Enhancing disinfection and microcontaminant removal by coupling LED driven UVC and UVA/photo-Fenton processes in continuous flow reactors.

For the first time, the sequential combination of UVC-LED (276 nm) and photo-Fenton/UVA-LED (376 nm) process has been assessed in continuous flow mode for wastewater reclamation according to the new European Regulation for reuse in agricultural irrigation (EU 2020/741). The results show that it is possible to obtain water quality class B (Escherichia coli ≤ 100 CFU/100 mL) by UVC-LED irradiation alone, operating the system with a hydraulic residence time (HRT) of 6.5 min and liquid depth of 5 cm in the case of secondary effluents with low Escherichia coli load (8.102-3.1.103 CFU/100 mL). As for high bacteria concentrations (1.2-4.2.104 CFU/100 mL), HRTs longer than 30 min are required. The bacterial load has not influenced decontamination, removing 18 ± 4 % of microcontaminants. Coupling the UVC (30-min HRT and 5.0 cm liquid depth) and the UVA/photo-Fenton (60-min and 15-cm liquid depth) systems allows 58 ± 4 % of real organic microcontaminants to be removed, in addition to achieving water quality class B.

Impact of COVID-19 on poultry market in Bangladesh.

As a result of COVID-19 spread, Bangladesh implemented a range of measures including general holidays, lockdown, no lockdown, and strict lockdown which resulted in the dramatic ups and downs of the price level of the products. This study aimed to examine the influence of COVID-19 on poultry products (meat and eggs) in Bangladesh using Gazipur-an intensive poultry growing area - as a case study. Monthly market price data of poultry meat and eggs, and primary panel data from the same respondents using a random sampling technique through a structured questionnaire-based interview, Focus Group Discussion (FGD), and Key Informant Interview (KII) were collected. The results reveal that after the incidence of COVID-19, the price of poultry products at farmgate, wholesale and retail levels dropped drastically for the first three months (February to April 2020). Following that, the market price of farm (broiler) chicken and eggs increased by 40% and more than 30%, respectively. On the other hand, the price of local (deshi) chicken increased by 15%, which was already high on the market. However, in the early phase of COVID-19, many smallholder poultry farmers and hatchery owners were forced to shut down due to less demand/no demand of the product along with high feed cost and inadequate support from external sources. The government should provide financial support with low or no-interest rate to the smallholder growers in order to enhance their resilience against shocks like COVID-19 pandemic, natural disasters, etc.

Influence of water matrix components and peroxide sources on the transformation products and toxicity of tebuthiuron under UVC-based advanced oxidation processes.

Coupling of UV-C irradiation to different peroxides (H2O2, S2O82- and HSO5-) has great potential to degrade persistent organic compounds due to the formation of HO• or SO4•- species. However, an in-depth comparison between the performance of different UV-C/peroxide processes as a function of (i) target compound degradation, (ii) generated transformation products and (iii) lethal/sub lethal toxicity effects has not yet been performed. To this end a comparison study was carried out to evaluate the effectiveness of different UV-C/peroxide processes using the herbicide tebuthiuron (100 or 500 µg L-1) as a model pollutant. TBH degradation experiments were performed at lab-scale in real municipal wastewater treatment plant effluent and distilled water. Faster degradation occurred by increasing peroxide concentration from 735 to 2206 µmol L-1 in the municipal wastewater treatment plant effluent, mainly for S2O82-. Experiments performed in the presence of peroxide trapping agents - HO• and SO4•- (methoxibenzene) or HO• (2-propanol) - revealed that oxidation in the UV-C/S2O82- system occurs mainly through SO4•-. Lower toxicity for the MWWTP effluent was obtained after oxidative treatments using hydrogen peroxide or monopersulfate as oxidants which react mainly through HO• radicals. Two mechanistic pathways were proposed for tebuthiuron degradation: (i) hydrogen abstraction by HO• (H2O2 and HSO5-) and (ii) electron transfer by SO4•- (S2O82-). In addition, one unprecedented transformation product was identified. In conclusion, results emphasize the relevance of comparing the degradation of toxic compounds in the presence of different peroxide sources and matrices and simultaneouly evaluating responses chemical and biological endpoints.

