scholarly journals Fly Ash from Thermal Conversion of Sludge as a Cement Substitute in Concrete Manufacturing

2021 ◽  
Vol 13 (8) ◽  
pp. 4182
Author(s):  
Gabriela Rutkowska ◽  
Marek Chalecki ◽  
Mariusz Żółtowski

Striving for reduction of production costs and constraints on natural resources cause the use of waste materials as substitutes of traditional raw materials to become increasingly important. Dynamic development of sewerage systems and sewage treatment plants observed over the recent years leads to increase of mass of the produced sewage sludge. According to the Waste Law, the municipal sewage sludge can be used if it is properly stabilized, e.g., through thermal processing. This process results in significant quantities of fly ash which must be properly utilized. The paper presents results of investigations of influence of partial replacement of cement by the fly ash from sewage sludge on concrete parameters. It was designed as a C20/25 class concrete mix, based on the Portland cement CEM I 42.5R with various ash content. Physical and chemical properties of the ash as well as frost resistance and the compressive strength of the concrete after 28, 56 and 365 days of curing were investigated. The obtained results of investigations confirm the possibility of application of fly ash wastes as a cement substitute in the concrete manufacturing. If a predefined quantity of cement is replaced by the fly ash, then one can obtain cement composite with good strength parameters.

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5039
Author(s):  
Gabriela Rutkowska ◽  
Mariusz Żółtowski ◽  
Michał Liss

Production cost reduction and constraints on natural resources cause the use of waste materials as substitutes of traditional raw materials to become increasingly important. The dynamic development of sewerage systems and sewage treatment plants leads to increases in the produced sewage sludge. According to the Waste Law, municipal sewage sludge can be used if it is properly stabilized. This process results in significant quantities of fly ash that must be utilized. This paper presents investigation results of partial cement replacement influence by the fly ash from sewage sludge on concrete parameters. The results confirm the possibility of fly ash waste applications as a cement substitute in concrete manufacturing. In the later parts of the publication, a pilot study was conducted using the modal analysis methodology and aimed at checking the hypothesis of whether vibration methods can be used in the assessment of the amount of the admixture used in concrete and the effect it has on concrete properties. This is the first time that vibration tests have been used to determine the diversity of the concrete mix composition and to distinguish the percentage of ash added. There are no studies using modal analysis to distinguish the composition of a concrete mix in the scientific literature. The article shows that the vibration test results show the differentiation of concrete composition and can be further improved as a method for determining the composition of mixtures and for distinguishing their mechanical properties. These are only pilot studies, which, in order to develop the target cognitive inference, should be performed in the future on a significantly enlarged number of the studied samples.


Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 487 ◽  
Author(s):  
Gabriela Rutkowska ◽  
Piotr Wichowski ◽  
Małgorzata Franus ◽  
Michał Mendryk ◽  
Joanna Fronczyk

This article focuses on the impact of fly ash from the combustion of municipal sewage sludge (FAMSS) as a cement additive in the amounts of 5%, 10%, 15%, 20% and 25% (by mass) on selected concrete properties. In the course of the experimental work, water penetration depth and compressive strength measurements were made at various periods of curing (from 2 to 365 days). In addition, the potential impact of FAMSS on the natural environment was examined by determining the leachability of heavy metals. FAMSS-modified concretes showed small values of water penetration depth (lower than 50 mm), as well as good compressive strength (reaching minimum class C30/37 after 130 days of maturing)—similar to the compressive strength obtained for conventional concrete. In addition, the partial replacement of cement with FAMSS has environmental benefits, expressed as a reduction in CO2 emissions. In addition, study has shown that compliance with environmental requirements is associated with heavy metal leaching.


