A new dihydroflavone and a new polyacetylene glucoside from Bidens parviflora.

A new dihydroflavone, 2(S)-isookanin-4'-methoxy-8-O-ß-D-glucopyranoside (1), and a new polyacetylene glucoside, (10S)-tridecane-2E-ene-4,6,8-triyne-1-ol-10-O-ß-D-glucopyranoside (2), along with seven known compounds (3-9), were isolated from the herb of Bidens parviflora Willd. The structures of all the extracted compounds were elucidated by HR-ESI-MS, 1 D and 2 D NMR spectra, as well as circular dichroism (CD).

[Effect of surfactant on the evaporation of p-chloronitrobenzene and naphthalene in the turbulent process].

Effect of surfactant on the evaporation of p-chloronitrobenzene and naphthalene in the turbulent process was studied in order to understand the effect of surfactant on the evaporation of complex contaminants in dynamic water system. Sodium dodecyl sulfate (SDS), cetyltrimethyl ammonium bromide (CTMAB) and polyethylene glycol sorbitan monolaurate (Tween 20) were used in the experiment. The results showed that the evaporation of p-chloronitrobenzene and naphthalene from surfactant solution in set turbulence intensity followed the first kinetic equation and all the correlation coefficients were above 0.99. The evaporative loss velocity of component was increased in dynamic water,while it decreased in surfactant solution, comparing with static pure water. The combined impact of these two factors was mainly presented promoting. When the turbulence intensity was above 39 r/min and 65 r/min respectively and the concentrations of surfactants were set from 150 mg/L to 2000 mg/L, the corresponding evaporative loss velocity of naphthalene and p-chloronitrobenzene both increased clearly. The evaporative loss velocity of p-chloronitrobenzene and naphthalene in the same turbulence intensity were decreased because of the straining ability of surfactant with the rule: CTMAB > Tween 20 > SDS. The impact of both surfactant and turbulence on naphthalene (with higher H) was more distinct than p-chloronitrobenzene (with lower H).

[Sorption and mechanism of surfactants on bentonite in combined pollution].

Sorption of cationic surfactant cetyl pyridinium chloride (CPC), anionic surfactant sodium dodecylbenzene sulfonate (SDBS) and nonionic surfactant Triton X-100 (TX-100) on bentonite was studied. The influences of cation-exchange capacity (CEC), temperature and salinity on the sorption of CPC were also discussed. The results indicate that the sorption of CPC on Na-bentonite is greater than that of TX-100 and SDBS, and SDBS hardly shows any sorption. CPC is adsorbed to Na-bentonite through a combination of hydrophobic bonding and cation-exchange. While TX-100 is adsorbed to Na-bentonite via the formation of an adsorption layer of twain surfactant molecule and hydrogenolysis of silicon-oxygen surface of bentonite and TX-100. The amount of SDBS adsorbed on Ca-bentonite increases with increasing surfactant concentration, reaching a maximum at 1.5 critical micelle concentration (CMC), and then decreases with increasing surfactant loading. The mechanism of the retention appears to be formation of a sparingly soluble Ca-SDBS species, and dissolution in the micelle. The amount of CPC adsorbed on bentonite decreases with increasing temperature, and increases with increasing CEC. NaCl can enhance the sorption of CPC on bentonite.