Reliable e-nose for air toxicity monitoring by filter diagonalization method

This paper introduces a compact, affordable electronic nose (e-nose) device devoted to detect the presence of toxic compounds that could affect human health, such as carbon monoxide, combustible gas, hydrogen, methane, and smoke, among others. Such artificial olfaction device consists of an array of six metal oxide semiconductor (MOS) sensors and a computer-based information system for signal acquisition, processing, and visualization. This study further proposes the use of the filter diagonalization method (FDM) to extract the spectral contents of the signals obtained from the sensors. Preliminary results show that the prototype is functional and that the FDM approach is suitable for a later classification stage. Example deployment scenarios of the proposed e-nose include indoor facilities (buildings and warehouses), compromised air quality places (mines and sanitary landfills), public transportation, mobile robots, and wireless sensor networks.

Municipal Solid Waste Management through Sustainable Landfilling: In View of the Situation in Karachi, Pakistan

Open disposal is the most common technique used for municipal solid waste (MSW) management due to the absence of sanitary landfills in Pakistan. The major cities and small towns in Pakistan have become a showcase of negligence and mismanagement of MSW, which results in deterioration of the environmental and social-life quality. Moreover, research has proved that inefficient handling (disposal) of MSW results in uncontrolled emissions of greenhouse gases (GHGs), mainly methane, and adds a significant share in global climate change. This study aims to estimate methane emissions from MSW disposed of at dumpsites and compare the GHG mitigation potential of different landfill strategies in specific climate and waste compositions in Karachi. The GHG estimations are based on lab-scale investigations conducted by simulating landfill conditions through the landfill simulation reactor (LSR) experiment. The synthetic MSW sample representing the composition of MSW generated in Karachi was used in the LSR experiment. Environmental sustainability and GHG mitigation potential of different landfilling strategies was evaluated by analyzing gas formation potential (GP21) and respiration activity (RI4) at the end of the experiment. This study revealed that the quantity of solid waste annually disposed of at dumpsites in Karachi possesses the potential to release about 3.9 Mt CO2-eq. methane (with specific methane potential of 1.8 tCO2-eq./tonne DM disposed) due to the biological decomposition of the organic fraction. Results show that the fresh waste disposed of at landfill sites in Karachi possesses about 92% and 94% higher GP21 and RI4, respectively, than the German allocated criteria for mechanically and biologically treated (MBT) waste for landfills Furthermore, sanitary landfills with post-aeration conditions showed higher GHG mitigation potential and low biological activity in the waste. The second highest GHG mitigation potential and lowest biological activity of the waste was noticed from bioreactor landfills with post-aeration conditions. The third number in GHG mitigation and reduced waste activity was noticed in the waste sampled from bioreactors without aftercare approach. The least GHG mitigation potential was noticed from the uncontrolled waste dumping (existing) approach with high residual gas potential and respiration index level. This lab-scale landfill simulation study can provide baseline data for further research and planning the development of new sustainable landfills in Karachi, Pakistan and in the region.

A Long-Standing Problem: A Review on the Solid Waste Management in the Philippines

Solid waste management is considered a pressing global issue calling for an immediate response from the government and its people. The Philippines has a continuously rising amount of waste and is expected to further increase in the succeeding years. As reviewed, associated problems with solid waste management in the country include an increasing amount of solid waste, weak law implementation, scarcity of sanitary landfills, and improper disposal. The ultimate solution existing in the country is the RA 9003 or the Ecological Solid Waste Management Act of 2000 which highlights the practices of segregation, proper disposal, and waste diversion. The importance of envisioning a trash-free Philippines and encouraging people’s participation and awareness is also emphasized. Another possible solution to solid waste management is valorization which can also address other environmental problems such as the depletion of natural resources. These solutions enumerated will only be possible with the presence of good governance, active participation of the people of the country, and the cooperation of all constituents and agencies in the Philippines.

