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: The experiment revealed that the N mineralisation rate and emissions of CO2 and N2O decreased as a function of treatment time in the STRBs, revealing that combining fresh and more stabilised sludge residue ensures high N availability and reduces N2 O emissions when applied to land.
8 citations
TL;DR: In this paper, the feasibility of carbonized solid fuel (CSF) production from abundant sewage sludge (SS) and digestate (D) via torrefaction was investigated.
Abstract: Sustainable solutions are needed to manage increased energy demand and waste generation Renewable energy production from abundant sewage sludge (SS) and digestate (D) from biogas is feasible Concerns about feedstock contamination (heavy metals, pharmaceuticals, antibiotics, and antibiotic-resistant bacteria) in SS and D limits the use (eg, agricultural) of these carbon-rich resources Low temperature thermal conversion that results in carbonized solid fuel (CSF) has been proposed as sustainable waste utilization The aim of the research was to investigate the feasibility of CSF production from SS and D via torrefaction The CSF was produced at 200~300 °C (interval of 20 °C) for 20~60 min (interval 20 min) The torrefaction kinetics and CSF fuel properties were determined Next, the differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) of SS and D torrefaction were used to build models of energy demand for torrefaction Finally, the evaluation of the energy balance of CSF production from SS and D was completed The results showed that torrefaction improved the D-derived CSF’s higher heating value (HHV) up to 11% (p < 005), whereas no significant HHV changes for SS were observed The torrefied D had the highest HHV of 20 MJ∙kg−1 under 300 °C and 30 min, (the curve fitted value from the measured time periods) compared to HHV = 18 MJ∙kg−1 for unprocessed D The torrefied SS had the highest HHV = 148 MJ∙kg−1 under 200 °C and 20 min, compared to HHV 146 MJ∙kg−1 for raw SS An unwanted result of the torrefaction was an increase in ash content in CSF, up to 40% and 22% for SS and D, respectively The developed model showed that the torrefaction of dry SS and D could be energetically self-sufficient Generating CSF with the highest HHV requires raw feedstock containing ~154 and 459 MJ∙kg−1 for SS and D, respectively (assuming that part of feedstock is a source of energy for the process) The results suggest that there is a potential to convert biogas D to CSF to provide renewable fuel for, eg, plants currently fed/co-fed with municipal solid waste
8 citations
Cites background from "Utilization of sewage sludge in EU ..."
...Large quantities of SS and D are still used in agriculture [14,15]....
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...Contaminated SS needs to be stabilized and then landfilled or incinerated [14], i....
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TL;DR: A comprehensive review of the recent literature shows that chemical pre-treatment of biosolids can concurrently achieve demineralization, heavy metals removal and hydrolysis, which add further value to the overall pyrolysis upcycling of the treated biosols as mentioned in this paper .
8 citations
TL;DR: In this article, quantitative data on sludge handling over the period 2014-2016 was gathered for Wastewater treatment plants (WWTPs) with a hydraulic capacity greater than 1000 m3/day.
Abstract: Sludge processing and biosolids management represent significant ongoing activities for the wastewater treatment industry. Historically, a substantial inventory of sludge processing technologies and operating practices have been developed within regions to manage sludges and produce products that meet disposition requirements. However, access to system-wide information on sludge handling practices that would be of interest to a variety of wastewater industry stakeholders is often not available. As an example, there is little system-wide information available on the types of sludge processing technologies employed and the quantity and quality of biosolids produced at wastewater treatment plants in Ontario. In the present study quantitative data on sludge handling over the period 2014–2016 was gathered for Wastewater treatment plants (WWTPs) with a hydraulic capacity greater than 1000 m3/day. The types of technologies employed were sorted by the design hydraulic capacity (DHC) of the WWTPs. Data on key biosolids properties (i.e. solids content, pathogen indicators, metals, nitrogen and phosphate) were sorted by WWTP DHC and related regulations. Drivers that are expected to impact biosolids handling practices in Ontario in the future are proposed and discussed in context of the current practices.
7 citations
TL;DR: In this paper , the authors propose a solution to tackle the plastic waste flood by closing the carbon loop through plastic reuse, mechanical and molecular recycling, carbon capture, and use of the greenhouse gas carbon dioxide.
Abstract: Today, plastics are ubiquitous in everyday life, problem solvers of modern technologies, and crucial for sustainable development. Yet the surge in global demand for plastics of the growing world population has triggered a tidal wave of plastic debris in the environment. Moving from a linear to a zero-waste and carbon-neutral circular plastic economy is vital for the future of the planet. Taming the plastic waste flood requires closing the carbon loop through plastic reuse, mechanical and molecular recycling, carbon capture, and use of the greenhouse gas carbon dioxide. In the quest for eco-friendly products, plastics do not need to be reinvented but tuned for reuse and recycling. Their full potential must be exploited regarding energy, resource, and eco efficiency, waste prevention, circular economy, climate change mitigation, and lowering environmental pollution. Biodegradation holds promise for composting and bio-feedstock recovery, but it is neither the Holy Grail of circular plastics economy nor a panacea for plastic littering. As an alternative to mechanical downcycling, molecular recycling enables both closed-loop recovery of virgin plastics and open-loop valorization, producing hydrogen, fuels, refinery feeds, lubricants, chemicals, and carbonaceous materials. Closing the carbon loop does not create a Perpetuum Mobile and requires renewable energy to achieve sustainability. This article is protected by copyright. All rights reserved.
7 citations
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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