Percorrer por autor "Pietrobelli, Juliana"
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- Eco-friendly cement mortar with wastewater treatment plant sludge upcyclingPublication . Grabowski, Thais; Pietrobelli, Juliana; Martins, RamiroThis study aimed to investigate the technical feasibility of replacing cement in mortar production with sludge generated in wastewater treatment plants (WWTPs), prepared using different treatments. The sludge used in the experiments was processed using four different methods to investigate the effect of processing on the mechanical strength of the specimens. The sludge was then mixed with mortar in different proportions, and samples were produced for flexural and compressive strength tests. The results showed that specimens with 7% sludge from the burned treatment exhibited the highest resistance, surpassing the standard. Specimens with sludge from the drying treatments showed similar results. This study found that using sludge in mortar production could lead to energy savings compared to traditional cement production methods. Moreover, the incorporation of sludge resulted in mortars that met the specifications of the EN 998-1:2018 standard, thereby indicating their technical feasibility. Therefore, this study demonstrated the potential of using sludge from WWTPs as a substitute for cement in mortar production, which could contribute to the reduction in the environmental impacts caused by civil construction and the development of sustainable alternatives for the disposal of sludge generated in WWTPs.
- Mining waste as an eco-friendly adsorbent in the removal of industrial basazol 5G dye and incorporation in mortarsPublication . Hawerroth, Mariane; Pereira, Eduardo; Almeida, Lariana; Martins, Ramiro; Pietrobelli, JulianaThe circular economy seeks to better use materials and minimize waste generation. This article evaluated the use of granite rock powder, a mining residue, as an adsorbent for the Basazol Yellow 5G (BY5G) dye and the reuse of the residue generated by the by treating this effluent in construction products. Characterization of the adsorbent material by N2 physisorption indicated a surface area of 1514 m2 g1. Energy-dispersive spectrometry (EDS) and X-ray diffraction (XRD) confirmed the presence of silica in the sample and the absence of amorphous halos. The kinetic study showed a removal of approximately 98% at 298 K, and the pseudo-second-order model obtained the best fit. The adsorption isotherm satisfied the Langmuir model and was consistent with the L-type isotherm. The negative value of the Gibbs energy (DG ) and the positive value of the enthalpy (DH ) indicate that the process is spontaneous and endothermic. The activation energy (Ea) indicates the occurrence of chemical adsorption. The desorption rate was low for the adsorbate, demonstrating the possibility of using residual adsorbent material as a filler in mortar and concrete. The material did not exhibit pozzolanic characteristics and, even after adsorption, it showed favorable results when replacing 10% of the cement with GRP viable for use in civil construction even after the adsorption process
- Toward greener mortars with wastewater sludge as cement replacementPublication . Martins, Ramiro; Pietrobelli, JulianaThe cement industry significantly impacts environmental issues, leading to growing demand and research into developing alternatives that result in more environmentally friendly building materials. This research investigates the potential of using sludge from the Bragança Wastewater Treatment Plant (WWTP) as a partial substitute for cement in the formulation of mortar, offering a more eco-friendly solution while promoting waste reutilization. The sludge was prepared using five different methods to evaluate this possibility. M1 was oven-dried, M2 and M3 were sun-dried, M4 was incinerated in a muffle furnace, and M5 was pyrolyzed. Compression tests were carried out to evaluate the mechanical strength of the mortar. Different mixtures were formulated and analyzed, and the M3 specimen containing 7% sludge, showed the highest strength, outperforming the control mortar and those with M1, M2, and M4 sludge preparations, which displayed similar results. On the other hand, the mixture subjected to the pyrolysis treatment (M5) showed the least satisfactory results in terms of strength, even lower than those obtained for the control mortar. Considering the environmental perspective and the pressing need to move towards a circular economy, evaluating the associated energy consumption and mechanical performance is essential. The findings indicated that partial substitution of cement with treated sludge led to a noticeable decrease in energy demand, particularly when low-energy processes like solar drying were employed. It is important to highlight that all the modified mortars, following different methods, were shown to comply with the EN 998-1:2018 standard for compressive strength, which attests to their viability for practical applications. The incorporation of WWTP sludge in mortar production not only reduces cement consumption but also minimises the environmental impacts associated with this industry. At the same time, it contributes to sustainable waste management and economic valorization. The study highlights the feasibility of using mortars incorporating sludge as a cost-effective alternative that also plays a role in mitigating environmental issues. Further studies should assess long-term durability and potential environmental trade-offs, in order to clarify the practical impact of this strategy in actual construction scenarios.
- Tracking urban impacto n the Fervença river via water quality indexPublication . Martins, Ramiro; Pietrobelli, JulianaWater quality is crucial for the survival of living organisms and their environment. The Water Quality Index (WQI) is commonly used to monitor and minimize pollution. This study utilized The WQI was used to evaluate the water quality of the Fervença River in Bragança, Portugal, from January to June 2022. Water samples were collected monthly at five locations along the river. The WQI, which is based on physical, chemical, and biological parameters, provides a comprehensive numerical assessment, ranging from 0 to 100. In general, points 1-4 exhibited a good WQI and showed similar results. However, at point 5, reduced WQI values were consistently observed in all sampling campaigns, indicating a likely connection with discharge from the nearby wastewater treatment plant. The winter season, which is typically characterized by higher rainfall in the region, experienced severe drought during the study period. Consequently, the influence of rainfall on the WQI parameters could not be evaluated as expected, particularly from January to March. Comparing the obtained results, it is evident that as the Fervença River flows through the city of Bragança, the water quality indices decrease in most campaigns, particularly after Point 5. This finding highlights the negative influence of cities on the river water quality. This study highlights the importance of assessing water quality. Points 1 to 4 demonstrated good water quality, whereas point 5 showed reduced quality, linked to the wastewater treatment plant. Drought and city influence affect river water quality, which is crucial for the survival of living organisms and their environments.
- Upcycling wastewater treatment plant sludge into eco-friendly cement mortarPublication . Grabowski, Thais; Pietrobelli, Juliana; Martins, RamiroAiming to create alternatives for the disposal of sludge generated in wastewater treatment plants (WWTP) considering the circular economy principles and contributing to the reduction of environmental impacts generated by civil construction, the objective of this work was to evaluate the technical feasibility of the partial replacement of cement in the production of mortars by the sludge produced at the Bragança WWTP. The sludge was characterised, and different methods were used to prepare the sludge for the mortar. The sludge was incorporated by replacing part of the concrete mass of the mortar mixture. The specimens were tested for compressive strength. The specimen with 7% of sludge ash obtained the best result, the specimens with sludge from the drying-only treatments showed a result similar among themselves. The incorporation of the sludge resulted in mortars within the specification of the standard EN 998-1: 2018 and consequently have technical feasibility.