Proposals for the redevelopment of deactivated landfill areas

Large amounts of the most diverse waste are produced in urban environments, being the landfill one of the most common forms of disposal of these wastes. The need for research on the redevelopment of landfill areas lies in the dynamism and externalities of urban spaces, which generates the need to rebuild degraded areas to promote economic, social, and environmental benefits. In Brazil, there is an expectation that open and controlled dumpsites will be replaced by sanitary landfills. In this sense, the present study seeks to identify alternatives to re-urbanization for areas of deactivated landfills as a way to increase the sustainability of cities, presenting solutions already adopted in Brazil and international trends. To this end, a bibliometric analysis and an extensive bibliographic review were conducted. The main alternatives found were: open spaces (parks, sports and leisure centers), use for agriculture, woods and reforestation areas, intensive use for commercial purposes, housing and energy generation. The main contribution of this article is to open the discussion about what will be the use of these new landfills in the post-closure phase of waste disposal, having in mind an adequate planning of these new landfills, allowing them not to become environmental liabilities when they are deactivated.

Multi-Attribute Assessment of Waste-to-Energy Technologies for Medical, Industrial, and Electronic Residual Wastes

There is a global need for residual waste management to prevent environmental and health hazards and reduce its volume for disposal to sanitary landfills. A waste-to-energy (WtE) facility can provide solutions by converting energy from waste to generate electricity. In this study, a method of selecting the most appropriate WtE technology for residual wastes from medical, industrial, and electronic sectors was formulated and implemented through multi-attribute decision analysis. The preference of the investigators with technical knowledge from different fields of expertise were considered in ranking the most important parameters in the study. From the comparison of seven waste conversion technologies and four power generation technologies, the pyrolysis-Brayton plant was found to be the most suitable WtE technology for residual waste. Using empirical, literature, and industry data, a pyrolysis-Brayton WtE power plant was simulated at capacities of 1, 3, and 10 tons per day (tpd) for the three waste sectors. The results of the study show that a WtE plant can reduce the volume of residual wastes up to 90% and generate electricity up to 1.2 MW for 10tpd plant simulations. The flexibility and small footprint of the pyrolysis-Brayton set-up is suitable for installment in clustered locations. Pilot demonstration is recommended for future studies.

Comparison of Hygrothermal Comfort and Life Cycle Between Recycled Plastic Block and Concrete Blocks in a Social Housing in The City of Cuenca

The qualitative and quantitative housing deficit in the city of Cuenca Ecuador is high, to provide help to the homeless, the Ecuadorian government decreed “Casa Para Todos” project in 2018. This type of housing focuses on providing an accessible alternative for people with limited resources, however, the type of housing that is granted does not comply with the conditions and materials that guarantee the comfort of the users. Additionally, there is a large percentage of plastic garbage that is collected every day by the city's cleaning system, part of it is recycled and another part is deposited in sanitary landfills due to poor handling within the recycling chain and process. The main objective of this research is to determine the hygrothermal comfort and life cycle of a housing prototype with recycled and processed plastic material for the manufacture of modules that together form the walls of the proposed houses. To achieve the proposed objective, traditional concrete block systems are compared to recycled plastic (polyethylene and polypropylene) walls, using the K coefficient (thermal conductivity) in the Desing Builder software, obtaining simulations of hygrothermal comfort and relative humidity. As a complement to the research, the analysis of the life cycle and environmental impact was carried out with the SimaPro software. As result of the simulations, it was obtained that the relative humidity in the analyzed environments, parents' bedroom, and living room, has a value of between 40 and 60% in the two construction systems, being within the comfort ranges. The internal temperature in the concrete block system fluctuates between 15 to 20 ° C while with the recycled block it is in the ranges of 17 to 20 ° C, which allows evidence that the house made up of recycled blocks has higher thermal gain in prolonged periods during the day and that the concrete block house has great heat losses due to the porosity of the material, so the use of recycled plastic blocks is recommended; deepen research on the life cycle and its environmental impact, as the results indicate that the recycled plastic block has a greater environmental impact in its life cycle than the concrete block.

