel group of protist small subunit (SSU) rDNA sequences that do not correspond to any phylogenetic group previously identified. Comparison with other sequences obtained from cultures of heterotrophic protists showed that the environmental sequences grouped together with Telonema, a genus known since 1913 but of uncertain taxonomic affinity. Phylogenetic analyses using four genes (SSU, Hsp90, alpha-tubulin and beta-tubulin), and accounting for gamma- and covarion-distributed substitution rates, revealed Telonema as a distinct group of species branching off close to chromist lineages. Consistent with these gene trees, Telonema possesses ultrastructures revealing both the distinctness of the group and the evolutionary affinity to chromist groups. Altogether, the data suggest that Telonema constitutes a new eukaryotic phylum, here defined as Telonemia, possibly representing a key clade for the understanding of the early evolution of bikont protist groups, such as the proposed chromalveolate supergroup.

Introducing biological phosphorus removal in an alternating plant by means of control: a full scale study.

In this paper, a control strategy for introducing enhanced biological phosphorus removal (EBPR) in an alternating plant designed for enhanced biological nitrogen removal (EBNR) is presented. Alternating aerobic and anaerobic conditions to promote EBPR are provided by controlling the phases of the operational cycle, instead of a separate anaerobic volume. By utilising the control schemes already built in the STAR control system for nitrogen removal, the control strategy is fully integrated in the system. The control system relies on on-line measurements of nitrogen (ammonia and/or nitrate) and orthophosphate. The control strategy has been implemented in full-scale operation at the Avedøre wastewater treatment plant in Denmark and the results show clear indications of success. The control strategy has operated robustly for several months with a 60% decrease in use of precipitation chemicals.

The ultrastructure of Commation gen. nov. (Stramenopiles incertae sedis), a genus of heterotrophic nanoplanktonic flagellates from antarctic waters.

Commation gen. nov. is a genus of planktonic, unicellular protists characterized by a circular to oval (sometimes flattened) cell body and a proboscis. Cells move predominantly by gliding. The mitochondria are tubulocristate and the two flagellar basal bodies are furnished with microtubular roots as well as a rhizoplast. The single emerging flagellum, which is rarely observed, apparently carries tripartite hairs. These features suggest that Commation should be listed among the genera and groups of organisms assembled in the informal group stramenopiles. Two species, C. eposianum sp. nov. (previously referred to as the "comma-shaped amoeba") and C. cryoporinum sp. nov., are described from Antarctic waters. The species are distinguished by differences in, e.g., the morphology of the proboscis, the complexity and details of the cytoskeleton, and the number of types of extrusomes present. Commation spp. appear to be ubiquitous in Antarctic waters at cell abundancies typically ranging from 10(3)-10(4) cells per litre.