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Among the water-polluting substances, heavy metals stand out due to their carcinogenic and toxic effects on the creatures and environment. This study aimed to scrutinize the effectiveness of sewage sludge-based activated carbon in the removal of copper and cadmium from aqueous solutions in column study. Detection of breakthrough curves and related parameters was conducted by varying bed depths (3, 6, and 9 cm). The solution with an initial metal concentration (IMC) of 100 ppm was pumped to the column at a flow rate of 2 mL/min. In the process of copper removal, the breakthrough points for depths 3 cm, 6 cm, and 9 cm were achieved at 10 min, 15 min, and 60 min, respectively, whereas breakthrough points of similar depths in cadmium removal process were achieved at 5 min, 10 min, and 30 min, respectively. Adsorption kinetics were analyzed using the Adams–Bohart, Yoon–Nelson, and Thomas kinetics models. The Adams–Bohart model described only the initial part of breakthrough curves. The Thomas model represented the adsorption process with coefficients of determination (R2) ranging between 0.90–0.95 for cadmium removal and 0.89–0.96 for copper removal, while the coefficients of determination of Yoon–Nelson ranged between 0.89–0.94 for cadmium and 0.95–0.97 for copper. Yoon–Nelson was fitted well with copper removal data, while removal of cadmium data was best described by the Thomas model. This study demonstrated that using sewage sludge-based activated carbon to remove heavy metals is an alternative, more cost-effective option to reach the objectives of sustainable development.

The bond strength between the steel fiber and the ultra-high performance concrete (UHPC) matrix plays a significant role in improving the behavior of plain UHPC. This paper compiles the existing experimental research database on the pullout bond performance of steel fibers embedded in UHPC. The variations of key parameters in the database are the steel fiber type and geometry, fiber volume fractions, and fiber embedded length. The effects of these parameters are analyzed and discussed in detail. Based on the analysis of the results, it was found that the deformed steel fibers, i.e., the hooked-end, half-hooked-end, and twisted steel fibers clearly provided higher average bond strengths than that straight fibers. The average pullout bond strength was obtained by increasing of fiber volume fraction in the UHPC matrix up to 2% (11.21MPa) with an increment of 20.4%. When the steel fiber volume fractions increase beyond 2%, the average bond strength decreases. Additionally, it was also found that using smaller embedded lengths in deformed steel fibers could result in the improvement of bond strength. This could be due to the fact that the bond is controlled by the mechanical anchorage of the end-hook rather than the physio-chemical bond in the straight portion. Conversely, increasing the embedded length of steel fiber could greatly contribute to the enhancement of pullout resistance resulting in increased bond strength between the UHPC matrix and steel fibers.

A significant issue for the ecosystem is the presence of boron in water resources, particularly in produced water. Batch and dynamic experiments were used in this research to extract boron in the form of boric acid from aqueous solutions using boron selective resins, DIAION CRB05. DIAION™ CRB05 is an adsorbent that is effective in extracting boron from aqueous solutions due to its high binding capacity and selectivity for boron ions, and it is also regenerable, making it cost-effective and sustainable. Field Emission Scanning Electron Microscopy (FESEM), X-ray diffraction (XRD), and FTIR analysis for DIAION CRB05 characterization. To increase the adsorption capacity and find the ideal values for predictor variables such as pH, adsorbent dose, time, and boric acid concentration, the Box–Behnken response surface method (RSM) was applied. The dosage was reported to be 2000 mg/L at pH 2 and boron initial concentration of 1115 mg/L with 255 min for the highest removal anticipated from RSM. According to the outcomes of this research, the DIAION CRB05 material enhanced boron removal capability and has superior performance to several currently available adsorbents, which makes it suitable for use as an adsorbent for removing boric acid from aqueous solutions. The outcomes of isotherm and kinetic experiments were fitted using linear methods. The Temkin isotherm and the pseudo-first-order model were found to have good fits after comparison with R2 of 0.998, and 0.997, respectively. The results of the study demonstrate the effectiveness of DIAION™ CRB05 in removing boron from aqueous solutions and provide insight into the optimal conditions for the adsorption process. Thus, the DIAION CRB05 resin was chosen as the ideal choice for recovering boron from an aqueous solution because of its higher sorption capacity and percentage of boron absorbed.

The volume of sludge is a growing problem worldwide due to the increase in the population and the growing in industry and agriculture. Therefore, sludge management and disposal are becoming problematic and required more intensive and creative efforts. The objective of this study was to produce activated carbon using sewage sludge as raw material. Preparation conditions of sewage sludge based activated carbon were optimized by applying Box-Behnken Design (BBD) in response surface methodology (RSM). Optimization process investigated the impact of interaction between chemical activation ratio, contact time and activation temperature on the surface area of activated carbon. A series of activated carbons were chemically activated using potassium hydroxide (KOH) and physically activated by pyrolysis process in tube furnace. The response of optimization process was the surface area of activated carbon which was depicted by the second-order polynomial regression model created by ANOVA. Optimum activated carbon characterizations were conducted by surface area (BET), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and Thermogravimetric analysis TGA. The maximum surface area of 377.7 m2/g was achieved at chemical activation ratio of 1, activation contact time of 3 hours and activation temperature of 500 ℃. According statistical analysis, the most significant parameter was the contact time, followed by chemical activation ratio and activation temperature.