Synthesis of Remdesivir Derivate as a Generation of Anti-COVID-19 Drugs Through Acetylation Reactions.

Remdesivir, a competitive inhibitor of viral RNA-dependent RNA polymerase, is the drug of choice for anti-COVID-19 treatment. However, the instability of these substances in plasma raises doubts about their therapeutic potency. Additionally, SARS-CoV-2-infected cells may exhibit a variety of antiviral behaviors due to intricate activation pathways. Therefore, this study aimed to develop a synthesis for the remdesivir derivative. The remdesivir derivative was synthesized using acetyl chloride as a reagent in a ratio of 1:3 in dichloromethane and tetrahydrofuran solvent at 30°C for 6 h. Thin-layer chromatography and spectrophotometers (1H NMR and 13C NMR) were used to identify the produced molecule, which was a brownish-yellow crystalline powder.  The results of the synthesis yielded 0.8 gr (77.34%), and the Rf value of the remdesivir derivate was 0.54. The characterization with 1H NMR at δ2.5 ppm (3H, s) indicated the presence of a proton in the H-C-C=O structure caused by the substitution of the acetyl group in the remdesivir structure. The 13C NMR data indicated the presence of aromatic carbons, alkenes, C≡N, and carbon bonds with electronegative O. This remdesivir derivate chemical can be a potential candidate for an anti-COVID-19 drug that has more potency because it has substitutions of acetyl groups at positions 2' and 3' in the structure of remdesivir.

Climate change adaptation responses among riparian settlements: A case study from Bangladesh.

As transition areas between aquatic ecosystems and the adjacent terrestrial ones, riparian regions are highly exposed to coastal climate hazards. This article describes how climate change and extreme weather impact vulnerable riparian communities and settlements. The analysis is done by reviewing past research and empirical case studies from riparian rural communities of the impact zone of the Sundarbans in Bangladesh, the world's most extensive mangrove forest. The article discusses the climate-related impacts on households through a Severity Index of Vulnerability and assesses the adaptation responses they may pursue. The principal climate-related vulnerabilities and impacts due to increases in temperature, storm surges, sea flooding, and sea-level rise are seawater intrusion and riverbank erosion. Many households have adopted several autonomous reactive adaptation strategies rather than planned ones, to cope with these impacts. However, government organisations and NGOs provide less than optimal technical and financial support to households for planned and anticipatory adaptive responses. The main barriers to adaptation were the high cost of improved crop varieties, inadequate agricultural extension services, and a lack of knowledge on effective climate adaptation. The restoration of the mangrove ecosystem may increase its resilience and, among other things, make local communities less exposed. The article also presents some adaptation measures proper to reduce the climate-related vulnerability of riparian settlements.

Effect of Iron Complex Source on MWWTP Effluent Treatment by Solar Photo-Fenton: Micropollutant Degradation, Toxicity Removal and Operating Costs.

Benzophenone-3, fipronil and propylparaben are micropollutants that are potential threats to ecosystems and have been detected in aquatic environments. However, studies involving the investigation of new technologies aiming at their elimination from these matrices, such as advanced oxidation processes, remain scarce. In this study, different iron complexes (FeCit, FeEDTA, FeEDDS and FeNTA) were evaluated for the degradation of a mixture of these micropollutants (100 µg L−1 each) spiked in municipal wastewater treatment plant (MWWTP) effluent at pH 6.9 by solar photo-Fenton. Operational parameters (iron and H2O2 concentration and Fe/L molar ratio) were optimized for each complex. Degradation efficiencies improved significantly by increasing the concentration of iron complexes (1:1 Fe/L) from 12.5 to 100 µmol L−1 for FeEDDS, FeEDTA and FeNTA. The maximum degradation reached with FeCit for all iron concentrations was limited to 30%. Different Fe/L molar ratios were required to maximize the degradation efficiency for each ligand: 1:1 for FeNTA and FeEDTA, 1:3 for FeEDDS and 1:5 for FeCit. Considering the best Fe/L molar ratios, higher degradation rates were reached using 5.9 mmol L−1 H2O2 for FeNTA and FeEDTA compared to 1.5 and 2.9 mmol L−1 H2O2 for FeEDDS and FeCit, respectively. Acute toxicity to Canton S. strain D. melanogaster flies reduced significantly after treatment for all iron complexes, indicating the formation of low-toxicity by-products. FeNTA was considered the best iron complex source in terms of the kinetic constant (0.10 > 0.063 > 0.051 > 0.036 min−1 for FeCit, FeNTA, FeEDTA and FeEDDS, respectively), organic carbon input and cost-benefit (USD 327 m−3 > USD 20 m−3 > USD 16 m−3 > USD 13 m−3 for FeEDDS, FeCit, FeEDTA and FeNTA, respectively) when compared to the other tested complexes.

