scholarly journals Bi/mZVI Combined with Citric Acid and Sodium Citrate to Mineralize Multiple Sulfa Antibiotics: Performance and Mechanism

Antibiotics ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 51
Author(s):  
Xiaoming Su ◽  
Hao Lv ◽  
Jianyu Gong ◽  
Man Zhou

The oxidative mineralization of sulfanilamide drugs (SAs) using micro-size zero-valent iron (mZVI) cooperated with a citric acid buffer solution was evaluated. In this study SM2, SMX, and SD could be removed at 66%, 89%, and 83%, respectively, in a 0.5% Bi/mZVI+CA+NaCA system within 2 h. Based on our analysis, the produced ·OH could be ascribed from the complexation between citrate iron (Fe(II)[Cit]−) and the generated H2O2 resulting from the activation of O2 on the mZVI surface in the Bi/mZVI+CA+NaCA system, further inducing the mineralization of antibiotics. The related possible degradation pathways were proposed. Two similar degradation pathways of SM2, SMX, and SD in the mixed liquid, including hydroxylation and SO2 extrusion, were solved. Meanwhile, there was an additional proposed degradation pathway for SMX to be degraded more effectively, as reflected in the opening of the N-O bond on the benzene ring. Therefore, this work provides an experimental basis and theoretical support for the efficient treatment of antibiotic wastewater in real industry by using an iron-based method.

2013 ◽  
Vol 680 ◽  
pp. 141-144 ◽  
Author(s):  
Qing Ye Liu ◽  
Gui Qing Wen ◽  
Kun Li ◽  
Ai Hui Liang

In pH 6.6 Na2HPO4- citric acid buffer solution and in the presence of KCl, the immunoreaction between hCG and nanosilver-labeled anti-hCG took place, the immunonanosilver-complex was formed and deposited, caused the resonance Rayleigh scattering (RRS) intensity at 510 nm decreased. In the optimal condition, the decreased RRS intensity responds linearly with the concentration of hCG over 0.125-1.75 µg/mL. Based on this, a new and simple RRS method has been proposed for the determination of hCG in serum samples, with satisfactory results.


2012 ◽  
Vol 20 (3) ◽  
pp. 376-383 ◽  
Author(s):  
Rodrigo Cavassim ◽  
Fábio Renato Manzolli Leite ◽  
Daniela Leal Zandim ◽  
Andrea Abi Rached Dantas ◽  
Ricardo Samih Georges Abi Rached ◽  
...  

2021 ◽  
Author(s):  
Junhui Li ◽  
Paul Dijkstra ◽  
Qihong Lu ◽  
Shanquan Wang ◽  
Shaohua Chen ◽  
...  

AbstractEffective degradation of N,N-Dimethylformamide (DMF), an important industrial waste product, is challenging as only few bacterial isolates are known to be capable of degrading DMF. Aerobic remediation of DMF has typically been used, whereas anoxic remediation attempts are recently made, using nitrate as one electron acceptor, and ideally include methane as a byproduct. Here, we analyzed 20,762 complete genomes and 28 constructed draft genomes for the genes associated with DMF degradation. We identified 952 genomes that harbor genes involved in DMF degradation, expanding the known diversity of prokaryotes with these metabolic capabilities. Our findings suggest acquisition of DMF-degrading gene via plasmids are important in the order Rhizobiales and genus Paracoccus, but not in most other lineages. Degradation pathway analysis reveals that most putative DMF degraders using aerobic Pathway I will accumulate methylamine intermediate, while members of Paracoccus, Rhodococcus, Achromobacter, and Pseudomonas could potentially mineralize DMF completely under aerobic conditions. The aerobic DMF degradation via Pathway II is more common than thought and is primarily present in α-and β-Proteobacteria and Actinobacteria. Most putative DMF degraders could grow with nitrate anaerobically (Pathway III), however, genes for the use of methyl-CoM to produce methane were not found. These analyses suggest that microbial consortia could be more advantageous in DMF degradation than pure culture, particularly for methane production under the anaerobic condition. The identified genomes and plasmids form an important foundation for optimizing bioremediation of DMF-containing wastewaters.ImportanceDMF is extensively used as a solvent in industries, and is classified as a probable carcinogen. DMF is a refractory compound resistant to degradation, and until now, only few bacterial isolates have been reported to degrade DMF. To achieve effective microbial degradation of DMF from wastewater, it is necessary to identify genomic diversity with the potential to degrade DMF and characterize the genes involved in two aerobic degradation pathways and potential anaerobic degradation for methane production. A wide diversity of organisms has the potential to degrade DMF. Plasmid-mediated degradation of DMF is important for Rhizobiales and Paracoccus. Most DMF degraders could grow anaerobically with nitrate as electron acceptor, while co-cultures are required to complete intermediate methanogenesis for methane production. This is the first genomics-based global investigation into DMF degradation pathways. The genomic database generated by this study provides an important foundation for the bioremediation of DMF in industrial waste waters.Abstract Figure


