Plastics are non-biodegradable and the increasing generation of plastics creates a problem of disposal. One promising approach to address this problem is to find other uses for plastics after they are used. While studies on the incorporation of waste materials in concrete abound, little attention has been given to the incorporation of plastic wastes in concrete. Also, these few studies have focused on cylindrical concrete specimens -none in online published articles, to the authors' knowledge, has focused on concrete hollow blocks. The present study narrowed that gap by shifting the focus of research from the conventional cylindrical specimen to concrete hollow block. Thus, the main objective of the study was to assess the potential of concrete hollow blocks with PP pellets as partial replacement for sand. Polypropylene (PP), which is a subset of these plastics, were pelletized and incorporated in concrete hollow blocks as partial replacement for sand. Five batches of specimens, each with 0%, 10%, 20%, 30%, 40% PP replacement (by volume) were molded and cured for 28 days. The compressive strength and bulk density of the specimens from these batches were determined and compared. Results showed that, generally, compressive strength and bulk density decrease as percent replacement increases; however, it was observed that the compressive strength of the specimens from batch with 10% PP replacement were higher compared to batches with 0% PP replacement.

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Carbon dioxide (CO2) from the transport sector is by far considered as the major contributor of Greenhouse Gas (GHG) emission into the atmosphere. Many transport engineers and planners nowadays have shifted focus on the development of new approaches or tools that provide fast and reliable means of assessing different transportation strategies to achieve low-carbon transportation system. In this study, a new mathematical Origin-Destination (O-D) approach of estimating energy demand and CO2 emissions is presented using inter-regional passenger and freight flow data. The lengths of three major road segments were used as independent variables to model fuel consumption for buses and trucks. The estimated energy demand under business as usual (BAU) scenario was compared to five different low-carbon policy scenarios. Study shows that the energy demand from inter-regional public buses and freight road transport under BAU scenario substantially increased from 6,358.86ktoe in 2015 to 36,410.43ktoe in 2050. These findings equate to 19.71 and 112.93 Megatons of CO2 emissions in 2015 and 2050, respectively. Results also show that shifting to low-carbon alternative fuel such as Compressed Natural Gas (CNG) for buses and trucks provide the highest reduction in the overall inter-regional CO2 emissions as compared other policy measures. Simultaneous implementation of the three selected policy measures would substantially reduce the CO2 emissions by almost two-third (74.24%) in 2050.

A ten-year integrated solid waste management plan was established for the University of the Philippines Los Baños which complies with the provisions of RA 9003. An end-of-pipe Waste Analysis and Characterization Study (WACS) was performed to identify the classification of wastes in UPLB. Waste generation was found to be 593.67 kg/day on the average and is expected to increase by 2% per year which is 709.49 kg/day on the year 2027. The waste composition by weight of the non-biodegradable wastes are as follows: plastic (55.68%); paper (35.77%); glass bottles (5.22%); metal (2.77%); and residuals (0.55%). A large portion of the wastes, which is 99.45% by weight, are recyclables.  The loose density of wastes is 131.93 kg/ m3. Feasible collection points were assigned to improve efficiency of the collection of wastes in the university. Building units inside the campus were clustered and was assigned to dispose wastes to a single temporary storage facility per cluster. There are 181 units of 240-L garbage bin needed for the 39 clusters in UPLB. Two sets of dimensions of a proposed temporary storage facility were provided for the temporary storage facility; 5 2 2.2 m and 3.5 2 2.2 m. Conceptual design and structural plans of the materials recovery facility were provided. Mass balance was performed, and the theoretical diversion efficiency of the materials recovery facility is 99.445%.

Agricultural and livestock farms are the major sources of freshwater pollution in rural areas in the Philippines.  Small and unregulated dairy farms operate without appropriate wastewater treatment before discharge because it is too expensive to do so. With this scenario, the emergence of the need for a sustainable and cheaper alternative for wastewater treatment gave rise to the research and development studies of the efficiency of constructed wetlands. The study aims to analyze the treatment efficiency of series type vertical subsurface flow constructed wetlands planted with Napier Grass (Pennisetum Purpureum Schumach) on University of the Philippines Los Baños (UPLB) Dairy Farm wastewater with a focus on fecal coliform concentration, electric conductivity, total dissolved solids content, nitrite and nitrate concentration and pH level. The study showed that after treatment using the vertical subsurface flow constructed wetlands, all the parameters except the fecal coliform concentration were below the standard limits set by the Department of Agriculture with average removal efficiencies of 12.94% on Electric Conductivity (EC), 12.86% on Total Dissolved Solids (TDS), 216.44% on Nitrite (NO2-N), -125.64% on Nitrate (NO3-N), and -25.64% on Fecal Coliforms (FC). With the results of the analysis, a design of series type vertical subsurface flow constructed wetland for dairy farm wastewater treatment is suggested. Doi: 10.28991/cej-2021-03091654 Full Text: PDF