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A chitosan/poly(vinyl alcohol)-stabilized copper nanoparticle (CP@Cu NPs) was used as a heterogeneous catalyst for the borylation of α, ß-unsaturated ketones, MBH alcohols, and MBH esters in mild conditions. This catalyst not only demonstrated remarkable efficiency in synthesizing organoboron compounds but also still maintained excellent reactivity and stability even after seven recycled uses of the catalyst. This methodology provides a gentle and efficient approach to synthesize the organoboron compounds by efficiently constructing carbon-boron bonds.
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Greywater has attracted global attention as a feasible alternative water source over the last few decades. Reuse and recycling of greywater is an economically viable and attractive option for meeting the future water demand. However, its treatment and reliable reuse continue to be based on conventional parameters such as BOD, COD, turbidity, suspended solids and pathogen level. The current investigative study focused on the characterization of segregated grey wastewater (greywater from bathroom, laundry and kitchen) from different economic classes of Indian households which included physical and chemical parameters, organics, nutrients, pathogens, heavy metals, oil and grease and surfactants. Apart from this, the data related to water consumption, frequency and products used for their daily activities were gathered using a questionnaire survey. The average water consumption among different household was found to be 108 L per capita per day. The maximum concentrations of organics such as BOD (678.6 ± 179 mg/L), COD (1507 ± 508 mg/L) and TOC (176.4 ± 131 mg/L) were found in kitchen wastewater. However, maximum concentrations of surfactants (14.02 ± 3.74 mg/L) were obtained in laundry wastewater. Faecal coliform concentration was more in the households which had inhabitants of children below 4 years. Statistical analysis revealed that the parameters monitored differ significantly between different economic classes. The present study showed that the characteristics of greywater highly depend on the wastewater source, household behaviour and activities. This study will be helpful to design a sustainable cost-effective treatment system, enabling greywater generated from different sources to be safely recycled and reused by households. Graphical abstract.
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Eliminação de Resíduos Líquidos , Poluentes Químicos da Água/análise , Criança , Monitoramento Ambiental , Humanos , Reciclagem , Águas ResiduáriasRESUMO
Emerging contaminants (ECs) have become an increasing area of concern due to the likely impacts of these compounds on human health and the environment. Generally, products which are used for households and personal care activities contribute to major percentage of ECs in household greywater. Not much information on the presence of xenobiotic organic compounds in greywater is currently available. Therefore, the present study focused on the qualitative and quantitative analyses of emerging contaminants from different classifications of Indian households. The qualitative screening of emerging pollutants by solid-phase extraction-gas chromatography and mass spectroscopy (SPE-GC-MS) showed the presence of 78 different emerging contaminants from three different sources, which are categorized into ten different groups based on their chemical properties. The quantitative analysis of few selected target pollutants such as phthalic esters, namely diethyl hexyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, triclosan, bisphenol A, caffeine, acetaminophen, 3-methyl salicylic acid, 4-octylphenol, and 4-nonylphenol were found to be 0.38 ± 0.39 µg/L, 1.57 ± 1.54 µg/L, 4.77 ± 2.57 µg/L, 0.712 ± 0.17 µg/L, 5.82 ± 1.85 µg/L, 11.08 ± 2.64 µg/L, 2.30 ± 1.19 µg/L 13.18 ± 4.48 µg/L, 3.75 ± 1.90 µg/L, 4.95 ± 2.21 µg/L, and 5.96 µg/L, respectively. Risk assessment indicated that 63 compounds identified in the greywater can be considered priority pollutants. Based on the results obtained in the present study, effective zero-discharge liquid system can be designed for different sources of greywater and it can be recycled and reused without much risk. Graphical abstract .
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Poluentes Químicos da Água/análise , Cromatografia Gasosa , Monitoramento Ambiental , Humanos , Extração em Fase SólidaRESUMO
The dissolution of cellulose in double salt ionic liquids (DSILs) was studied in detail and compared with the dissolution in individual constituent ionic liquids (ILs). The DSILs, [C4mim](CH3CO2)xCl1-x (x is the mole fraction of the single component ILs), were synthesized using acetate and chloride salts of 1-butyl-3-methylimidazolium. These DSILs were then used for the investigation of the solubility of cellulose in the whole mole fraction range. Commercial cellulose (CC) powder, kraft pulp (KP), and prehydrolysis kraft pulp (PHKP) of jute were chosen as cellulose sources. The solubility of cellulose increased with an increasing temperature for [C4mim](CH3CO2)0.6Cl0.4 and with increasing amount of [C4mim]Cl in DSILs. The maximum solubility of CC powder was 32.8 wt% in [C4mim](CH3CO2)0.6Cl0.4 at 100 °C, while for KP and PHKP, solubilities were 30.1 and 30.5 wt%, respectively under the identical condition. Cellulose could be regenerated from the DSILs using water as an antisolvent. Structure, morphology, and thermal stability of the regenerated cellulosic materials were analyzed. DSILs could be recycled >99 % without a discernible change in structure. This work demonstrates that DSILs display enhanced solubility over ILs system and have potential as a chemical processing methodology.