Assessing returns to research investments in rice varietal development: Evidence from the Philippines and Bangladesh.

•This study estimates economic returns to investments in rice varietal development in the Philippines and Bangladesh.•The net returns to IRRI and national partners' investments remain strongly positive.•However, the returns are decreasing at a faster rate in the Philippines (24%) than in Bangladesh (6%).•IRRI and national partners should continue investing in rice R&D, especially to develop superior rice varieties.

A review toward contaminants of emerging concern in Brazil: Occurrence, impact and their degradation by advanced oxidation process in aquatic matrices.

This work presents data regarding the occurrence and treatment of Contaminants of Emerging Concern (CECs) in Brazil in the past decade. The literature review (2011-2021) revealed the detection of 87 pharmaceutical drugs and personal care products, 58 pesticides, 8 hormones, 2 illicit drugs, caffeine and bisphenol A in distinct matrices (i.e.: wastewater, groundwater, sea water, rainwater, surface water, drinking water and hospital effluent). Concentrations of CECs varied from ng-µg L-1 depending on the location, compound and matrix. The inefficiency of conventional wastewater treatment methods on the removal of CECs and lack of basic sanitation in some regions in the country aggravates contamination of Brazilian aquatic environments and poses potential environmental and health risks. Advanced oxidation processes (AOPs) are pointed out as viable and efficient alternatives to degrade CECs and prevent environmental contamination. A total of 375 studies involving the use of AOPs in Brazilian aqueous matrices were published in the last decade. Fenton and photo-Fenton processes, photo-peroxidation, ozonation, electrochemical advanced oxidation and heterogeneous photocatalysis are some of the AOPs applied by Brazilian research groups. Although many works discuss the importance of applying these technologies for CECs removal in real treatment plants, most of these studies assess the treatment of distilled water or simulated effluent. Therefore, the conduction of studies applying AOPs in real matrices are critical to drive the implementation of these processes coupled to conventional water and wastewater treatment in real plants in order to prevent the contamination of environmental matrices by CECs in Brazil.

Does climate change stimulate household vulnerability and income diversity? Evidence from southern coastal region of Bangladesh.

Bangladesh is one of the most climate-vulnerable countries globally, where the livelihood of agro-based dependent people became vulnerable due to different natural hazards, especially in the southern coastal part. This study investigates the influence of climate change on household vulnerability and income diversity, data collected from the climate-vulnerable coastal areas of Bangladesh. Both panel data regression and structural equation model were employed to examine the vulnerability status, whereas income diversity was measured through diversity index and "Type-66" livelihood strategy. Results reveal that sources of income have diversified over time. However, the study also reveals that climate change-especially the increase in salinity has affected crop production, resulting in increased income vulnerability of small and marginal farmers who are highly reliant on farm income. Moreover, findings reveal that climate change has influenced households to diversify into low-income sources that do not help to overcome their income vulnerability. Therefore, a cooperative land management system, establishment of embankment, training, and skill development programs are needed to generate feasible alternative income sources to improve the livelihood of coastal people.

The Influence of Women's Empowerment on Poverty Reduction in the Rural Areas of Bangladesh: Focus on Health, Education and Living Standard.

