The adsorption and desorption processes of Zn(Ⅱ) on γ-MnOOH as a function of particle concentrations(C p) were studied. An obvious C p effect was observed in this adsorption system. The degree of adsorption hyster...The adsorption and desorption processes of Zn(Ⅱ) on γ-MnOOH as a function of particle concentrations(C p) were studied. An obvious C p effect was observed in this adsorption system. The degree of adsorption hysteresis increased greatly with the increasing of C p, indicating that the extent of the real metastable-equilibrium states deviating from the ideal equilibrium state was enhanced with the increasing of C p. The C p-reversibility relationship confirmed the metastable-equilibrium adsorption(MEA) inequality(Pan, 1998a), which was the core formulation of the MEA theory. Because the MEA inequality was based on the basic hypothesis of MEA theory that adsorption density Γ is not a state variable, the C p-reversibility relationship gave indirect evidence to the basic hypothesis of MEA theory.展开更多
A simple and low-cost method to obtain cyanobacterial toxin microcystin-LR(MC-LR) was developed. A new strain of Microcystis aeruginosa, named DC-1, producing microcystin-LR but not microcystin-RR, was separated from ...A simple and low-cost method to obtain cyanobacterial toxin microcystin-LR(MC-LR) was developed. A new strain of Microcystis aeruginosa, named DC-1, producing microcystin-LR but not microcystin-RR, was separated from the field blooming algae samples of Dianchi Lake, in southwest of China. Following three times' freeze and thaw treatment, the cultivated DC-1 cells were extracted with 40% methanol in water. The extract was centrifuged and the supernatant applied to a Hydrophilic-Lipophilic Balance(HLB) SPE cartridge. Eluted impurities with a certain gradient from 30% to 50% methanol in water, MC-LR was finally eluted from the HLB cartridge with 60% methanol in water, and samples containing 3.85% to 14.8% of MC-LR were obtained. These MC-LR samples may be used in adsorption and biodegradation experiments instead of using expensive standard reagents.展开更多
文摘The adsorption and desorption processes of Zn(Ⅱ) on γ-MnOOH as a function of particle concentrations(C p) were studied. An obvious C p effect was observed in this adsorption system. The degree of adsorption hysteresis increased greatly with the increasing of C p, indicating that the extent of the real metastable-equilibrium states deviating from the ideal equilibrium state was enhanced with the increasing of C p. The C p-reversibility relationship confirmed the metastable-equilibrium adsorption(MEA) inequality(Pan, 1998a), which was the core formulation of the MEA theory. Because the MEA inequality was based on the basic hypothesis of MEA theory that adsorption density Γ is not a state variable, the C p-reversibility relationship gave indirect evidence to the basic hypothesis of MEA theory.
文摘A simple and low-cost method to obtain cyanobacterial toxin microcystin-LR(MC-LR) was developed. A new strain of Microcystis aeruginosa, named DC-1, producing microcystin-LR but not microcystin-RR, was separated from the field blooming algae samples of Dianchi Lake, in southwest of China. Following three times' freeze and thaw treatment, the cultivated DC-1 cells were extracted with 40% methanol in water. The extract was centrifuged and the supernatant applied to a Hydrophilic-Lipophilic Balance(HLB) SPE cartridge. Eluted impurities with a certain gradient from 30% to 50% methanol in water, MC-LR was finally eluted from the HLB cartridge with 60% methanol in water, and samples containing 3.85% to 14.8% of MC-LR were obtained. These MC-LR samples may be used in adsorption and biodegradation experiments instead of using expensive standard reagents.
