Volatile organic compound (VOC) emissions have become a key air pollution concern due to adverse health and environmental effects. The refractory nature of organic compounds combined with the toxicity of secondary metabolites limit the physical-chemical treatment processes and conventional biological processes. To overcome these drawbacks, the development of innovative advanced oxidation processes (AOPs) for the degradation of gaseous organic compounds is of major interest.
This work presents the results of two AOPs in the degradation of gaseous VOCs (toluene as a representative compound) – UV irradiation with ozonation (UV/O3) and ultrasonication (US) – considering various operating parameters such as initial toluene concentration, ozone dosage, and ultrasound frequency. For the UV/O3 process, increase in inlet concentration resulted to a decrease in toluene removal while increase in ozone dosage lead to a higher removal. An additional water scrubbing step for the UV/O3 process enhanced the abatement up to 99% due to solubilization of ozone and further oxidation of contaminants. For the US process, increase in inlet concentration had varying effects at different frequencies. Increase in US frequency and additional water recirculation lead to an increase in the removal efficiency. However, addition of ozone proved to be inhibitory for the process. In comparison, UV/O3 proved to be more efficient in terms of toluene removal at lower inlet load while US resulted to higher elimination at higher loading.

Hydrocarbon underground contamination particularly LNAPL remains a significant challenge in the regulation of subsurface pollution in the Philippines. On July 12, 2010, residents of West Tower Condominium (WTC) in Bgy. Bangkal, Makati City detected water leakage contaminated with gasoline fuel in its 4-level basement. Efforts to recover the oil from the extracted LNAPL-water mixture was done, potentially for reuse, using an oil-water separator system. In the recovery efforts, approximately 322,000 liters (equivalent to 1,610 drums) of LNAPL-water mixture were extracted. Monitoring wells were installed to measure LNAPL thickness, oil concentration of the groundwater, and map the contaminant plumes. The plumes demonstrate the behavior of LNAPL using data from 45 monitoring wells and give the extent of the contaminant area.
After Environmental Site Assessments, FPIC and UP-NIGS developed the following hypotheses:1.) Fuel was dissolved by added volumes of groundwater and spread laterally; 2.) Fuel hid beneath the soil water column.; 3.) LNAPL portions were attached to the vadose zone and the unsaturated soil forming the solid phase component. A major unresolved issue is determining the fate of the estimated one million liters of spilled LNAPL, especially after groundwater levels rose due to rainfall—an event that coincided with a sudden contraction of the contaminant plume. And how long will it take to fully remediate the subsurface of the contaminated site.
The study used the GMS AQUAVEO Modelling solution to investigate the LNAPL behavior underground and compare the results from the FPIC and UP-NIGS findings, and satisfy the following objectives: To analyze and explain the behavior of LNAPL plumes in relation to predicted values; To assess the performance and reliability of computer simulation models in replicating LNAPL plume behavior through quantitative comparison with field data; To analyze and characterize the movement and distribution of LNAPL plumes in the subsurface by integrating field observations with predictive model results; To validate the accuracy of the model by comparing its predicted values with observed field data; To describe the spill episode and highlight novel insights that enhance understanding of LNAPL behavior, contributing to advancements in groundwater contamination research; and To estimate the remaining volume of LNAPL and possible clean-up time frame under a business-as-usual scenario.
The LNAPL plumes at different time series follow advection and dispersion patterns influenced by groundwater flow. Findings also indicate that dissolved BTEX compounds remained subsurface until the activation of the Multi-Phase Extraction (MPE) system. Model-calculated LNAPL volumes suggest that a significant portion of the contaminant remains undissolved within the aquifer, emphasizing the need to focus remediation efforts on soil contamination. Of the estimated 253,500 liters of LNAPL released in June 2011, approximately 236,736 liters are still retained in the soil. The undissolved LNAPL, along with oil
adsorbed onto the solid matrix, will be recovered through MPE. Any remaining residues may be further treated through bioremediation. The timeline for complete remediation will depend on the residual BTEX concentrations, which will be regularly monitored to ensure they remain below the regulatory threshold of 5 ppb for benzene.

