Dried Sludges and Sludge-Based Chars for H2S Removal at Low Temperature: Influence of Sewage Sludge Characteristics

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• 作者：Anna Ros ; Miguel A. Montes-Moran ; Enrique Fuente ; Daniela M. Nevskaia ; and Maria J. Martin
• 刊名：Environmental Science & Technology
• 出版年：2006
• 出版时间：January 1, 2006
• 年：2006
• 卷：40
• 期：1
• 页码：302 - 309
• 全文大小：386K
• 年卷期：v.40,no.1(January 1, 2006)
• ISSN：1520-5851

文摘

The use of sewage sludge as a precursor of adsorbent/catalyst materials for environmental applications has beenencouraged during the past few years. Due to theheterogeneous nature of sludges, there exists a lack ofinformation regarding the characteristics of these low-costprecursors and how their physicochemical propertiesaffect the final performance of materials prepared fromthem. In this work, three sewage-sludges collected at WWTPswith assorted sludge/wastewater treatment schemeswere used as precursors of adsorbents/catalysts for H₂Sremoval at room temperature. All the solids were characterizedto establish their textural properties and chemicalcomposition, including the speciation of the adsorbents/catalysts inorganic fraction. Thermal treatment (gasification)of the raw (dried) sludges increased the H₂S removalability in all cases. For these thermally treated materials,catalytic conversion to elemental sulfur and sulfate moietieswas found to be the main route of H₂S removal. Resultsindicate that adsorbents based on an iron/calcium-containingsludge were the most reactive and exhibited the highestcapacities for H₂S retention. For this particular type of sludge,a reasonably good performance was observed evenwhen the dried (raw) sludge was used as adsorbent/catalyst. Alternatively, the oxidation of H₂S by chars obtainedfrom the other two sludges under study was related totheir textural properties.