2016 ◽  
Vol 63 (1) ◽  
pp. 47-61 ◽  
Author(s):  
Paweł Falacinski ◽  
Łukasz Szarek

Abstract In Poland, in recent years, there has been a rapid accumulation of sewage sludge - a by-product in the treatment of urban wastewater. This has come about as a result of infrastructure renewal, specifically, the construction of modern sewage treatment plants. The more stringent regulations and strategic goals adopted for modern sewage management have necessitated the application of modern engineering methodology for the disposal of sewage sludge. One approach is incineration. As a consequence, the amount of fly ash resulting from the thermal treatment of municipal sewage sludge has grown significantly. Hence, intensive work is in progress for environmentally safe management of this type of waste. The aim of the experiment was to evaluate the possibility of using the fly ash that results from municipal sewage sludge thermal treatment (SSTT) as an additive to hardening slurries. This type of hardening slurry with various types of additives, e.g. coal combustion products, is used in the construction of cut-off walls in hydraulic structures. The article presents the technological and functional parameters of hardening slurries with an addition of fly ash obtained by SSTT. Moreover, the usefulness of these slurries is analysed on the basis of their basic properties, i.e. density, contractual viscosity, water separation, structural strength, volumetric density, hydraulic conductivity, compressive and tensile strength. The mandated requirements for slurries employed in the construction of cut-off walls in flood embankments are listed as a usefulness criteria. The article presents the potential uses of fly ash from SSTT in hardening slurry technology. It also suggests directions for further research to fully identify other potential uses of this by-product in this field.


2019 ◽  
Vol 26 (3) ◽  
pp. 583-595 ◽  
Author(s):  
Jacek Antonkiewicz ◽  
Andrzej Kuc ◽  
Robert Witkowicz ◽  
Monika Tabak

Abstract Municipal sewage sludge from rural sewage treatment plants is characterized by a substantial content of organic matter and macronutrients, which can be used in cultivation of cereals. In a farm located in the commune of Iwanowice in the south of Poland (Malopolska province), municipal sewage sludge was applied under spring wheat cultivation. The experiment was set up on heavy soil with slightly acid reaction and medium content of available forms of P, K, Mg. Application of sewage sludge in a dose of 23 Mg fresh matter per hectare (4.21 Mg d.m.) led to no significant changes in chemical properties of the soil. Application of sewage sludge significantly increased yield of spring wheat. That increase led to a significant decrease in the content of N, P, K, Na, Mg and Ca in spring wheat. Utilization of N, Mg, K, P and Ca from sewage sludge by spring wheat was at a level of 82, 63, 44, 36, 9 %, respectively, of the amount introduced with the waste. Application of municipal sewage sludge significantly decreased the value of Ca : P ratio in spring wheat grain and straw. The sewage sludge did not cause a significant change in the values of Ca : Mg, K : Na, K : (Ca+Mg), K : Mg and K : Ca ratios in spring wheat grain and straw. Municipal sewage sludge can be used environmentally, including for fertilization of cereals, provided that environmental standards are kept.


2018 ◽  
Vol 64 (3) ◽  
pp. 131-144 ◽  
Author(s):  
Łukasz Szarek ◽  
Paweł Falaciński ◽  
Małgorzata Wojtkowska

AbstractThe growing number of municipal sewage treatment plants in Poland raises the problem of managing more and more sludge. The thermal treatment of municipal sewage sludge (TTMSS), which significantly reduces the volume of waste, results in an increase in the concentration of heavy metals in the fly ashes – the final products of the process. The search for methods of utilization of fly ash from TTMSS resulted in attempts to use it in hardening slurries widely used in hydro-engineering. Due to the nature of the application of this material in the cut-off walls (exposure to groundwater flow) one of the key issues is the degree of heavy metal immobilization. The paper attempted to determine the degree of leaching of selected heavy metals from the hardened hardening slurry, composed of fly ash from TTMSS. For this purpose, the eluates were prepared from samples, after various periods of curing, using a dynamic short-term method called “Batch test”. The liquid used for leaching was: distilled water and 0.1 molar EDTA solution – to determine the amount of potentially mobile heavy metal forms. The results show the possibility of the safe usage of fly ash from TTMSS as an additive for hardening slurries.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3106
Author(s):  
Tomasz Kalak ◽  
Kinga Marciszewicz ◽  
Joanna Piepiórka-Stepuk

Recently, more and more attention has been paid to the removal of nickel ions due to their negative effects on the environment and human health. In this research, fly ash obtained as a result of incineration of municipal sewage sludge with the use of circulating fluidized bed combustion (CFBC) technology was used to analyze the possibility of removing Ni(II) ions in adsorption processes. The properties of the material were determined using analytical methods, such as SEM-EDS, XRD, BET, BJH, thermogravimetry, zeta potential, SEM, and FT-IR. Several factors were analyzed, such as adsorbent dose, initial pH, initial concentration, and contact time. As a result of the conducted research, the maximum sorption efficiency was obtained at the level of 99.9%. The kinetics analysis and isotherms showed that the pseudo-second order equation model and the Freundlich isotherm model best suited this process. In conclusion, sewage sludge fly ash may be a suitable material for the effective removal of nickel from wastewater and the improvement of water quality. This research is in line with current trends in the concepts of circular economy and sustainable development.