This study assessed retrofits for energy efficiency improvement of the University of the Philippines College of Fine Arts New Building atrium. Using EnergyPlus simulation software, the baseline annual energy consumption of the atrium was 39,022.06 kWh. The effects of wall, window, and roof insulation retrofits on energy consumption were evaluated. Wall insulations included polystyrene, fiberglass, gypsum board, aerogel-based coating, polystyrene-gypsum board, and fiberglass-gypsum board. Except for gypsum board and aerogel-based coating, all wall insulations in the atrium resulted in reduced energy consumption. This reduction is primarily due to decreased cooling loads, directly reducing air conditioning unit (ACU) usage. Since ACUs are the main energy consumers in the atrium, this decrease leads to overall energy savings. Reduced cooling loads are attributed to significantly lower heat gain or OTTV through the walls. External heat gain through the building envelope constitutes a substantial part of the atrium's heat load. By minimizing external heat gain, less energy is needed to cool the atrium, thereby reducing the ACU consumption and overall energy consumption. Window insulations evaluated were single clear exterior film, single reflective tinted exterior film, single clear interior film, single reflective tinted interior film, double clear film, and double reflective tinted film. All window insulations resulted in an insignificant reduction in energy consumption due to minimal decreases in cooling loads. The negligible reduction in cooling load can be attributed to negligible OTTV reduction through the windows. Consequently, this leads to negligible decrease in energy consumption and energy savings. Roof insulations assessed are polystyrene, fiberboard sheathing, gypsum board, polyurethane foam, roof membrane paint, and opaque glass. All roof retrofits resulted in negligible energy consumption reduction. It is due to insignificant decrease in cooling load which is to the negligible OOTV reduction. Subsequently, this leads to the negligible reduction in energy consumption and minimal energy savings. Moreover, it was also found that the baseline OTTV for wall, window and roof exceed the maximum allowable OTTV mandated in the DOE guidelines. This indicates that the current set-up of the atrium is not energy efficient. Excessive solar heat gain leads to thermal stratification which occurs when warm air rises to the ceiling and cold air sinks to the floor, thereby increasing the indoor temperatures and causing uneven solar radiation distribution. Subsequently, resulting in high cooling load demand and high energy consumption. Additionally, interactions between retrofits showed no significant effect on energy consumption. Financial analysis identified fiberglass as the most cost-effective retrofit, reducing annual energy consumption to 36,279 kWh, generating annual savings of Php 40,876, and achieving a payback period of 4.01 years.

This study aims to investigate the effects of accelerated aging on withdrawal strength of different nail diameters in coconut lumber, assess the sensitivity of ultrasonic test parameters on the damage induced by accelerated aging in wood-nail materials, and develop a regression model for estimating nail withdrawal strength in coconut lumber subjected to accelerated aging. The prepared samples were subjected to different number of accelerated aging cycles. Ultrasonic and withdrawal tests were then implemented. The results show that all nail groups exhibited lower withdrawal strength after one cycle due to high fiber deterioration rate. From two to six cycles, cracking and corrosion influenced withdrawal strength. The smallest nail diameter group demonstrated a continuous increase in withdrawal strength because it developed less cracks but more rust resulting in net increase in withdrawal strength. However, larger nail diameter groups showed a fluctuating trend in withdrawal strength from two to four cycles since they developed more cracks but less rust. After six cycles, these groups showed an increase in withdrawal strength due to continuous corrosion development while fiber deterioration remained roughly the same. Moreover, the results indicate that ultrasonic pulse velocity (UPV) is the most reliable parameter for late damage monitoring while sideband peak count-index (SPC-I) is the most effective parameter for early damage detection in wood-nail materials. Combining SPC-I and UPV will provide a more holistic approach for monitoring damage progression of non-engineered structures in the Philippines. Lastly, based on several performance indicators and adequacy tests, an overall best model was selected. The best model achieved an R2 value of 0.6381. The results also revealed that the lower-prediction bound of the developed model (i.e., best model) in this study may supplement the structural codes and be used to
estimate withdrawal strength of coconut lumber in non-engineered structures in the Philippines.

Carbon dioxide (CO2) electrolysis using Solid Oxide Electrolysis Cells (SOECs) plays a key role in CO2 utilization technologies, such as the production of O2 gas. While Ni-YSZ is a widely used cathode material, it suffers from carbon deposition under dry CO2 conditions, limiting its long-term stability. Perovskite-based cathodes, particularly the composite of La0.6Sr0.4Co0.2Fe0.8O3-δ and CeO2-Gd2O3 (LSCF-GDC), have emerged as promising alternatives due to their mixed ionic-electronic conductivity and structural stability. In this study, symmetrical SOECs were fabricated with LSCF-GDC composite cathodes deposited on YSZ substrates using the screen-printing technique, with varying LSCF-GDC weight ratios of 30:70, 50:50, and 70:30 LSCF-GDC. The cells were characterized by their microstructure, morphology, and total conductivity. SEM/EDS analysis confirmed good homogeneity between LSCF and GDC phases and adequate porosity for gas diffusion with an observed thin film thickness of <20um. Electrochemical impedance spectroscopy revealed that the total conductivity for different studied composition ranges from 10-7 to 10-4 S/cm. The total conductivity trend shows that it is increasing as GDC weight percentage increases. The total conductivity in a CO2 environment was lower compared to O₂, likely due to the lower oxygen partial pressure and reduced availability of reactive oxygen species. In addition, initial investigation of the electrolysis performance was conducted for the 30:70 LSCF-GDC, which resulted in a current density of 51mA/cm2 and a 0.09% O2 production rate at 800℃. Thus, this study successfully fabricated a symmetrical LSCF-GDC cell for dry CO2 electrolysis; however, further optimization is needed to increase its performance