Construction element from debris and demolition waste as a post-disaster strategy

In Mexico and the world, the events due to natural disasters that occurred in the last decade have led us to reflect on the commitment of Architecture, it is necessary to understand and measure the responsibility of the architect in disaster areas, it is essential to submit to analysis the teaching of architecture as an agent that generates well-being with social responsibility. The problems that derive from natural disasters, have an impact of considerable duration, the impact of an earthquake for example, not only affects the moment of the event itself, but its consequences infer a wide spectrum of affectations. One of the great concerns is the management and final disposal of waste, in the affected areas of Mexico it is a critical situation, which worsens as the volume of waste generation grows, coupled with it, the customary way its disposal is carried out in open-air dumps, which causes great effects on the natural environment. The environmentally adequate final disposal complicates the capacity of the collection services, the infrastructure and the sanitary landfills, however, the need for their correct handling and control opens the possibility of recycling. This article calls for reflection and presents a research project arising from the classroom, which is based mainly on the design of a mold to create modules as a building element (Block) with the use of construction waste and demolition, as recycled aggregates product of rubble and demolitions, one of the objectives of the project is to verify their effectiveness and thus be able to use them in the reconstruction and construction of another alternative housing at low cost.

The Bio-Based Learning Experiences optimizing Storytelling Approach for Kids Case Study Teras Hijau Project, Bandung, Indonesia

Since the promotion of the United Nations' Sustainable Development Goals (SDGs), some programs have been conducted to increase environmental awareness and concern. To meet the goals, it requires substantial efforts by all stakeholders in society. However, to our knowledge, there is still a limited number of academics whose research is focused on communicating environmental awareness to the public. While organizing communication about SDGs has faced challenges and new concerns, such as skepticism towards sustainability issues, rural and environmental issues seem to be the main agenda of development (Murphy, 2012). Thus, implementing the right communication methods is fundamental to delivering information to navigate the public's environmental orientation (Genç, 2017). Urban waste management in Indonesia still faces many obstacles, especially in terms of landfill existence. Only 60-70% of wastes can be transported and disposed in sanitary landfills (Badan Pusat Statistik, 2018). It creates so much waste, particularly related to food waste, over-packaging, and e-waste, all causing particular problems (Zaman and Lehmann, 2011). Limited natural resources force people to think hard about how to save existing natural resources.Teras Hijau Project (THP) was established out of a growing concern with the situation of the city of Bandung, Indonesia, especially in responding and improving themselves to be more sustainable. It is inspired by the Bio-Economic Initiative of European Union countries, which applies a "Circular Economy" as a basis of Regional Development. Keywords: Study Kid's Urban Farming, Communicating Cities, Storytelling, Sustainable Communication

Mitigation of CH4 emissions in sanitary landfills: An efficient technological arrangement to reduce Greenhouse gas emission.

Problems related to the solid waste have been shown a relevant subject, by contributing to global warming and climate change. The MSW is one of the main sources of Greenhouse Gases (GHG) emissions, especially the methane gas (CH4). Towards this concern, the general objective of this research is to estimate CH4 emissions produced at the Dom Antonio Barbosa II Sanitary Landfill, situated in the City of Campo Grande, state of MS. Its aim, specifically, is to verify the gravimetric composition of these residues, as well as measure the amount of the MSW already existing and also the volume placed in the mentioned sanitary landfill. The CH4 emissions were estimated in an accumulated total of 2,364,556.28 tCO2eq. It was obtained a total reduction of 1,479,693.87 tCO2eq by methane burning, transforming it into CO2, thus it was possible mitigating the emissions of 62.65% of CH4 generated in DAB II landfill. It is expected that the results from this research contribute to the attenuation of the problems related to the MSW impact on the environment, as well as reflect on the effectiveness of the current adopted technological model.

Biopolymers: Impact of Polymers that Replace Conventional Plastics, An Option for a Sustainable Future

The work carried out focuses on the importance and characteristics of bioplastics, which is why the bibliographic sources consulted recall that the plastic manufactured from biopolymers has been increasing due to its practicality and in supporting the reduction of pollution of solid waste worldwide. Viable alternatives are currently being sought to replace packaging and coatings made from non-renewable raw materials, as these cause millions of tons of waste each year, damaging the environment. The production process of biodegradable plastics has a certain resemblance to the production of conventional plastics, it consists of a mixer of raw materials with additional components, for a subsequent blowing and sealing, passing through a quality control. One of the problems with conventional plastics is that they are manufactured from raw materials obtained from non-renewable resources, which each day becomes scarcer and therefore more expensive. Also the problem of persistence in the medium for very long times, which cause them to occupy space in sanitary landfills, which are causing problems in the country due to lack of space.