A systematic mapping study on the development of permeable reactive barrier for acid mine drainage treatment

Acid mine drainage is a result of exposure of sulfide ore and minerals to water and oxygen. This environmental pollutant has been considered the second biggest environmental problem after global warming. On the other hand, permeable reactive barrier is an emerging remediation technology which can be used to treat acid mine drainage. However, the effectiveness of this proposed remediation technology greatly depends on the reactive media. Also, treatment of acid mine drainage using permeable reactive barrier is still in the infancy stage, and long-term performance is still unknown. Hence, this study was conducted to identify what have been studied, addressed and what are currently the biggest challenges and limitations on the use of permeable reactive barrier for acid mine drainage treatment. Through systematic mapping approach, the results have shown that the reactive media used in permeable reactive barrier can be categorized into five namely iron-based, organic-based, inorganic minerals-based, industrial waste-based, and combined media. The data revealed that majority of the papers which is about 40% use combined media as the reactive substrate. The future direction is toward the use of combined media as a reactive material for AMD treatment, for instance, use of geopolymer with mine tailings and silts as reactive media in combination with organic-based medi

Development of nanosilver-coated geopolymer beads (AgGP) from fly ash and baluko shells for antimicrobial applications

Geopolymers are a class of materials formed from treating alumina (Al2O3) and silica (SiO2) containing materials with an alkali activator. They are most notable for being environmentally-friendly substitutes to Ordinary Portland Cement; however, recent findings have shown that they may have potential as support matrices for antimicrobial agents such as nanosilver, particularly with the addition of foaming agents and setting time accelerators. In this study, nanosilver-coated geopolymer beads (AgGP) were made from fly ash (FA), calcined Baluko shells or pen shells (BS), and hydrogen peroxide (H). Addition of BS and H reduces the setting time and increases the porosity of the geopolymer beads. The beads were then dipped in AgNO3 and NaBH4 respectively to provide the nanosilver coating. When immersed in water, a controlled release of silver ions leaches out from the beads, neutralizing any bacteria in the water. It was found that the AgGP removed as much as 99.96% of the E. coli in a suspension originally at 105 CFU/mL

Synthesis of geopolymer spheres with photocatalytic activity

Geopolymer is an emerging “green” cementitious material which has a potential to valorize waste such as rice hull ash (RHA). Geopolymer is a kind of alkali-activated material which forms from the reaction of alumino-silicates in an alkaline solution. This study uses RHA as the raw material for alkaline activator while metakaolin (MK) serves as a geopolymer precursor to synthesize the so-called geopolymer sphere. Then its capacity as a porous matrix was explored upon incorporation of TiO2 nanomaterial using horizontal vapor phase growth (HVPG) technique to enhance its photocatalytic property. Indication suggests that the synthesized MK-geopolymer spheres activated with RHA-based water glass solution (WGS) were comparable to that of commercial WGS. Furthermore, the geopolymer spheres were successfully coated with TiO2 in the form of nanocrystals. Its photocatalytic activity was evaluated in terms of methylene blue degradation. This material’s potential environmental application for water purification and wastewater treatment will be investigated for future works

Artificial Intelligence and its Potential Adverse Impacts on the Philippine Economy

Recent developments in artificial intelligence (AI) and deep learning techniques are expected to reshape the nature of the working environment in many economic sectors through the automation of many white collar jobs. This technological breakthrough poses threats of job obsolescence in several industries, particularly for a labor abundant country such as the Philippines. With human capital as one of its largest resources, the services sector is a major contributor to the country’s economy, contributing around 60% of the total gross domestic product and employing about 22.8 million workers (Philippine Statistics Authority, 2017)

Preparing for Shortages of Future COVID-19 Drugs: A Data-Based Model for Optimal Allocation

Drugs for the treatment of Covid-19 are currently beign tested, and those that are apporved for use are likely to be in short supply due to the global scale of the pandemic. This policy brief proposes a model for optimally allocating future Covid-19 drugs to patients to minimize deaths under conditions of resource scarcity. A linear programming model is developed that estimates the potential number of deaths that may result from Covid-19 under two scenarios: with antivirals and without antivirals. It takes into account patient risk level, the severity of their symptoms, resource availability in hospitals (i.e. hospital beds, critical care units, ventilators), observed mortality rates, and share of the Philippine population. Based on simulations, the model can make actionable recommendations on how to prioritize the allocation of the drugs

Prioritization of sustainability indicators for promoting the circular economy: The case of developing countries

