Utilització de fangs de depuradora en restauració: Manual d’aplicació en activitats extractives i terrenys marginals.

Alcañiz JM, Ortiz O, Carabassa V (2008) Utilització de fangs de depuradora en restauració: Manual d’aplicació en activitats extractives i terrenys marginals. Agència Catalana del Aigua, Generalitat de Catalunya, (1ª edició novembre 2008), 115p. ISBN 978-84-393-7936-2.

Aprofitament de fangs de depuradora en la restauració de pedreres. In: A. Freixes (editor). Volum de ponències de les III Jornades Tècniques de Gestió de Sistemes de Sanejament d’Aigües Residuals: tractament i valorització de fangs.

Alcañiz JM, Carabassa V, Ortiz O (2008) Aprofitament de fangs de depuradora en la restauració de pedreres. In: A. Freixes (editor). Volum de ponències de les III Jornades Tècniques de Gestió de Sistemes de Sanejament d’Aigües Residuals: tractament i valorització de fangs. Agència Catalana de l’Aigua, 664 p. pp: 315 – 326 B-39458-2008.

Toxic effects of digested, composted and thermally-dried sewage sludge on three plants

Ramírez W.A., Domene X., Ortiz O., Alcañiz J.M. (2008) Toxic effects of digested, composted and thermally-dried sewage sludge on three plants. Bioresource Technology. 99: 7168-7175.
Enllaç
Doi: 10.1016/j.biortech.2007.12.072

Resum:

In order to evaluate potential toxic effects of stabilized sewage sludge that are currently applied to agricultural soils, three types of municipal sewage sludge and one pig slurry were subjected to phytotoxicity assays using three plants (Brassica rapa, Lolium perenne and Trifolium pratense). Equivalent batches of aerobically and anaerobically-digested sludge (F) from two municipal wastewater treatment plants, were composted (C) or thermally dried (T). In addition, one anaerobically-digested and thermally-dried pig slurry (P) was tested. A seedling growth test was performed in accordance with the OECD Guideline 208A, using seed emergence and shoot length as endpoints to identify the inhibition of plants growing in increasing doses of sludge. A correlation analysis between EC50 and physico-chemical parameters or the pollutant burden of the biosolids was also calculated. In all tests, lower germination rates were observed for T. pratense than for L. perenne and B. rapa. A moderate stimulatory effect on shoot length at low doses was observed for the three plants. In these wastes, a strong positive correlation was found between higher values of EC50 (less toxicity) and the stability degree of their organic matter, and a negative correlation between EC50 and total N, hydrolysable N or NH4-N content. No correlations were found with heavy metal or organic pollutant content in those wastes. Results indicate that digested sludge, thermally-dried sludge and thermally-dried pig slurry have non-negligible short term phytotoxic effects, and confirm that composting is an effective sludge treatment for the reduction of phytotoxicity. © 2008 Elsevier Ltd. All rights reserved.

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Differences on nitrogen availability in a soil amended with fresh, composted and thermally-dried sewage sludge

Tarrasón D., Ojeda G., Ortiz O., Alcañiz J.M. (2008) Differences on nitrogen availability in a soil amended with fresh, composted and thermally-dried sewage sludge. Bioresource Technology. 99: 252-259.
Enllaç
Doi: 10.1016/j.biortech.2006.12.023

Resum:

Anaerobically-digested sludge called fresh sludge (F), composted sludge (C) and thermally-drying sludge (T), all from the same batch, were applied to the surface of a calcareous Udic Calciustept with loamy texture. Dosage equivalent was 10 t ha-1 of dry matter. The concentration of mineral nitrogen (ammonium and nitrate) in the soil was measured in order to estimate the effects of the post-treatments to which the different kinds of sewage sludge are subjected in relation to the availability of N in the surface layer of the soil. The most significant differences in NH4-N and NO3-N concentrations due to the transformation of the organic matter were observed during the first three weeks following soil amendment. Thermally-dried and composted sludge initially displayed higher concentrations of ammonium and nitrate in soil. Five months after the amendment, soil applied with fresh sludge showed the highest concentrations of NH4-N and NO3-N (6.1 and 36.6 mg kg-1, respectively). It is clear that the processes of composting and thermal-drying influence the bioavailability of nitrogen from the different types of sewage sludge. © 2007 Elsevier Ltd. All rights reserved.

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