Thai Environmental Engineering Journal

Impact of COVID-19 Pandemic on Greenhouse Gas Emissions from Municipal Solid Waste Disposal of Bangkok Metropolitan

2023-10-23T20:55:56+07:00

The impact of COVID-19 pandemic on greenhouse gas emissions from solid waste disposal in Bangkok was evaluated using statistics of waste quantities disposed by composting, incineration, and landfill methods from the transfer stations during pre-pandemic period (2015-2019) and pandemic period (2020-2022). The potential emissions of greenhouse gases from these activities were evaluated using the 2006 IPCC and 2019 Refinement methodologies. During pre-pandemic period, the emissions was estimated at 1147.98 GgCO₂-eq/year in which waste disposal in landfills contributed majority at 1002.58 GgCO₂-eq/year. The landfill emissions gradually decreased to 861.23, 809.78, and 754.73 GgCO₂-eq in 2020-2022, respectively. Meanwhile, greenhouse gas emissions from composting and incineration of general wastes during the pandemic were maintained at the same levels as the pre-pandemic period. During the pandemic period, greenhouse gas emissions from infectious waste incineration were significantly increasing to 10.79 GgCO₂/year from those during pre-pandemic period (5.42-7.25 GgCO₂/year). Despite of these increases, total GHG emissions from waste disposal in Bangkok in 2022 was reduced by 22% from those in 2018 due to the decreasing amount of general waste produced during the pandemic period.

Evaluation of Green Roof Performance in Slowing Down Stormwater Runoff in Urban Catchment, The Case of Samut Prakan, Thailand

2023-10-23T20:53:13+07:00

Urbanization implies a reduction of vegetation leading to an increase of bare lands coverage and the expansion of impervious surfaces. Such circumstances are significantly influence the hydrological cycle, reduce evapotranspiration losses, and accumulate surface runoff, raising the risk of floods, particularly in rapidly developing urban areas. Green roofs are considered as one of the most suitable Green Infrastructure (GI) for densely urbanized areas because they can incorporate into new construction or added to existing buildings during renovation or reroofing without further land consumption. This study aims to evaluate the effectiveness of green roofs in helping to slow down water runoff in response to flood risks in Samut Prakan municipal area. The hydrological model EPASWMM 5.1 was created with rain estimated based on historical data and the green roof installation scenarios. 12 green roof scenarios, consisting of 4 main scenarios, are categorized based on the rainfall events (average extreme rainfall, 10-year return period, 20-year return period, 50-year return period). The simulation results show that green roofs significantly reduce surface runoff and peak flow. Specifically, extensive green roofs in Samut Prakan achieved runoff reduction rates of 14.6% to 54.51%, and peak flow reduction rates of 7.43% to 19.6%. Considering the runoff reduction rate, green roof can provide more hydrological benefit than that of traditional storm management system. While the performance of green roofs in tropical climates may be less effective compared to those in arid and temperate zones, the results of this study are consistent with previous research and provide valuable insights for optimizing green roof design and implementation in tropical country as Thailand.

Microbial Contamination of Groundwater in Rural Area of Sittwe District, Rakhine State, Myanmar

2023-10-23T21:00:48+07:00

Rakhine state has high rates of open defecation compared to other parts of Myanmar. In the rural area of Sittwe district, pit latrines were constructed near the water sources such as boreholes, wells, lakes, creeks and river. The discharge of chemical and microbial contaminants from pit latrines to groundwater may have a negative impact on human health and drainage and solid waste disposal are major challenges in both urban and rural area. Open defecation, lack of waste management disposal, construction of pit latrines near water sources lead to fecal contamination or pollution of groundwater table. Groundwater samples in rural area of Sittwe district, Rakhine State, Myanmar were characterized microbiological properties of groundwater. For microbiological analysis, water samples were analyzed qualitative analysis of total coliform and quantitative analysis of fecal coliform (Escherichia coli; E. coli.) by membrane filtration technique (MFT) to determine the safety aspect on utilization of groundwater as a source of drinking purpose. Almost all the indicator organisms’ counts in collected samples were above WHO guidelines for drinking water quality and Myanmar national drinking water quality standard (MNDWQS). The presence of fecal coliform bacteria indicates that the water is contaminated with fecal waste from human or warm-blooded animals and the present of total coliform indicate that the groundwater is contaminated with both fecal waste and other coliform species from the environment. Safe drinking water, adequate sanitation and hygiene are crucial to prevent microbiological contamination of drinking water which can produce diseases such as diarrhea. Reduction of open defecation, construction of systematic latrines, proper waste disposal and management can protect the groundwater pollution and also increase the quality of drinking water.

Assessment on Health Impacts and Costs of Fine Particulate Matter from Passenger Transport in Bangkok Metropolitan Region

2023-08-21T13:36:12+07:00

The world has faced fine particulate matter (PM₂_.₅) problems affecting human health. Globally, PM₂_.₅ has caused 4.14 million pre-mature deaths, which is the fourth leading cause of death in the world. According to the annual report of the Pollution Control Department, the PM₂_.₅ value in Bangkok exceeded the national standards for 89 days in 2022. Transport was the dominant source of fine particulate matter in Bangkok. This research aims to develop an emission inventory and assess the health impacts and health costs of fine particulate matter from passenger transport in the Bangkok Metropolitan Region. The emission inventory was divided into two parts : fuel use and fuel production. Health impacts and health costs were quantified in the units of disability-adjusted life years (DALY) and Baht, respectively. According to research results in 2022 and 2027, the scenario that shifts 30% of private passenger transport to electric trains can reduce health impacts to 15,202 DALY/year and 9,011 million Baht (in 2022) and to 17,178 DALY/year and 10,883 million Baht (in 2027). Future policies should promote electric public transport and minimize the use of private vehicles.

