BackgroundVietnam is one of the most disaster-prone countries in the world. The country suffers from many kinds of natural disasters, of which the most common and serious one is flooding. Long and heavy rainfall during the last days of October and the first week of November 2008 resulted in a devastating flood unseen for over three decades in the capital city of Hanoi. It caused a substantial health impact on residents in and around the city and compromised the capacity of local health services.ObjectiveThe aim of this study is to ascertain the vulnerability and health impacts of the devastating flood in Hanoi by identifying the differences in mortality, injuries, and morbidity patterns (dengue, pink eye, dermatitis, psychological problems, and hypertension) between flood affected and non-affected households.DesignA cross-sectional study was carried out involving 871 households in four selected communes (two heavily flood affected and two comparatively less affected) from two severely flooded districts of Hanoi. Participants were interviewed and information collected on the social, economic, and health impacts of the devastation within 1 month after the flood.ResultsThe self-reported number of deaths and injuries reported in this study within 1 month after the heavy rainfall were a bit higher in severely affected communes as compared to that of the less affected communes of our study. The findings showed higher incidences of dengue fever, pink eye, dermatitis, and psychological problems in communes severely affected by flood as compared to that of the controlled communes.ConclusionsFor people in flood prone areas (at risk for flooding), flood prevention and mitigation strategies need to be seriously thought through and acted upon, as these people are exposed to greater health problems such as psychological issues and communicable diseases such as pink eye or dermatitis.

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Vu 6 , t. t. pham 7 , thi nu nguyen 8 , n. V. Quang 9 & X. c. nguyen 10,11* this study presents the removal of phosphate from aqueous solution using a new silver nanoparticlesloaded tea activated carbon (Agnps-tAc) material. in order to reduce costs, the tea activated carbon was produced from tea residue. Batch adsorption experiments were conducted to evaluate the effects of impregnation ratio of Agnps and tAc, pH solution, contact time, initial phosphate concentration and dose of Agnps-Ac on removing phosphate from aqueous solution. Results show that the best conditions for phosphate adsorption occurred at the impregnation ratio AgNPs/TAC of 3% w/w, pH 3, and contact time lasting 150 min. The maximum adsorption capacity of phosphate on AgNPs-TAC determined by the Langmuir model was 13.62 mg/g at an initial phosphate concentration of 30 mg/L. The adsorption isotherm of phosphate on AgNPs-TAC fits well with both the Langmuir and Sips models. The adsorption kinetics data were also described well by the pseudo-first-order and pseudo-secondorder models with high correlation coefficients of 0.978 and 0.966, respectively. The adsorption process was controlled by chemisorption through complexes and ligand exchange mechanisms. this study suggests that Agnps-tAc is a promising, low cost adsorbent for phosphate removal from aqueous solution.

Magnetic modified-corncob biochar with an impregnation ratio of iron at 20% (w/w) was used for removal of Cr(vi) from aqueous solution.

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In this study, freshwater snail shells (FSSs) containing CaCO3 were used as a low-cost biosorbent for removing Cr(VI) from aqueous solutions. The characteristics of FSS and mechanism of Cr(VI) adsorption onto FSS were investigated. The FSS biosorbent was characterized using nitrogen adsorption/desorption isotherm, X-ray diffraction, scanning electron microscopy with energy dispersive spectroscopy, and Fourier transform infrared spectroscopy. The adsorption mechanism was determined by conducting various batch adsorption experiments along with fitting experimental data with various adsorption models. Batch adsorption experiments were conducted as a function of solution pH, contact time, biosorbent dose, and initial Cr(VI) concentration. Results indicated that pH = 2, a contact time of 120 min, and an initial Cr(VI) concentration of 30 mg/L at 20°C were the best conditions for adsorption of Cr(VI) onto FSS. The Cr(VI) adsorption onto FSS decreased with an increase in temperature from 20 to 40°C. The obtained maximum adsorption capacity was 8.85 mg/g for 2 g/L of FSS dose with 30 mg/L of initial Cr(VI) at 20°C. The adsorption equilibrium data fit well with the Sips and Langmuir isotherm models at 20°C with a high R2 of 0.981 and 0.975, respectively. Also, a good correlation between the experimental data and the pseudo-second-order model was achieved, with the highest R2 of 0.995 at 20°C. The adsorption mechanisms were electrostatic interaction and ion exchange. Simultaneously, this mechanism was also controlled by film diffusion. The Cr(VI) adsorption process was irreversible, spontaneous (−∆G°), exothermic (∆H° is negative), and less random (∆S° is negative). In conclusion, freshwater snail shells have the potential as a renewable adsorbent to remove toxic metals from wastewater.

