Best Available Technology for P-Recycling from Sewage Sludge—An Overview of Sewage Sludge Composting in Austria

In order to close the phosphorus cycle in the long term, efficient recycling processes are necessary to ensure that this critical nutrient can be returned to arable land. Sewage sludge recycling is of particular importance due to the relatively high phosphorus content of sewage sludge. In this article, the current recycling paths of Austrian sewage sludge are highlighted, focusing on the advantages and limitations of sewage sludge composting. In addition to nutrient contents, pollutant loads were also analyzed in order to also discuss the limitations of this recycling pathway. Therefore, data from Austrian composting plants with focus on sewage sludge are used. The results show that the currently relevant pollutants (heavy metals) are predominantly below the limits prescribed for recycling and spreading on arable land. However, in order to decide on a recycling path at an early stage, a pollutant monitoring system must be in place. Due to pollution, mono-incineration with subsequent phosphorus recovery is also currently being discussed in Austria. Mono-incineration can represent an important component of sewage sludge disposal, because some sewage sludges are not suitable for composting due to potential environmental hazards. Therefore, it is important that evidence-based limit values and measures for the reduction in pollutants for input sources are determined.

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Stabilization of heavy metals in sewage sludge composting process

Water Science & Technology ◽

10.2166/wst.2001.0591 ◽

2001 ◽

Vol 44 (10) ◽

pp. 95-100 ◽

Cited By ~ 10

Author(s):

K.-Y. Chiang ◽

S.-D. Yoi ◽

H.N. Lin ◽

K.-S. Wang

Keyword(s):

Heavy Metals ◽

Sewage Sludge ◽

Total Concentration ◽

Physicochemical Characteristics ◽

Limit Values ◽

Sludge Compost ◽

Composting Process ◽

Agricultural Applications ◽

Maturation Rate ◽

Sludge Composting

This study investigated the stabilization of heavy metals in a sewage sludge composting process using kaoline addition. The results indicate that the temperature increased rapidly to the thermophilic phase (>55°C) at day 1. The additives enhanced the rate of biodegradation and microbial activity during the co-composting process. The changes in pH (ranging from 8 to 8.5) and electrical conductivity (EC) (≤3 mS/cm) were in compliance with the best conditions during the co-composting process. The C/N ratio was determined in each co-compost sample as an indicator of the co-compost maturity. From the end product of the co-compost experiment, changes in the ratios indicate that the additives promote the co-compost maturation rate. Based on the physicochemical characteristics of the co-compost, the potential use for sewage sludge resource recovery as manure is suggested. The total concentrations of Pb, Cd, Cr, Cu, and Zn in the co-compost product were far below the limit values for agricultural use. The leachability of Pb, Cu, and Cr decreased with increasing co-composting time. That is, the kaoline additive has an inhibitory capacity for leaching heavy metals. The Cd concentrations in the sludge compost were below the detection limits. Because the total concentration of Zn was high in the sludge compost and most soluble Zn was leachable, the leachability of Zn ranged from 25% to 29%. As a result of the physicochemical characteristics and heavy metal stabilization, the selected additive was shown to improve the sewage sludge compost quality and provide information for agricultural applications.

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The effect of long-term fertilization on the 0.01 M CaCl2 extractable nutrient content of a meadow soil

Acta Agraria Debreceniensis ◽

10.34101/actaagrar/50/2569 ◽

2012 ◽

pp. 73-79

Author(s):

Emese Bertáné Szabó

Keyword(s):

Recommendation System ◽

Arable Land ◽

Soil Nutrient ◽

Nutrient Content ◽

Limit Values ◽

Nutrient Contents ◽

Ammonium Lactate ◽

Supply Capacity ◽

Mineralizable Nitrogen

During my research, I studied the 0.01 M CaCl2 extractable NO3--N, NH4+-N, Norg, P and K contents of the soil samples originated from a long term fertilisation trial in the experimental site Hajdúböszörmény. Relationships among the soil nutrient contents, the agronomic nutrient balances of the 2009 year, and fertilization were studied. From the results of the study it was concluded as follows:– Fertilization significantly increased the CaCl2 extractable NO3--N, NH4+-N, and K contents of soil.– Norg fraction increased as a function of the increasing yield. Hence, it can be assumed that the greater the produced yield, the more the stubble and root residues remain on the arable land. These organic residues can result significant increase in the Norg content of soils.– The CaCl2 extractable P and K contents were compared with the calculated P and K limit values. According to these, the experimental soil has a good phosphorus and lower potassium supply capacity. These results are in accordance with the results of the conventional Hungarian fertilization recommendation system.– It can be stated that the 0.01 M CaCl2 is able to determine not just inorganic N forms but Norg fraction as well that characterize the easily mineralizable nitrogen reserves. The results proved that AL-P and -K (ammonium lactate acetic acid, traditional Hungarian extractant) are in good agreement with the P and K reserves, but it is important from the aspect of environmental protection and plant nutrition to measure the easily soluble and exchangeable K-, and P-contents of soil. 0.01 M CaCl2 method is recommended for this.

