Cavitation as a potential technology for wastewater management - an example of enhanced nutrient release from secondary pulp and paper mill sludge

an example of enhanced nutrient release from secondary pulp and paper mill sludge

Mija Sežun (Author), Janez Kosel (Author), Mojca Zupanc (Author), Marko Hočevar (Author), Janez Vrtovšek (Author), Martin Petkovšek (Author), Matevž Dular (Author)

Abstract

Wastewater recycling and sludge removal in the paper industry account for about 60 % of all process costs. New and environmentally friendly wastewater treatment techniques are, therefore, continually being developed. Cavitation exploitation is currently a well-investigated topic that is also interesting for the paper production industry. This study investigates efficiency of hydrodynamic cavitation alone and in combination with the addition of NaOH for the treatment of secondary pulp and paper mill sludge in order to enhance nutrient release. First, two laboratory-scale devices were tested: the blow-through and the rotating hydrodynamic cavitation generator. The latter set-up proved to be more efficient: therefore, further experiments were performed on its pilot-scale version. The results showed an increase of soluble chemical oxygen demand (CODs) by 514 mg/L, total nitrogen (Nt) by 17.4 mg/L, and total phosphorous (Pt) by 2.3 mg/L. To further increase nutrient release combination of cavitation and sludge sample alkalinization was tested. The addition of NaOH and 30 min cavitation of secondary sludge (500 L) significantly improved CODs and Nt release by 2400 mg/L and 120 mg/L, respectively. Microbiological photos revealed a definite disintegration of sludge flocks. According to our estimates, 1.9 kg of released CODs from alkaline pre-treated and cavitated sludge would cost only one euro.

Keywords

hydrodynamic cavitation;nutrients;paper mill plants;secondary sludge;

Data

Language:	English
Year of publishing:	2019
Typology:	1.01 - Original Scientific Article
Organization:	UL FS - Faculty of Mechanical Engineering
UDC:	532.528(045)
COBISS:	16942363
ISSN:	0039-2480
Parent publication:	Strojniški vestnik
Views:	574
Downloads:	332
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Other data

Secondary language:	Slovenian
Secondary title:	Kavitacija kot potencialna tehnologija za revitalizacijo odpadnih voda: primer povečanega sproščanja hranil iz odpadnega biološkega mulja papirne industrije
Secondary keywords:	hidrodinamska kavitacija;hranila;papirna industrija;odpadni biološki mulj;razgradnja mulja;razgradnja muljev;obdelava odpadnih voda;
Type (COBISS):	Article
Pages:	str. 641-649, SI 83
Volume:	ǂVol. ǂ65
Issue:	ǂno. ǂ11/12
Chronology:	Nov.-Dec. 2019
DOI:	10.5545/sv-jme.2019.6328
ID:	11392456