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Publication Open Access Assessment of the Potential Climate Change on Rice Yield in Lower Ayeyarwady Delta of Myanmar Using EPIC Model(2018) Naw Mar Lar; Noppol Arunrat; Soe Tint; Nathsuda PumijumnongClimate change has been occurring and its consequences are a threat to rice production and hence food security. In this study, the effect of climate change on rice yield has been assessed by using the Environmental Policy Integrated Climate model under climate change scenarios RCP4.5 (medium emissions) and RCP8.5 (high emissions) and to propose alternative adaptive measures for farmers’ livelihoods in the lower Ayeyarwady Delta. The results show that the average yield increase of early rice are 11.84% and 7.56% and the average yield reduction of late rice are 37.37% and 50.89% under both scenarios. The study found that rice yield reduction will be significantly higher under the RCP8.5 than that of RCP4.5 for both rice. Yield reductions are attributed to increases in mean maximum and minimum temperatures and variation in rainfall pattern. The model result suggests that changing the sowing date is a good option for compensating the future rice yield reduction. The other adaptations that offset the rice yield response to climate change include providing farming machines, irrigation facilities, improving infrastructure, improvement in cultivars that resist disease, pest and drought, better weather forecast and extension systems.Publication Open Access Color Removal of Pulp and Paper Mill Wastewater Using Residual Eucalyptus Wood(2022) Kanjana Yupin; Thanakrit Neamhom; Chatchawal Singhkant; Siranee Sreesai; Supawadee PolprasertThis study investigated the color removal efficiency of pulp and paper mill wastewater using residual eucalyptus wood as a method to minimize the solid wastes generated from pulp and paper processes. The activated carbon used in this study as the color adsorbent was produced from residual eucalyptus wood. The carbon was activated with phosphoric acid and carbonized in a furnace at 500°C for 60 min. Effects of types and amounts of activated carbon on color removal efficiency were evaluated. Three types of solid wastes, consisting of wood chip, bark, and mixed wood (wood chip:bark, 1:1), were investigated at a loading of 1, 3, 5, and 7 g/100 mL under contact times of 30, 60, 90, and 120 min. The results showed that 7 g of wood chip activated carbon/100 mL under all contact times gave color removal efficiency of 94-97%. However, the highest adsorption capacity of 216 ADMI/g occurred at 1 g of adsorbent used. Freundlich isotherms were satisfactorily fitted to experimental data for the best condition with high correlation coefficients. The color removal efficiency depended on surface area, pore volume, structure, and characteristics of the activated carbon.Publication Open Access Microplastic Pollution in an Urban Wastewater Treatment Plant: Unravelling Problems and Proposing Solutions(2025) Anh Tuan Ta; Sandhya Babel; Lukas Klocke; Andreas HaarstickMicroplastics (MPs) are detected ubiquitously in aquatic environments worldwide, with wastewater treatment plants (WWTPs) serving as significant pathways for their entry. This study investigates MP removal efficiency and suggests improvements in a conventional municipal WWTP in Bangkok, Thailand. Wastewater samples were collected using a volume-reduced method and filtered into three size ranges (0.05-0.5, 0.5-1.0, and 1.0-5.0 mm). Particles bigger than 0.5 mm were assessed for abundance using an optical microscope and identified for polymer types using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, while smaller particles were analyzed using fluorescence microscopy and micro-FTIR. The average concentration of MPs entering the WWTP was 16.55±9.92 MPs/L, whereas the concentration discharged into the environment was 3.52±1.43 MPs/L. The resultant MP removal efficiency of the Bangkok WWTP stands at approximately 78%, a figure lower than that of WWTPs in developed countries. This discrepancy is attributed to the absence of a primary clarifier within the Bangkok WWTP and an under-designed grit channel. Thus, the implementation of a filter system using activated carbon is suggested. Based on the calculations, 21 filter units are required for the Bangkok WWTP to improve MPs’ removal effectiveness. This study provides vital data on the presence of MPs in a Bangkok WWTP, emphasizing challenges that impede effective removal efficiency. Additionally, this study proposes potential solutions to enhance the removal of MPs and address these issues.Publication Open Access Factors in Community Adaptation for Climate Change Mitigation in Thailand(2024) Tipmol Traiyut; Patranit Srijuntrapun; Wee RawangThis study reflects the experiences of communities who have adapted to climate change in three different geological locations in the country of Thailand: by the riverside, coast, and in the mountains. The communities presented the lessons learned and identified key adaptation factors. The study used in-depth interviews and focus group discussions, with results showing that the community’s learning and adaptation to climate change were at a high level. The results broaden understanding of climate change in these locations and provide information for resource management approaches. Among the seven factors, five factors illustrated that they were highly adapted, including: (1) applying knowledge about nature, ecosystems, and