Women's empowerment has a great influence on health, nutrition, education, and the overall well-being of societies as well as of the children and households. This study investigates the effect of women's empowerment on poverty reduction and focuses on household deprivation, in terms of education, health, and standard of living. Primary data was collected from 914 married women from rural areas of Bangladesh using a well-structured questionnaire and a random sampling technique. Descriptive statistics, logistic regression, and ordinary least squares models were used in this study. The results indicate that increased women's access to education, asset ownership, decision-making power on children's health and education, and access to medical facilities, have caused a significant decline in income poverty and multidimensional poverty. However, gender violence, taking resources against women's will, and preventing women from working outside, have caused a considerable decline in per capita income and an increase in income poverty and multidimensional poverty. Overall, it is found that women's empowerment has a great impact on the reduction of income poverty and multidimensional poverty in society. The findings of the study can assist and guide policymakers to initiate appropriate strategies for women's empowerment to reducing poverty in Bangladesh while making progress towards other social and developmental goals.

Impact of COVID-19 on vegetable supply chain and food security: Empirical evidence from Bangladesh.

In Bangladesh, the COVID-19 pandemic is likely to have substantial effects on the livelihood of people, but smallholder vegetables growers will be even more affected because of the perishability nature of the product. The first case of COVID-19 was confirmed in Bangladesh on 8th March, 2020 and consequently the country went into lockdown on 26 March, 2020. This study has made a survey of vegetables farmers through a mobile phone to understand the impact of COVID-19 on vegetables supply chain, gross margin and the future production plan of the growers. In Bangladesh, the lockdown has disrupted the food supply chain and increases the likelihood of food insecurity. Lockdown has impeded vegetable farmers' access to markets, thus limiting their productive and sales capacities. The price of yield has dropped by more than half resulting in huge loss for vegetable growers. The loss incurred by the farmers for producing Brinjal, Cucumber, Pointed gourd, Yardlong beans and Bottle gourd are BDT 4900, BDT 10900, BDT 57400, BDT 52500 and BDT 18500 per acre respectively as a result of COVID-19. The decreased income increases farmers' likelihood of vulnerability and food insecurity and poses a challenge to continued produce. 'Cash support' is more important than 'food support' in order to keep vegetable farmers in farming, to ensure a ready supply of necessary low-cost resources, and to help fight against the upcoming food shortage.

Effect of meteorological factors on COVID-19 cases in Bangladesh.

This work is intended to examine the effects of Bangladesh's subtropical climate on coronavirus diseases 2019 (COVID-19) transmission. Secondary data for daily meteorological variables and COVID-19 cases from March 8 to May 31, 2020, were collected from the Bangladesh Meteorological Department (BMD) and Institute of Epidemiology, Disease Control and Research (IEDCR). Distributed lag nonlinear models, Pearson's correlation coefficient and wavelet transform coherence were employed to appraise the relationship between meteorological factors and COVID-19 cases. Significant coherence between meteorological variables and COVID-19 at various time-frequency bands has been identified in this work. The results showed that the minimum (MinT) and mean temperature, wind speed (WS), relative humidity (RH) and absolute humidity (AH) had a significant positive correlation while contact transmission had no direct association with the number of COVID-19 confirmed cases. When the MinT was 18 °C, the relative risk (RR) was the highest as 1.04 (95%CI 1.01-1.06) at lag day 11. For the WS, the highest RR was 1.03 (95% CI 1.00-1.07) at lag day 0, when the WS was 21 km/h. When RH was 46%, the highest RR was 1.00 (95% CI 0.98-1.01) at lag day 14. When AH was 23 g/m3, the highest RR was 1.05 (95% CI 1.01-1.09) at lag day 14. We found a profound effect of meteorological factors on SARS-CoV-2 transmission. These results will assist policymakers to know the behavioral pattern of the SARS-CoV-2 virus against meteorological indicators and thus assist to devise an effective policy to fight against COVID-19 in Bangladesh.

Chemical and toxicological evaluation along with unprecedented transformation products during photolysis and heterogeneous photocatalysis of chloramphenicol in different aqueous matrices.

