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Publication Open Access Use of Agricultural Residues to Remove Iron from Groundwater in Modified Airlift Aerator(2019) Thanakrit Neamhom; Mahidol University. Faculty of Public Health. Department of Environmental Health ScienceThis work investigated groundwater iron adsorption capacity from rice husk, rice straw, water hyacinth and coconut shell, agricultural residues commonly found in Thailand. This study also investigated the adsorption behavior... can be sustainably used to adsorb iron in groundwater. At equilibrium, the adsorption isotherm was fitted to the Freundlich equation with an R2value of 0.9805. This implied that the adsorption sites on the rice huskPublication Open Access Factors Affecting the Prevalence of Fecal Pathogen Infections: Approaches for Health Risk Protection(2021) Thammarat Koottatep; Achara Taweesan; Thongchai Kanabkaew; Chongrak Polprasert; Asian Institute of Technology. Resources and Development. School of Environment; Ramkhamhaeng University. Faculty of Science. Department of Environmental Science; Mahidol University. Faculty of Public Health. Department of Sanitary Engineering; Thammasat University. Faculty of Engineering. Department of Civil EngineeringSeptic tank sludge or fecal sludge (FS) is often discharged on public areas without any treatment, causing environmental and adverse public health effects. Millennium Development Goal 7c (MDG 7c) targets improved access to water and sanitation because 85% of the world’s total FS is often discharged on public areas. Like other countries, Thailand faces fecal slugde management (FSM) problems leading to significant fecal pathogen infections, especially in the north and northeastern regions. This study assessed the effects of unsafely-managed FS on human health risks in two cities, Natan City and Tham Lod City in Thailand, that have relatively high liver fluke and diarrhea infections, and identified the factors relating to FSM practices that affect the prevalence of liver fluke and diarrhea infections due to FS. Specific measures were proposed in delivering integrated FSM solutions and health risk protection toward the Sustainable Development Goal No. 6 (SDG6) targets of safely managed sanitation and hygiene services. Based on data collected from these cities from February to May 2019, factors relating to FSM practices that affect the prevalence of liver fluke and diarrhea infections were identified and analysed using multiple regression analysis. Based on the findings, specific measures in delivering integrated FSM solutions and health risk protection toward the Sustainable Development Goals 6 (SDG 6) are proposed. Because no FS treatment facilities operate in Natan City and Tham Lod City, almost 100% of FS is discharged directly into open drains, resulting in diarrhea and liver fluke infections among local people. The findings identified the factors relating to FSM practices that affect the prevalence of liver fluke and diarrhea infections and proposed specific measures in delivering integrated FSM solutions and health risk protection, such as promoting education programmes, avoiding direct FS discharges into open drains and nearby streams, and providing innovative FSM technologies to eradicate fecal pathogen infections.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 Polprasert; Mahidol University. Faculty of Public Health. Department of Sanitary Engineering; Mahidol University. Center of Excellence on Environmental Health and Toxicology (EHT); Mahidol University. Faculty of Tropical Medicine. Department of Social and Environmental Medicine; Mahidol University. Faculty of Tropical Medicine. Department of Tropical Pathology; Chulalongkorn University. Environmental Research Institute; Thammasat University. Faculty of Engineering. Department of Civil EngineeringIron 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 การปนเปื้อนของแบคทีเรียบริเวณที่ตั้งถังขยะในโรงอาหาร(2561) เนตรชนก กำลังมาก; ชัชวาล สิงหกันต์; วิชระ สิงหะคเชนทร์; ธวัช เพชรไทย; Netchanok Kamlangmak; Chatchawal Singhakant; Vajira Singhakajen; Tawach Prechthai; มหาวิทยาลัยมหิดล. คณะสาธารณสุขศาสตร์. ภาควิชาวิทยาศาสตร์อนามัยสิ่งแวดล้อมThis study was a survey research, designed to determine characteristics of waste bins and bacteria contamination on the fl oor near to waste bins of three canteens at an educational institution. The study included 2 parts to evaluate general... and sanitary characteristics of both combined waste and food waste bins using a sanitary checklist and determining bacterial contamination on the fl oor at 0, 20, 40, 60, 80, 100, and 300 cm distances from waste bins. In addition, the total bacteriaPublication Open Access Simultaneous Detection of Feces - specific Bacteriophages of Bacteroides fragilis with a Duplex PCR Assay(2018) Natcha Chyerochana; Benjarath Pupacdi Javed; Pornjira Somnark; Skorn Mongkolsuk; Kwanrawee Sirikanchana; Chulabhorn Research Institute. Research Laboratory of Biotechnology; Chulabhorn Research Institute. Translational Research Unit; Mahidol University. Faculty of Science. Department of BiotechnologyBacteriophages of the Bacteroides fragilisstrains 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. fragilisstrains 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 10-5and 10-4ng 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 PCRassay demonstrated potential for the environmental monitoring of Bacteroidesbacteriophages, decreasing the analysis time to a few hoursPublication Open Access Systematic review and consensus guidelines for environmental sampling of Burkholderia pseudomallei(2013-03) Direk Limmathurotsakul; ดิเรก ลิ้มมธุรสกุล; Dance, David A. B.; Vanaporn Wuthiekanun; Kaestli, Mirjam; Mayo, Mark; Warner, Jeffrey; Wagner, David M.; Apichai Tuanyok; Wertheim, Heiman; Cheng, Tan Yoke; Mukhopadhyay, Chiranjay; Puthucheary, Savithiri; Day,Nicholas P. J.; Steinmetz, Ivo; Currie, Bart J.; Peacock, Sharon J.; Direk Limmathurotsakul; Mahidol University. Faculty of Tropical Medicine. Department of Tropical Hygiene; Mahidol University. Faculty of Tropical Medicine. Mahidol-Oxford Tropical Medicine Research Unit; Mahidol University. Faculty of Tropical Medicine. Department of Microbiology and ImmunologyBACKGROUND: Burkholderia pseudomallei, a Tier 1 Select Agent and the cause of melioidosis, is a Gram-negative bacillus present in the environment in many tropical countries. Defining the global pattern of B. pseudomallei distribution underpins efforts to prevent infection, and is dependent upon robust environmental sampling methodology. Our objective was to review the literature on the detection of environmental B. pseudomallei, update the risk map for melioidosis, and propose international consensus guidelines for soil sampling. METHODS/PRINCIPAL FINDINGS: An international working party (Detection of Environmental Burkholderia pseudomallei Working Party (DEBWorP)) was formed during the VIth World Melioidosis Congress in 2010. PubMed (January 1912 to December 2011) was searched using the following MeSH terms: pseudomallei or melioidosis. Bibliographies were hand-searched for secondary references. The reported geographical distribution of B. pseudomallei in the environment was mapped and categorized as definite, probable, or possible. The methodology used for detecting environmental B. pseudomallei was extracted and collated. We found that global coverage was patchy, with a lack of studies in many areas where melioidosis is suspected to occur. The sampling strategies and bacterial identification methods used were highly variable, and not all were robust. We developed consensus guidelines with the goals of reducing the probability of false-negative results, and the provision of affordable and 'low-tech' methodology that is applicable in both developed and developing countries. CONCLUSIONS/SIGNIFICANCE: The proposed consensus guidelines provide the basis for the development of an accurate and comprehensive global map of environmental B. pseudomallei.