Implementing a decentralized sanitation system for the under-served urban community of Thongkhankham Nea Village, Lao PDR.

Thongkhankham Nea village, is the largest slum community in Vientiane capital city. Although it is located in the core area of the city it is still an underserved community in terms of sanitary infrastructure. The probability of serving the village by a centralized sanitation system in near future is low. Hence a study was conducted to explore the prospects of implementing a decentralized system. The research results reveal that a decentralized sanitation sytem will satisfy the current needs and meet the affordability level of inhabitants. Therefore, a decentralized system is seen as a viable alternative

Sanitation biomass recovery and conversion

In Cookey, P. E.; Koottatep, T.; Gibson, W. T.; Polprasert, C. (Eds.). Integrated functional sanitation value chain: the role of the sanitation economy. London, UK: IWA Publishin

Comparison of rapid methods for detection of Giardia spp. and Cryptosporidium spp. (Oo)cysts using transportable instrumentation in a field deployment

Reliable, sensitive, quantitative, and mobile rapid screening methods for pathogenic organisms are not yet readily available, but would provide a great benefit to humanitarian intervention units in disaster situations. We compared three different methods (immunofluorescent microscopy, IFM; flow cytometry, FCM; polymerase chain reaction, PCR) for the rapid and quantitative detection of Giardia lamblia and Cryptosporidium parvum (oo)cysts in a field campaign. For this we deployed our mobile instrumentation and sampled canal water and vegetables during a 2 week field study in Thailand. For purification and concentrations of (oo)cysts, we used filtration and immunomagnetic separation. We were able to detect considerably high oo(cysts) concentrations (ranges: 15-855 and 0-240 oo(cysts)/liter for Giardia and Cryptosporidium, respectively) in 85 to 300 min, with FCM being fastest, followed by PCR, and IFM being slowest due to the long analysis time per sample. FCM and IFM performed consistently well, whereas PCR reactions often failed. The recovery, established by FCM, was around 30% for Giardia and 13% for Cryptosporidium (oo)cysts. It was possible to track (oo)cysts from the wastewater further downstream to irrigation waters and confirm contamination of salads and water vegetables. We believe that rapid detection, in particular FCM-based methods, can substantially help in disaster management and outbreak prevention

Removal and monitoring acetaminophen-contaminated hospital wastewater by vertical flow constructed wetland and peroxidase enzymes

© 2019 Elsevier Ltd Hospital wastewater contains acetaminophen (ACT) and nutrient, which need adequate removal and monitoring to prevent impact to environment and community. This study developed a pilot scale vertical flow constructed wetland (CW) to (1) remove high-dose ACT and pollutants in hospital wastewater and (2) identify the correlation of peroxidase enzyme extruded by Scirpus validus and pollutants removal efficiency. By that correlation, a low-cost method to monitor pollutants removal was drawn. Plants, such as Scirpus validus, generated peroxidase enzymes to alleviate pollutants’ stress. Results showed that the CW removed 3.5 to 6 logs of initial concentration 10 mg ACT/L to a recommended level for drinking water. The CW eliminated COD, TKN and TP efficiently, meeting the wastewater discharged standards of Thailand and Vietnam. By various multivariable regression models, concentrations of ACT in CW effluent and enzymes in S. validus exhibited a significant correlation (p < 0.01, R2 = 68.3%). These findings suggested that (i) vertical flow CW could remove high-dose ACT and nutrient and (ii) peroxidase enzymes generated in S. validus, such as soluble and covalent ones, could track ACT removal efficiency. This would help to reduce facilities and analytical cost of micro-pollutants

intI1 gene abundance from septic tanks in Thailand using validated intI1 primers.

