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Resilience has gained significant prominence in the management of climate-related shocks and the minimization of disaster risks. Assessing flood resilience is, therefore, crucial in identifying areas lacking support and opportunities for development. Comprehensive risk assessments are urgently required, especially in areas prone to floods. By applying the Analytical Hierarchy Process (AHP), stakeholder meetings, and keyword analysis, this study aims to assess the flood resilience of Phra Nakhon Sri Ayutthaya Province (PNSAP) in Thailand, an area at high risk of flooding and home to a UNESCO World Heritage Site. According to the Arup and Rockefeller Foundation's City Resilience indicators, the key elements for building resilience in PNSAP include effective emergency response services, comprehensive hazard monitoring and risk assessment, and emergency medical care. In addition, the focus group discussions and keyword analysis identified the following critical components for strengthening flood resilience: "financial aspects", "community awareness and preparedness", "multi-stakeholder collaboration", "citizen engagement", and "urban flood monitoring and data management." Moreover, to gain insight into the perceptions of people in local communities, the results of a household survey (n = 552) indicated that approximately one-third of the respondents had never engaged in flood preparedness activities. Neither the gender nor the education level of the respondents significantly influenced their engagement in flood preparedness. The respondents also perceived that infrastructure flexibility, affordable transport networks, flood monitoring and data management, the adequate provision of critical services, and reliable communication systems in building resilience were important during a flood disaster. These results provide valuable insight into the community's perception of the effectiveness of disaster risk reduction mechanisms for building flood resilience in PNSAP and can serve as a useful guide for future resilience-building initiatives. By addressing these factors, PNSAP could enhance its resilience to the impacts of flooding and contribute to the global field of flood management and resilience building. [ABSTRACT FROM AUTHOR]

Oxygen scarcity may significantly affect the process performance since it has low aqueous solubility and high demand by chemical and biological processes. The oxygen mass transfer is therefore necessary to enhance. This work aimed to develop the gas-liquid reactor, named Modified Airlift Reactor (MALR) for improving the oxygen transfer efficiency in terms of internal configurations and aeration parameters by equipping a vertical baffle for creating liquid circulation phenomena, and installing slanted baffles in the reactor riser to extend air-bubbles retention time and to improve their distributions. Since extremum conditions of the investigated factors may inefficient, optimum levels are required to identify. 2k factorial and response surface design of Design of Experiment (DOE) methodology were applied to optimize these complex variables in terms of overall liquid mass transfer coefficient (KLa) of clean water. As a result, the main effective factors of MALR with their optimum value are amount of baffles (Nb ∼ 3 baffles), baffle angle (α ∼ 50°), position of base area (Yr ∼ 10 cm), open space on baffle (As ∼ 90 cm2), and gas flow (Qg). Increasing Qg resulted better KLa for the studied ranges (2–18 LPM). At the optimum condition, the improvement of MALR in terms of KLa coefficient was increased up to 97% and 28% compared to the regular bubble column and airlift reactor, respectively, at a certain gas flow without any extra energy. The correlation models of KLa coefficient with significant variables and power consumption were constructed for future estimation purposes. [ABSTRACT FROM AUTHOR]

Removal of TiO2 nanoparticles (NPs) from water by coagulation and microfiltration (MF) was investigated at various ionic species and strengths. Appropriate coagulant doses were determined based on the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, and coagulation with ferric chloride (FeCl3) at 0.1–0.2 mM or poly-aluminum chloride (PACl; [Al2(OH)nCl6-n]m) at 0.2–0.4 mM improved removal of TiO2 NPs to more than 90%, and, simultaneously, turbidity was significantly reduced. Using 0.2 mM FeCl3 as a coagulant, the mean particle size of suspended TiO2 NPs decreased from 145 to 43 nm after coagulation and sedimentation as a result of effective floc formation. Microfiltration (nominal pore size: 0.45 μm and 0.10 μm) of uncoagulated TiO2 NP suspensions produced lower NP concentrations in the filtrate than that in the filtrate of pre-coagulated water. This is because pre-coagulation and settling removed large NPs in the feed water that reduce the number of smaller particles than the pore sizes by clogging or blocking membrane pores. Results suggest that removal of NPs by coagulation/sedimentation followed by membrane filtration may be less efficient than direct membrane filtration. Addition of salts (NaCl 0.3–15 mM or CaCl2 0.1–5 mM) to TiO2 NP suspensions before coagulation led to significant reduction (0.28–0.47 mg/L) of TiO2 concentrations in supernatant after sedimentation. Phosphate addition (0.01, 0.1, and 1.0 mM) increased TiO2 NP concentration after FeCl3 or PACl coagulation and settling, but TiO2 NP removal rate by MF was improved by phosphate addition except for filtering TiO2 NP suspension with 1.0 mM phosphate by a 0.45 μm membrane. [ABSTRACT FROM AUTHOR]