As the presence of antibiotics in environmental waters enhances antimicrobial resistance, photolysis and heterogeneous photocatalysis of chloramphenicol (CAP) were evaluated in deionized water (DW) and in sewage treatment plant (STP) effluent under black light and solar irradiation. Processes were compared in terms of CAP degradation, reaction kinetics, and electrical energy per order, as well as regarding theoretical toxicity, biodegradability, carcinogenicity, and mutagenicity of transformation products (TPs). Rate constants obtained under photolysis (0.008 min-1) and heterogeneous photocatalysis (0.18 min-1) only differed in DW. This is due to the generation of photo-active reactive oxygen species (HO· and HO2·-/O2·-) under photolysis in STP effluent, as verified by experiments in the presence of 2-propanol and chloroform. Natural organic matter and HCO3- were the main responsible for reducing CAP degradation in STP effluent. Fifteen TPs were identified during both processes in DW, 13 of which are unprecedented. TPs were formed mainly via HO· preferential attack on the aromatic ring and on the α-carbon, and some of them were classified as persistent and toxic, genotoxic, or carcinogenic by Toxtree software. Results confirm that solar photocatalysis is less costly than to photocatalysis under black light for wastewater treatment.

Reducing toxicity and antimicrobial activity of a pesticide mixture via photo-Fenton in different aqueous matrices using iron complexes.

This is the first study to investigate ethylenediamine-N,N'-disuccinic acid (EDDS)/photo-Fenton process to polish real wastewater containing pesticides for possible water reuse. To this end, simultaneous degradation of pesticides ametrine, atrazine, imidacloprid and tebuthiuron was evaluated in distilled water (DW) and in sewage treatment plant (STP) effluent at initial pH 6.0. Several operational parameters (Fe3+-EDDS concentration, Fe3+-EDDS molar ratio, EDDS addition patterns and radiation source) were evaluated. 80-98% removal of target pesticides were obtained in DW using 30 µmol L-1 of Fe3+-EDDS with a molar ratio of 1:2 (300 µmol L-1 of H2O2). In addition, the proposed Fe3+-EDDS photo-Fenton at pH 6 was more efficient than classic photo-Fenton at pH 2.7 (30-84% removal). Experiments conducted in the presence of radical trapping agents (2-propanol or chloroform) revealed that HO• was the most active radical during treatment. Matrix composition strongly affected the degradation of target pesticides as a six-fold higher concentration of reagents (180 µmol L-1 of Fe3+-EDDS and 1800 µmol L-1 of H2O2) was needed to reach the same efficiency in STP compared to DW. Even so, first order rate constants corresponding to the degradation of pesticides in DW (k = 0.098-0.85 min-1) were nearly two-fold higher than in STP (k = 0.079-0.49 min-1) under the same radiation source (black-light or solar radiation). Finally, acute toxicity towards Vibrio fischeri and Drosophila melanogaster flies, and antibacterial activity assessed for Escherichia coli were eliminated after the application of the proposed treatment, thus indicating environmental safety for either discharge or reuse of treated wastewater for crop irrigation in agriculture.

Degradation mechanism of fipronil and its transformation products, matrix effects and toxicity during the solar/photo-Fenton process using ferric citrate complex.

This study presents the degradation of fipronil in sewage treatment plant (STP) effluent by photo-Fenton at near neutral pH (pH 6.0) using Fe3+/Citrate complex. 83% of fipronil degradation was reached using a molar iron/citrate ratio of 1:3 (192 µmol L-1 of Fe3+/576 µmol L-1 of citrate). Photo-Fenton reduced the toxicity of treated solutions as according to the survival of Drosophila melanogaster exposed to non-treated and treated samples. Control experiments performed in distilled water using 32 µmol L-1 of Fe3+/96 µmol L-1 of citrate achieved 98% of fipronil degradation within 100 kJ m-2 (UV-A radiation, k = 30 × 10-3 kJ-1 m2 and t1/2 = 23 kJ m-2), thus indicating that fipronil degradation is impaired by natural organic matter and inorganic ions present in STP effluent. Degradation was faster under solar radiation, as the same efficiency (98%) was obtained after 75 kJ m-2 (k = 63 × 10-3 kJ-1 m2 and t1/2 = 11 kJ m-2). In addition, pathways of fipronil degradation using Fe3+/Citrate under solar and UV-A radiation were investigated and transformation products proposed. Results revealed that the HO• attack occurred preferentially in the pyrazole ring. Eight transformation products were identified by UHPLC-Q-TOF-MS and four are unprecedented in the literature. Control experiments in distilled water demonstrated that toxicity reduction is related to fipronil degradation and that transformation products are less toxic than fipronil. Furthermore, toxicity of STP fortified with fipronil was reduced after photo-Fenton. These results demonstrate the feasibility of applying this process using Fe3+/Citrate complex for fipronil degradation in a real matrix.

