Implementation of enhanced biological phosphorus removal (ebpr) wastewater treatment processes enriched with different microbial communities

The EBPR (Enhanced Biological Phosphorus Removal) is a type of secondary treatment in WWTPs (WasteWater Treatment Plants), quite largely used in full-scale plants worldwide. The phosphorus occurring in aquatic systems in high amounts can cause eutrophication and consequently the death of fauna and flora. A specific biomass is used in order to remove the phosphorus, the so-called PAOs (Polyphosphate Accumulating Organisms) that accumulate the phosphorus in form of polyphosphate in their cells. Some of these organisms, the so-called DPAO (Denitrifying Polyphosphate Accumulating Organisms) use as electron acceptor the nitrate or nitrite, contributing in this way also to the removal of these compounds from the wastewater, but there could be side reactions leading to the formation of nitrous oxides. The aim of this project was to simulate in laboratory scale a EBPR, acclimatizing and enriching the specialized biomass. Two bioreactors were operated as Sequencing Batch Reactors, one enriched in Accumulibacter, the other in Tetrasphaera (both PAOs): Tetrasphaera microorganisms are able to uptake aminoacids as carbon source, Accumulibacter uptake organic carbon (volatile fatty acids, VFA). In order to measure the removal of COD, phosphorus and nitrogen-derivate compounds, different analysis were performed: spectrophotometric measure of phosphorus, nitrate, nitrite and ammonia concentrations, TOC (Total Organic Carbon, measuring the carbon consumption), VFA via HPLC (High Performance Liquid Chromatography), total and volatile suspended solids following standard methods APHA, qualitative microorganism population via FISH (Fluorescence In Situ Hybridization). Batch test were also performed to monitor the NOx production. Both specialized populations accumulated as a result of SBR operations; however, Accumulibacter were found to uptake phosphates at higher extents. Both populations were able to remove efficiently nitrates and organic compounds occurring in the feeding. The experimental work was carried out at FCT of Universidade Nova de Lisboa (FCT-UNL) from February to July 2014.

Bioavailability of pharmaceuticals in waters close to wastewater treatment plants: use of fish bile for exposure assessment

Pharmaceuticals are ubiquitous in surface waters as a consequence of discharges from municipal wastewater treatment plants. However, few studies have assessed the bioavailability of pharmaceuticals to fish in natural waters. In the present study, passive samplers and rainbow trout were experimentally deployed next to three municipal wastewater treatment plants in Finland to evaluate the degree of animal exposure. Pharmaceuticals from several therapeutic classes (in total 15) were analyzed by liquid chromatography-tandem mass spectrometry in extracts of passive samplers and in bile and blood plasma of rainbow trout held at polluted sites for 10 d. Each approach indicated the highest exposure near wastewater treatment plant A and the lowest near that of plant C. Diclofenac, naproxen, and ibuprofen were found in rainbow trout, and their concentrations in bile were 10 to 400 times higher than in plasma. The phase I metabolite hydroxydiclofenac was also detected in bile. Hence, bile proved to be an excellent sample matrix for the exposure assessment of fish. Most of the monitored pharmaceuticals were found in passive samplers, implying that they may overestimate the actual exposure of fish in receiving waters. Two biomarkers, hepatic vitellogenin and cytochrome P4501A, did not reveal clear effects on fish, although a small induction of vitellogenin mRNA was observed in trout caged near wastewater treatment plants B and C.

Energy consumption in an urban wastewater treatment plant: the case of Murcia Region (Spain)

Of all the costs associated with the operation and maintenance of wastewater treatment plants (WWTPs), those associated with energy use tend to be the most significant. From this point of view, it is hence logical that energy efficiency and saving strategies should be one of the current focuses of debate amongst those involved with the management of WWTPs. The present study's objective is to determine the correlation between size and energy consumption for a WWTP. To this end, 90 WWTPs currently in service were analysed and their energetic impact quantified in terms of kWh/m3 of water treated. The results obtained demonstrate that energy consumption ratio increases as the size of WWTPs decreases, either in terms of treatment volume or population equivalent served.

Conditional Order-m Efficiency of Wastewater Treatment Plants: The Role of Environmental Factors

The growing economic and environmental importance of managing water resources at a global level also entails greater efforts and interest in improving the functioning and efficiency of the increasingly more numerous wastewater treatment plants (WWTPs). In this context, this study analyzes the efficiency of a uniform sample of plants of this type located in the region of Valencia (Spain). The type of efficiency measure used for this (conditional order-m efficiency) allows continuous and discrete contextual variables to be directly involved in the analysis and enables the assessment of their statistical significance and effect (positive or negative). The main findings of the study showed that the quality of the influent water and also the size and age of the plants had a significant influence on their efficiency levels. In particular, as regards the effect of such variables, the findings pointed to the existence of an inverse relationship between the quality of the influent water and the efficiency of the WWTPs. Also, a lower annual volume of treated water and more modern installations showed a positive influence. Additionally, the average efficiency levels observed turned out to be higher than those reported in previous studies.

National Conference on Less Costly Wastewater Treatment Systems for Small Communities, U.S. Environmental Protection Agency, Date: April 12, 13, and 14, 1977, Location: Reston, Virginia.

Mode of access: Internet.

Evaluation of operation and maintenance factors limiting municipal wastewater treatment plant performance /

Mode of access: Internet.

Environmental monitoring of a wastewater treatment plant /

"Grant no. R805533."

The Effects of wastewater treatment facilities on wetlands in the Midwest /

Mode of access: Internet.

Biodetoxification of RCRA, Superfund, and other toxic wastes using resources of central wastewater treatment plants.

Mode of access: Internet.

Evaluation of flow equalization at a small wastewater treatment plant /

Mode of access: Internet.

Beneficial disposal of water purification plant sludges in wastewater treatment /

Mode of access: Internet.

A demonstrated approach for improving performance and reliability of biological wastewater treatment plants /

Mode of access: Internet.

Grants and loans for municipal water supply and watewater [i.e. wastewater] treatment systems : water conservation provisions : final report of Task Force 11 /

Mode of access: Internet.