MBT scrubber effluent: Wastewater or fertiliser?

The design of waste air cleaning in Mechanical Biological Treatment (MBT) plants frequently includes acid scrubbing followed by biofiltration. The main purpose of the former process is to remove ammonia from the exhaust air, which produces odours and is toxic for the biofilter microorganisms. The ammonia is then solubilised as ammonium sulphate or ammonium nitrate, according to the acid used in the scrubber (sulphuric or nitric acid, respectively). When the washing solution reaches a preset conductivity, it is partially discharged and replaced by fresh water. As a consequence, an effluent with high ammonia concentration is produced, which is difficult and expensive to treat in a waste water treatment plant. Yet, if we see it in the agronomical perspective, an ammonia rich solution may not be a pollutant but a fertiliser.

Further Authors:
H. Ribeiro - Technical University of Lisbon
D. Catalino - AMARSUL S.A.

The objective of the present study was to evaluate the potential of the scrubber effluent from Amarsul MBT plant in Setúbal, Portugal, to be used as a nitrogen liquid fertiliser. The experiments were carried out with wheat and grass. These species were selected so that land application of the product could be performed all around the year. In the wheat experiment, nitrogen fertilisation supplied by the scrubber effluent was compared to the conventional fertilisation with ammonium sulphate. Results showed that the obtained yields, considering grain and straw fresh and dry weight, were not significantly different, independently from the nitrogen source. No significant differences were also observed in the grass experiment, in which three nitrogen applications were carried out: one at the beginning of the experiment and the other two following the first and second cuts. Grass yield was determined after each cut. In both experiments, soil analysis indicated a more expressive drop in pH (relative to the control) for the treatment with mineral fertilisation, comparing to that receiving scrubber effluent. The composition of the scrubber effluent was determined in order to detect eventual pollutants such as heavy metals, organic compounds and pathogens. The results show that it fulfils the quality required in Portuguese legislation for irrigation water (DL 236/98) and for sewage sludge used in agriculture (DL 276/2009). Besides evaluating the agronomic and environmental quality of the potential fertiliser, it is important to optimise the product logistics, considering storage in the MBT plant and transport to the client site. Hence, different scrubber operation regimes were tested with the objective of maximising the ammonium sulphate concentration of the effluent, without causing damage to the equipment or affecting the odour removal performance. Results demonstrated that it is possible to reach compatibility between air treatment operation requests and fertiliser logistics. This study demonstrates that the scrubber effluent from exhaust air treatment in Amarsul MBT plant could be an environmentally safe good quality ammonia fertiliser, with high potential under an agronomic point of view.



Copyright: © European Compost Network ECN e.V.
Source: Orbit 2012 (Juni 2012)
Pages: 8
Price: € 8,00
Autor: Dr. Maria J. Sebastião
E. Vasconcelos

Send Article Add to shopping cart Comment article


These articles might be interesting:

Composting of pic Faeces with corn stalks in China - Microbiological examinations; hygienic aspects and sanitation capacity
© European Compost Network ECN e.V. (6/2012)
With the increasing demand for meat (pork) the pig production in China increased over the last years,especially in the Northern East of China around mega cities like Beijing. Increasing pig production in large scale pigfarms head to enormous amounts of organic wastes (such as pig faeces), over-fertilization of agricultural areas andenvironmental pollution in regions with high pig production and density. Further Authors: Wang M., He C., Ling Y., Liu Y - China Agricultural University

Pflichten des Deponiebetreibers aus Vorschriften zu Arbeitsschutz und Anlagensicherheit
© Verlag Abfall aktuell (1/2015)
Auf einer Deponie sind insbesondere die Beschäftigten in der Deponiegasanlage einer Reihe von Gefährdungen ausgesetzt. Es ist die Pflicht des Deponiebetreibers, die Anlage so sicher zu betreiben, dass keine unzulässigen Beeinträchtigungen der Bevölkerung und der Umwelt entstehen sowie den Betrieb so zu regeln, dass von den eingesetzten Arbeitsmitteln (Werkzeuge, Geräte, Maschinen und Anlagen) keine Gefährdungen für seine Beschäftigten ausgehen bzw. die Gefährdungen so gering wie möglich gehalten werden.

Auslaufmodell MBA? – Ein Situationsbericht aus der Steiermark
© Lehrstuhl für Abfallverwertungstechnik und Abfallwirtschaft der Montanuniversität Leoben (11/2014)
Durch bestehende Überkapazitäten im Bereich der thermischen Abfallbehandlung und dem damit einhergehenden Preisverfall bei der Müllverbrennung, ist in der Steiermark zuletzt ein starker Trend zur Umstellung der bestehenden MBA-Anlageninfrastruktur vom üblichen Endrottebetrieb zu einem Trocknungsbetrieb zu beobachten. Ziel der mechanisch-biologischen Behandlung ist damit nicht mehr die Erzeugung eines deponiefähigen stabilisierten Abfalles, sondern lediglich dessen Trocknung für die nachfolgende thermische Verwertung. Von den sieben in der Steiermark in Betrieb befindlichen MBA-Anlagen haben vier auf reinen Trocknungsbetrieb umgestellt.

SolidWasteSim – Simulation of Solid Waste Treatment
© Lehrstuhl für Abfallverwertungstechnik und Abfallwirtschaft der Montanuniversität Leoben (11/2014)
A critical analysis of mechanical processes in waste treatment plants hints at vulnerable spots in the interaction of plant units and deployed heterogeneous materials. The Simulation of mechanical processes in waste treatment may depict the total material flow in a plant and as such, contribute to a better understanding of the behaviour in heterogeneous materials, to identify bottlenecks, to check plant modifi cations and hence, to support planning and reducing time for implementation period.

Restmüllanalysen in der Steiermark
© Lehrstuhl für Abfallverwertungstechnik und Abfallwirtschaft der Montanuniversität Leoben (11/2014)
Vom Amt der Steiermärkischen Landesregierung, A14 Referat Abfallwirtschaft und Nachhaltigkeit, wurde die ARGE Ingenieurgemeinschaft Innovative Umwelttechnik GmbH (IUT) und Fa. Saubermacher Dienstleistungs AG (SDAG) beauftragt, landesweite Sortieranalysen von Restmüll durchzuführen. Um die saisonalen Unterschiede zu berücksichtigen, wurden die Analysen in drei Durchgängen durchgeführt. Für die Stichprobenplanung wurden Teilgebiete aus allen Bezirken der Steiermark berücksichtigt, die einzelnen Stichprobengemeinden wurden einer ländlichen oder städtischen Struktur zugeordnet.

Username:

Password:

 Keep me signed in

Forgot your password?