Social vulnerability, impacts and adaptations strategies in the face of natural hazards: insight from riverine islands of Bangladesh.

BACKGROUND: Bangladesh is one of the countries at risk of natural disasters due to climate change. In particular, inhabitants of its riverine islands (char) confront ongoing climatic events that heighten their vulnerability. This study aims to assess social vulnerability, impacts, and adaptation strategies to climate change in the riverine island areas of Bangladesh. METHODS: A mixed-method approach incorporating qualitative and quantitative procedures was used on data collected from 180 households of riverine islands in Gaibandha, Bangladesh. The social vulnerability of riverine island communities was assessed based on their adaptation capacity, sensitivity, and exposure to climatic stressors. RESULTS: The findings show that char dwellers' vulnerability, impacts, and adaptation capability to climate change vary significantly depending on their proximity to the mainland. Social vulnerability factors such as geographical location, fragile and low-grade housing conditions, illiteracy and displacement, climate-sensitive occupation and low-income level, and so on caused to the in-height vulnerability level of these particular areas. This study also displays that climate change and its associated hazards cause severe life and livelihood concerns for almost all households. In this case, the riverine dwellers employed several adaptation strategies to enhance their way of life to the disaster brought on changing climate. However, low education facilities, deficiency of useful information on climate change, poor infrastructure, and shortage of money are still the supreme hindrance to the sustainability of adaptation. CONCLUSION: The findings underscore the importance of evaluating the susceptibility of local areas to climate change and emphasize the need for tailored local initiatives and policies to reduce vulnerability and enhance adaptability in communities residing in char households.

Characterization of the volatile organic compounds produced from green coffee in different years by gas chromatography ion mobility spectrometry.

The effect of storage time on green coffee volatile organic compounds (VOCs) was studied by their separation via head space solid-phase microextraction and identification via gas chromatography-ion mobility spectrometry. In total, 38 kinds of VOCs, mainly composed of alcohols, aldehydes, esters and ketones, were identified. The fingerprint showed that the VOCs produced by green coffee in different years had obvious differences, especially, acrolein, 3-methylbutyl acetate, butanoic acid, heptan-3-ol, and so on, that could be used to predict the storage time. In addition, with the increase of storage time, the contents of butanal, ethanol, dimethyl sulfide, propanal, butan-2-one had no obvious change, and could be considered as typical aroma characteristics of green coffee or special aroma components for variety identification. Meanwhile, principal component analysis (PCA) and "nearest neighbor" fingerprint analysis could also effectively distinguish green coffee with different storage times. Comprehensive analysis showed that GC-IMS technology could provide strong and favorable support for coffee storage.

Construction of a C-decorated and Cu-doped (Fe,Cu)S/CuFe2O4 solid solution for photo-Fenton degradation of hydrophobic organic contaminant: Enhanced electron transfer and adsorption capacity.

To effectively treat the hydrophobic organic contaminant and utilize an industrial solid waste manganese residue (MR), a novel starch-derived carbon (SC)-decorated and Cu-doped (Fe,Cu)S/CuFe2O4 solid solution (CFS/CFO@SC) was prepared from MR via mechanical activation treatment of precursor materials followed by one-step pyrolysis and applied as a photo-Fenton catalyst to treat a hydrophobic organic compound, 17α-ethinylestradiol (EE2). Characterization results showed that the CFS/CFO@SC solid solution with unique crystal and electronic structures exhibited high adsorption capacity and catalytic activity, ascribed to that Cu doping and C decorating enhanced its hydrophobicity and BET surface area. The CFS/CFO@SC showed excellent degradation efficiency with nearly 100% of EE2 removal rate in 40 min (degradation rate constant of 0.112 min-1), and a high mineralization degree with 95.2% of TOC removal in 180 min. This could be ascribed to that C decorating and the formation of CFS/CFO solid solution promoted the charge transfer in a continuous band, resulting in effective separation of photogenerated holes-electrons (h+-e-). The strong interaction of Fe-Cu collaborating with the photoelectron could effectively accelerate the recycle of Fe3+/Fe2+ and Cu2+/Cu+, thus generating more active radicals. Moreover, CFS/CFO@SC showed promising stability and recyclability with the EE2 removal rates all >95% after five cycles. This work brings a valuable approach for the rational design of high-performance Fe-based photo-Fenton catalysts for environmental remediation and the valorization of MR.

Effects of oxidative stress reaction for the Eisenia fetida with exposure in Cd2.

Earthworms are widely used in all kinds of pollutants as sensitive bio-indicator organisms because of their immediately oxidative stress response under the stress of heavy metal. However, there are a large number of indexes associated with the oxidative stress response. Finding out the key monitoring indexes in the stress process becomes a practical demand of the pollution monitoring and warning process. We studied two groups, the short-term test and the long-term test. The former one is for 10 days, taking out an earthworm every day. The latter test lasted 30 days, taking out an earthworm every 10 days. The Cd2+ concentration was set at 50, 100, 125, 250, and 500 mg kg-1. Post-clitellum segments of earthworms were chosen to determine superoxide enzyme (SOD), peroxidase (POD), glutathione peroxidase (GSH-Px), glutathione-S transferase (GST), catalase (CAT), vitamin E (VE), malondialdehyde (MDA), and acetylcholinesterase (AChE). The results showed that the main bio-indicators associating with oxidative stress reaction in short-term group were CAT, SOD, and POD. MDA could be used as a bio-indicator in the early and mid-term. VE was only the bio-indicator in the mid-term stress. While with the long-term test, the main bio-indicators associated with oxidative stress reaction were GSH-Px and MDA. The AChE activity was only suitable for oxidative stress response caused by heavy metal stress more than 30 days.