The Potential of Green Engineering Solutions for Energy Conservation in Residential Buildings Towards Sustainability: A Case Study of Saudi Arabia

Developing countries in hot climate regions such as Saudi Arabia have witnessed rapid population growth, which has led to greater resource consumption as a result of the increased demand for new buildings. This research proposes a multi-objective evaluation of the potential green engineering solutions to conserve energy using a building within the ROSHN housing project, which is one of the mega projects in Saudi Arabia, as a case study for this paper with the aid of simulation software, taking into consideration the context of the sustainability concept. The results showed that traditional passive architectural design, whether courtyards or Mashrabiya, had the nearly greatest influence, with percentages ranging from −4% to −5.15% for varied parameters and designs compared to the base case energy usage. Furthermore, energy efficiency solutions for the building envelope’s external insulation and finish system (EIFS) enabled a drop in the U-value that lowered energy usage to −5.40%. However, the wall insulation thickness beyond 300 mm in this system has no substantial influence on energy savings. This research’s most clear finding is that a P2P system for PV panels on a district scale can supply enough energy to meet its needs after implementing the optimal strategy of the other proposed solutions

Anaerobic biodegradation of fluoxetine using a high-performance bacterial community

Fluoxetine (FLX), an antidepressant extensively used worldwide is considered an emerging pollutant. The present work intends to investigate for the first time the capacity of a bacterial community containing sulphate-reducing bacteria (SRB) enriched from an anaerobic sludge to biodegrade and use FLX as sole carbon source, since current literature suggests that this drug is poorly biodegraded being mainly removed by adsorption to sediments, where it persists. FLX was biodegraded under sulphate reducing conditions until reaching its lowest and reliably detectable concentration, when 20 mg/L of the drug was used as sole carbon source, while 66 ± 9% of 50 mg/L FLX was removed, after 31 days. The initial bacterial population was mainly constituted by Desulfomicrobium and Desulfovibrio whereas during the experiments using FLX as unique carbon source a clear shift occurred with the increase of vadinBC27 wastewater-sludge group, Macellibacteroidetes, Dethiosulfovibrio, Bacteroides, Tolumonas, Sulfuricurvum, f_Enterobacteriaceae_OTU_18 that are assumed for the first time as FLX degrading bacteria. Although the main mechanism of FLX removal described in literature is by adsorption, in the results herein presented anaerobic biodegradation appears to play the main role in the removal of the FLX, thus demonstrating the potentialities that the anaerobic processes can play in wastewater treatment aiming the removal of new emerging compounds.UIDB/04326/2020info:eu-repo/semantics/publishedVersio

Impact of a Chronic Obstructive Pulmonary Disease (COPD) comprehensive case management program on hospital length of stay and readmission rates

Chronic Obstructive Pulmonary Disease (COPD) is a common chronic airway disease characterized by progressive airway limitation and significant social and economic burden. Hospitalizations due to COPD account for the greatest portion of the economic costs for this disease. Unplanned COPD readmissions greatly impact the patient and healthcare costs and, to some extent, are related to gaps in the healthcare system such as discharge planning and post-discharge care and follow-up. Identifying and targeting factors contributing to unplanned rehospitalizations could reduce healthcare costs and improve COPD patients' health outcomes. We retrospectively examined the outcome and efficacy of a comprehensive case management program in reducing the length of stay and hospital readmissions in patients with COPD across five large hospitals in Vancouver, BC, Canada. A total of 1,564 patients with a clinical diagnosis of COPD were identified from 2,719 hospital admissions during the 3 years of study. The disease management program reduced COPD-related hospitalizations by 30% and hospitalizations for all causes by 13.6%. Similarly, the rate of readmission for all causes showed a significant decline, with hazard ratios (HRs) of 0.55 (year 1) and 0.51 (year 2) of intervention (P<0.001). In addition, patients’ mean LOS (days) for COPD-related admissions declined significantly from 10.8 to 6.8 (P<0.05).Medicine, Faculty ofExperimental Medicine, Division ofGraduat

Morphological, thermal, and biodegradation properties of LLDPE/treated date palm waste composite buried in a soil environment

In this study, date palm waste that was naturally treated as a filler in a linear-low density polyethylene (LLDPE) matrix was recycled to prepare green composites. Two types of LLDPE, based on basic additives, were used. UV stabilizer and the slip and anti-block were added as basic additives. The objective of this study was to examine the effect of these basic additives and the treated filler on the biodegradation, morphological, and thermal properties of the prepared samples by a soil burial test. The samples were characterized by Fourier-transform infrared (FT-IR) spectroscopy and X-ray diffraction (XRD). Weight loss was calculated to investigate the biodegradation of the sample, and SEM and thermogravimetric analyses were performed to reveal the morphology and thermal properties before and after burial, respectively. Results showed that the presence of the bio-filler accelerated the biodegradation of the composites. The UV stabilizer had a positive impact on biodegradation factors whereas anti-block additives appeared resistant to biodegradable factors. The morphology and thermal stability of all the prepared samples changed after burial due to the effects of biodegradation during the burial. Keywords: Polymer composites, Soil burial, Date palm, Linear low-density polyethylene, Biodegradatio

Applications of polystyrene/graphite composites in water purification as a semiconductor visible-light photocatalyst for organic pollutant degradation

