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《Arabian Journal of Chemistry》2020,13(2):4111-4125
The extreme nitrate (NO3−) species in drinking water leads to methemoglobinemia (blue baby syndrome) disease in new born toddlers whereas the excess phosphate (PO43−) and NO3− contents lead to the eutrophication (algae growth) problem of water sources. Upto date, the environmental researchers have developing the suitable adsorbent materials for providing NO3− and PO43− free water system. In present study, a low-cost alginate (Alg) assisted kaolin (KN) (AlgKN) composite beads were prepared and utilized for the removal of NO3− and PO43−. To improve the sorption capacity (SC) and stability, Zr4+ ions were coated onto AlgKN to get Zr@AlgKN composite beads which were prepared via., hydrothermal (Hydro) and in situ precipitation (In situ) methods. The hydro assisted Zr@AlgKN composite beads possess an enhanced SC than the in situ assisted adsorbents. In batch scale, the parameters responsible for the adsorption process such as contact time, co-ions, adsorbent dosage, pH, initial ions concentration and temperature were optimized. The adsorbents were characterized by XRD, FTIR, BET, EDAX and SEM analysis. The adsorption experimental data was fitted with isotherms, kinetics and thermodynamic parameters. The regeneration and field applicability study of the Zr@AlgKN composite beads were also investigated. 相似文献
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A new route for the synthesis of linear and vinyl thioethers has been demonstrated using bare silica nanoparticle as catalyst at room temperature under solvent-free conditions. The catalyst can be reused up to six times without loss of catalytic activity. 相似文献
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A study involving the scope of substrate in the Knoevenagel reaction in an IL medium has been conducted. Reactivity trends favor formation of the condensation product using electron deficient aryl aldehydes. Use of electron rich aldehydes and ketones lead to lower levels of conversion and no measurable amounts of condensation products, respectively. A recycling study confirmed that the reaction medium could be used multiple times affording, with each run, the desired condensation product 1a in excess of 90% conversion. Post-run analyses of the IL documented that the IL medium was unaltered upon reuse. 相似文献
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For industrialised economy of ourdays, remanufacturing represents perhaps the largest unexploited resource and opportunity
for realising a greater growth of the economy in an environmental-conscious manner. The aim of this paper is to investigate
of the impact of remanufacturing in the economy from an economic-efficiency point of view. In static context this phenomenon
was analysed in the literature. We use the multi-sector input–output framework in a dynamic context to study intra-period
relationships of the sectors of economy. We extend the classical dynamic input–output model taking into consideration the
activity of remanufacturing .We try to answer the question, whether the remanufacturing/reuse increases the growth possibility
of an economy. We expose a sufficient condition concerning the effectivity of an economy with remanufacturing. By this evaluation
we analyse a possible sustainable development of the economy on the basis of the product recovery management of industries. 相似文献
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A. Cano P. Cañizares C. Barrera C. Sáez M.A. Rodrigo 《Electrochemistry communications》2011,13(11):1268-1270
In the search for new disinfection technologies for reused water, in this work the effect of current density on the disinfection capability, during the electrolyses with conductive diamond anodes of the effluent of a municipal wastewater treatment plant was evaluated. It was found that this electrolytic technology can disinfect completely for current densities ranging from 1.3 to 130 A m− 2, but the disinfection rate and chlorine speciation are significantly affected by particular current density applied. In order to avoid the occurrence of non desired species, the lower value of this range is proposed. In those conditions, complete disinfection can be obtained and hypochlorite and chloramines are the main species, not being produced chlorate, perchlorate or organo-chlorinates species. 相似文献
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We have demonstrated the remarkable catalytic activity of silica nanoparticles (NPs) in the unusual bis-Michael addition of active methylene compounds to conjugated alkenes at room temperature. The catalyst silica NPs were reused up to seven runs without appreciable loss of catalytic activity. 相似文献
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二苯醚烷基化反应中酸性离子液体的循环使用 总被引:3,自引:0,他引:3
使用酸性离子液体催化二苯醚与十二烯烷基化反应,考察了离子液体的失活原因,提出了循环使用离子液体的解决办法.在二苯醚与十二烯烷基化反应中, Lewis酸性离子液体不能多次循环使用的原因是离子液体与二苯醚相互作用导致具有催化活性的Al2Cl72-分解、流失.改变离子液体的阳离子不能从本质上解决其与二苯醚间的相互作用.适时补加损失量的AlCl3使离子液体的Lewis酸性得以恢复,可以解决体系中酸性离子液体循环使用问题,循环使用8次后产物产率仍保持90%左右. 相似文献
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A novel method of hydrogenation of aromatic ketones in the ionic liquid [BHEA][HCO2] was developed; this method is more enhanced in terms of flammability and reusability as compared to the conventional method (H2 and Pd/C). The reductive selectivities of aromatic and aliphatic ketones in this method were observed. 相似文献
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Batistella L Lerin LA Brugnerotto P Danielli AJ Trentin CM Popiolski A Treichel H Oliveira JV de Oliveira D 《Ultrasonics sonochemistry》2012,19(3):452-458
This work reports the transesterification of soybean oil with ethanol using two commercial immobilized lipases under the influence of ultrasound irradiation. The experiments were performed in an ultrasonic water bath, following a sequence of experimental designs to assess the effects of temperature, enzyme and water concentrations, oil to ethanol molar ratio and output irradiation power on the reaction yield. Results show that ultrasound-assisted lipase-catalyzed transesterification of soybean oil with ethanol might be a potential alternative route to conventional alkali-catalyzed method, as high reaction yields (∼90 wt.%) were obtained at mild irradiation power supply (∼100 W), and temperature (60 °C) in a relatively short reaction time, 4 h, using Lipozyme RM IM as catalyst. The repeated use of the catalyst under the optimum experimental condition resulted in a decay in both enzyme activity and product conversion after two cycles. The use of Novozym 435 led to lower conversions (about 57%) but the enzyme activity was stable after eight cycles of use, showing, however, a reduction in product conversion after the forth cycle. 相似文献