Gas discrimination by simultaneous sound velocity and attenuation measurements using uncoated capacitive micromachined ultrasonic transducers

Chemically functionalized or coated sensors are by far the most employed solution in gas sensing. However, their poor long term stability represents a concern in applications dealing with hazardous gases. Uncoated sensors are durable but their selectivity is poor or non-existent. In this study, multi-parametric discrimination is used as an alternative to selectivity for uncoated capacitive micromachined ultrasonic transducers (CMUTs). This paper shows how measuring simultaneously the attenuation coefficient and the time of flight under different nitrogen mixtures allows to identify hydrogen, carbon dioxide and methane from each other and determine their concentration along with identification of temperature and humidity drifts. Theoretical comparison and specific signal processing to deal with the issue of multiple reflections are also presented. Some potential applications are monitoring of refueling stations, vehicles and nuclear waste storage facilities.

Investigating atmosphere’s environmental components and work environment of a household landfill’s platform

Household landfills can be important sources of air quality contamination if they do not comply with technological sorting and storage procedures. Also, workers' exposure to environmental hazards endangers their health over time. A significant amount of household waste is stored in cells, monthly, after a sorting process that leaves a considerable ecological footprint. In this study we analysed air quality at the boundary of a compliant household landfill, as well as the quality of work environment of landfill’s workers. To do this, we performed measurements on two levels (air quality and work environment) over three months, following different phases of waste disposal and different activities involving workers serving the facilities. From an applied perspective, results obtained from research activities provide clear answers to questions related to ways in which environmental components are affected by waste storage activities, and workers are exposed to professional noxious. Results show that the landfill deteriorates environment quality, over time, as well as health of workers. Topic relevance is in connection with its potential future contribution to development of knowledge in the approached field, to be able to quantify progress, once integrated systems for modern ecological collection and storage have legislative regulations.

Implementasi Sensor Ultrasonik Dalam Mendeteksi Volume Limbah B3 Pada Tempat Sampah Berbasis Internet of Things

In the process of monitoring the capacity of the B3 waste storage facility at PT Fadira Teknik, the manual method is still used to determine whether the waste load is full (ready to be disposed) or not. Where in the process, workers must come and look directly at the B3 waste storage area. This will increase jobs for factory workers because they must always monitor the level of B3 waste before or after carrying out work. Apart from being harmful to humans, the B3 waste disposed of from the factory is in the form of small particles such as invisible dust which can be accidentally inhaled by the nose or into the eyes of the workers. Therefore the aim of this research is to create a smart trash can system that can monitor the volume of B3 waste in the trash, where the trash uses the IoT (Internet of Things) system by utilizing the Arduino Uno component as a microcontroller and ultrasonic sensor to detect the volume of waste then sends waste volume data to the Blynk application via the internet network to display information on the capacity of the trash. The research method used is the experimental method starting from system analysis, system design, system implementation, testing and evaluation. Testing on this smart trash system uses black box testing with the results of these tests being quite good where each test case is as expected.

Assessment of Solid Waste Management at Source in Compliance With Guidelines Among Residents of Kawempe Division, Kampala, Uganda

Background: Solid waste management poses a big challenge for many urban households, municipalities and cities, especially in developing countries, partly due to increasing urbanization. Overcrowding and informal settlements have emerged with illegal and indiscriminate waste disposal. Guidelines for proper management of solid waste are least observed at house hold level in such settings. The purpose of the study was to assess solid waste management at source in compliance with guidelines among residents of Kawempe municipality Kampala district. Methods: It was descriptive and analytical cross-sectional study design, with both quantitative and qualitative methods. 385 households heads and four local leaders were interviewed using researcher administered questionnaires and interview guide. Results: The study found that only 37.9% of households complied with guidelines for solid waste management at source. Factors of waste management practices were waste reduction (p=0.005), separation (p=0.001), reuse (p=0.001) and composting (p=0.027). Determinants such as gender (p=0.007), marital status (p=0.016), level of education (p<0.0001), occupation (p=0.007), household size (p=0.025), medium of community sensitization (p<0.0001), enforcement of bi-laws (p=0.005), type of waste generated (p<0.0001) and waste storage method (p=0.009) were implicated. Conclusion: Compliance with guidelines in the management of household solid waste at source was still very low within the city. Authorities ought to intensify household solid waste management awareness campaigns.

