Slope anomaly in the vapour pressure curve of Hg
The investigation of normally-metallic fluids at reduced densities has created considerable experimental and theoretical interest. Hensel1 has presented evidence for transitions, related to electronic properties, in both the liquid and vapour phases of Hg, and predicted that these would affect the liquid–vapour transition. We present here evidence that the vapour pressure curve of Hg, p(T), has an unusual and probably unique form in that the In p against 1/T plot showed a sharp change of slope at temperature T = T′ = 1,361 K and saturated liquid density ρL = 10.7 g cm−3. The latter is about the density at which Hensel1 deduced that the electronic mean free path equalled the mean interatomic spacing, and which he took to be associated with the electronic-property related transition in the liquid phase.
The Metal–Nonmetal Transition in Fluid Mercury: Landau–Zeldovich Revisited
The paper reviews recent experimental results, which show that the formation of a mixed phase of metallic and nonmetallic domains following the putative ‘Landau–Zeldovich first-order metal–nonmetal transition’ noticeably influences the liquid–vapor transition of fluid mercury. An attempt is made to connect the observable consequences of the mixed phase existence with the scenario of noncongruent evaporation.
Treatment of oily wastewater by organic–inorganic composite tubular ultrafiltration (UF) membranes
A tubular UF module equipped with polyvinylidene fluoride membranes modified by inorganic nano-sized alumina particles was used to purify oily wastewater from an oil field. The membrane water permeations of the UF process were analyzed. Retentions of chemical oxygen demand and total organic carbon were more than 90% and 98%, respectively. The results indicate that after UF treatment, oil content was below 1 mg/L, suspended solids content was below 1 mg/L, and solid particle median diameters were less than 2 μm. The quality of the permeation water met the requirement by oilfield injection or drainage. Fouled membranes and washed membranes were analyzed by scanning electron microscopy, and fouled membranes were backwashed with different solutions. Results show that the addition of nanosized alumina particles improved membrane antifouling performance, and the flux recovery ratio of modified membranes reached 100% washing with 1 wt% of OP-10 surfactant solution (pH 10).