The paper presents an experimental study of suspension flow patterns and velocity field inside a circular settling tank with continuous operation. Research was focused on the impact of a specific ...flow pattern on the sedimentation efficiency of the prototype settling tank. The latter differed from a common circular settling tank in that it was peripherally fed and had the central draw-off. Experiment was carried out on a settling tank section made of plexiglass and represented a radial slice of a prototype settling tank. The flow field and local suspension concentration was determined by computer-aided visualization. Sedimentation efficiency was assessed relatively by comparison of the amount of settled particles (sludge height measurements) between different types of flow in a certain time period of the settling tank operation. Results showed that there were two types of flow in the settling tank that were initiated by a horizontal or vertical inflow from the distribution ring. The type of inflow (horizontal or vertical) was a function of the suspension height in the settling tank. Significant differences in sedimentation efficiency were observed between both types of flow, particularly at lower inlet suspension concentrations. Horizontal inflow proved to be less efficient in terms of settling.
An island in front of Izola Steinman, Franci; Gosar, Leon
Urbani izziv,
06/2002, Letnik:
13, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Maritime construction in front of Izola restitutes an enriched former state. The island is positioned in a place where there are no legal regimes enforced by the state or local community. Legal ...regimes that determine the exploitation of water rights and limitations (management, exploitation, use) can actually limit all. Therefore their synthesis has to be the starting point for analysing the harmony of present uses and for planning future uses of the sea and coastal area. For example the aquatorium of the shellfish mariculture positioned in the Strunjan Bay without adequate analysis of the prevailing conditions is causing conflicts of uses, unacceptable limiting of general use of the sea and prohibitive limitations in neighbouring areas. The analysis done for the island in front of Izola shows that there are no such consequences. Only uses in the public interest were proposed, since when assessing suitability first public and then common interests where considered, possible specific (e.g. entrepreneurial) uses were permitted only if the afore mentioned weren’t obstructed. Thus integral management of the coastal area was enabled, with respect to functional ties between the land and sea.
Today spatial data is directly or indirectly dealt with by states, local communities, companies, numerous government and non-government organisations, societies and other informal groups. The publics ...demand to be informed and have to be informed about spatial occurrences in their living environment, which projects and activities are underway and subsequently voice their opinions and act to affect quality improvements in space. Information tied to space and physical projects is dispersed. Even efficient interchange of information between government and municipal authority is not practised. Spatial planning is a multi-disciplinary activity, with numerous participating disciplines and levels. Successful activity in physical planning needs efficient cooperation between all responsible parties involved in physical planning – the state and local communities, independent governmental departments and the local communities themselves. Exchange of information is crucial for the process of physical planning, but can be enabled only with a good system for information gathering and delivery.
S prostorskimi podatki se danes posredno ali neposredno ukvarjajo država, lokalne skupnosti, podjetja, številne vladne in nevladne organizacije, društva in druge neformalne skupine. Javnost želi in ...mora biti obveščena, kaj se dogaja v prostoru, v katerem živi, kateri projekti in aktivnosti se dogajajo, in ob tem s svojim mnenjem in aktivnostmi vplivati na čim bolj kakovostno bivanje v prostoru. Informacije, povezane s prostorom in prostorskimi projekti, so razpršene. Tudi učinkovita izmenjava informacij med občinami in državnimi upravnimi organi se še ne izvaja. Prostorsko načrtovanje je multidisciplinarna dejavnost z veliko sodelujočimi področji in ravnmi. Za uspešno delovanje v prostorskem načrtovanju je treba zagotavljati učinkovito sodelovanje med vsemi nosilci urejanja prostora – med državo in lokalnimi skupnostmi, med posameznimi organi državne uprave ter med lokalnimi skupnostmi samimi. V procesu prostorskega načrtovanja je zato izredno pomembna izmenjava informacij, kar pa je mogoče le z dobrim sistemom za njihovo zbiranje in posredovanje.
Uveljavitev pravnega reda Evropske unije prinaša obsežno strokovno delo tudi v vodno gospodarstvo. Na vodilno, Okvirno direktivo o vodah (WFD) se navezujejo številne druge. Izpolnjevanje določil ...Direktive o ravnanju z odpadnimi komunalnimi vodami (UWWTD) in Direktive o celovitem preprečevanju in omejevanju onesnaževanja (IPPCD) bo tudi v Sloveniji zahtevalo znatne investicije. Področje komunalnih voda na operativni ravni ureja občina, država pa mora izpolnjevati prevzete državne obveznosti do EU. Pravočasno doseganje ciljev zahteva koordinacijo aktivnosti, temelječo na strokovnih podlagah. V UWWTD je eden osnovnih parametrov aglomeracija kot zaokroženo območje tako zgoščene poselitve, da zanj veljajo posebna določila in dinamika iz direktive. Merilo zgoščenosti je število prebivalcev na hektar. Za Slovenijo so bili izdelani najprimernejša mreža eno-hektarskih kvadratnih celic in trije tipi celic poselitve. Območje posamezne aglomeracije sestavljajo celice dveh najgostejših tipov poselitve, ki se stikajo. Površina aglomeracij je mnogo manjša od površine naselij iz RPE, zato so skupne slovenske obveznosti iz direktiv manjše, kar pokaže tudi strokovna podlaga za nacionalni program zbiranja in čiščenja odpadnih komunalnih in padavinskih voda. Izdelane aglomeracije so osnovni element načrtovanja in ukrepanja tudi za druga vodnogospodarska načrtovanja (npr. proti poplavni ukrepi), lahko pa si bi jih uporabilo tudi za programe komunalnega opremljanja in druga razvojna načrtovanja v prostoru.
Enforcement of the European Union’s legal order is bringing substantial expert involvement even in water management. The main act, the Water Framework Directive (WFD), is followed by numerous others. ...Substantial investments will be demanded even in Slovenia to comply with the Uniform Waste Water Treatment Directive (UWWTD) and Integrated Pollution Prevention and Control Directive (IPPCD). On the operative utilities are dealt with by municipalities, while states have to fulfil national responsibilities to the EU. Timely achievement of goals demands coordinated activities based on expert guidelines. One of UWWTD’s basic parameters is the agglomeration, which is a uniform area of such compact settlement, to which special stipulations and dynamics from the directive can be applied. The criteria for compactness is population density per hectare. A suitable grid of square one-hectare cells was devised for Slovenia, with three types of settlement cells. Areas of particular agglomerations are formed by two adjoining cells whose population is most dense. The area of agglomerations is much smaller than settlement area in the register of territorial units, thus Slovene summary obligations from the directive are much smaller, as was shown in the expert guidelines for the National programme for collecting and treating waste communal and atmospheric water. These agglomerations are the basic element for planning and intervention even in other water resource planning (flood prevention measures etc.) and could also be used for programmes of provision of utilities, as well as other physical development plans.
The paper presents a study of the influence of integral parameters of an industrial settling tank on the process of sedimentation. An organic water suspension was used in the experiment where the ...impact of the suspension age on sedimentation was determined experimentally and by computer-aided visualization. Measurements of the inlet- and outlet suspension concentration, the difference in the level of suspension between the reservoir and settling tank as well as the suspension volume flow rate were carried out on a newly developed continuous sedimentation tank. The results of the measurements served as the basis for a phenomenological multi-regression model that was developed to determine the functional dependence of the ratio between inlet- and outlet suspension concentration on the independent parameters of the process. According to the obtained results of the model, the most influential parameters of the sedimentation process are the inlet concentration and the mass flow of the suspension.
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