EN 14702-3:2019

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.REPRþMLKCharakterisierung von Schlämmen - Absetzeigenschaften - Teil 3: Bestimmung der SinkgeschwindigkeitCaractérisation et management des boues - Détermination des propriétés de sédimentation - Partie 3: Détermination de la vitesse de sédimentationCharacterisation of sludges - Settling properties - Part 3: Determination of zone settling velocity (ZSV)13.030.20Liquid wastes. SludgeICS:Ta slovenski standard je istoveten z:EN 14702-3:2019SIST EN 14702-3:2019en,fr,de01-april-2019SIST EN 14702-3:2019SLOVENSKI
STANDARD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 14702-3
February
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s uä r u rä t r English Version
Characterisation of sludges æ Settling properties æ Part
uã Caractérisation des boues æ Propriétés de sédimentation æ Partie
u ã Détermination de la vitesse
Charakterisierung von Schlämmen æ Absetzeigenschaften æ Teil
uã Bestimmung der Sinkgeschwindigkeit This European Standard was approved by CEN on
s v December
t r s zä
egulations which stipulate the conditions for giving this European Standard the status of a national standard without any alterationä Upætoædate lists and bibliographical references concerning such national standards may be obtained on application to the CENæCENELEC Management Centre or to any CEN memberä
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s v y r tæ uã t r s { ESIST EN 14702-3:2019

Settling apparatus . 11 Annex B (informative)
Measurement of settling velocity according to different cases . 12 B.1 Measurement of settling velocity by measuring the interface position between supernatant and settled particles . 12 B.2 Measurement of settling velocity in absence of interface . 13 Annex C (informative)
Determination of the theoretical area of the thickener by Talmage and Fitch method . 15 Annex D (informative)
Results of validation trials for zone settling velocity (ZSV) and Compression point . 16 Bibliography . 21
s v y r t-3:2019) has been prepared by Technical Committee CEN/TC 308 “Characterization and management of sludge”, the secretariat of which is held by AFNOR. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by August 2019, and conflicting national standards shall be withdrawn at the latest by August 2019. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN shall not be held responsible for identifying any or all such patent rights. The EN
s v y r t series consists of the following parts: — Characterisation of sludges — Settling properties — Part 1: Determination of settleability (Determination of the proportion of sludge volume and sludge volume index); — Characterisation of sludges — Settling properties — Part 2: Determination of thickenability; — Characterisation of sludges — Settling properties — Part 3: Determination of zone settling velocity (ZSV). According to the CEN-CENELEC Internal Regulations, the national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. SIST EN 14702-3:2019

— water supply treatment plants. This method is also applicable to sludge and sludge suspensions of other origins. 2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN
s v y v t, Characterization of sludges — Laboratory chemical conditioning procedure EN 16323, Glossary of wastewater engineering terms 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 16323 and the following apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses:
IEC Electropedia: available at http://www.electropedia.org/
ISO Online browsing platform: available at http://www.iso.org/obp 3.1 settleability ability of solids of a suspension to separate from water under gravity 3.2 zone settling (or sedimentation) velocity ZSV vertical distance covered by a group of particles per time unit 3.3 compression point critical time in a sedimentation under gravity where the sludge in the thickening zone begins to compress 3.4 theoretical thickener area required area per unit of solids and time to concentrate sludge according a given factor SIST EN 14702-3:2019

Key X time Y interface height Figure 1 — Compression point (5) in a gravity sedimentation (1) clear liquid, (2) uniform concentration (3) particles in compression, (4) final particles deposit 5 Interferences Initially, when following the interface height versus time, there is usually an induction period that is followed by the linear settling portion, which is supposed to be characteristic of the initial solids concentration in the column. It is attributed to the formation of the solids structure most appropriate for settling. The settling velocity of flocculated suspension depends on the conditions under which the aggregates were formed. The flocculation step shall be carried out according to EN
s v y v t. The settling of particles in a fluid generally takes place in a container of finite dimensions that could be expected to have some effects on the sedimentation velocity. The effect is bound to be related to the size of the solids relative to the container d/D and it is likely to be more relevant for dilute systems where particle/particle and particle-wall hydrodynamic interaction effects could be of the same order. The diameter should be much greater than the particle diameter, generally at least 4 to 5 orders of magnitude greater. Pump under vacuum can lead with presence of nitrates to the formation of N2 gas bubbles. SIST EN 14702-3:2019

s v y v t. An example of appropriated dimensions is: Height: 40 cm to 44 cm Diameter: 25 cm to 26 cm Exit pipe at the bottom of the tank, in the middle point, minimum diameter: 25 mm 6.2 Stirrer. A mechanical stirrer with 3 or 4 horizontal perpendicular blades is set in the storage tank, allowing the modification and control of mixing speed. NOTE In case of important sludge volumes, a 3 or 4 staged PVC blades (15 cm to 20 cm x 3 cm x 0,5 cm) impeller can be used with a distance of 10 cm between each blade. 6
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