Design of an industrial solid waste processing line to produce refuse-derived fuel.

Municipal Solid Waste (MSW) from the city of Boa Esperança, Minas Gerais, Brazil, was used to produce refuse-derived fuel (RDF). The MSW contains residues from human society, including product packaging, bottles, batteries, organic waste, fines, textiles, health textiles, plastics, glass, and metals, among others. The following protocol was performed during the conversion of MSW to RDF: (i) the raw MSW was placed in a silo and sent to a primary crusher using a metal conveyor belt, which reduced the particle size to 80 mm; (ii) the biomass was transferred to a selective waste collection platform by a rubber conveyor belt, and the recyclable waste, metals, and glasses were separated manually; (iii) residual metals were removed by a magnetic separator; (iv) the waste was transferred to a secondary crusher which reduced the particle size to 60 mm; (v) the waste passed through an airborne separator to remove materials with high density, such as glass, stones, and organic materials, using a metallic conveyor belt; (vi) the particle size was reduced to 40 mm by a tertiary crusher; (vii) the aluminium was separated from the non-metallic materials (plastic, paper, rubber, etc.) using an eddy current separator; (viii) the particle size was reduced to 25 mm using a quaternary crusher; (ix) the MSW was introduced into a rotary dryer using a metal conveyor belt, where the moisture content was reduced to close to 15 wt%, which required thermal energy equivalent to 186 kWh; (x) the RDF was used in a thermochemical reactor and 4148 kWh of thermal energy was produced. In addition, the MSW and RDF were analysed, and the elemental composition and combustion characteristics were determined. Based on these results, the protocol evaluated was found to be effective in the conversion of MSW to RDF, which can be used as a source of renewable fuel.

Correlation between pH and molar iron/ligand ratio during ciprofloxacin degradation by photo-Fenton process: Identification of the main transformation products.

Ciprofloxacin has been determined with high frequency in studies involving environmental waters matrixes. However, no study evaluating the correlation between the initial pH and molar iron/organic ligand ratio has been published. This paper describes the degradation of the antibiotic ciprofloxacin by the photo-Fenton process using different sources of iron (Fe2+, Fe3+ and Fe3+-citrate and Fe3+-oxalate, named FeCit and FeOx, respectively) and molar iron/organic ligand ratios at initial pH values of 2.5 and 6.5. The best results at initial pH 2.5 were achieved using FeCit and FeOx at molar iron/organic ligand ratios of 1:1 and 1:3 respectively, when the ciprofloxacin concentration reached values below the quantitation limit of the HPLC after 20 min of treatment. However, at initial pH 6.5, improvements in the results (15% for FeCit, and 46% for FeOx) were achieved by increasing the molar iron/organic ligand ratios to 1:4 (FeCit) and 1:9 (FeOx), respectively. Three transformation products, (C17H19FN3O4, m/z 348; C17H21FN3O5, m/z 366; and C13H12FN2O3, m/z 263) of ciprofloxacin degradation were identified, one of them not yet being reported in the literature (C17H21FN3O5, m/z 366). Their formation and degradation was monitored and the initial steps of their formation and degradation were proposed. The results show that the piperazine ring is more susceptible to hydroxyl radical attack than the quinolone ring, which persists in the intermediates identified. Therefore, this process can be a good alternative for the treatment of this type of pollutant at near-neutral conditions.

Integrating coagulation-flocculation and UV-C or H2O2/UV-C as alternatives for pre- or complete treatment of biodiesel effluents.

