background preloader


Facebook Twitter

Trattamento delle acque reflue. Da Wikipedia, l'enciclopedia libera. Vista aerea di un impianto di depurazione delle acque. Si definisce trattamento delle acque reflue (o depurazione delle acque reflue) il processo di rimozione dei contaminanti da un'acqua reflua di origine urbana o industriale, ovvero di un effluente che è stato contaminato da inquinanti organici e/o inorganici. Le acque reflue non possono essere reimmesse nell'ambiente tal quali poiché i recapiti finali come il terreno, il mare, i fiumi ed i laghi non sono in grado di ricevere una quantità di sostanze inquinanti superiore alla propria capacità autodepurativa. Il ciclo depurativo è costituito da una combinazione di più processi di natura chimica, fisica e biologica. Tipologia di reflui[modifica | modifica wikitesto] Acqua reflua prima del trattamento.

Si può notare l'elevata torbidità del campione di acqua prelevato, indice di un elevata concentrazione di solidi sospesi. Classificazione dei solidi da rimuovere[modifica | modifica wikitesto] si ottiene: Combined sewer. Combined sewer system. During dry weather (and small storms), all flows are handled by the publicly owned treatment works (POTW). During large storms, the relief structure allows some of the combined stormwater and sewage to be discharged untreated to an adjacent water body. A combined sewer is a sewage collection system of pipes and tunnels designed to also collect surface runoff. This type of gravity sewer design is no longer used in building new communities (because current design separates sanitary sewers from runoff), but many older cities continue to operate combined sewers.[1] Combined sewers can cause serious water pollution problems during combined sewer overflow (CSO) events when wet weather flows exceed the sewage treatment plant capacity.

The discharges contain human and industrial waste, and can cause beach closures, restrictions on shellfish consumption and contamination of drinking water sources.[2] Background[edit] Combined sewer overflows (CSOs)[edit] Health impacts[edit] Flood Control and Drainage Engineering, Fourth Edition - S.N. Ghosh. Overflow. From Wikipedia, the free encyclopedia Overflow may refer to: Computing and telecommunications[edit] Other[edit] 0verflow, a Japanese video game developerSanitary sewer overflow, a condition whereby untreated sewage is discharged into the environment, escaping wastewater treatment. COD - Chemical Oxygen Demand - LAR Process Analysers. Thermal Oxidation (High Temperature Method) LAR's QuickCOD-analyzers use a special thermal combustion method at 1,200°C, which allows a catalyst-free oxidization of the complete sample including any particles. Following which an oxygen detector determines the amount of oxygen consumed by the combustion.

This very fast analysis has a cycle time of only 3 minutes and does not require any chemicals. The QuickCODultra analyzer measures the oxygen demand of all oxidisable substances in the waste water including organic nitrogen. Correlation between TOC and COD The COD concentration is calculated by use of this method that is correlated by a factor and the TOC concentration in the waste water is determined by use of a standard TOC analysis method. Electrochemical measurement principle With the patented Lead-Dioxide-Electrode by LAR OH-radicals are produced. This method offers a fast, simple, accurate and pollution-free alternative to the common dichromate method (wet chemical method). Total suspended solids.

TSS was previously called non-filterable residue (NFR), but was changed to TSS because of ambiguity in other scientific disciplines. Measurement[edit] TSS of a water or wastewater sample is determined by pouring a carefully measured volume of water (typically one litre; but less if the particulate density is high, or as much as two or three litres for very clean water) through a pre-weighed filter of a specified pore size, then weighing the filter again after the drying process that removes all water on the filter. Filters for TSS measurements are typically composed of glass fibres.[2] The gain in weight is a dry weight measure of the particulates present in the water sample expressed in units derived or calculated from the volume of water filtered (typically milligrams per litre or mg/L). If the water contains an appreciable amount of dissolved substances (as certainly would be the case when measuring TSS in seawater), these will add to the weight of the filter as it is dried.