Devising the technology for localizing environmental pollution during fires at spontaneous landfills and testing it in the laboratory

This paper reports an analysis of current issues related to storing solid household waste, and, specifically, the problem of environmental pollution when unsorted solid household waste (SHW) is ignited. A technology has been developed to improve environmental safety and ensure a reduction in the anthropogenic load on the atmosphere, hydrosphere, and lithosphere in the event of fires at the sites of solid waste storage. The operation of the proposed equipment, taking into consideration all the provided operating modes and additional options, is energy-saving and automated (or semi-automatic), which makes it especially relevant under modern conditions. The technology significantly improves the efficiency of the processes to eliminate the ignition of SHW and localize their environmental consequences for the territories adjacent to landfills. Laboratory tests were carried out, which proved the effectiveness of practical application for the designed equipment of a new environmentally active adsorption mixture for the purpose of cleaning the waste filtrate, as well as its use for the formation of an anti-filtration screen in the mound of SHW. Experiments have shown that the tested sample of the aqueous suspension of the proposed environmentally active mixture adsorbs calcium (by 92 %), overall iron (by 91 %), overall phosphorus (by 75 %), zinc (by 31 %), and ammonium (by 19 %). This leads to a decrease in the overall toxicity of the solution and indicates the possibility of improving the environmental safety of waste fires when operating the proposed technical solution by purifying the filtrate released during fires in landfills. The reported results, specifically, the technology for localizing the environmental consequences of uncontrolled waste ignition could be used in the process of modernizing the technical support for sanitary treatment schemes in urban areas.

Design suggestions on modified self-sustainable space toilet

The present research investigates the design of compact and lightweight waste collection system (WCS) for interplanetary missions such as Mars, and the Moon as well as the space with the required features of NASA’s lunar loo challenge (released date: 25th June, 2020). Existing space toilets’ WCS store waste in small plastic bags and these bags are thrown in the space which increases the space junk. If these WCS are used on planets, they could pollute the planets. The newly designed—unisex and self-sustainable space toilet meets its objective of intimacy and warmth for the astronauts as it is equipped with all essential features such as (a) the basin for vomit collection, (b) the rotating waste storage based on the mechanism of artificial gravity, and (c) the noiseless bellow pump for air flow flushing system (AFFS). The WCS is designed for the storage of urine, faeces, vomit, diarrhoea, and menses. In the first half of the research article, the focus is kept on improving self-sustainability of the present WCS. In the second half of the present investigation analyses are done for multiphase flows of the CFD analysis in ANSYS fluent to simulate the flow of air through the nozzle provided with (a) the seat, (b) the urine funnel, and (c) the basin for air flow flushing system (AFFS). The design of the present self-sustainable space toilet proposed herewith is justified suitable for different gravitational conditions such as (a) Mars (3.721 m/s2), (b) the Moon (1.62 m/s2), and (c) the zero—or microgravity i.e., the space gravity. The proposed solar-operated WCS could be integrated to function with (a) water recovery and management (WRM) system, (b) the inbuilt composting unit, and (c) the bioregenerative life support system (BLSS). Furthermore, the assessment of the required electrical energy derived from the solar energy (harnessed using efficient solar photovoltaic (PV) modules) is conceptualized for the effective functioning of the present self-sustainable WCS. Article highlights The present investigation explores into the design of lightweight and compact WCS for interplanetary missions such as Mars and the Moon, as well as space missions with the functionality listed by NASA's lunar toilet competition (released date: 25th June, 2020). The actual space toilets, which are used on the International Space Station (ISS), are not designed to withstand varying gravity circumstances. The new advanced—unisex and self-sustaining space toilet achieves its goal of intimacy and warmth for astronauts by including all necessary features such as (a) a vomit collection basin, (b) rotating waste storage based on artificial gravity mechanism, and (c) a noiseless bellow pump for air flow flushing system (AFFS).

Reburning of Animal Waste Based Biomass with Coals for NOx Reduction, Part II: Dairy Biomass (DB) and Coal–DB Blends

Concentrated animal feeding operations (both slaughter and dairy cattle) lead to land, water, and air pollution if waste storage and handling systems are not effectively managed. At the same time, cattle biomass (CB), which includes both slaughter/feedlot biomass (FB) and dairy biomass (DB), have the potential to be a source of green energy at coal-fired power plants. Part I presented results on NOx reductions with pure FB or Coal: FB blends as reburn fuels. Part II deals with results from reburning with pure DB or Coal: DB blends as reburn fuels. A mixture of NG with a small amount of NH3 was used to generate the baseline NOx of 400–420 ppm (or 185–194 g/GJ). NOx emissions were found to be reduced by as much as 96% when reburning with FB. The effects of reburn fuel type, equivalence ratio (ERRBZ) in the reburn zone, vitiated air, several injection configurations of reburn fuel and initial NO concentrations on NOx emissions were investigated. The ERRBZ shows a significant effect on the NOx reduction. The 20% heat input by reburning was the better operating condition for the long-term operation due to its ash production. The results reveal that reburn with DB fuels is an effective technology for NOx emission control when the initial NOx emission is higher than 275 ppm (or 127 g/GJ or 0.3 lb/MMBtu).