The concept of the circular economy has gained well-recognition across the world for the past decades. With the heightening risk of the impact of climate change, resource scarcity to meet the increasing world population, the need to transition to a more sustainable development model is urgent. The circular economy is often cited as one of the best solutions to support sustainable development. However, the diffusion of this concept in the industrial arena is still relatively slow, particularly in the developing country, which collectively exerts high potential to be the world’s largest economies and workforce. It is crucial to make sure that the development of these nations is sustainable and not bearing on the cost of future generation. Thus, this work aims to provide a comprehensive review of the circular economy concept in developing country context. Furthermore, a novel model is proposed by adopting Fuzzy Analytics Network Process (FANP) to quantify the priority weights of the sustainability indicators to provide guidelines for the industry stakeholders at different stages of industry cycle to transition toward the circular economy. The results revealed that improvement in economic performance and public acceptance are they key triggers to encourage stakeholders for sustainable development. The outcomes serve as a reference to enhance the overall decision-making process of industry stakeholders. Local authorities can adopt the recommendations to design policy and incentive that encourage the adoption of circular economy in real industry operation to spur up economic development, without neglecting environmental well-being and jeopardizing social benefits

Prioritization of sustainability indicators for promoting the circular economy: The case of developing countries

The concept of the circular economy has gained well-recognition across the world for the past decades. With the heightening risk of the impact of climate change, resource scarcity to meet the increasing world population, the need to transition to a more sustainable development model is urgent. The circular economy is often cited as one of the best solutions to support sustainable development. However, the diffusion of this concept in the industrial arena is still relatively slow, particularly in the developing country, which collectively exerts high potential to be the world’s largest economies and workforce. It is crucial to make sure that the development of these nations is sustainable and not bearing on the cost of future generation. Thus, this work aims to provide a comprehensive review of the circular economy concept in developing country context. Furthermore, a novel model is proposed by adopting Fuzzy Analytics Network Process (FANP) to quantify the priority weights of the sustainability indicators to provide guidelines for the industry stakeholders at different stages of industry cycle to transition toward the circular economy. The results revealed that improvement in economic performance and public acceptance are they key triggers to encourage stakeholders for sustainable development. The outcomes serve as a reference to enhance the overall decision-making process of industry stakeholders. Local authorities can adopt the recommendations to design policy and incentive that encourage the adoption of circular economy in real industry operation to spur up economic development, without neglecting environmental well-being and jeopardizing social benefits

Phosphorus recovery from wastewater and sludge

Wastewater and sludge are potential resource of phosphorus (P) for fertilizer production. One method of recovering phosphorus is via chemical precipitation. In the study, phosphorus was recovered from wastewater and sludge. First, hydrolysis was carried out to release the phosphorus in the sludge by the addition of 1.0M acid (sulfuric acid) or base (sodium hydroxide) solution mixed for three hours at 200 rpm. The hydrolyzed sludge was filtered, and the pH of the solution was adjusted to 9.0. Precipitation for both wastewater and hydrolyzed sludge solution was carried out using magnesium chloride hexahydrate (MgCl2•6H2O) and ammonium chloride (NH4Cl). The mixture was stirred for an hour for crystallization. Precipitates were allowed to settle for 24 hours before it was filtered and dried in an oven at 55-58oC for 24 hours. The dried sample was grinded and characterized using Fourier transform infrared spectroscopy (FTIR), x-ray fluorenscence (XRF), and scanning electron microscope with energy-dispersive x-ray spectroscopy(SEM-EDX)

Bio+mine project: empowering the community to develop a site-specific system for the rehabilitation of a legacy mine

The rehabilitation of legacy mines continues to be a big challenge because of the difficulties in returning them to safe and stable conditions and ensuring that the mined-out areas become productive to support the economic activity of the host community. Previous efforts are often focused on purely technical and environmental aspects, leading to resistance from the local community due to their exclusion from the rehabilitation process. To address the issues associated with legacy mines and lack of participation of the community, we have developed a project, Biodiversity Positive Mining For The Net Zero Challenge (Bio + Mine), focusing on the abandoned Sto. Niño copper mine (Benguet, Philippines). The mine was closed in 1982 without a plan involving local stakeholders and leaving a significant ongoing negative legacy. Using the social-ecological-technological system framework, we will explore the intersections of the structure and functions of socio-economicdemographic, ecological, and technological data useful in devising a more inclusive mitigation strategy for the reconstruction of the supporting ecosystem. We aim to develop a site-specific system, underpinned by the local community's knowledge and practices, that can be a model for wider implementation in other legacy and active mines worldwide