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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01 Jan 2014
TL;DR: In this paper, the mass and energy flows through core municipal wastewater treatment plant (WWTP) subprocesses were analyzed and two configurations for sludge-handling were proposed: incineration and gasification.
Abstract: Municipal wastewater treatment and associated sludge handling is an essential process for modern society and contributes to both human and environmental health. However, it is energy intensive. There has been a focus on cleaning efficiency in the subprocesses, e.g. activated sludge treatment; however, a holistic approach that reviews different system setups in detail is lacking. The aim of this project is to analyze the mass and energy flows through core municipal wastewater treatment plant (WWTP) subprocesses and propose holistic measures to improve the total efficiency. Two configurations for sludge-handling are proposed: incineration and gasification; additionally, detailed models of the mass and energy flows in/out of each subprocess are created. Unit processes such as a heat pump, heat exchangers, and combined heat and power plants are incorporated into each model configuration to maximize the energy efficiency. The result is that the gasification option is self-sufficient in heat and saves over half of the electricity needs. The incineration option is also self-sufficient in heat but still requires significant electricity. Both options contain inspiring characteristics for the future generation of WWTPs.
2 citations
TL;DR: In this article, a processo de higienizacao termica de lodo de esgoto using irradiacao solar media was evaluated in 16 ensaios experimentais.
Abstract: O uso de lodo de esgoto na agricultura se tornou pratica corrente em diversos paises, sendo atrativa em muitos aspectos, principalmente no fornecimento de materia orgânica e nutrientes ao solo. Embora os beneficios ambientais e agricolas do uso de lodo sejam consideraveis, tal pratica deve ser realizada de forma sanitariamente segura. Neste contexto, o objetivo deste estudo foi avaliar a eficiencia de um processo de higienizacao termica de lodo de esgoto utilizando energia solar. O lodo era aquecido atraves de um trocador de calor, construido com tubos de cobre e instalado dentro do reator, onde circula agua aquecida em coletores solares planos. Foram realizados 16 ensaios experimentais em diferentes condicoes de irradiacao solar. A inativacao termica da Escherichia coli foi avaliada atraves do modelo cinetico de primeira ordem em condicoes nao isotermicas. O processo mostrou-se eficiente em ensaios realizados com irradiacao solar media do periodo acima de 500 W.h.m -2 , com reducao de E. coli entre 4,2 e 7,1 log 10 e de coliformes totais entre 4,8 e 7,4 log 10 . Os ensaios realizados em dias com menores indices de irradiacao solar tiveram a eficiencia de higienizacao comprometida, devido as baixas temperaturas atingidas pelo lodo.
2 citations
21 Jun 2016
TL;DR: This research presents an identification model related to a sewage sludge incineration process based on subspace N4SID algorithms and a mathematical model has been developed and simulation output data were compared with real incineration measurement.
Abstract: Regarding the new standards and environmental legislation, the research area of automatic bioprocesses is in sharp increase. This aims at improving performance of biological treatment processes. Facing the growth of urban wastewater treatment plants and toxic quality of sewage sludge, the incineration represents one of the potential methods that manage the large amount of generated sludge and reduce toxicity. In this goal, the daily operating cycle treatment and the implementation mechanisms have increased the need to take measures in order to analyse and control the effluents incineration variables. In this research, we present an identification model related to a sewage sludge incineration process based on subspace N4SID algorithms. As a result, a mathematical model has been developed and simulation output data were compared with real incineration measurement.
2 citations
Cites background from "Utilization of sewage sludge in EU ..."
...The treatment of sewage sludge is one of the most important challenges in waste-water management [4] especially in the context of disposal and recycling of sludge....
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TL;DR: Sludge aggregates-particles produced under exposure to minimal doses of PIX and the Al electro-coagulant were characterized by the lowest SpS values, and the lowest PIX dose produced the least uniform particles.
2 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