Papers by Keyword: Nitrophenol

Abstract: This paper establishes the HPLC method of determining three nitrophenol isomers in municipal sewage, surface water and tap water. After the sample is filtered and distilled, conduct the monitoring analysis on the distillate with HPLC-DAD and quantify it in external standard method. In the municipal sewage treated in bioanalysis method one type of target object o-nitrophenol is found, whose content is 0.11mg·L^-1, no target object is found in all the other samples. This method has the adventages of high separation efficiency and high analysis rate. The experiment result shows that the linear correlation coefficient is above 0.983, the recovery rate lies between 78.6% and 105.2%, the minimum detection limit is 0.05mg·L^-1(S/N=3.0).

Abstract: In this study, co-metabolism reduction of p-nitrophenol (PNP) under anaerobic condition was investigated in an upflow anaerobic sludge blanket (UASB) reactor. p-Aminophenol (PAP) was identified as the dominant product of PNP reduction in UASB, and no further degradation of PAP was observed under anaerobic condition in UASB. The performance of three cosubstrates, namely sodium acetate, glucose and methanol, was compared, demonstrating that sodium acetate had the best performance as the external cosubstrate. Both PNP removal and PAP formation increased with the increase of acetate concentrations and the increase of hydraulic retention times (HRTs). Both PNP removal and PAP formation was significantly influenced by initial PNP concentration, exhibiting the inhibitory nature of PNP.

Abstract: The degradation kinetics of 2,4-dinitrophenol (2,4-DNP) and 2,6-dinitrophenol (2,6-DNP) were investigated in this paper. The degradation kinetics experiments were conducted in sequencing batch reactor (SBR) and the degradation model was analyzed by nonlinear regression to estimate parameters including the degradation rate K_max, half saturation constant K_S and the inhibition constant K_I in the Andrews inhibition equation. The degradation inhibition in the condition of 2,4-DNP as solo substrate is more serious than that of the situation with glucose as co-substrate and K_max decreases with the increase of inflow 2,4-DNP concentration. As for 2,6-DNP, K_max gets maximum value is 0.019 mg/(mgSS×d) at the inflow concentration is 20mg/L. K_S increases with the increasing of inflow 2,6-DNP concentration but there is no regularity for K_I.

Abstract: This work describes chemically functionalized nanoporous silica as a novel catalyst for the rapid hydrolysis of a phenyl ester. Work demonstrates a very simple and flexible approach to control surface reactivity on the nanometer scale using a self-assembled organic monolayer consisting of polar, (dihydroxyl, carboxyl, ethylene-diamine, and dihydroimidazole), and non-polar (isobutyl) groups. All five functional groups are an essential requirement in preparing an enzymelike catalyst because of the synergistic effect and hydrophobic partitioning, which has been verified by a 13C CP- MAS solid-state NMR technique. Catalytic activities were obtained from the catalytic efficiency constant and specificity constant using Michaelis-Menten kinetics. Catalytic activities were close to those of a natural enzyme when 12% of the surface was covered by hydrophobic isobutyl silane. The rate of enzyme catalyzed activity was dependent on the energy of the transition state as defined in terms of an energy barrier derived from the relationship between transfer free energy and specificity constant.