Utilization of sewage sludge in EU application of old and new methods—A review
TL;DR: In this article, the authors review past and future trends in sludge handling, focusing mainly at thermal processes (e.g. pyrolysis, wet oxidation, gasification) and the utilization of sewage sludge in cement manufacture as a co-fuel.
Abstract: The European Union has made progress in dealing with municipal wastewater in individual countries and as a corporate entity. However, it intends to make still further and substantial progress over the next 15 years. Currently, the most widely available options in the EU are the agriculture utilization, the waste disposal sites, the land reclamation and restoration, the incineration and other novel uses. The selection of an option on a local basis reflects local or national, cultural, historical, geographical, legal, political and economic circumstances. The degree of flexibility varies from country to country. In any case sludge treatment and disposal should always be considered as an integral part of treatment of wastewater. There is a wide range of other uses for sludge, which exploit its energy or chemical content, namely the thermal processes. The present paper sought to review past and future trends in sludge handling, focusing mainly at thermal processes (e.g. pyrolysis, wet oxidation, gasification) and the utilization of sewage sludge in cement manufacture as a co-fuel.
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TL;DR: In this article, the difference between hydrothermal carbonization and vapothermal carbonization for the densification of the energy content of biomass has been investigated systematically for the first time, and the experiments show that the process efficiency can be increased due to two reasons: the carbon losses in the liquid phase are decreased and less water needs to be heated up during carbonization.
87 citations
TL;DR: In this paper, a comprehensive investigation was conducted to use municipal sewage sludge (MSS) as a promising feedstock for bioenergy production via pyrolysis process using thermogravimetric analysis (TGA).
Abstract: In this study, a comprehensive investigation was conducted to use municipal sewage sludge (MSS) as a promising feedstock for bioenergy production via pyrolysis process. Using thermogravimetric analysis (TGA), MSS was subjected to thermal decomposition experiments at four different heating rates of 5, 10, 30 and 50 °C/min. TGA curves were divided into three distinctive stages, namely drying zone (T ≤ 200 °C), active pyrolysis zone (200 0.9999) and accurate results regarding different train-test data categories. Further employed was Pyrolysis–Gas Chromatography/Mass Spectroscopy (Py-GC/MS) at 700 °C to characterize the potential chemical products, which indicated the presence of a range of aromatic and aliphatic hydrocarbons, nitrogen-containing compounds, alcohol, furans and sulfur compounds. Finally, three alternative scenarios associated with the planned project were presented and techno-socio-economic assessment (TSEA) of the alternative scenarios were evaluated, for the first time, by means of economic indexes and considering social aspects. Net present value (NPV) of all alternative scenarios of the pyrolysis plant over the 20-year plant lifetime was positive compared to the base case, indicating that the project was feasible. Sensitivity analysis of the optimistic scenario showed that the profitability of pyrolysis plant was highly dependent on bio-oil selling price and total production cost.
87 citations
TL;DR: It was suggested that dewatered sludge could be reduced toxicity/risk before utilization by pyrolysis or liquefaction technology, especially for Cu and Zn in slaughterhouse sludge.
87 citations
TL;DR: In this paper, a life cycle assessment (LCA) was performed on five commonly applied sewage sludge treatment practices: dewatering of mixed sludge (DMS), lime stabilisation of dewatered sludge, anaerobic digestion (ADS) and incineration of dewatered anaerobically-digested sludge.
86 citations
Additional excerpts
...121 These five sludge treatment scenarios were chosen because they are typical management 122 options for centralised European municipal wastewatr treatment systems (Fytili and Zabaniotou, 2008)....
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TL;DR: In this paper, the effect of heating rates (10, 40, 70, and 100 °C/min) on the thermal behavior and biofuel properties of sewage sludge pyrolysis from room temperature to 1000 °C was investigated.