2011 ◽  
Vol 383-390 ◽  
pp. 3799-3804
Author(s):  
Xiao Xu Fan ◽  
Lei Zhe Chu ◽  
Li Guo Yang

The fuel characteristics of municipal sewage sludge are suitable for dual fluidized bed(DFB) gasification, which can get middle calorific value gas through volatile pyrolysis, and reduce volume through char combustion. The hot test results of municipal sewage sludge on DFB rig were showen that the temperature distribution along combustor heigh is uniform, and the carbon content of fly ash is about 2~3%. In the experiment, with the increase of gasifier temperatrue, the more volatile of the sewage sludge was pyrolyzed. When the temperature of the gasifier reached 800°C, the calorific value of gas was 6.9MJ/Nm3; the emissions of SO2, NOx and HCl were appropriate to the standard. The leaching toxicity of heavy metal of the fly ash was lower than the discharge standard.


2013 ◽  
Vol 671-674 ◽  
pp. 2736-2741
Author(s):  
Yin An Ming ◽  
Tao Tao

To reuse municipal sewage sludge safely, experiment was carried out on grapefruit trees fertilized with composted sludge from Shiweitou Sewage Treatment Plant in Xiamen City of China, and a method was introduced of how to assess the environmental quality of grapefruit trees soil fertilized with sludge by Set Pair Analysis (SPA) model. The results showed that the soil in the surface layer (0-15cm) and the deeper layer (15-30cm) was less clean, and the environment of soil was not polluted. Thus it was feasible to use sludge as fruit fertilizer. The maximum service life of sludge for continuous land application was estimated by taking Cd as the limiting factor, which would provide scientific guide and technical support for safe land application of sludge.


2012 ◽  
Vol 209-211 ◽  
pp. 1245-1252
Author(s):  
Zheng Zhong Zeng ◽  
Xiao Li Wang ◽  
Yu Pan ◽  
Zhong Ren Nan

The land use has become the international mainstream and the favorable direction to dispose the municipal sewage sludge in recent years. The heavy metals, however, are the major barrier that limit the land utilization. Batch aerobic composting experiments were conducted to investigate the effect of composting and co-composting with fly ash on the shape of the heavy metals (Ni & Cd) in sludge by using the sawdust to regulate the C/N ratio. Results have shown that co-composting with fly ash can significantly change Ni & Cd species distribution, leading unstable state content of Ni lower than composting only. However, the result is not as good as composting only in terms of Cd. At the same time the fly ash dosage equaling 14% of the dry sludge mass was the optimized quantity to guarantee the lowest exchangeable fraction amount of the two heavy metals.


2016 ◽  
Vol 22 (3) ◽  
pp. 157-166 ◽  
Author(s):  
Elżbieta Włodarczyk ◽  
Marta Próba ◽  
Lidia Wolny

Abstract Aim of this study was to evaluate the ecotoxicity of municipal sewage sludge conditioned with polyelectrolytes, taken from selected sewage treatment plant. Using the bioindication analysis overall toxicity was assessed, which allows to know the total toxicity of all the harmful substances contained in sewage sludge, in many cases acting synergistically. To prepare a sample of sludge for the basic test, all analyses were performed with a ratio of liquid to solid of 10:1 (water extract). Daphnia pulex biological screening test was used. A dilution series of an water extract of sludge were prepared to include within its scope the lowest concentration that causes 100% effect and the highest producing less than 10% of the effect within a specified range of the assay. The results of the test were read after 24 and 48 hours. Based on the research and analysis of test results it proved that the sewage sludge conditioned with polyelectrolytes exhibit the characteristics of eco-toxic.


Sign in / Sign up

Export Citation Format

Share Document