The feasibility of biodiesel effluent treatment combining coagulation-flocculation with a photolytic process was evaluated, being the photolytic process involving the irradiation of the effluent by UV-C, or by UV-C irradiation with simultaneous addition of H2O2 (H2O2/UV-C). The coagulation-flocculation was performed at the natural pH of the effluent (pH 2.9) using different Fe3+ salts (chloride, nitrate and sulfate) at different concentrations (0.25, 0.50 and 1.0 mmol L-1) of the counterions. The best results were achieved using 0.50 mmol L-1 Fe(NO3)3. Following, the degradation of the organic load and toxicity reduction of the pre-treated effluent by UV-C irradiation was evaluated. The H2O2/UV-C process showed to be advantageous, mainly when multiple additions of H2O2 were used during the course of the reaction. Additionally, the influence of the initial pH on the degradation was also evaluated. A high level of mineralization (94%) was achieved after 6 h of irradiation concomitantly with multiple additions of 2,000 mg L-1 H2O2, and with the effluent at the natural pH. Thus, using coagulation-flocculation followed by the H2O2/UV-C process, it was possible to achieve a favourable condition for reuse of the pre-treated effluent, since, in addition to the significant reduction of the organic load, the final DBO5 (<120 mg L-1) and oils & fats (<50 mg L-1) are below the limits established by the Brazilian legislation. Furthermore, a reduction of 78% of acute toxicity to V. fischeri (from 89% to 20%) was reached. The results suggest, therefore, that this process is a viable option for treatment of this kind of effluent.

Livelihood Cycle and Vulnerability of Rural Households to Climate Change and Hazards in Bangladesh.

Rural riverine households in Bangladesh are confronted with many climate-driven hazards, including riverbank erosion, which results in loss of productive land and other natural resources of the riverine households, and thus threatens their livelihoods and food security. This study assesses the main drivers of vulnerability and livelihood cycle of vulnerable riparian households in Bangladesh. The study utilises the IPCC framework of vulnerability and develops a weighted approach by employing the livelihood vulnerability index and the climate vulnerability index. The results reveal that the livelihood vulnerability index and the climate vulnerability index differ across locations, however, a high index value for both measures indicates the households' high livelihood vulnerability to climate change and hazards. The main drivers that influence the vulnerability dimensions are livelihood strategies and access to food, water and health facilities. These hazard-prone households are also vulnerable due to their existing low livelihood status that leads to a vicious cycle of poverty. The findings of this study are crucial for policymakers to formulate and implement effective strategies and programs to minimise vulnerability and to enhance the local adaptation processes in order to improve such households' livelihood across Bangladesh.

Optimization of fipronil degradation by heterogeneous photocatalysis: Identification of transformation products and toxicity assessment.

In this work it was studied the degradation of the insecticide fipronil (FIP) by heterogeneous photocatalysis induced by TiO2 P25. Using chemometric methods (Factorial Design and Response Surface Methodology), it was possible to evaluate the role of interaction between pH of the reaction medium, the reaction time and concentration of TiO2, optimizing the conditions for degradation using artificial radiation. Under the optimized conditions (79.4 mg L-1 TiO2 and 66.3 min of reaction time for 1.1 mg L-1 of FIP, at pH 5.6-5.8 (natural pH of the irradiated suspension)), 90.9% of FIP degradation was achieved at a degradation rate of 1.54 × 10-2 m2 kJ-1 in terms of accumulated UVA radiation, corresponding to a pseudo-first order rate constant of 1.34 × 10-2 min-1 and a half-life of 51.7 min. Under the same conditions, these assays were extended to the use of solar radiation, when the degradation rate was 14% higher, with half-life of 45 min, suggesting that in both cases FIP degradation was successful. Four by-products of FIP photocatalytic degradation could be separated, identified, and their formation and consumption followed by UHPLC-Q-TOF. Although the same intermediates have been obtained using both irradiation sources, a faster degradation of the transformation products (TPs) was observed under solar irradiation due to its expressive photonic flux covering the UVA and UVB. It is noteworthy that both the untreated effluent and the identified compounds have low toxicity with respect to V. fischeri, suggesting that the heterogeneous photocatalysis may be a good alternative for treatment of wastewaters containing FIP and its TPs, mainly when solar radiation is the source of radiation, since under this condition the power consumption during the treatment can be significantly reduced.