Cavitation as a Potential Technology for Wastewater Management – An Example of Enhanced Nutrient Release from Secondary Pulp and Paper Mill Sludge
| Autor: | Matevž Dular, Martin Petkovšek, Marko Hočevar, Mija Sežun, Janez Kosel, Mojca Zupanc, Janez Vrtovšek |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
0209 industrial biotechnology
Chemistry business.industry Mechanical Engineering Pulp (paper) Chemical oxygen demand Paper mill 02 engineering and technology engineering.material Pulp and paper industry Environmentally friendly 6. Clean water 020901 industrial engineering & automation Nutrient Wastewater Mechanics of Materials Cavitation engineering Sewage treatment business |
| Zdroj: | Strojniški vestnik – Journal of Mechanical Engineering Strojniški vestnik |
| ISSN: | 0039-2480 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|