Obrada aktivnog mulja ultrazvukom

undergraduate thesis

• Title (english): Solubilisation of waste-activated sludge by ultrasonic treatment
• Author: Katarina Hviezd
• Mentor: Mladen Brnčić (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Process Engineering); (Laboratory for Unit Operations); Zagreb
• Defense date and country: 2012-07-25, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

S ciljem povećanja učinkovitosti anaerobne razgradnje, proučeno je djelovanje ultrazvuka na aktivni mulj. Cilj ovog rada bio je proučiti kako primjena ultrazvuka visokih intenziteta i različitih amplituda utječe na obradu aktivnog mulja. Koristio se ultrazvučni uređaj maksimalne nominalne snage 400 W i frekvencije 24 kHz. Uzorci aktivnog mulja bili su podvrgnuti ultrazvučnim valovima 5, 15 i 25 minuta. Obrada se provodila ultrazvukom amplitude 60% i 90%. Nakon obrade, udio otopljenih organskih tvari mjeren kao kemijska potrošnja kisika (KPK), porastao je (38,4%), uz istovremeno smanjenje udjela suspendiranih organskih tvari (37,55%). Upotrebom veće amplitude dobiveni su bolji rezultati obrade. Veličina čestica u suspenziji smanjila se nakon primjene ultrazvuka. U smislu biorazgradnje, primjena ultrazvuka doprinijela je udjelu topivih tvari zbog čega bi proizvodnja bioplina digestijom mulja trebala biti uspješnija.

Abstract (english)

In order to enhance the efficiency of anaerobic digestion, the effects of ultrasonic treatment have been studied on waste–activated aludge. The aim of this work was to investigate the impact of hi–intensity ultrasound and different amplitudes on solubilisation of waste-activated sludge. Ultrasound device working at frequency of 24 kHz with a power capacity about 400 W was used for ultrasound treatment. Samples of sludge were exposed for 5, 15 and 25 minutes to the ultrasound waves. The amplitudes used were 60% and 90%. After treatment, volume of dissolved organic matter was measured as chemical oxygen demand (COD), it increased (38,4%), simultaneously volume of suspended organic matter decreased (37,55%). Use of a larger amplitudes obtained better results processing. Particle size in suspension decreased after the ultrasound treatment. In terms of biodegrability, the use of ultrasound contributed to the soluble part of sludge what leads to the more successfull production of biogas by digestion.

• Keywords: ultrazvuk; biorazgradnja; veličina čestica; otpadni mulj; anaerobna razgradnja
• Keywords (english): ultrasound; biodegrability; particle size; sewage sludge; anaerobic digestion
• Language: croatian
• URN:NBN: urn:nbn:hr:159:820383
• Study programme: Title: Biotechnology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-05-16 10:33:15