Performance of Centralized Wastewater Treatment System in Thimphu, Bhutan

2023-12-19T09:33:03+07:00

The main objective of this research was to provide an evaluation of the performance of the Sequential Batch Reactor (SBR) employed in the centralized wastewater treatment system of Babesa, Thimphu, the capital city of Bhutan. The performance was analyzed based on the respective plant’s flow capacity, pH of effluent, and removal of Total Suspended Solids (TSS), Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), and Fecal Coliform (FC), using Standard Method of Examination of Wastewater, APHA, as well as the capital cost and sustainability of the treatment system. Removal efficiencies of the SBR for TSS, COD, and BOD ranged from 93-97±1.131, 67-84±4.791, and 65-89±6.662, respectively. In addition, the SBR effluent samples analyzed from April 2022 to August 2022 revealed a consistent and successful removal of TSS, BOD, COD, and FC with the effluent meeting the industrial effluent discharge standards set by the National Environment Commission (NEC). Not only was SBR found to be feasible economically and capacity-wise, but the success of the technology was a function of its compatibility with Thimphu’s specific characteristics. The conclusion of this study hopes to encourage a more rigorous consideration of treatment options to invest in Bhutan’s growing urban cities in the future, as well as a redefinition in how we evaluate the success of wastewater treatment systems.

Municipal Solid Waste Management Development Model through Participatory Process based on Circular Economy in Highland Tourism Area

2023-12-16T08:47:46+07:00

The goal of waste management in Pai District's highland areas is to learn from local initiatives for participatory rubbish management. In this study, the following questionnaires were used: (1) the questionnaire on prototype project satisfaction (public/private), (2) the questionnaire on prototype research project satisfaction (Entrepreneurs), (3) the questionnaire on overall project satisfaction, and (4) the questionnaire on the level of satisfaction with the project's promotion aspects. A 300-person purposive sample was used. The descriptive statistics used in the analytical data included percentages, means, and standard deviations. As a result, the level of satisfaction with the prototype research project was high for public/private and moderate for entrepreneurs. The assessment of satisfaction with the research extension project revealed a very high degree of satisfaction with both the overview project and the promoted project elements. Furthermore, this study tracks recycled garbage sales and the outcomes of waste separation operations for 18 months, indicating the success of operations in the Pai district. The proceeds from the sale of recycled garbage have been set aside for community purposes such as funeral expenses. It is a management strategy that can result in a more sustainable approach to Municipal Solid Waste Management.

Improving Indoor Air Quality: Utilizing Tropical Ornamental Plants for Carbon Dioxide Reduction

2023-12-21T10:06:45+07:00

This study investigates types of ornamental plants for improve indoor air quality by specifically reducing CO₂ levels. The fourteen plant types examined are Epipremnum aureum, Spathiphyllum sp., Nephrolepis Exaltata, Chlorophytum Comosum, Codiaeum Variegatum Blume, Epipremnum Aureum (Linden & André) G. S. Bunting, Crinum asiaticum, Dracaena trifasciata, Diffenbachia picta Schott, Portulacaria afra f. variegata, Peperomia obtusifolia (L.) F.Dietr, Aglaonema cochinchinense, Pilea Cadierei, and Cordyline fruticose (L.) A.Chev. The ability of each ornamental plant to reduce CO₂ levels was recorded over a 24-hour period. It was observed that Epipremnum aureum exhibited superior CO₂ absorption capabilities compared to other ornamental plants in this study. It had an average CO₂ absorption and release of -36 and 2 ppm, respectively, in the closed chamber, both during the daytime and nighttime. It is suggested to incorporate these plants in various living areas such as the living room, kitchen, bedroom, or office spaces.

Creating Alternative Model to Developed Municipal Solid Waste Management Pratices for Local Government Organization with Analytical Hierarchy Process

2023-12-21T11:04:06+07:00

This study aimed to find factors used in the selection of appropriate waste management systems and guidelines of Lam Ta Sao municipality, Lamtasao town municipality, Ayutthaya province, Thailand to create a choice of project formats that guide the future of municipal solid waste development. The Analytical Hierarchy Process (AHP) is used to analyze important factors and the results of prioritization are used to determine guidelines for creating final municipal solid waste management system options. The study found that personnel and cognitive factors have the highest priority (14.95%), followed by cooperation and process factors (14.34%), area conditions factors (12.90%), strategic waste management support factors (11.03%), economic factors (10.36%), social conditions factors (9.56%), waste management systems factors (8.53%), personnel potential factors (8.38%), budget factors (5.14%) and material factor (4.81%) respectively. The results of prioritizing factors can be used to create alternative models to develop waste management guidelines, which can be divided into 5 characteristics: (1) Options for determining personnel development guidelines. (2) Choice of various methods and processes for waste disposal to support the disposal of each type of waste. (3) Appropriate waste management options through participatory processes. (4) Options for setting waste management guidelines in multiple situations with a spatially integrated method and (5) Choice of concepts and working principles that are consistent with the waste management strategy. The factors obtained from this study can be used as the main guideline for selecting a waste management model in the study area. Other related spatial data can also be added as supplementary data for determining the other necessary details. However, this study still requires the use of many working mechanisms, especially those of the government sector. Moreover, this study also requires the use of up-to-date studies of all dimensions of data to be able to develop better efficiency.