TOXIC AND HAZARDOUS WASTE (B3) MANAGEMENT AT PT. PAL INDONESIA (PERSERO)

ABSTRACTPT. PAL Indonesia (Persero) is a state-owned enterprise (BUMN) engaged in the shipbuilding industry. Disposal of hazardous and toxic waste (B3) produced by PT. PAL Indonesia can cause negative impacts on the environment and health if special handling procedures are not taken. In order to avoid this, PT. PAL Indonesia (Persero) carries out B3 waste management. The purpose of this study was to provide an overview of the implementation of B3 waste management in PT. PAL Indonesia (Persero), including identification of B3 waste, packaging and labeling B3 waste, storage, collection and transportation of B3 waste. The research method used was the qualitative descriptive method with data collection techniques of observation, interviews, and documentation. The instrument in this study was a questionnaire. The results of the study show that in the production process, PT. PAL Indonesia (Persero) produced hazardous and toxic (B3) waste in the form of solid and liquid B3 waste in the form of used TL lamps, contaminated cotton waste, silica sand from sand blasting processes, used oil, and sludge oil. The B3 waste contained heavy metals such as Pb, Cu, Hg, Fe, and Zn. The conclusion of this research is that the implementation of B3 waste management in PT. PAL Indonesia (Persero) has not complied with implemented regulations. This study suggests the supervision of B3 waste management in PT. PAL Indonesia (Persero) as well as increased awareness of workers to wear protective equipment in managing B3 waste. Keyword: B3 waste management, PT. PAL Indonesia (Persero), B3 waste content.

Consolidated nuclear waste storage in Andrews, Texas: An integrated technical and policy risk analysis

Over the last 50 years, nuclear energy has reduced US energy-related CO2 emissions by over 30 gigatons compared to if the same electricity were produced by fossil fuels such as coal and natural gas. However, many kilotons of spent nuclear fuel have accumulated at different sites across the country, and sociopolitical factors have frustrated efforts to address the challenge of nuclear waste disposal. Presently, a consolidated interim storage facility in Andrews, Texas, provides a promising temporary solution. In this paper, we compare the technical and policy risks of the project to continued storage at independent spent fuel storage installations. Our results indicate that the cost of the radiological risk is low (<$30,000) for both scenarios. However, policy and societal considerations will impact the viability of the proposed consolidated interim storage facility. The safety and suitability of this interim storage facility will be affected by when a permanent repository becomes available, whether insurance for offsite waste storage is available, and the impact of climate risks. Although a consolidated interim storage facility at Andrews can potentially serve as a safe and economically advantageous solution, we highlight why these concerns must be addressed for the successful implementation of this facility, and more broadly for the future of the US nuclear industry.

The Secret of the Copper Box: public experiments and the prospects of living archives of Swedish nuclear waste

This paper approaches the question of nuclear safety in relation to the prospects of living archives, and in particular, it explores two public events where sociocultural aspects of nuclear waste management in Sweden were enacted. Drawing on an ongoing research collaboration with the Swedish Nuclear Fuel and Waste Management Company (SKB), the paper examines (1) a grass-roots play entitled Kopparkistans hemlighet (or The Secret of the Copper Box), and (2) a drawing competition hosted by schools located near a nuclear waste storage facility in the Östhammar municipality, considering how these events help reproduce certain kinds of social and cultural responsibility. Contributing to critical debates in the social sciences and humanities intersecting questions of memory preservation, nuclear waste, and post-nuclear natures, we consider how the forms of responsibility produced through these public experiments inform important, albeit unconventional, modes of nuclear waste management insofar as they suggest how long-lived nuclear waste sites might become living archives without assuming a narrow notion of heritage and human memory preservation for all time and space. To conclude, we evaluate how the legacy of the two events might be incorporated into wider strategies of nuclear waste management.