1,721,069 research outputs found
Wastewater Storage Basins for Irrigation Reuse and P/N Removal: Finishing Lagoons in Imola, Bologna, Italy
No full textWater scarcity has become more prominent in the last decades so since the ’70 many studies focused on the use of natural basins both for treatment and storage of wastewater for irrigation. Afterwards, interesting projects of lagoons for reuse have been implemented in all Mediterranean countries. The irrigation water requirements depend on different factors as crops typology, soil structure, environmental features, seasonal variations etc. Consequently, the key point for a correct irrigation management is the possibility to store the proper water volume in storage basins where it is always available on demand. In this contest the aim of the present paper is to study the natural finishing processes occurring in lagoon basins in order to optimize the management policies. Those policies must take into account three main features: 1) respect of the legal thresholds for wastewater reuse, 2) satisfy the irrigation needs with an appropriate water volume 3) set the finishing capacity of the basin to regulate the best ratio Phosphorus/Nitrogen (P/N) in output in relationship with the amount requested by the different crops for their growth. The study focuses on the data collected in the first basin of the natural finishing part of the Santerno wastewater treatment plant. The plant is located in Imola (Bologna, Italy) and can be divided in two main parts: primary/secondary treatment and natural finishing treatment. The second part of the plant consists of five natural treatment basins. The monitoring campaigns focuses on the first basin called Basin 1 as the plant management company, HERA S.p.A., intends to destine the outlet of this basin to irrigation reuse. The Hydraulic Retention Time and wet surface area of Basin 1 are 2 days and 14000 m2 respectively
SFS-H Phytotreatment for irrigation reuse channels: Oxi-Nitro efficiency tested on pilot plant
No full textPILOT PLANT EXPERIENCES ON Escherichia Coli AND NUTRIENTS REMOVAL IN THE UPPER AEROBIC LAYER OF FINISHING LAGOONS FOR WASTEWATER IRRIGATION REUSE
No full textThe implementation of good practices in Wastewater Treatment Plants management allows to reach different goals as wastewater reuse, energy production and raw material reservoir. In the last decades the use of natural treatment systems for wastewater reuse is increasing as they are efficient with low energy consumption. Lagoons, also called ponds, are natural or artificial basins commonly used for natural wastewater treatment, where occurring chemical, biochemical and physical natural processes. More in details, three processes are in equilibrium: photosynthesis, aerobic oxidation and anaerobic decomposition. The regulator of this equilibrium is the oxygen availability.
In this context this study focuses on the processes occurring in the aerobic layer (around 60cm) of a hybrid natural treatment plant: aerobic lagoon/Phytotreatment FWS with Lemna. This layer is crucial to reduce the concentrations under the legal thresholds of the following nutrients: Nitrogen Ammonia, Orthophosphate, Total Nitrogen, Total Phosphorus and Escherichia coli. The aim of the study is to verify the nitrification and disinfection capacity in this layer. The results are also connected with the management policies adopted. Moreover, the phosphorus variations have been verified in relationship with nitrification.
To this aim a pilot plant was built in the Santerno WWTP area in the city of Imola in Italy. The influent flow comes from the outlet of the full-scale plant. Monthly monitoring campaigns have been carried on two sampling points located in input and output of the pilot plant, for one year
Organic matters and nitrogen removal in FWS basins: comparisons in mediterranean WWT plants
No full textWastewater finishing in Cesenatico’s Channels open to tidal flow
No full textAim of the present investigation is to verify the effect of transitory water volumes in completing water treatment before discharging in coastal sea and to give information about water depth regulation and flowrate management in order to influence natural phenomena. Freshwater coming from discharging systems of Wastewater Treatment Plants (WWTPs), and discharged in coastal areas, is often responsible of low seawater quality in bathing sea zone. Usually in, urbanized coastal territories, treated and untreated effluents outfall into transition volumes, which provide to discharge into sea according with unsteady tidal flow. When ground and basin morphology implicate an extended system of channels and storage capabilities permit Hydraulic Retention Time (HRT) of the same order of HRT in WWTPs, significant finishing effects are foreseeable on water quality discharged to sea, because of combined aerobic and anoxic natural phenomena. This work, following the first experimental campaigns (ML Mancini in MEDCOAST 07 proceedings) extends the investigations to the role of algal/bacterial balance in conditioning the main finishing effects.