2020 ◽  
Vol 9 (4) ◽  
pp. 106-110
Author(s):  
Tue Nguyen Ngoc ◽  
Nghia Nguyen Trong ◽  
Thuong Nghiem Thi ◽  
Quang Tran Thuong ◽  
Trung Nguyen Duc

In this article, the results of the research on organic pollutant treatment in the wastewater of printing processes on fabric by H2O2 under the catalytic role of the complex between ion Ni2+ and Citric acid (H4L) were presented. The condition of pH, H4L/Ni2+, H2O2, Ni2+ concentration has been explored to get the optimal conditions for improving COD efficient treatment. The results provide the solutions of the homogeneous complex  catalysts in the industrial wastewater treatment at room temperature and atmosphere. 


2006 ◽  
Vol 54 (4) ◽  
pp. 129-137 ◽  
Author(s):  
U. Zaher ◽  
M.S. Moussa ◽  
I.N. Widyatmika ◽  
P. van Der Steen ◽  
H.J. Gijzen ◽  
...  

The observed acclimatisation to biodegradable toxicants in anaerobic cassava wastewater treatment is explained by modelling anaerobic cyanide degradation. A complete degradation pathway is proposed for cyanide. Cyanide degradation is modelled as enzymatic hydrolysis to formate and ammonia. Ammonia is added to the inorganic nitrogen content of the digester while formate is degraded by the hydrogenotrophic methanogens. Cyanide irreversible enzyme inhibition is modelled as an inhibition factor to acetate uptake processes. Cyanide irreversible toxicity is modelled as a decay factor to the acetate degraders. Cyanide as well as added phosphorus buffer solution were considered in the chemical equilibrium calculations of pH. The observed reversible effect after acclimatisation of sludge is modelled by a population shift between two aceticlastic methanogens that have different tolerance to cyanide toxicity. The proposed pathway is added to the IWA Anaerobic Digestion Model no.1 (ADM1). The ADM1 model with the designed extension is validated by an experiment using three lab-scale upflow anaerobic sludge bed reactors which were exposed to different cyanide loadings.


1935 ◽  
Vol 18 (2) ◽  
pp. 97-104 ◽  
Author(s):  
Hugh L. Templeton ◽  
H.H. Sommer
Keyword(s):  

Desalination ◽  
2020 ◽  
Vol 486 ◽  
pp. 114482 ◽  
Author(s):  
Weiwei Zhang ◽  
Hui-Jing Li ◽  
Liwei Chen ◽  
Jiani Sun ◽  
Xingyi Ma ◽  
...  

Fibers ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 56 ◽  
Author(s):  
Nafeesa Mohd Kanafi ◽  
Norizah Abdul Rahman ◽  
Nurul Husna Rosdi ◽  
Hasliza Bahruji ◽  
Hasmerya Maarof

The potential use of carboxymethyl sago pulp (CMSP) extracted from sago waste for producing hydrogel nanofibers was investigated as a methylene blue drug carrier. Sago pulp was chemically modified via carboxymethylation reaction to form carboxymethyl sago pulp (CMSP) and subsequently used to produce nanofibers using the electrospinning method with the addition of poly(ethylene oxide) (PEO). The CMSP nanofibers were further treated with citric acid to form cross-linked hydrogel. Studies on the percentage of swelling following the variation of citric acid concentrations and curing temperature showed that 89.20 ± 0.42% of methylene blue (MB) was loaded onto CMSP hydrogel nanofibers with the percentage of swelling 4366 ± 975%. Meanwhile, methylene blue controlled release studies revealed that the diffusion of methylene blue was influenced by the pH of buffer solution with 19.44% of MB released at pH 7.34 within 48 h indicating the potential of CMSP hydrogel nanofibers to be used as a drug carrier for MB.


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