The aim of this study was to prepare a polymer/graphite composite thin film as a cheap, and nontoxic photocatalyst that could be activated by visible light. It was characterized using ultraviolet/visible spectrophotometry and X-ray diffraction. Scanning electron microscopy was used to examine the photocatalyst surface before and after a photodegradation process. The photocatalyst showed activity under visible light and was used for the photodegradation of methylene blue (MB) and rhodamine B (Rh-B) as target pollutants. The process was studied with different pH values, initial dye concentrations, and light intensities from the radiation source to evaluate their effects. The results revealed that the photodegradation was affected by the initial dye concentration, and also showed that the best conditions for the photodegradation reactions of both dyes were an alkaline medium and a light intensity of 80 wt. The films prepared under the conditions reported herein could be promising materials in water purification. Keywords: Photocatalyst, Photodegradation, Rhodamine B, Methylene blu

Effect of cationic-surfactant-modified Saudi bentonite on the thermal and flammability properties of poly(vinyl alcohol)-based nanocomposite films

In this study, poly(vinyl alcohol) (PVA)-modified Saudi bentonite nanocomposite films were prepared using the solution method. Two surfactants, cetylpyridinium chloride and tetrabutyl phosphonium bromide, were used to modify the clay after the ion-exchange process by Na+ ions. The effect of the addition of modified Saudi bentonite (2.5%) on the thermal and flammability properties of the nanocomposite films was investigated. The prepared samples were characterized using Fourier-transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. Thermogravimetric analysis and differential scanning calorimetry were carried out to observe the thermal behaviour of the PVA-based nanocomposite films. Vertical flammability tests (UL94 VB) were also carried out to study the flame retardancy behaviour of the nanocomposite films. The nanocomposite films showed better flammability than pure PVA, wherein the ignition time of the nanocomposites increased and flame propagation rate decreased. The thermal stability of the nanocomposites increased by approximately 10% for the onset and endset temperature of decomposition. The type of surfactant played an important role in dispersion of the clay into the polymeric matrix and enhancing the flammability properties of the films wherein the tetrabutyl phosphonium bromide was better flame retardant than cetylpyridinium chloride

Removal of Crystal Violet Dye from Aqueous Solutions onto Date Palm Fiber by Adsorption Technique

The adsorption of crystal violet (CV) onto date palm fibers (DPFs) was examined in aqueous solution at 25°C. The experimental maximum adsorption capacity value was 0.66×10−6. Langmuir, Freundlich, Elovich and Temkin models were applied to describe the equilibrium isotherms. The influence of pH and temperature on dye removal was evaluated. The percentage removal of CV dye by adsorption onto DPF at different pH and temperatures showed that these factors play a role in the adsorption process. Thermodynamic analysis was performed, and the Gibbs free energy ΔGο, enthalpy change ΔHο, and entropy ΔSο were calculated. The negative values of ΔGο indicate spontaneous adsorption. The negative value of ΔHο indicates that the interaction between CV and DPF is exothermic, and the positive value of ΔSο indicates good affinity between DPF and CV. The kinetic data were fitted to a pseudo-second-order model

An Experimental Study of Photocatalytic Degradation of Congo Red Using Polymer Nanocomposite Films

Eco-friendly polymer nanocomposite films were synthesized using biodegradable polymers of chitosan and polyvinyl alcohol as polymeric matrices and carbon black nanoparticles as the reinforcement. These films were applied to study their applicability to industrial wastewater purification as a photocatalyst for degradation of Congo red as a target pollutant and to study the effect of the polymeric matrix types of the films on their performance as a semiconductor photocatalyst. Fourier-transform infrared (FT-IR) spectra and X-ray diffraction (XRD) were used to characterize the films. Visible light photocatalytic degradation of Congo red as a pollutant under various operational conditions of pH, dye concentration, contact time, and light intensity was performed. Photocatalytic results revealed that the polymeric substrate type does not play a major role in the photodegradation of the dye, and the best operational conditions were at a pH of 6 and a dye solution concentration of 8 mg/L

Study of the Photocatalytic Degradation of Highly Abundant Pesticides in Agricultural Soils

Organic pesticides are major sources of soil pollution in agricultural lands. Most of these pesticides are persistent and tend to bio accumulate in humans upon consumption of contaminated plants. In this study, we investigate different natural soil samples that were collected from agricultural lands. The samples revealed the presence of 18 pesticides that belong to four different groups including organochlorines (OCP), organophosphorus (OPP), carbamates (Carb), and pyrethroids (Pyrth). The photocatalytic degradation of the five most abundant pesticides was studied in the presence and absence of 1% TiO2 or ZnO photocatalysts under UV irradiation at a wavelength of 306 nm. The five abundant pesticides were Atrazine (OCP), Chlorpyrifos methyl (OPP), Dimethoate (OPP), Heptachlor (OCP), and Methomyl (Carb). The results showed that photolysis of all pesticides was complete under UV radiation for irradiation times between 64&ndash;100 h. However, both photocatalysts enhanced photocatalytic degradation of the pesticides in comparison with photolysis. The pesticides were photocatalytically degraded completely within 20&ndash;24 h of irradiation. The TiO2 photocatalyst showed higher activity compared to ZnO. The organochlorine heptachlor, which is very toxic and persistent, was completely degraded within 30 h using TiO2 photocatalyst for the first time in soil. The mechanism of photocatalytic degradation of the pesticides was explained and the effects of different factors on the degradation process in the soil were discussed