Forecasts for the concentration of petroleum gas leakage diffusion under different liquid level heights of a sealing ring of sizeable floating roof tank.

The sealing ring of the external floating roof tank is prone to petroleum gas leakage due to material aging and oil corrosion. Petroleum gas leakage and diffusion easily accumulate above the floating deck. When it is within the explosion limit range, there will be the risk of explosion and fire. To deal with the explosion accident of storage tank caused by the concentration distribution of petroleum gas leakage for the sealing ring, and to study the influence of petroleum gas diffusion and concentration distribution after sealing ring leakage on the control area above the floating deck in the tank farm environment, this paper established numerical models of sealing ring leakage under different liquid level heights for 10 × 104 m3 external floating roof tank. Through numerical calculation, it is found that the diffusion concentration of petroleum gas is related to the wind speed, the range of the control area above the floating deck, and leakage when sealing rings leak at different liquid levels. Through dimensionless analysis, the functional relationship of gas leakage diffusion concentration distribution under different liquid level heights of external floating roof tank sealing rings is verified by numerical calculation results. The results show that the numerical results are consistent with those predicted by the formula.

Norepinephrine-functionalised nanoflower-like organic silica as a new adsorbent for effective Pb(II) removal from aqueous solutions.

In order to remove Pb(II) ions efficiently from aqueous solutions, a new effective adsorbent of norepinephrine-functionalised nanoflower-like organic silica (NE-NFOS) was synthesised by a biomimetic method. Biomimetic functionalization with norepinephrine has the advantages of environment-friendly and easy operation. Characterization of the NE-NFOS using scanning electron microscopy, transmission electron microscopy, Brunauer-Emmett-Teller method, and Fourier-transform infrared spectroscopy revealed that the NFOS was modified successfully by norepinephrine. Furthermore, the influences of different parameters including adsorption kinetics, solution pH, adsorption isotherms, concentrations of Na+, K+, Ca2+, and Mg2+, desorption and reusability were studied. The adsorption experiments showed that the capacity of NE-NFOS to adsorb Pb(II) ions improved greatly after functionalisation and adsorption equilibrium was attained within 90 min at a pH of 6.0. The Na+, K+, Ca2+, and Mg2+ concentrations had little influence on the adsorption, and after recycling for five times, the Pb(II) ion removal efficiency of the adsorbent was more than 79% of its initial value. Thus, it was demonstrated that the NE-NFOS with excellent adsorption performance could be a suitable adsorbent for Pb(II) ions removal in practical applications.

Dopamine-functionalized mesoporous onion-like silica as a new matrix for immobilization of lipase Candida sp. 99-125.

Dopmine functionalized mesoporous onion-like silica (DPMS) was synthesized via a biomimetic coating, and lipase Candida sp. 99-125 (LCS) was immobilized in DPMS (LCS@DPMS) by physical adsorption in this study. The DPMS was characterized by SEM, TEM, BET and FT-IR, and it was shown that the DPMS had clear multishell structures with large surface area of 419 m2/g. The activity, pH stability, thermal stability, storage stability, and reusability of the LCS@DPMS were investigated in detail. The stabilities of LCS@DPMS were improved significantly compared to the free lipase and LCS@MS (LCS immobilized in unfunctionalized mesoporous onion-like silica by physical adsorption). All the results indicated that the DPMS had high efficiency and improved stability for lipase immobilization.

[Identification of Magnolia biondii Pamp by X-Ray diffraction Fourier pattern method].

OBJECTIVE: To establish a new identification and analysis method of Magnolia biondii Pamp. METHODS: Powder X-Ray diffraction fourier fingerprint pattern method. RESULT: Experiment and analysis were carried out on five samples. The standard X-Ray diffraction Fourier fingerprint pattern method and characteristic diffraction peaks of Magnolia biondii Pamp were obtained. CONCLUSION: The method can be used for the identification of Magnolia biondii Pamp.

Experimental and numerical investigations on reliability of air barrier on oil containment in flowing water.

Air barriers have been recently developed and employed as a new type of oil containment boom. This paper presents systematic investigations on the reliability of air barriers on oil containments with the involvement of flowing water, which represents the commonly-seen shearing current in reality, by using both laboratory experiments and numerical simulations. Both the numerical and experimental investigations are carried out in a model scale. In the investigations, a submerged pipe with apertures is installed near the bottom of a tank to generate the air bubbles forming the air curtain; and, the shearing water flow is introduced by a narrow inlet near the mean free surface. The effects of the aperture configurations (including the size and the spacing of the aperture) and the location of the pipe on the effectiveness of the air barrier on preventing oil spreading are discussed in details with consideration of different air discharges and velocities of the flowing water. The research outcome provides a foundation for evaluating and/or improve the reliability of a air barrier on preventing spilled oil from further spreading.