Abstract: Treatment of sewage sludge is a major environmental concern for society. One treatment option that converts wastes into valuable biofuels is pyrolysis. The aim of this study was to investigate the effect of heating rates (10, 40, 70, and 100 °C/min) on the thermal behavior and biofuel properties of sewage sludge pyrolysis from room temperature to 1000 °C. Thermogravimetric analysis indicated three main reaction zones in respective temperature ranges of 600 °C for the sewage sludge pyrolysis. The most intense mass loss rate took place at 210–600 °C, with a maximum value of 0.2 wt %/°C at around 330 °C. Increasing the heating rate resulted in shifting of the mass loss peaks to higher temperatures. Computer-aided thermal analysis was applied to identify the specific heat and reaction heats of sludge during heating. The endothermic reaction peaks at 150–300 °C and exothermic peaks at 500–600 °C shifted to higher temperatures when increasing the heating rate. Gas chromatography results show...
86 citations
References
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TL;DR: In this paper, an analytical procedure involving sequential chemicai extractions was developed for the partitioning of particulate trace metals (Cd, Co, Cu, Ni, Pb, Zn, Fe, and Mn) into five fractions: exchangeable, bound to carbonates, binding to Fe-Mn oxides and bound to organic matter.
Abstract: An analytical procedure involving sequential chemicai extractions has been developed for the partitioning of particulate trace metals (Cd, Co, Cu, Ni, Pb, Zn, Fe, and Mn) into five fractions: exchangeable, bound to carbonates, bound to Fe-Mn oxides, bound to organic matter, and residual. Experimental results obtained on replicate samples of fluvial bottom sediments demonstrate that the relative standard deviation of the sequential extraction procedure Is generally better than =10%. The accuracy, evaluated by comparing total trace metal concentrations with the sum of the five Individual fractions, proved to be satisfactory. Complementary measurements were performed on the Individual leachates, and on the residual sediments following each extraction, to evaluate the selectivity of the various reagents toward specific geochemical phases. An application of the proposed method to river sediments is described, and the resulting trace metal speciation is discussed.
10,518 citations
"Utilization of sewage sludge in EU ..." refers background in this paper
...Over the last decades, a great variety of extraction schemes, both simple and sequential have been developed and, although some methods have been widely used [12,13] none has been unreservedly accepted by the scientific community....
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Book•
01 Jan 1972
TL;DR: Wastewater Engineering: An Overview of Wastewater Engineering, Methods and Implementation Considerations as mentioned in this paper is a good starting point for a discussion of the issues of wastewater engineering. But, it is not a complete survey of the entire literature.
Abstract: Wastewater Engineering: An Overview. Wastewater Flowrates. Wastewater Characteristics. Wastewater Treatment Objective, Methods, and Implementation Considerations. Introduction to Wastewater Treatment Plant Design. Physical Unit Operations. Chemical Unit Processes. Biological Unit Processes. Design of Facilities for Physical and Chemical Treatment of Wastewater. Design of Facilities for the Biological Treatment of Wastewater. Advanced Wastewater Treatment. Design of Facilities for the Treatment and Disposal of Sludge. Natural-Treatment Systems. Small Wastewater Treatment Systems. Management of Wastewater from Combined Sewers. Wastewater Reclamation and Reuse.
3,826 citations
TL;DR: In this article, a review of the current and future issues related to the combustion of sewage sludge is presented, and a number of technologies for thermal processing of sludge are discussed in three groups, i.e., mono-combustion, cocombustions and alternative processes.
1,026 citations
"Utilization of sewage sludge in EU ..." refers background in this paper
...Multiple hearth and fluidized bed furnaces are the most popular and the latter is becoming widely applied [24]....
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...Analysis has shown that about 78–98% of Cd, Cr, Cu, Ni, Pb and Zn present in the sewage sludge are retained in the ash, whereas up to 98% of the Hg may be released into the atmosphere with the flue gas [24]....
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...The whole process is occurring in two distinctive regimes [24]:...
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TL;DR: In this article, the authors proposed a standardization with respect to grain size effects, commonly achieved by analyzing the sieve fraction <63μm, which is used to pin point major sources of metal pollution and to estimate the toxicity potential of dredged materials.
Abstract: Sediment analyses are used to pin‐point major sources of metal pollution and to estimate the toxicity potential of dredged materials on agricultural land. For source assessments (Part I of the present review) standardization is needed with respect to grain size effects, commonly achieved by analyzing the sieve fraction <63μm. Further aspects include sampling methods, evaluation of background data and extent of anthropogenic metal enrichment.
530 citations