Improvement of the quality of sewage sludge compost by adding natural clinoptilolite

• Published in: Desalination Vol. 224; no. 1; pp. 240 - 249
• Main Authors: Stylianou, M.A., Inglezakis, V.J., Moustakas, K.G., Loizidou, M.D.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 15-04-2008; Elsevier
• Subjects: Applied sciences; Biological and medical sciences; Biotechnology; Chemical engineering; Clinoptilolite; Composting; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Heavy metals; Ion exchange; Methods. Procedures. Technologies; Other industrial wastes. Sewage sludge; Others; Pollution; Reactors; Sludge; Various methods and equipments; Wastes; Clinoptilolite; Composting; Sludge; Heavy metals; Cation exchange; Compost; Organic matter; Adsorption capacity; Zeolite; Sewage sludge; Uptake; Heavy metal; Bioreactor; Phytotoxicity; pH; Ion exchange
• ISSN: 0011-9164; 1873-4464
• DOI: 10.1016/j.desal.2007.06.009

Zeolites are naturally occurring minerals characterized by high cation exchange and adsorption capacity and, thus, are used for metal uptake from sewage sludge subjected to composting process. In the present paper, changes in the physicochemical characteristics of sewage sludge samples after composting were recorded and analysed. The composting process was carried out for 120 days in pilot bioreactors, which were filled with 20% w/w clinoptilolite and sludge. The experimental results indicated differences in the metal content of the initial sludge and essential changes in pH, %C
org, % organic matter (OM), %N values and heavy metals content. Furthermore, the phytotoxicity tests that were performed showed that sludge samples affected seed germination and root elongation, but no phytotoxic effects were observed. According to the experimental results, it is concluded that the use of natural clinoptilolite leads to the improvement of the quality of the composted sewage sludge.