Batik industrial effluent wastewater (BIE) contains toxic dyes that, if directly channeled into receiving water bodies without proper treatment, could pollute the aquatic ecosystem and, detrimentally, affect the health of people. This study is aimed at assessing the adsorptive efficacy of a novel low-cost sewage-sludge-based biochar (SSB), in removing color from batik industrial effluent (BIE). Sewage-sludge-based biochar (SSB) was synthesized through two stages, the first is raw-material gathering and preparation. The second stage is carbonization, in a muffle furnace, at 700 °C for 60 min. To investigate the changes introduced by the preparation process, the raw sewage sludge (RS) and SSB were characterized by the Brunauer–Emmett–Teller (BET) method, Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy. The surface area of biochar was found to be 117.7 m2/g. The results of FTIR showed that some functional groups, such as CO and OH, were hosted on the surface of the biochar. Continuous fixed-bed column studies were conducted, by using SSB as an adsorbent. A glass column with a diameter of 20 mm was packed with SSB, to depths of 5 cm, 8 cm, and 12 cm. The volumes of BIE passing through the column were 384 mL/d, 864 mL/d, and 1680 mL/d, at a flow rate of 16 mL/h, 36 mL/h, and 70 mL/h, respectively. The initial color concentration in the batik sample was 234 Pt-Co, and the pH was kept in the range of 3–5. The effect of varying bed depth and flow rate over time on the removal efficiency of color was analyzed. It was observed that the breakthrough time differed according to the depth of the bed and changes in the flow rates. The longest time, where breakthrough and exhausting points occurred, was recorded at the highest bed and slowest flowrate. However, the increase in flow rate and decrease in bed depth made the breakthrough curves steeper. The maximum bed capacity of 42.30 mg/g was achieved at a 16 mL/h flowrate and 12 cm bed height. Thomas and Bohart–Adams mathematical models were applied, to analyze the adsorption data and the interaction between the adsorption variables. For both models, the correlation coefficient (R2) was more than 0.9, which signifies that the experimental data are well fitted. Furthermore, the adsorption behavior is best explained by the Thomas model, as it covers the whole range of breakthrough curves.

The use of various tools for construction waste management throughout the planning and design (P&D) stage has several advantages. According to some research, building information modelling, or BIM, could be a valuable tool for predicting waste. This paper discusses how BIM could be used for pre-empting waste and reducing the course of the planning and design process of constructing a building. In Malaysia, a questionnaire survey of 340 construction experts was undertaken. Simultaneously, a regression analysis was carried out in order to determine the impact of BIM on the management of construction waste during the planning and design stage. This research could help many stakeholders in the construction industry to recognise various aspects of waste management, beginning with the planning and design stage of a project, which can be represented by designing a model that can be applied to mitigate waste during the construction of a building.

This paper examines the economic and environmental impacts of district cooling systems (DCS) that are integrated with renewable energy sources and thermal energy storage (TES). Typically, a DCS offers a highly efficient and environmentally friendly alternative to traditional air conditioning systems, providing cool air to buildings and communities through a centralized system that uses chilled water. However, the integration of renewable energy and thermal energy storage into these systems can further increase their sustainability and efficiency, reducing their dependence on fossil fuels and improving their ability to handle fluctuations in demand. The goal of this paper is to provide a comprehensive review of the current state of the art of renewable energy-driven DCS with TES integrated and to highlight the benefits and challenges associated with these systems. Finally, the findings of this paper offer valuable insights into the potential for renewable energy-powered district cooling systems to contribute to a more sustainable and efficient built environment.

The concrete-filled double skin steel tube (CFDST) is a more viable option compared to a concrete-filled steel tube (CFST) due to consisting a hollow section, while degradation is enhanced simply by using carbon fiber-reinforced polymer (CFRP). Hence, the stabilization of a concrete&rsquo, s ductile strength needs high- performance fiber-reinforced cementitious conmposite. This study investigates the behavior of high-performance fiber-reinforced cementitious composite-filled double-skin steel tube (HPCFDST) beams strengthened longitudinally with various layers, lengths, and configurtion of CFRP sheets. The findings showed that, with increased CFRP layers, the moment capacity and flexural stiffness values of the retrofitted HPCFDST beams have significantly improved. For an instant, the moment capacity of HPCFDST beams improved by approximately 28.5% and 32.6% when they were wrapped partially along 100% with two and three layers, respectively, compared to the control beam. Moreover, the moment capacity of the HPCFDST beam using two partial layers of CFRP along 75% of its sufficient length was closed to the findings of the beam with two full CFRP layers. For energy absorption, the results showed a vast disparity. Only the two layers with a 100% full length and partial wrapping showed increasing performance over the control. Furthermore, the typical failure mode of HPCFDST beams was observed to be local buckling at the top surface near the point of loading and CFRP rapture at the bottom of effect length.

In recent years, application of precast post-tensioned (PT) segmental columns consisting of a number of precast segments and footing foundation aligned and connected altogether by post tensioning strands, has shown increasing focus in seismic regions due to their advantages over traditional columns including self-centering capability with low residual displacement and permanent deformation under severe lateral seismic loading. Recently, there have been an emerge of interest to use ultra-high strength concrete (UHSC) due to their great tensile and compressive strengths. In this study, a three dimensional (3D) nonlinear finite element model for PT segmental columns are developed and the results are validated with the experimental test conducted. A parametric study is carried out to investigate the influence of UHCS with different compressive strengths of 126 MPa, 150 MPa and 193 MPa; and tensile strengths of 6.0, 8.9 and 12.3 MPa on lateral response of PT segmental columns. In this study, PT segmental columns with normal strength; High strength concrete fully replaced with normal strength concrete throughout the columns; and UHSC as jacketing around the first segment are investigated. The influence of compressive strength and tensile strength on stiffness, lateral load capacity and ductility of the segmental columns with different concrete strengths are discussed. Also, strengthening of PT segmental columns with UHSC jacketing were examined and the results are compared.