traditional wisdom; (2) management that allowed the use of adaptations; (3) a shared vision of success; (4) collaboration; and (5) having a variety of options and approaches. Two factors that illustated that the community was only moderately adapted included: (1) learning about violent events and disasters; and (2) following government guidelines. It was found that a lack of information about the ecosystems and environmental resources they required for large-scale infrastructure construction caused issues. This is a problem, and the government must consult with local communities when setting long-term plans and assessing needs, because communities have diverse livelihoods and depend on natural resources. Hence, future studies should include climate change awareness and understanding of what is required by adding community needs linked to climate change adaptation into state development plans as well as utilizing the wisdom and traditional knowledge involving ecology held by these communities into sustainability plans.Publication Open Access Climatic Factors Influencing Dengue Hemorrhagic Fever in Kolaka District, Indonesia(2018) Ramadhan Tosepu; Kraichat Tantrakarnapa; Suwalee Worakhunpiset; Kanchana NakhapakornDengue hemorrhagic fever in Indonesia is one of the serious health problems and requires understanding the occurrence of this disease. Climate Factors have a role that needs attention in the prevention of DHF disease. Understanding of disease patterns will benefit the health surveillance system and provide a way to tackle this problem. The records of dengue fever cases and climate data for the years 2010-2015 were obtained from the Health Office Kolaka District, southeast Sulawesi province and Meteorology, Climatology and Geophysics Agency in Southeast Sulawesi province, respectively. Data for the period 2010 to 2014 were used for model development through multiple linear regressions. The prediction model was used to forecast dengue cases in 2015 and the predicted results were compared with reported dengue cases in Kolaka in the past and forecasting period. Rainfall, humidity, temperature average, minimum temperature, and maximum temperature are significantly correlated with monthly cases of dengue fever. Predicted results showed a good performance where the model was able to predict 3 out of 5 epidemic outbreak events that occurred in January-March 2015 and November-December 2015. The sensitivity of detecting the outbreaks was estimated to be 60%, the specificity was 100%, positive and negative predictive value were estimated to be 100% and 77.8%, respectively. Climate has a major influence on the occurrence of dengue hemorrhagic fever infection in Kolaka district. Although the predictive model has some limitations in predicting the number of cases of monthly dengue fever, it can estimate the possibility of an outbreak three months in advance with a fairly high accuracy. The predictive model can be used to explain the incident rate of DHF of approximately 71%.Publication Open Access Simultaneous Detection of Feces-specific Bacteriophages of Bacteroides fragilis with a Duplex PCR Assay(2017) Natcha Chyerochana; Benjarath Pupacdi Javed; Pornjira Somnark; Skorn Mongkolsuk; Kwanrawee SirikanchanaBacteriophages of the Bacteroides fragilis strains HSP40 and RYC2056 are used as indicators of human-specific and general (non-host specific) fecal pollution in water bodies. However, conventional anaerobic cultivation methods require 1-2 days of incubation. To overcome this limitation, in this study, we developed a DNA-based method to simultaneously detect representative bacteriophages (B40-8 and B56-3) that infect B. fragilis strains HSP40 and RYC2056, respectively. Both phages yielded a 224-bp amplicon with the primer pair BT5414/BT5415, and an additional 152-bp PCR product was observed for B40-8 with the primer pair BT5579/BT5580. The detection limits for B40-8 and B56-3 were 10-5 and 10-4 ng of pure DNA, and 1 and 50 ng of DNA template when 5 and 5,000 PFU/mL were spiked into distilled water, respectively. The assay exhibited a higher sensitivity for sewage samples, with < 0.1 and 15 PFU/mL of phages infecting HSP40 and RYC2056, respectively. The assay did not produce false positive results for the Bacteroides phages PG76, HB13, and GA17 or for the enterococcal phages AIM06 and SR14. The assay also detected RYC2056 phages that were isolated from sewage samples and the phage B40-8 when it was spiked into raw sewage. Thus, the newly developed PCR assay demonstrated potential for the environmental monitoring of Bacteroides bacteriophages, decreasing the analysis time to a few hours.Publication Open Access Fast and Efficient Removal of Hexavalent Chromium from Water by Iron Oxide Particles(2018) Duangta Kitkaew; Athit Phetrak; Sumate Ampawong; Rachaneekorn Mingkhwan; Doungkamon Phihusut; Kamolnetr Okanurak; Chongrak PolprasertIron oxide particles (IOPs) were synthesized by chemical co-precipitation technique and further used as an adsorbent in removing hexavalent chromium (Cr(VI)) from aqueous solutions during batch adsorption. The IOP adsorbent had specific surface area of 65 m2/g, total pore volume of 0.25 cm3/g and mostly contained a mesoporous structure. The analysis of scanning and transmission electron microscopy indicated that the adsorbent contained a substantial amount of iron oxide of about 66%, which was well distributed throughout the adsorbent. The IOP adsorbent showed a rapid and efficient Cr(VI) removal that