PurposeThis paper examines whether guests contribute sWOM (social word of mouth) on different SNSs (social networking sites) regarding various personal motivations. SNSs have changed the way guests eat and experience their food and dishes. Marketing managers have effectively targeted SNSs as a marketing tool, yet have little research about drivers of guests' sWOM contribution on SNSs has been done. A model including the significant motives: (1) experiences, (2) opinion leadership, (3) reflection of self and (4) need for unique is tested to investigate their positive effects on contribution behavior of social media guests.Design/methodology/approachThe data collected from 411 guests by using the snowball method was used for analysis. The structural equation modeling was applied to examine the relationships among the constructs and test the eight proposed hypotheses.FindingsResults reveal that experiences, opinion leadership, reflection of self and need for unique were positively associated with contributing sWOM of restaurants. Furthermore, those who have positive experiences tend to be opinion leadership and reflection of self. And guests who show reflection of self, they are more likely to have opinion leaders and show need for uniqueness. Our study expands the existing frameworks of sWOM contribution by identifying various motivations and labeling sWOM. Findings provide restaurant managers with managerial implications for online marketing strategies on SNSs to attract sWOM contribution among guests.Research limitations/implicationsIt has some limitations while discovering the motivations of positive sWOM contribution. First, we only focused on the motivation of contributing positive sWOM, while negative sWOM received many arguments in changing attitudes toward buying products or services. Second, we collected data in Vietnam only without comparing with different countries. Future research could explore further cross-cultural perspectives to fill the gap. Third, this study explored sWOM contribution in service environment, sWOM contribution from service context may be slightly different from those of product brands.Practical implicationsThese findings highlight the motivations of sWOM contribution that restaurant managers must recognize and make use of it. SNSs have given power to consumers to post everything at anytime and anywhere they like, therefore restaurant managers need to deeply understand why their consumers contribute sWOM. In digital era, customers and guests have become the ultimate tools for promoting product or service brands. The marketing managers should create an online platform in order to facilitate their consumers to discuss their brand frequently (Charu et al., 2018). Restaurants should have policies to push positive eWOM maximally and also reduce advertising costs.Originality/valueThis is one of the first studies on sWOM contribution of what motivate guests to contribute their sWOM on SNSs. Theoretically, this study offers deep insights into the links between various motivations and sWOM in foodservice context. Managerially, understanding these motivations allow marketing managers create effective policies that motivate guests to contribute positive word of mouth.

In this study, Fe3O4 nanoparticle-loaded biochar derived from the pomelo peel (FO-PPB) was synthesized and applied as an affordable material for the adsorption of Reactive Red 21 (RR21) in an aqueous solution. The characteristics of FO-PPB were evaluated by scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), X-ray diffraction (XRD), Raman spectra, Fourier transform infrared spectra (FTIR), and Brunauer–Emmett–Teller (BET) surface area. The adsorption process of FO-PPB with RR21 was evaluated through batch experiments to examine various parameters including solution pH, contact time, adsorbent dose, initial RR21 concentration, and solution temperature. Results show that FO-PPB produced by the impregnation ratio between iron (Fe) and pomelo peel biochar (PPB) of 5 : 1 (w/w) had the best adsorption performance. The adsorption capacities of PPB and FO-PPB at optimum experimental conditions (solution pH 3, contact time of 60 min, solution temperature of 40°C, initial RR21 concentration of 300 mg/L, and adsorbent dose of 2 g/L) were 18.59 and 26.25 mg/g, respectively. The adsorption isotherms of RR21 on PPB and FO5-PPB were described well by Langmuir and Sips models with high R2 values of 0.9826 and 0.9854 for FO5-PPB and 0.9701 and 0.9903 for PPB, respectively. The obtained data also well matched the pseudo-first-order and pseudo-second-order models with R2 values ≥ 0.96. Chemisorption through sharing or electronic exchange was determined as the main adsorption mechanism.