Antimicrobial resistance (AMR) poses a serious global health threat, and wastewater treatment (WWT), including septic tanks, is a source of AMR. In Thailand, antibiotics are unregulated, and septic tanks are commonly used. Yet, their impact on the spread or mitigation of AMR is unknown. We monitored household and healthcare conventional septic tanks (CST) and household solar septic tanks (SST) in Thailand using the class 1 integron-integrase (intI1) gene abundance as a proxy for AMR. A systematic review of the literature found 65 intI1 primers. We evaluated the coverage and specificity of each, including a new MGB TaqMan primer-probe, against clinical and environmental intI1, intI1-like, and non-intI1 databases. The three best primers were selected, laboratory validated for DNA and mRNA quantification, and used to quantify septic tank intI1 gene abundance. No primer set could distinguish between intI1 and intI1-like sequences. While primer choice did not affect gene abundance of the same sample (P-value &gt; 0.05), sometimes when comparing the same samples quantified by different primers, statistical differences were observed for one but not the other primer set. This may lead to different interpretations of AMR risk. Irrespective of primers or reactor type intI1 gene abundance was greatest in influent &gt; effluent &gt; sludge. intI1 gene abundance was lowest in the effluent of the SST-household &lt; CST-household &lt; CST-healthcare. 31% to 42% of intI1 was removed by the CST-household tank, indicating while septic tanks remove some intI1 they remain a source to the surrounding environment. Toward the goal of achieving standardization across studies, we recommend the F3-R3 primer for intI1 quantification

Microbial risk assessment in Vietnam: Translating research and training into policy

Until recently, the availability of training in risk assessment in general was very limited in Vietnam, and training in microbial risk assessment (MRA) was not available at all. To fill this gap we developed a training course in MRA by compiling existing MRA trainings, contextualising them, and adapting them to the local context. The resulting course teaches participants the concept of risk analysis, the steps of an MRA and how to implement these steps, as well as risk communication and management. A first one-week training course was successfully held. MRA was also used for assessing health risks related to wastewater reuse in agriculture and food safety in Vietnam. Diverse scenarios of exposure to wastewater when working with wastewater for agriculture, as well as consumption of pork meat were studied to quantify health risk. The results showed that water and vegetables were heavily contaminated with pathogens; risk in the scenarios tested was high and largely exceeded the acceptable level stipulated by WHO. The results also revealed the most critical issues in terms of risk, thereby pointing to topics on which interventions should focus. The findings can serve to improve policies on and practices of waste reuse. MRA has been recognised by health staff, lecturers, researchers, and policymakers at the Ministry of Health (MOH) as a useful tool that provides scientific evidence for decisionmaking and risk management. A book on MRA was published in Vietnamese with support from the Ministry of Health and the World Health Organization (WHO) in Vietnam. It serves as a guideline on MRA, which is a component in Vietnam’s Food Safety Law. The university has adapted the health risk assessment course for undergraduate and graduate public health students. Further initiatives to intensify research on MRA are ongoing, and researchers of the team have been selected to become part of the MOH’s national task force on risk assessment

Bridging the Form and Function Gap in Urban Green Space Design through Environmental Systems Modeling

Using a case study approach from past projects in Singapore, Australia, Cambodia, Thailand and Vietnam, we examine the benefits, but also some of the challenges, to implementing green space in urban design. Green space can have multiple physical and psychological wellbeing benefits, as well as environmental benefits, including urban runoff quantity and quality management, urban heat island abatement, air quality improvement, and noise reduction. Water sensitive urban design (WSUD) can be an important element of green space design and here we explore how modeling of ecosystem services and dynamic modeling of WSUD can help to facilitate sound planning and management decision making in support of green space implementation. As we illustrate with examples for Australia, Singapore and Cambodia, we believe that application of an urban ecosystem services modeling approach can elucidate environmental benefits of urban green space that otherwise may not be considered. Engineers may include dynamic modeling of WSUD in support of an urban master plan, or urban redevelopment, but generally urban planners are less conversant in applying models. We discuss some of the challenges to integrating multidisciplinary visioning and modeling of green space design and performance evaluation through our experience with a stormwater and wastewater design study for Cha Am, Thailand, that included landscape architecture and engineering classes at Thammasat University, Mahidol University, and AIT. Through a case study of Phnom Penh, we illustrate how modeling and 3D visualization can be used to effectively explore the benefits of green space. We conclude that a user-friendly decision support system is needed to integrate modeling and visualization tools and thereby bridge the gap between form and function in urban green space design.</jats:p