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EFFECTS OF THE DIFFERENT IMPLEMENTATION OF LEGISLATION RELATING TO SEWAGE SLUDGE DISPOSAL IN THE EU

Detritus ◽

10.31025/2611-4135/2020.13944 ◽

2020 ◽

pp. 92-99

Author(s):

Torben Bauer ◽

Lale Andreas ◽

Anders Lagerkvist ◽

Linus Ekman Burgman

Keyword(s):

Sewage Sludge ◽

Agricultural Soil ◽

Agricultural Soils ◽

Phosphorus Recovery ◽

The European Union ◽

Member States ◽

Limit Values ◽

European Directive ◽

Eu Directive ◽

The Eu

The European Directive 86/278/EEC implemented in 1986 was a means adopted by the European Union to improve use of the valuables in sewage sludge by applying treated sludge on agricultural soils. To prevent an accumulation of pollutants, the Directive provided suggestions limiting concentrations of toxic elements in sewage sludge and agricultural soil. The Directive was implemented diversely throughout EU member states, with current national legislations only partly reflecting the initial intentions of the EU Directive from 30 years ago. This study demonstrates how the European Directive was implemented in three countries currently at different stages of replacing the agricultural application of sewage sludge with incineration (Netherlands, Germany and Sweden). Additionally, recent changes in the legislation with regards to the re-use and final disposal of sewage sludge in the three chosen member states are analysed. The aim was to investigate how each member state has solved the conflict between improvement of nutrient recovery from sludge and limitation of pollutants in agricultural soil. Based on this review, limit values are not necessarily reflected in application rates of sewage sludge in agriculture. Following changes in current legislation, phosphorus recovery will become a priority task. The recovery of other valuables from sewage sludge is currently not regulated in the legislation of the three member states investigated.

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Phosphorus cycle - possibilities for its rebuilding.

Acta Biochimica Polonica ◽

10.18388/abp.2013_2048 ◽

1970 ◽

Vol 60 (4) ◽

Cited By ~ 2

Author(s):

Katarzyna Gorazda ◽

Zbigniew Wzorek ◽

Barbara Tarko ◽

Anna K Nowak ◽

Joanna Kulczycka ◽

...

Keyword(s):

Sewage Sludge ◽

Extraction Methods ◽

Phosphorus Recovery ◽

Acid Extraction ◽

Phosphorus Cycle ◽

Sewage Sludge Ash ◽

Sludge Incineration ◽

Phosphorus Form ◽

Sludge Ash ◽

The Right

The rebuilding of the phosphorus cycle can be performed with the use of both biotechnology and chemical technology. This paper presents a review of the phosphorus cycle and the different approaches that can be taken to the recovery of phosphorus from phosphate-rich waste. Critical issues in the phosphorus cycle are also discussed. Methods for the recovery of phosphorus form sewage sludge ash are widely explored and divided into two groups: wet extraction methods and thermochemical methods. Laboratory-scale methods are described, as well as proposed industrial technologies, with particular regard to the possibilities for their implementation in Poland. Phosphorus recovery methods from SSA (sewage sludge ash) in our country seems to be promising due to the increasing number of sewage sludge incineration plants, which could easily supply ash to future recovery installations. For the effective recovery of P from sewage sludge ash, it is essential to make the right choice in determining the appropriate method to use with respect to the particular properties of the ash composition available. A patented method of phosphorus recovery by acid extraction methods, developed by Cracow University of Technology, results in an efficiency of 80-96% for phosphorus recovery. 3000 to 4000 tons of phosphorus per year can be recycled and introduced back into the environment, that covers around 7% of the total amount of phosphorus ore imported into Poland between 2008 and 2009.

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Phosphorus Recovery – A Voyage From Sewage Sludge To Johannes Vermeer

10.31988/scitrends.40862 ◽

2018 ◽

Author(s):

P. Wilfert ◽

L. Korving ◽

M.C.M. Van Loosdrecht

Keyword(s):

Sewage Sludge ◽

Phosphorus Recovery ◽

Johannes Vermeer

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Sewage Sludge Treatment by Hydrothermal Carbonization: Feasibility Study for Sustainable Nutrient Recovery and Fuel Production

Energies ◽

10.3390/en14092697 ◽

2021 ◽

Vol 14 (9) ◽

pp. 2697

Author(s):

Gabriel Gerner ◽

Luca Meyer ◽

Rahel Wanner ◽

Thomas Keller ◽

Rolf Krebs

Keyword(s):

Liquid Phase ◽

Sewage Sludge ◽

Hydrothermal Carbonization ◽

Economic Feasibility ◽

Phosphorus Recovery ◽

High Yield ◽

Nutrient Recovery ◽

Waste Biomass ◽

Sludge Treatment ◽

Sewage Sludge Treatment

Phosphorus recovery from waste biomass is becoming increasingly important, given that phosphorus is an exhaustible non-renewable resource. For the recovery of plant nutrients and production of climate-neutral fuel from wet waste streams, hydrothermal carbonization (HTC) has been suggested as a promising technology. In this study, digested sewage sludge (DSS) was used as waste material for phosphorus and nitrogen recovery. HTC was conducted at 200 °C for 4 h, followed by phosphorus stripping (PS) or leaching (PL) at room temperature. The results showed that for PS and PL around 84% and 71% of phosphorus, as well as 53% and 54% of nitrogen, respectively, could be recovered in the liquid phase (process water and/or extract). Heavy metals were mainly transferred to the hydrochar and only <1 ppm of Cd and 21–43 ppm of Zn were found to be in the liquid phase of the acid treatments. According to the economic feasibility calculation, the HTC-treatment per dry ton DSS with an industrial-scale plant would cost around 608 USD. Between 349–406 kg of sulfuric acid are required per dry ton DSS to achieve a high yield in phosphorus recovery, which causes additional costs of 96–118 USD. Compared to current sewage sludge treatment costs in Switzerland, which range between 669 USD and 1173 USD, HTC can be an economically feasible process for DSS treatment and nutrient recovery.

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