02499nas a2200265   4500008004100000022001400041245014800055210006900203260000800272300001100280490000800291520156300299653001901862653001801881653002401899653001301923653002601936653002701962100002201989700001802011700002302029700002302052700002702075856013102102       2020                        eng d  a0045-653500aScreening of zero valent mono/bimetallic catalysts and recommendation of Raney Ni (without reducing agent) for dechlorination of 4-chlorophenol0 aScreening of zero valent monobimetallic catalysts and recommenda  cJUL  a1262980 v2503 a<p>Chlorophenol (CP) is considered as environmentally hazardous material due to its acute toxicity, persistent nature and strong bioaccumulation. The dechlorination of 4-CP was investigated by using various catalysts such as bimetallic (Fe-0/Cu-0, Al-0/Fe-0), Pd/C, Raney Ni and Fe-0 at room temperature. Among the catalysts studied, Raney Ni proved to be very economical and efficient catalyst that worked without the use of an external reducing agent. The dechlorination of 4-CP by Raney Ni was therefore further explored. Complete dechlorination of 4-CP (30 mg L-1) was achieved in 6 hat an optimum Raney Ni catalyst loading of 3 g L-1. The effect of triethylamine (TEA) and tripropylamine (TPA) was also investigated and it was observed that 100% dechlorination is possible in presence of 45 mg L-1 of TEA. The kinetics of dechlorination of 4-CP was investigated and found to be first order with a rate constant of 0.017 min(-1) at 50 degrees C, and it enhances to 0.109 min(-1) with addition of TEA. In the absence of a reducing agent, acidic to neutral pH favors dechlorination of 4-CP. The final product of dechlorination was estimated to be phenol by performing HPLC, LCMS and NMR analysis. Based on the results, a probable dechlorination mechanism of 4-CP is also proposed. It can be concluded that the catalytic hydrodechlorination is an effective and economical technique for dechlorination of 4-CP and it has a potential for the dechlorination of other toxic derivatives of chlorinated aromatics. (C) 2020 Elsevier Ltd. All rights reserved.</p>
10a4-Chlorophenol10aCl- scavenger10aHydrodechlorination10aRaney Ni10aRecycling of catalyst10aWithout reducing agent1 aRaut, Sandesh, S.1 aShetty, Rohit1 aRaju, Nikhi, Maria1 aKamble, Sanjay, P.1 aKulkarni, Prashant, S.  uhttps://library.ncl.res.in/content/screening-zero-valent-monobimetallic-catalysts-and-recommendation-raney-ni-without-reducing02025nas a2200241   4500008004100000022001400041245016300055210006900218260000800287300001600295490000700311520115500318653001701473653001901490653001901509653002601528653001701554653001501571100002201586700002301608700002701631856012501658       2021                        eng d  a0944-134400aImproved photocatalytic efficiency of TiO2 by doping with tungsten and synthesizing in ionic liquid: precise kinetics-mechanism and effect of oxidizing agents0 aImproved photocatalytic efficiency of TiO2 by doping with tungst  cAPR  a17532-175450 v283 a<p>The degradation of nitroaromatics/toxic energetic compounds contaminated water is a major cause of concern. W-doped TiO2 nanoparticles (NPs) were synthesized in ionic liquid, ethyl methyl imidazolium dicyanamide (EMIM-DCA) by a solvothermal method. The developed NPs were sintered at 500 degrees C and characterized by UV-Vis-DRS, FT-IR, FE-SEM, XRD, XPS, and BET techniques. The 30-40-nm-sized NPs were subjected to photocatalytic degradation of the toxic energetic compound, tetryl (2,4,6-trinitrophenylmethylnitramine) under UV-Vis light. Various operating parameters such as the effect of concentration of catalyst, pH of feed phase, oxidizing agents, and recycling of catalyst were studied in detail. For the first time, the degradation-mechanism pathway and kinetics of tetryl were evaluated. The degradation products were precisely analyzed by using HPLC, GC-MS, and TOC techniques. The USEPA has prescribed a drinking water limit of 0.02 mg L-1, and it was found that 0.5 g of 4% W-TiO2 could totally degrade tetryl (50 mg L-1) within 8 h. The kinetic rate constant of 4% W-TiO2 was 0.356 h(-1), whereas pure TiO2 showed 0.207 h(-1).</p>
10aIonic liquid10aNitroaromatics10aPhotocatalysis10aRecycling of catalyst10aW-doped TiO210awastewater1 aRaut, Sandesh, S.1 aKamble, Sanjay, P.1 aKulkarni, Prashant, S.  uhttps://library.ncl.res.in/content/improved-photocatalytic-efficiency-tio2-doping-tungsten-and-synthesizing-ionic-liquid