Search results for "sewage"
showing 10 items of 480 documents
Identification and quantification of microbial populations in activated sludge and anaerobic digestion processes
2014
Eight different phenotypes were studied in an activated sludge process (AeR) and anaerobic digester AnD) in a full-scale wastewater treatment plant by means of fluorescent in situ hybridization (FISH) and automated FISH quantification software. The phenotypes were ammonia-oxidizing bacteria, nitrite-oxidizing bacteria, denitrifying bacteria, phosphate-accumulating organisms (PAO), glycogen-accumulating organisms (GAO), sulphate-reducing bacteria (SRB), methanotrophic bacteria and methanogenic archaea. Some findings were unexpected: (a) Presence of PAO, GAO and denitrifiers in the AeR possibly due to unexpected environmental conditions caused by oxygen deficiencies or its ability to survive …
UCT-MBR vs IFAS-UCT-MBR for Wastewater Treatment: A Comprehensive Comparison Including N2O Emission
2017
In this study the performance (in terms of carbon and nutrient removal) and N2O emission of two plant configurations adopting innovative technologies were investigated. With this regards, an University Cape Town (UCT) membrane bioreactor (MBR) plant and an Integrated Fixed Film Activated Sludge (IFAS) -UCT-MBR plant were monitored. Both plants treat real wastewater under two different values of the influent carbon nitrogen ratio (C/N = 5 mgCOD/mgN and C/N = 10 mgCOD/mgN). Results have shown the highest carbon and nutrients removal efficiencies for the IFAS-UCT-MBR configuration during both the two investigated C/N values. Furthermore, the lowest N2O emission occurred for the IFAS-UCT-MBR.
Increase of rotifer diversity after sewage diversion in the hypertrophic lagoon, Albufera of Valencia, Spain
2001
The Albufera of Valencia is a large oligohaline hypertrophic lagoon, regulated by sluice gates according to the needs of the surrounding rice field cultivation. It is in a turbid state with permanent cyanobacterial blooms. A slight improvement was detected after diversion in the 1990s of part of the sewage flowing into it. After sewage diversion, we found that: (1) Chlorophyll concentration and rotifer densities decreased; (2) Rotifer proportions declined, due mainly to a relative increase in cladocerans; (3) Rotifer diversity increased. The two dominants of the 1980s, Polyarthra spp. in the colder period and Brachionus angularis in the warmer one, reverted after sewage diversion to a more …
Distribution of aquatic Oligochaeta in the Finnish Lake District
1980
SUMMARY. The distribution of oligochaetes was examined at sampling stations grouped into three types: (1), in eutrophic and dystrophic areas or in areas polluted by pulp-mill wastewaters; (2), slightly eutrophic stations; (3), ‘clean’ stations unaffected by sewage or other inputs. Limnodrilus hoffmeisteri and Potamothrix hammoniensis were practically the only species in group 1, and the same species accounted for two thirds of the total numbers in group 2, although Peloscolex ferox and some other species also occurred. At the cleanest stations the dominating species were P. ferox, Psammoryctides barbatus, Stylodrilus heringianus and Tubifex tubifex. A factor analysis showed that L. hoffmeis…
Evaluation of biomass activity and wastewater characterization in a UCT-MBR pilot plant by means of respirometric techniques
2011
Abstract Over the last two decades, Membrane Bioreactors (MBRs) emerged even more for wastewater treatment, ensuring high removal efficiencies as well as very small footprint requirements. Indeed, in this kind of process, a modification in biomass activity and viability can exist compared to that of a CAS process. In this context, respirometric analysis represents a reliable tool in order to evaluate the actual biomass kinetic parameters, to insert in mathematical models in the design phase, as well as to monitor the biomass viability, especially when these processes are operated with high SRT values. The paper presents some results of respirometric techniques applied for the characterisati…
Liquid co-substrates repower sewage microbiomes
2018
AbstractA range of parameters are known to shape the methanogenic communities of biogas-producing digesters and to strongly influence the amount of biogas produced. In this work, liquid and solid fractions of grass biomass were used separately for semicontinuous batch methanation using sewage sludge as seed sludge. During 6 months of incubation, the amount of input COD was increased gradually, and the underlying methanogenic microbiome was assessed by means of microscopy-based automated cell counting and full-length 16S rRNA high-throughput sequencing. In this sense, we prove for the first time the suitability of the ONT™MinION platform as a monitoring tool for anaerobic digestion systems. …
Ekstrakcja fosforu z osadów ściekowych i popiołów ze spalania osadów - analiza problemu
2016
Fosfor jako pierwiastek niezbędny do produkcji rolniczej, w miarę wyczerpywania się zasobów fosforytów, staje się komponentem coraz bardziej deficytowym. Koniecznym wydaje się wdrożenie metod taniego i efektywnego odzysku tego pierwiastka z wszelkiego rodzaju odpadów. Szczególnie cennym źródłem fosforu są popioły z osadów ściekowych i same osady. Optymalizacja metod sekwencyjnej ekstrakcji fosforu zawartego w popiele z termicznego przekształcania osadów ściekowych i odwodnionych osadów pozwala na wybór efektywnej i nieskomplikowanej technologicznie możliwości odzysku fosforu, przy jednoczesnym zachowaniu niskiego obciążenia eluatu metalami ciężkimi, które są jedną z głównych przyczyn ograni…
Assessing performance in the management of the urban water cycle
2011
This paper proposes the use of directional distance functions and Data Envelopment Analysis techniques to assess technical efficiency in the provision of the different stages of the urban water cycle in Andalusia, a Southern European region. Evaluating performance in the management of specific stages of the urban water cycle provides utility managers and regulating authorities with relevant information that may not be detected by more conventional approaches based on assessing performance at utility level. We find that Andalusian water and sewage utilities could achieve significant increases in the volume of water delivered without diminishing the output of their other services and using th…
Perfluorinated Compounds Distribution and Source Identification in Sediments of Lake Victoria Gulf Basin
2011
Perfluorooctanoic acid and perfluorooctane sulfonate were determined in the sediments from Winam Gulf, which is in the Kenyan side of Lake Victoria and in its source rivers. The sources of perfluorinated compounds within the Gulf of Lake Victoria have been identified and their levels determined for the first time, in this study, using SPE and HPLC-MS-MS analytical methodology. Variability in the concentrations of perfluorooctanoic acid and perfluorooctane sulfonate ranged from 1.4–99.1 and <1–57.5 ng/g in river sediments, respectively, which was higher than concentrations obtained from lake sediments (range perfluorooctanoic acid <1–24.1 ng/g and perfluorooctane sulfonate <1–4.0 ng/g). The …
Trace compounds of biogas from different biogas production plants
2007
Biogas composition and variation in three different biogas production plants were studied to provide information pertaining to its potential use as biofuel. Methane, carbon dioxide, oxygen, nitrogen, volatile organic compounds (VOCs) and sulphur compounds were measured in samples of biogases from a landfill, sewage treatment plant sludge digester and farm biogas plant. Methane content ranged from 48% to 65%, carbon dioxide from 36% to 41% and nitrogen from <1% to 17%. Oxygen content in all three gases was <1%. The highest methane content occurred in the gas from the sewage digester while the lowest methane and highest nitrogen contents were found in the landfill gas during winter. The amoun…