followed Langmuir adsorption isotherm model with maximum adsorption capacity of 2.39 mg-Cr(VI)/g-IOP, demonstrating a monolayer formation on the adsorptive sites of IOP. The kinetic adsorption of Cr(VI) on the IOP followed the pseudo-second-order model, suggesting chemisorption. Thus, the IOP adsorbent provides a potentially effective technology in eliminating of Cr(VI) from water since it can remove appreciable amounts of Cr(VI) with a relatively short contact time of 30 min.Publication Open Access Efficiency of Biochar and Bio-Fertilizers Derived from Maize Debris as Soil Amendments(2018) Kritsadapan Palakit; Khwanchai Duangsathaporn; Pichit Lumyai; Narapong Sangram; Purin Sikareepaisarn; Chokdee KhantawanUnsuitable handling of crop residues can result in many environmental problems such as air pollution and soil degradation. In the northern parts of Thailand, such problems are partly caused by the burning of agricultural debris after harvesting. The use of maize debris as an amendment for degraded soil can reduce such problems. The aims of this research were twofold. Firstly, to produce biochar and bio-fertilizer from maize debris to improve the quality of degraded agricultural soil. Secondly, to study the efficiency of biochar and bio-fertilizer in Chinese kale (Brassica alboglabra) cultivation with two different water regimes. From the study, it was found that 2.8 kg of dry maize debris could produce 1 kg of biochar and could store 13.6% organic carbon, while 0.5 kg of dry maize debris mixed with 1.1 kg of cow dung could produce 1 kg bio-fertilizer and could store 16.4% organic carbon. Watering once a day resulted in an increase in the yield which was comparatively greater than watering twice a day. By adding bio-fertilizer at 25% (w/w) in soil, the fresh weight of the kale plants was found to be about six times greater than those grown in an untreated soil. A suitable amount of bio-fertilizer to be added to soil for Chinese kale cultivation ranged between 15-30% (w/w), while a maximum of 25-30% (w/w) bio-fertilizer in soil was sufficient for plant growth and it was not necessary to add biochar to the soil.Publication Open Access Phosphorus Recovery and Bioavailability from Chemical Extraction of Municipal Wastewater Treatment’s Waste Activated Sludge: A Case of Bangkok Metropolis, Thailand(2022) Kay Thi Khaing; Chongchin Polprasert; Suwisa Mahasandana; Wanida Pimpeach; Withida Patthanaissaranukool; Supawadee PolprasertThis study evaluated the extractability and bioavailability of Phosphorus (P) recovered from waste activated sludge (WAS) so as to reduce dependence on the import of non-renewable P resources. P extraction was carried out using sulfuric acid (H2SO4). A response surface methodology was used to optimize conditions for the chemical leaching of WAS. The results showed the optimum condition for leaching WAS with 0.1 mol/L H2SO4 for 30 min, resulting in 97% P released. The efficiency of P recovery by P precipitation was associated with pH value and Mg:P. At pH 7, 9, and 11, P recovery was 92, 92, and 91% with uncontrolled Mg and 93, 93, and 92% with sea salt (Mg:P, 2:1), respectively. However, the yield of the produced struvite was much lower compared with that of added sea salt. From elemental analysis, the yield of struvite precipitated at pH 9 of Mg:P, 2:1 was about 26%, and the total P content of the precipitate was 12%. Available P was almost 80% after 35 days of operation, which was higher than that of commercial fertilizers. Results of this study are expected to provide fully comprehensive information to decision-makers regarding the suitability of implementing P-composite matter recovered from WAS. This will also help close the loop of the P cycle for food cultivation in the human ecosystem.Publication Open Access Estimation of Effects of Air Pollution on the Corrosion of Historical Buildings in Bangkok(2022) Nuttacha Daengprathum; Rattapon Onchang; Kanchana Nakhapakorn; Ornprapa Robert; Aungsiri Tipayarom; Peter Johann SturmHistorical buildings are recognized as the valuable cultural heritage of a nation. They may suffer material deterioration unavoidably because of exposure to air pollution. We used geographic information systems with dose-response functions (DRFs) to estimate the corrosion of copper and Portland limestone, and their risk of corrosion with regard to historical buildings in Bangkok, Thailand. The first step was to find a suitable spatial interpolation method considering the air pollution and meteorological measurement data for 2010-2019 from 26 monitoring stations in Bangkok and its neighborhoods. Applying multiple performance measures, the inverse distance weighting (IDW) method was found to be the most suitable. Predictions of the pollutant concentration in the spatial atmosphere showed that the concentration of all pollutants (SO2, NO2, O3, and PM10) tends to increase in 2028. Air pollution exposure time duration tends to be a key factor affecting the corrosion of material. The results of spatial corrosion estimations indicated that in 2010, the corrosion of copper and Portland limestone were at acceptable levels; however, the estimated corrosion levels for 2019 and 2028 are higher and beyond the acceptable levels. Moreover, both materials in the Rattanakosin historical area exceed their tolerable corrosion rates with considerably serious risks in 2028. The results can be further used to establish active measures to reduce the rate of corrosion of historical buildings in Bangkok.