2 research outputs found
Data_Sheet_1_Impacts of urea and 3,4-dimethylpyrazole phosphate on nitrification, targeted ammonia oxidizers, non-targeted nitrite oxidizers, and bacteria in two contrasting soils.docx
This study explored the effects of combined urea and 3,4-dimethylpyrazole phosphate (DMPP) on several components critical to the soil system: net nitrification rates; communities of targeted ammonia oxidizers [ammonia-oxidizing archaea (AOA) and bacteria (AOB) and complete ammonia-oxidizing bacteria (comammox)]; non-targeted nitrite-oxidizing bacteria (NOB) and bacteria. We conducted the study in two contrasting soils (acidic and neutral) over the course of 28 days. Our results indicated that DMPP had higher inhibitory efficacy in the acidic soil (30.7%) compared to the neutral soil (12.1%). The abundance of AOB and Nitrospira-like NOB were positively associated with nitrate content in acidic soil. In neutral soil, these communities were joined by the abundance of AOA and Nitrobacter-like NOB in being positively associated with nitrate content. By blocking the growth of AOB in acidic soil—and the growth of both AOB and comammox in neutral soil—DMPP supported higher rates of AOA growth. Amplicon sequencing of the 16S rRNA gene revealed that urea and urea + DMPP treatments significantly increased the diversity indices of bacteria, including Chao 1, ACE, Shannon, and Simpson in the acidic soil but did not do so in the neutral soil. However, both urea and urea + DMPP treatments obviously altered the community structure of bacteria in both soils relative to the control treatment. This experiment comprehensively analyzed the effects of urea and nitrification inhibitor on functional guilds involved in the nitrification process and non-targeted bacteria, not just focus on targeted ammonia oxidizers.</p
Catalytic gasification of phenol in supercritical water over bimetallic Co–Ni/AC catalyst
<p>Solid-solution bimetallic alloy catalysts containing no noble metals were developed via both simultaneous and sequential deposition in supercritical water (SCW). These bimetallic nano-catalysts were analyzed by Brunauer–Emmett–Teller, X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. Obvious downward shifts are observed in diffraction peaks, situated between the peak (1 1 1) for Co and the peak (1 1 1) for Ni. The shifts indicate the formation of NiCo solid-solution bimetallic alloy(s). The bimetallic nanoparticles show high activity for supercritical water gasification of phenol to produce gaseous fuels. The carbon gasification efficiency (CGE) of phenol in SCW can reach 95% on the Co–Ni/AC catalyst at conditions of 500°C and 30 min, showing nearly the same CGE as the commercial noble-metal-based catalyst, such as Ru/C (5 wt% Ru) from Sigma-Aldrich. The Co–Ni/AC catalyst also shows high stability. Therefore, deposition in SCW provides an effective way to create noble-metal-free solid-solution bimetallic alloy catalysts.</p