The use of conventional building materials in the construction sector significantly contributes to air pollution and greenhouse gas emissions, resulting in considerable environmental damage across Pakistan. Embracing sustainable building materials is crucial for mitigating pollution, conserving energy, and enhancing indoor air quality through the utilization of recycled and renewable resources, reducing environmental pollution. The focus of this study is to explore the adoption of green building materials within Pakistan's construction sector, particularly aiming to mitigate environmental impacts, including air pollution and greenhouse gas emissions. The objectives include identification of sustainable materials, evaluation of their benefits and drawbacks, and the provision of recommendations for effective implementation. The research methodology includes the administration of closed-ended questionnaires, the conduct of interviews, and the observation process, utilizing both planned and random sampling techniques to ensure the collection of reliable data. The findings indicate a limited interest in eco-friendly materials, constrained by factors such as high costs, low market demand, and logistical challenges. Cronbach's alpha value is 0.926, which shows high internal consistency and reliability. The study highlights that 73% of construction firms in Pakistan do not use green building materials. This research distinguishes itself through a thorough evaluation of sustainable materials specifically suited to Pakistan’s industry, providing strategic insights to address current challenges and foster green building practices. Doi: 10.28991/HEF-2024-05-03-015 Full Text: PDF

This research is aimed at investigating the mechanical behavior of the bitumen by the addition of high-density polyethylene (HDPE) and low-density polyethylene (LDPE) obtained from waste plastic bottles and bags. Polymers (HDPE and LDPE) with percentages of 0%, 2%, 4%, and 6% in shredded form by weight of bitumen were used to evaluate the spectroscopic, structural, morphological, and rheological properties of polymer-modified binders. The rheological properties for different factors; viscosity (ἠ) from Rotational Viscometer (RV), rutting factor G*/Sin (δ), fatigue characteristics G*. Sin (δ), for the modified binder from dynamic shear rheometer (DSR), Short and long-term aging from rolling thin film oven (RTFO), and pressure aging vessel (PAV) was determined. The thermal characteristics, grain size, and texture of polymers for both LDPE and HDPE were found using bending beam rheometer (BBR) and X-ray diffraction (XRD), respectively. Fourier transform infrared (FTIR) analysis revealed the presence of polymer contents in the modified binder. Scanning electron microscopy (SEM) images revealed the presence of HDPE and LDPE particles on the surface of the binder. Creep Rate (m) and Stiffness (S) analysis in relationship with temperature showed a deduction in stress rate relaxation. Results have revealed the best rutting resistance for 6% HDPE. It also showed an improvement of 95.27% in G*/Sin (δ) which increased the performance of the bituminous mix. Similarly, the addition of 4% LDPE resulted in maximum dynamic viscosity irrespective of the temperatures. Moreover, fatigue resistance has shown a significant change with the HDPE and LDPE. The festinating features of waste plastic modified binder make it important to be used in the new construction of roads to address the high viscosity and mixing problems produced by plastic waste and to improve the performance of flexible pavements all over the world.

The pervasive challenge of heavy metal pollution in water necessitates urgent interventions to mitigate chromium contamination. It poses significant threats to human health, aquatic ecosystems, and the environment. This research delves into the potential of date palm waste as a precursor of adsorbent for extraction of chromium from contaminated water, underscoring its potential in heavy metal remediation. Date palm waste, traditionally regarded as agricultural waste, underwent modification employing N-(3-chloro-2-hydroxypropyl) trimethylammonium chloride resulting in quaternized date palm waste (QDPW) as a prospective adsorbent for chromium extraction. The characterization techniques, including FTIR, SEM/EDX, BET, XRD, TGA/DTA, and element analysis, were employed to examine the structural and surface properties of both DPW and QDPW fibers. Optimal chromium uptake was achieved at a solution pH 6.5 over two hours, with a peak removal efficiency of 88% and an adsorption capacity of 22.26 mg/g. The equilibrium isotherms studies are consistent with Langmuir, Redlich-Peterson, and Sips isotherms, presenting a coefficient of determination (R²) of 0.989, 0.981, and 0.983, respectively. Moreover, the pseudo-second-order model was mostly aligned with the kinetics data with R² value of 0.999. These findings showed that the quaternized date palm waste can be considered a good option to recycle the date palm waste and reduce the environmental threats in aqueous solution.

The fabrication of carbon materials from biomass residues can be a promising economical approach for absorbing various target pollutants from aqueous phase. In the study, the adsorption of diphenolic acid (DPA) is investigated on activated carbons fabricated from wheat straw (ACWS) and commercial-activated carbon cloth (CACC). Adsorption kinetics, isotherms, and operational variables (solution pH and ionic strength) are analyzed for the adsorption capacity of the DPA on both carbons. The results show that the ACWS has a higher surface area (1164 m²/g) and volume of micropores (0.51 cm³/g) than those of the CACC. The second-order kinetics model fitted the experiment data better than the first kinetics models with a lower percentage of deviation. The adsorption capacity of the ACWS (264.90 mg/g) is higher than the CACC (168.19 mg/g) because of the higher surface area and volume of micropores of the ACWS. The adsorption isotherm shows that the adsorption of the DPA on the ACWS and CACC is consistent with the Langmuir and Freundlich isotherm models, respectively. The pH has a significant effect on DPA adsorption onto both carbons. The adsorption process is favored at the acidic pH, but the presence of electrolytes has no effect on the adsorption capacity of both carbons due to the screening effect. Thus, the preparation of activated carbon from wheat straw is an attractive option to recycle the wheat straw to added-value materials that can be used for the removal of such pollutants from aqueous solution. These findings can increase the research knowledge about the management of different straws in a sustainable way to produce activated carbon for different applications.

This paper explored synthesis, characterization, and adsorption modeling for the application of nano-metal-oxide (Al₂O₃) blended biochar (NMOBC) derived from date palm waste in removing iron (Fe³⁺) from contaminated water. The pseudo-second-order model provided a goodness-of-fit that was superior to the pseudo-first-order kinetic model based on the value of R² with all of the initial concentrations. The Elovich kinetic model also presented a good fit, indicating that chemisorption is a predominant mechanism in the adsorption process. The Langmuir, Freundlich, Redlich-Petersons, Temkin, and Sips models provided an exclusive perspective of the adsorption dynamics based on the high value of R². However, the Sips model suggested the best fit of all of the employed models, with the lowest RMSE value of 0.0239 mg/g and the maximum adsorption capacity of 22.680 mg/g for NMOBC. Both adsorbents were effectively regenerated and reused in multiple cycles, thus leading to sustainable practices. Numerous analytical techniques, including SEM/EDX, FTIR, and BET, were employed in characterizing the structural, morphological, and functional properties of the synthesized NMOBC and BC. Subsequently, it revealed that the adsorption process and the role of various interactions are attributed to surface area, porosity, and ion exchange.