Papers by Keyword: Sewage Sludge Ash

Abstract: The cement production process significantly contributes to greenhouse gas emissions, accounting for 25% of total industrial emissions. This study systematically examined new, underutilized materials—sewage sludge ash (SSA), marble waste (MW), and calcined clay (CC)—to evaluate their effects when partially replacing white Portland cement (WPC) in cement paste formulations. Various replacement proportions (10%, 20%, and 30%) were tested, along with different treatment temperatures (600°C, 630°C, 730°C, and 850°C) for SSA and CC. To gain a deeper understanding of the resulting materials, analyses such as XRF, XRD, and SEM were conducted. The highest compressive strength recorded for the 28-day cured cement paste was 91 MPa when 20% SSA (treated at 600°C) was used, compared to just 53 MPa for the control sample. Conversely, CC exhibited minimal enhancement in compressive strength, while MW had detrimental effects. Additionally, replacing WPC with SSA and CC at 9% and 21% resulted in slight improvements in compressive strength. This research highlights the potential of utilizing underexploited materials like SSA to improve the mechanical and chemical properties of cement paste, indicating that further investigation is necessary to enhance environmental sustainability.

Abstract: The utilization of Sewage Sludge Ash Pellets (SSAP) as an efficient sorbent material for dye removal is highlighted in this work. On MB removal, the effects of several factors such as contact time, agitation speed, solution pH, adsorbent dosage, and beginning concentration were investigated. When the MB concentration was 25 mg/L, the SSAP concentration was 30 g/L, and the speed was 250 rpm, the maximum removal efficiency was 98 %. The equilibrium time was found to be 60 minutes, and the maximum dye removal occurred at pH 10 for SSAP adsorbents. The Langmuir and Freundlich isotherm models were used to analyze the adsorption data. Adsorption isotherm studies revealed that the Langmuir model fits this case better. In most cases, the R² correlation coefficient value exceeds 0.95. According to the findings of this study, SSAP can be used as an effective adsorbent for the removal of MB from aqueous solutions.

Abstract: This work evaluates mortars using sewage sludge calcined at temperatures of 600°C and 700°C as a hydraulic binder replacing the cement. The percentages incorporated by mass to replace the Portland cement were 10%, 20% and 30%, using the 1:3:0,60 (cement: sand: factor a/c) trace. Sludge ash was characterized and tensile strength at flexion as well as tensile strength (pullout test) were evaluated. As a way of performing a comparison with conventional mortars, the same tests were carried out using reference mortar. The results of the flexural tensile strength tests indicated that results were higher than the reference traces of the mortars with the calcined sludge at a temperature of 700°C, a factor related to the increase of the calcination temperature and the incorporated percentage. With respect to the tests on the determination of tensile strength, it was observed that the specimens submitted to the test suffered rupture in the mortar, and that the calcination temperature of the sewage sludge was not influenced. The results obtained with the mortars using sewage sludge ash with partial replacement of the cement are shown within the normative standards and approximate to the results obtained with the tests executed with the reference mortar.

Abstract: The production of sewage sludge from waste water treatment plants is increasing all over the world. Disposal of sewage sludge ash is a serious environmental problem. If we think of the areas needed for sludge ash disposal, we clearly understand the importance of reusing sewage sludge ash in concrete. This paper presents results related to the replacement of sand by sewage sludge ash. The sludge was characterized for chemical composition (XRF analysis), crystalline phases (XRD analysis) and pozzolanic activity. The effects of incineration on crystal phases of dry sludge were investigated. Two (W/C) ratios (0.55 and 0.45) and three sludge percentages (5%, 10% and 20%) by cement mass were used. The mechanical performance of SSAC at different curing ages (3, 7, 28 and 90 days) was assessed by means of mechanical tests. Results show that sewage sludge ash leads to a reduction in density and mechanical strength. Results also show that concrete with 20% of sewage sludge ash and W/C=0.45 has a 28 day compressive strength of almost 30MPa.

Abstract: Nowadays, with increase amounts of sludge derived from the treatment of domestic sewage put pressure into research on systems for the adequate use of these materials. The aim of the present work is to study the use of sludge ash, from sintering and calcinated process, as a raw material for the ceramic industry. Using the sewage sludge ashes as ceramic raw material there will be no contamination of soil and underground water. Metals and toxic compounds like Al, Fe, Ba, Cr, Cu, Mn and Zn oxides were analyzed and characterized by X-ray fluorescence (XRF), scanning electron microscopy (SEM) and plasma emission spectroscopy (ICP-OES). The leached material was chemically analyzed where the integration of oxides into the ceramic matrix of sludge ash was observed. Residual decomposition was analyzed by TG, DTG and DTA curves.

Abstract: As a basic stage for developing new construction material utilizing sewage sludge ash, this study is identified by specific material characteristics through XRD, SEM, uniaxial compressive strength, porosity, and the drying shrinkage by manufacturing mortar with sewage sludge ash. The average drying shrinkage of sewage sludge ash mortar aged 7 days showed 88% of the strain of the one aged 28 days. The porosity of sewage sludge ash mortar was about 7~10%. The more quick lime and blast furnace slag were added, the less porosity appeared.