Surfactant. Proposed features/Harbour. Details see Hafen and harbour A harbour (also port, North American English Harbor) is a place where ships, boats, and barges can seek shelter from stormy weather. This article describes some of the many features associated with a harbour and the approach from the sea. Sample harbour Rock coastNatural jettyStone coastFootbridge or raftSlipwayQuayBollardGateDry dock, tidal harbourPierAnchorageSandy beachBeachStone jettyHarbour jetty with pier insideHarbour jetty with rock fill outsideCoastlineHarbour as a node Mapping a harbour The harbour node Every harbour should be marked with node tags to which all related properties are assigned as detailed below. A large harbour will also have a area using = and this may also be divided into several harbour basins which many have their own names. The harbour basin is surrounded by jetties or piers but should not be tagged as a separate area of water.

Name The =* should be the set to the official name for the harbour in the local language. Also: Amenities. Lift station. A European Flood Action programme - Environment. Additional tools Key documents on flood risk management Directive 2007/60/EC of the European Parliament and of the Council of 23 October 2007 on the assessment and management of flood risks Published in the Official Journal on 6 November 2007, page 27. Negotiation and adoption 18/9/2007 : The Council adopts the Floods Directive : Justice and Home Affairs Council Press release (see pa 32, provisional) Council voting list, including full document references with corrigendums.

Text of the Directive as adopted by the Council (please note that the text will only be legally binding once published in the Official Journal) Other language versions are available in the Council's document search engine [Search tip : look for document with the interinstiutional reference 2006/0005(COD), and note the corrigendums in the NL, DK, IT and SK versions.] Full information on the negotiations can also be accessed from Pre-lex. Search tips : Provisional Council conclusions (pdf, 227KB) Opinion n° 737/2006. 32000L0060. Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water policy Official Journal L 327 , 22/12/2000 P. 0001 - 0073 Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water policy Having regard to the Treaty establishing the European Community, and in particular Article 175(1) thereof, Having regard to the proposal from the Commission(1), Having regard to the opinion of the Economic and Social Committee(2), Having regard to the opinion of the Committee of the Regions(3), Acting in accordance with the procedure laid down in Article 251 of the Treaty(4), and in the light of the joint text approved by the Conciliation Committee on 18 July 2000, Whereas: (1) Water is not a commercial product like any other but, rather, a heritage which must be protected, defended and treated as such.

Article 1 Purpose Article 2. Disposal lines. Jhr94 3. Science in Your Watershed - General Introduction and Hydrologic Definitions. Climate and Land Use Change || Core Science Systems || Ecosystems || Energy, Minerals and Environmental Health || Natural Hazards || Water W. B. LANGBEIN and KATHLEEN T.ISERI Manual of Hydrology: Part 1. General Surface-Water Techniques GEOLOGICAL SURVEY WATER-SUPPLY PAPER 1541-A Methods and practices of the Geological Survey UNITED STATES DEPARTMENT OF THE INTERIORJAMES G.

Library of Congress catalog-card No. 73-600301 First printing 1972Second printing 1972Third printing 1983HTML Version 1995 CONTENTSIntroductionHydrologic definitionsA-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-S-T-U-V-W-X-Y-ZTopical finding listReferences Hydrologic techniques, capably applied, are essential for the sound development and management of water resources. Consider the planning for a water supply for a town or an irrigation project: How much water is available in the rivers? Floods pose a different set of hydrologic questions. Walter B.

Ablation. Absorption. Acre-foot. Anabranch. Anchor ice. Annual flood. Backwater. Valutazione delle portate di piena. Beven, Keith J. - Rainfall-Runoff Modelling. 1-D Saint Venant equation. Output from a shallow water equation model of water in a bathtub. The water experiences five splashes which generate surface gravity waves that propagate away from the splash locations and reflect off the bathtub walls. The shallow water equations (also called Saint-Venant equations in its unidimensional form, after Adhémar Jean Claude Barré de Saint-Venant) are a set of hyperbolic partial differential equations (or parabolic if viscous shear is considered) that describe the flow below a pressure surface in a fluid (sometimes, but not necessarily, a free surface). The shallow water equations can also be simplified to the commonly used 1-D Saint-Venant equation. The equations are derived[1] from depth-integrating the Navier–Stokes equations, in the case where the horizontal length scale is much greater than the vertical length scale.

While a vertical velocity term is not present in the shallow water equations, note that this velocity is not necessarily zero. Equations[edit] where and with. Free surface. Free surface of the sea, viewed from below In physics, a free surface is the surface of a fluid that is subject to zero parallel shear stress,[1] such as the boundary between two homogeneous fluids,[2] for example liquid water and the air in the Earth's atmosphere. Unlike liquids, gases cannot form a free surface on their own.[3] Fluidized/liquified solids, including slurries, granular materials, and powders may form a free surface.

