Aqueous Cr(VI) removal by a novel ball milled Fe0-biochar composite: Role of biochar electron transfer capacity under high pyrolysis temperature

Chemosphere ◽  
2020 ◽  
Vol 241 ◽  
pp. 125044 ◽  
Author(s):  
Kun Wang ◽  
Yuebing Sun ◽  
Jingchun Tang ◽  
Juan He ◽  
Hongwen Sun
2021 ◽  
Author(s):  
wentao yu ◽  
baoliang chen

<p>Pyrogenic carbon plays important roles in microbial reduction of ferrihydrite by shuttling electrons in the extracellular electron transfer (EET) processes. Despite its importance, a full assessment on the impact of graphitic structures in pyrogenic carbon on microbial reduction of ferrihydrite has not been conducted. This study is a systematic evaluation of microbial ferrihydrite reduction by Shewanella oneidensis MR-1 in the presence of pyrogenic carbon with various graphitization extents. The results showed that the rates and extents of microbial ferrihydrite reduction were significantly enhanced in the presence of pyrogenic carbon, and increased with increasing pyrolysis temperature. Combined spectroscopic and electrochemical analyses suggested that the rate of microbial ferrihydrite reduction were dependent on the electrical conductivity of pyrogenic carbon (i.e., graphitization extent), rather than the electron exchange capacity. The key role of graphitic structures in pyrogenic carbon in mediating EET was further evidenced by larger microbial electrolysis current with pyrogenic carbon prepared at higher pyrolysis temperatures. This study provides new insights into the electron transfer in the pyrogenic carbon-mediated microbial reduction of ferrihydrite.</p>


Author(s):  
Lars Mohrhusen ◽  
Jessica Kräuter ◽  
Katharina Al-Shamery

The photochemical conversion of organic compounds on tailored transition metal oxide surfaces by (UV) irradiation has found wide applications ranging from the production of chemicals to the degradation of organic...


Author(s):  
Jingwen Pan ◽  
Baoyu Gao ◽  
Pijun Duan ◽  
Kangying Guo ◽  
Muhammad Akram ◽  
...  

Nonradical pathway-based persulfate oxidation technology is considered to be a promising method for high-salinity organic wastewater treatment.


2020 ◽  
Vol 153 (18) ◽  
pp. 185101
Author(s):  
Nirmalendu Acharyya ◽  
Roman Ovcharenko ◽  
Benjamin P. Fingerhut

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2911
Author(s):  
Miriam Navarrete-Miguel ◽  
Antonio Francés-Monerris ◽  
Miguel A. Miranda ◽  
Virginie Lhiaubet-Vallet ◽  
Daniel Roca-Sanjuán

Photocycloreversion plays a central role in the study of the repair of DNA lesions, reverting them into the original pyrimidine nucleobases. Particularly, among the proposed mechanisms for the repair of DNA (6-4) photoproducts by photolyases, it has been suggested that it takes place through an intermediate characterized by a four-membered heterocyclic oxetane or azetidine ring, whose opening requires the reduction of the fused nucleobases. The specific role of this electron transfer step and its impact on the ring opening energetics remain to be understood. These processes are studied herein by means of quantum-chemical calculations on the two azetidine stereoisomers obtained from photocycloaddition between 6-azauracil and cyclohexene. First, we analyze the efficiency of the electron-transfer processes by computing the redox properties of the azetidine isomers as well as those of a series of aromatic photosensitizers acting as photoreductants and photo-oxidants. We find certain stereodifferentiation favoring oxidation of the cis-isomer, in agreement with previous experimental data. Second, we determine the reaction profiles of the ring-opening mechanism of the cationic, neutral, and anionic systems and assess their feasibility based on their energy barrier heights and the stability of the reactants and products. Results show that oxidation largely decreases the ring-opening energy barrier for both stereoisomers, even though the process is forecast as too slow to be competitive. Conversely, one-electron reduction dramatically facilitates the ring opening of the azetidine heterocycle. Considering the overall quantum-chemistry findings, N,N-dimethylaniline is proposed as an efficient photosensitizer to trigger the photoinduced cycloreversion of the DNA lesion model.


2016 ◽  
Vol 85 ◽  
pp. 1-11 ◽  
Author(s):  
Waled Suliman ◽  
James B. Harsh ◽  
Nehal I. Abu-Lail ◽  
Ann-Marie Fortuna ◽  
Ian Dallmeyer ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document