The research is carried out taking samples for laboratory analysis and monitoring profiles, by an YSI multiparameter probe, into an internal channel of Cesenatico harbour basin at five Km from the sea outlet. Along his length (almost 2000 m) this tract receives, in dry water conditions, only residual organic loading from Cesena municipal wastewater treatment plant (200.000 AE).
It presents low average depth (max 0,9-1,5 m) and almost constant width. Four fixed point, in output, middle and input cells, are monitored in order to verify active phenomena and finishing effects on discharged wastewater such in terms of C, N, P biological removal as in terms of physical removal during sedimentation phases related to low velocity cycles. In different tidal conditions are measured water depth, velocity, temperature, salinity, pH, redox, oxygen and are taken samples to analyse concentrations of ammonium, nitrate nitrogen, Chl a, Escherichia Coli (E. coli), Total Coliforms, suspended solids.
The focused internal part of the channel system has been modelled as an unsteady flow reactor tank where variations in depth and input/output discharge are provided by tide, but prevalent freshwater conditions are maintained by the high rate input of treated wastewater. Unsteady flow conditions, regulated by downstream level, according with tidal oscillations, are schematized, for water quality calculations, as four sequencing daily cycles of storage and discharge. Modelling of oxygen and biomass balances permit to quantify the different role of productive and oxidizing activities supported by mixed microalgal and bacterial populations during daily and nightly cycles.
Monitoring data present as largely prevalent, along water column, aerobic conditions supporting oxidizing and nitrifying activities. The natural disinfection efficiency has been evaluated enumerating the E. coli in the Cesena WWTP outfall section and four times during the day in the last section (Visdomina). The results show that the disinfection capacity of the channel depend on the tidal variation because they influence the HRT. The disinfection efficiency was 65.3 % in the afternoon when the tidal level was at its maximum as also showed by the modelling study of the trajectories
Pilot plant experiences on nutrients and E. coli removal in aerobic layer of WW finishing ponds
No full textCircular economy model encourages to develop new strategies in the wastewater treatment plants (WWTPs) management. The implementation of good practices in WWTPs management allows to reach different goals (wastewater reuse, energy production and raw material reservoir). At the same time, water scarcity has become more prominent in the last decades and reuse and valorization of water from WWTPs can help solving the problem.
The implementation of natural system as finishing treatment for wastewater reuse could be a smart alternative in existing urban WWTPs.
In this context this study focuses on the processes occurring in the aerobic layer of a hybrid natural treatment plant : aerobic lagoon/Phytotreatment FWS with Lemna. This layer is crucial to reduce the concentrations under the legal thresholds of the following parameters: 1) Escherichia coli 2) Nitrogen Ammonia 3)Total Nitrogen(TN). The aim of the study is to verify the disinfection and nitrification capacity in this layer to suggest more efficient management policies in terms of ratio between surface occupied (phytotreatment) and not occupied (lagoon) by Lemna.
To this aim, a pilot plant was built in the Santerno WWTP area (Imola, Italy). The influent flow comes from the outlet of the full scale plant pumped using a peristaltic pump (QIN = 0.03 l/s). The retention time is similar to a real lagoon and to obtain an adequate turbolent flow the output is recirculated with 0.55 kW pump in the inlet section (QREC = 1.03 l/s).
The monitoring results show the role of Lemna to guarantee the phosphorus (from 15% to 30%) and nitrogen (from 10% to 20%) compounds removal.
The influence of algal photosyntesys to the dissolved oxygen concentration in water column has been observed. In those cases interesting nitrification and nitrogen extraction removal rates were measured (from 15% to 40 %). Moreover, an E.coli removal efficiency around 90% was obtained
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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