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Celulose , Imidazóis , Líquidos Iônicos , Solubilidade , Celulose/química , Líquidos Iônicos/química , Imidazóis/química , Sais/química , TemperaturaRESUMO
A series of new kind green cellulose-supported bimetallic TiO2/Cu2O (Cell@TiO2/Cu2O) catalytic materials were obtained by in-situ reduction method employing cellulose as the carrier. The effects of metal percentage composition on the morphology and construction of the catalytic materials were systematically investigated. The Cell@TiO2/Cu2O were characterized by FT-IR, TG, XPS, SEM, TEM, EDS, and the element content was obtained by elemental analysis. Then, the achieved catalytic materials were applied to the chiral borylation reaction of α,ß-unsaturated compounds, including nitrile compounds, esters, and α,ß-unsaturated ketones. Remarkably, this approach provides an efficient strategy to gain an important class of chiral organic boron compounds with target chiral products in high yields as well as enantioselectivities. Besides, the Cell@TiO2/Cu2O could be easily recycled and effectively reused. This work constructed bimetallic TiO2/Cu2O on cellulose as a newly catalyst to obtain chiral boron compounds in aqueous phase.
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Celulose , Cobre , Titânio , Titânio/química , Cobre/química , Celulose/química , Catálise , Água/química , Compostos de Boro/químicaRESUMO
Both biochar (BC) and wood vinegar (WV) influence the nitrous oxide (N2O) and methane (CH4) emissions from agricultural systems. However, the impacts of BC and WV co-application on rice production, N2O and CH4 emissions are not well documented. We here conducted a two-year soil columns experiment with four treatments: WV (5 t WV ha-1), BC (7.5 t BC ha-1), WV + BC (5 t WV ha-1 +7.5 t BC ha-1) and a control (no treatment). The results showed that BC and WV + BC produced higher rice grain yield than the control by 14.1-15.9% in 2016 and by 4.1-5.2% in 2017, respectively. While WV increased rice grain yield by 11.2% in 2016, it had no significant influence on yield in 2017. Both WV and BC significantly mitigated N2O emissions by 22.4-41.8% in 2016 and 22.4-36.9% in 2017, respectively. Interestingly, WV + BC treatment showed the highest N2O mitigation efficiency, with a 52.9-62.8% mitigations in 2016 and 2017. Furthermore, the co-application of WV and BC significantly mitigated CH4 emissions by 42.6% in 2016 and 35.3% in 2017, respectively, while applying WV or BC alone had no annually-consistent mitigation effect on CH4 emissions. Overall, GWPt of rice growth cycle was most significantly suppressed by WV + BC with a 48.7-56.1% reduction, followed by WV and BC with 20.4-28.0% and 19.7-35.7% reductions, respectively. Consequently, the WV + BC treatment had the highest GHGI mitigation effect, averaging with 56.7% over two consecutive rice growth cycles. In conclusion, co-application of WV and BC is recommended for rice cultivation, which can both improve rice yield and minimize GHG emissions.
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Óxido Nitroso , Oryza , Ácido Acético , Agricultura , Carvão Vegetal , Metano , Metanol , SoloRESUMO
A composting system provides many benefits towards achieving sustainability such as, replacing fertilizer use, increasing the quantity of produce sold, and diverting organic wastes from landfills. This study delves into the many benefits a composting system provided by utilizing an established composting system at Kean University (KU) in New Jersey, as a scale project to examine the composters' environmental and economic impacts. The results from the study showed that composting food wastes in an in-vessel composter when compared to typical disposal means by landfilling, had lower impacts in the categories of fossil fuel, GHG emissions, eutrophication, smog formation and respiratory effects; whereas, its had higher impacts in ozone depletion, acidification human health impacts, and ecotoxicity. The environmental impacts were mainly raised from the manufacturing of the composter and the electricity use for operation. Applying compost to the garden can replace fertilizers and also lock carbon and nutrients in soil, which reduced all of the environmental impact categories examined. In particular, the plant growth and use stage reduced up to 80% of respiratory effects in the life cycle of food waste composting. A cost-benefit analysis showed that the composting system could generate a profit of $13,200 a year by selling vegetables grown with compost to the student cafeteria at Kean and to local communities. When educational and environmental benefits were included in the analysis, the revenue increased to $23,550. The results suggest that in-vessel composting and the subsequent usage of a vegetable garden should be utilized by Universities or food markets that generate intensive food wastes across the U.S.