Search

MOF/AgBr composite materials were synthesized using hydrothermal and in-situ precipitation methods, and applied to simulate the photocatalytic degradation of tetracycline hydrochloride (TC-HCl) under solar irradiation. The results showed that when the AgBr doping amount was 30%, the composite material MOF/AgBr-3 exhibited high photocatalytic activity after 180 minutes of visible light irradiation, with a degradation rate of 84.50% for TC-HCl. The reaction rate constant of the composite material is approximately 0.0121/min, which is about 6.1 times that of the original AgBr, according to the fitting of first-order kinetics. The single photon excitation pathway constructed between MOF-808 and AgBr improves the efficiency of photo generated carrier transport and separation, expands the visible light response range, and achieves effective separation of holes (h+) and electrons (e-) in space. Superoxide radicals (·O-²) and hydroxyl radicals (·OH) are the main active species in photocatalytic reactions. This composite material has good stability, and after five cycles, its photodegradation ability retention rate is as high as 84.35%. The degradation pathways of TC-HCl include its own hydrolysis, deamination, demethylation, oxidation, and ring opening processes. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective To establish a method for determination of ethanol content in intermediate products during the production of blood products by GC.Methods DB-624 column was used with FID detection.The temperature of the injector and detector was 230°C, 280°C, respectively. The column temperature was kept at 40°C for 5 minutes, then increased to 80°C at 10°C per minute, and finally to 230°C at 50°C per minute for 3 minutes. N-propanol was used as the internal standard. Results The standard curve was linear in the range of 0.05%-5%(r=1.000 0) for ethanol. The average recovery was 99.28% with RSD of 0.01%(n=9).Conclusion This method was simple,sensitive,accurate and reliable.It is suitable for the determination of ethanol content in intermediate products during the production of blood products. [ABSTRACT FROM AUTHOR]

The present study explored the physiological mechanism of the effects of different pH treatments on the growth, physiological characteristics, and stachydrine biosynthesis of Leonurus japonicus to provide references for the cultivation and quality control of L. japonicus. Under hydroponic conditions, different pH treatments(pH 5,6,7,8) were set up. The growth, physiology, and the content of stachydrine and total alkaloids of L. japonicus, as well as the content of key intermediate products in stachydrine biosynthesis pathway(i.e., pyruvic acid, α-ketoglutaric acid, glutamic acid, and ornithine) were monitored to explore the physiological mechanism of the effects of pH on the growth and active components of L. japonicus. The results showed that L. japonicus. could grow normally in the pH 5-8 solution. The pH treatment of neutral acidity was more conducive to the accumulation of photosynthetic pigments and the increase in soluble protein in leaves of L. japonicus. to promote its growth and yield. However, since stachydrine is a nitrogen-containing pyrrolidine alkaloid, its synthesis involves the two key rate-limiting steps of nitrogen addition: reductive ammoniation reaction and Schiff base formation reaction. High pH treatments promote the synthesis and accumulation of substrates and products of the above two reactions, indicating that the alkaline environment can promote the nitrogen addition reaction, thereby promoting the biosynthesis and accumulation of stachydrine.

Para - chloronitrobenzene degradation by Fenton-like with zero - valent iron and hydrogen peroxide was studied in depth for the purpose to solve the circulation of iron ions suffocated caused by the slow rate of Fe3+ returns Fe2+ in the traditional Fenton reaction. Different effects of hydrogen peroxide and iron dose, initial pH value and others factors were investigated. Para - chloronitrobenzene removal efficiency of 73% was achieved under optimal reaction conditions of pH value 5, with dosage of 200 mg/L zero - valent iron, and 3.5 mg/L of hydrogen peroxide after 20 min. The Removal efficiency of para - chloronitrobenzene by Fe0/H2O2 Fenton-like increased 20% - 30% than the traditional Fenton reaction under the same dosage of iron and hydrogen peroxide, and the same of pH value. And in 3 - 7 range of the pH value, para - chrornitrobenzene degradation effects were obvious by Fe0/H2O2 Fenton-like. The choro - (--Cl) and nitro- (--NO2) on the phenyl were transformed inorganic ions incomplete. The main intermediates were oxalic acid, glycolic acid, acetic acid, maleic acid, p - nitrophenol, p - chlorophenol, 2 - chloro - 5 - nitrophenol, 5 - chloro - 2 - nitrophenol. An degradation pathway of the para - chloronitrobenzene was also proposed. [ABSTRACT FROM AUTHOR]

The efficiency and mechanism of ozonation of dichlorvos (DDV) had been studied, and experimental result showed that ozone could effectively decompose DDV in the water, and the removal efficiency of DDV could be increased under basic condition. More than 90% of the DDV was removed within the initial 5 min. During the DDV ozonation degradation process, organic chlorine was almost completely converted into chloride. In the initial reaction stage, most of the TOC decomposition was finished during the first 5 min. The TOC removal rate increased with the increasing of ozone concentration. The analysis of GSMS showed that the main intermediate products were trimethyl phosphate, dichloroacetic acid (DCAA) and dichloro acetaldehyde. The quantitative analysis of DCAA showed that pH and reaction time had no obvious influence on the formation of DCAA. During the DDV ozonation process, there were three reaction modes: hydrolysis, direct ozone molecular oxidation and free radical reaction. The double bond of ethylene in the DDV molecule was first attacked by hydroxyl radical (⋅ OH) to form dimethyl phosphate and dichloroethylene radical, which were further oxidized to other kinds of product or mineralized to phosphoric acid, carbondioxide and chloride. [ABSTRACT FROM AUTHOR]