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 2011
TL;DR: The wet pyrolysis process, also known as hydrothermal carbonization, opens up the field of potential feedstocks for char production to a range of nontraditional renewable and plentiful wet agricultural residues and municipal wastes as discussed by the authors.
Abstract: The carbonization of biomass residuals to char has strong potential to become an environmentally sound conversion process for the production of a wide variety of products. In addition to its traditional use for the production of charcoal and other energy vectors, pyrolysis can produce products for environmental, catalytic, electronic and agricultural applications. As an alternative to dry pyrolysis, the wet pyrolysis process, also known as hydrothermal carbonization, opens up the field of potential feedstocks for char production to a range of nontraditional renewable and plentiful wet agricultural residues and municipal wastes. Its chemistry offers huge potential to influence product characteristics on demand, and produce designer carbon materials. Future uses of these hydrochars may range from innovative materials to soil amelioration, nutrient conservation via intelligent waste stream management and the increase of carbon stock in degraded soils.
1,360 citations
TL;DR: In this paper, three strategies of CO2 reduction including energy saving, carbon separation and storage as well as utilizing alternative materials in detail have been reviewed and the barriers against worldwide deployment of such strategies are identified and comprehensively described.
903 citations
TL;DR: The main objective of the current study was to outline the current situation and discuss future perspectives for sludge treatment and disposal in EU countries, where sludge reuse in land and sludge incineration seem to be the main practices further adopted in EU-27 (all Member States up to 2020.
853 citations
TL;DR: The high microplastic enrichment in marine sediments compared to most literature data for seawater at the surface supports the hypothesis of a seabed sink for these materials.
710 citations
TL;DR: An updated review on two subjects: the available alternatives to produce biochar from a biomass feedstock and the effect of biochar addition to agricultural soils on soil properties and fertility is provided.
Abstract: According to the International Biochar Initiative (IBI), biochar is a charcoal which can be applied to soil for both agricultural and environmental gains. Biochar technology seems to have a very promising future. Nevertheless, the further development of this technology requires continuing research. The present paper provides an updated review on two subjects: the available alternatives to produce biochar from a biomass feedstock and the effect of biochar addition to agricultural soils on soil properties and fertility. A high number of previous studies have highlighted the benefit of using biochar in terms of mitigating global warning (through carbon sequestration) and as a strategy to manage soil processes and functions. Nevertheless, the relationship between biochar properties (mainly physical properties and chemical functionalities on surface) and its applicability as a soil amendment is still unclear and does not allow the establishment of the appropriate process conditions to produce a biochar with de...
631 citations
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TL;DR: In this paper, the pyrolysis of two types of polyethylenes with different degrees of branching was performed in a continuous fluidized bed reactor with an inert sand bed and in a pyroprobe 1000, where secondary wax and tar cracking is small.
42 citations
TL;DR: In this article, the heavy metal extractability of chemically-fixed sewage sludge was studied using sequential extraction and single extraction, and the results of single extraction conducted at various pH suggested that this effect was attributed to the irreversible dissolution of the metals (e.g. Cu) having higher affinity to organics at very high pH (10.64-12.05).
39 citations
"Utilization of sewage sludge in EU ..." refers background or methods in this paper
...Hsiau and Lo [9] investigated the extractabilities of heavy metals in chemically fixed sewage sludge, including lime-treated sludge (CS), lime–sodium silicate-treated sludge (LSS), cement-treated sludge (CS) and cement–sodium silicate-treated sludge (CSS), using sequential extraction and single extraction....
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...Typical metal concentrations are indicated in Table 2 [1,9]....
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...Sources: [1,9]....
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...Because of the physical–chemical processes that are involved in activated wastewater sludge treatment, sludge tends to accumulate heavy metals existing in the wastewater [9]....
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...Heavy metals such as zinc (Zn), copper (Cu), nickel (Ni), cadmium (Cd), lead (Pb), mercury (Hg) and chromium (Cr) are principal elements restricting the use of sludge for agricultural purposes [9]....
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TL;DR: In this article, a review of the current sludge technologies and likely future trends associated with those technologies is presented, and the role of thickening, dewatering, pasteurization, stabilization, thermal destruction and product enhancement is discussed.
Abstract: This paper reviews the current sludge technologies and discusses likely future trends associated with those technologies. It describes the role of thickening, dewatering, pasteurization, stabilization, thermal destruction and product enhancement to satisfy environmental standards. Reference is made to technologies which, for decades, have been associated with sewage sludge but where market conditions have forced R and D initiatives to be introduced and commercialized.
35 citations
"Utilization of sewage sludge in EU ..." refers background in this paper
...The development of sludge recycling, in agriculture, collates, in a grade degree, with the possibilities to improve the quality of sludge itself and make the public confident in the above issue [19]....
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TL;DR: A parametric study of NOitx emissions has been carried out on a 150 mm2 × 7.3 m tall pilot scale fluidized bed combustor with coals of various ranks, including anthracite, bituminous, subbituminous and lignite, as well as one petroleum coke as mentioned in this paper.
34 citations
TL;DR: In this article, the authors compared the primary decomposition and the tar cracking of some wastes and discussed the influence of heat transfer in the Pyroprobe and the fluidized bed reactor, where the heating rate was very high and the samples decompose during the heating period.
27 citations
"Utilization of sewage sludge in EU ..." refers background in this paper
...(1995) [35] claim that thermogravimetric analysis (TGA) is capable of providing pyrolysis kinetic data of sludge at selected temperatures....
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