In a free liquid that is not affected by outside forces such as a gravitational field, internal attractive forces only play a role (e.g. Van der Waals forces, hydrogen bonds). Its free surface will assume the shape with the least surface area for its volume: a perfect sphere. Waves[edit] Rotation[edit] Free surface of a liquid in a rotating vessel is a paraboloid Consider a cylindrical container filled with liquid rotating in the z direction in cylindrical coordinates, the equations of motion are: Where is the density of the fluid, is the radius of the cylinder, Pipe Equations. Sorry to see that you are blocking ads on The Engineering ToolBox! If you find this page valuable and appreciate it is open and free for everybody - please contribute by • disabling your adblocker on The Engineering ToolBox!

•• How to? Cross Sectional inside Pipe Area Cross-sectional inside area of a pipe can be calculated as A = π (di / 2)2 = π di 2 / 4 (1) where A = cross-sectional inside area of pipe (m2, in2) di = inside diameter (m, in) Cross Sectional Pipe Wall Area The cross-sectional wall area - or area of piping material - can be calculated as Am = π (do / 2)2 - π (di / 2)2 = π (do 2 - di 2) / 4 (2) where Am = cross-sectional wall area of pipe (m2, in2) do = outside diameter (m, in) Weight of Empty Pipes Weight of empty pipes per unit length can be calculated as wp = ρm Am = ρm (π (do / 2)2 - π (di / 2)2) = ρm π (do2 - di2) / 4 (3) where wp = weight of empty pipe per unit length (kg/m, lb/in) ρs = density of pipe material (kg/m3, lb/in3) Weight of Liquid in Pipes where. Flow and pressure. Differential Pressure Flow meters | Omega Engineering. The calculation of fluid flow rate by reading the pressure loss across a pipe restriction is perhaps the most commonly used flow measurement technique in industrial applications (Figure 2-1).

The pressure drops generated by a wide variety of geometrical restrictions have been well characterized over the years, and, as compared in Table 2, these primary or "head" flow elements come in a wide variety of configurations, each with specific application strengths and weaknesses. Variations on the theme of differential pressure flow measurement (dp flow) include the use of pitot tubes and variable-area meters (rotameters), and are discussed later in this chapter. Primary Element Options In the 18th century, Bernoulli first established the relationship between static and kinetic energy in a flowing stream.

As a fluid passes through a restriction, it accelerates, and the energy for this acceleration is obtained from the fluid's static pressure. V = k (h/D)0.5 or Q = kA(h/D)0.5 or W = kA(hD)0.5. Open-channel flow. Open-channel flow, a branch of hydraulics and fluid mechanics, is a type of liquid flow within a conduit with a free surface, known as a channel. The other type of flow within a conduit is pipe flow. These two types of flow are similar in many ways but differ in one important respect: the free surface. Open-channel flow has a free surface, whereas pipe flow does not. Classifications of flow[edit] Open-channel flow can be classified and described in various ways based on the change in flow depth with respect to time and space. Time as the criterion Steady flow – The depth of flow does not change over time, or if it can be assumed to be constant during the time interval under consideration.

Unsteady flow – The depth of flow does change with time. Space as the criterion Uniform flow – The depth of flow is the same at every section of the channel. Varied flow – The depth of flow changes along the length of the channel. Varied flow can be further classified as either rapidly or gradually varied. Surge and transient flow | Fluid Mechanics Ltd. Transient flow, is flow where the flow velocity and pressure are changing with time. When changes occur to a fluid systems such as the starting or stopping of a pump, closing or opening a valve, or changes in tank levels, then transient flow conditions exist: otherwise the system is steady state. Often transient flow conditions persist as oscillating pressure and velocity waves for some time after the initial event that caused it. Transient flow is usually referred to as surge or water hammer, and the terms are commonly interchanged.

But strictly speaking surge is where the mass oscillation of the fluid is the dominating force and the compressibility of fluid is not significant, for example two connecting reservoirs oscillating up and down. Transient flow problems are commonly solved using a finite difference method known as the method of characteristics and other similar methods.

At Fluid Mechanics we have many years’ experience in solving transient flow problems. BM Tecnologie Industriali. Datasheettripod.