Jianguo Lin

Mathematical Model and Computer Simulation for Oil Spill in Ice Waters Around Island Based on FLUENT

The simulation of oil spill in ice waters was built by computational liquid dynamic software FLUENT. The coupling of pressure and velocity under unsteady-state conditions was solved by pressure implicit with splitting of operator algorithm. The boundary conditions of nonlinear free surface were solved by volume of fluid. And the numerical wave water flume was established by the user defined function with the help of C programming language. The whole process of the dispersion and diffusion of oil spill in ice waters was shown vividly and visually on screen in graphic mode dynamically. Also the distribution of velocity vector could be obtained. Basing on this intelligence simulation method, the movement characteristics of oil spill in ice waters were analyzed. The results showed that: with the ice sheet, the oil adhered to the ice lower surface easily, while its diffusion area was less than the one on the free sea surface in the same temperature; some oil was entrained to the ice upper surface and continued to transport, which accelerated the ice melting; the pollution area caused by oil spill near to the ice sheet was less than the one caused by oil spill far from the ice sheet. These simulation results were similar to some experimental phenomena and this computational method was validated to be effective. Index Terms—simulation, algorithm, ice waters, oil spill, software FLUENT

Sulfate reduction and mixotrophic sulfide-utilization denitrification integrated biofilm process for sulfate-laden wastewater treatment and sulfur recovery

A novel and integrated biofilm process--the sulfate reduction (SR) and mixotrophic (MR) sulfide-utilization denitrification process (SMSD)--was recently proposed for sulfate treatment and sulfur recovery. The process consisted of two bioreactors: a 5.1 L anaerobic upflow reactor for SR, and a 3.5 L anaerobic upflow reactor for MR desulfurization-denitrification. The experiment was conducted for 370 days to evaluate the performance of SMSD at various sulfate concentrations and hydraulic retention times. The process successfully achieved sulfate, organics and nitrogen compound removal efficiencies of 94.1, 97.7 and 99.1%, respectively. Sulfate was predominantly converted to element sulfur, while nitrate and nitrite were finally converted to nitrogen gas. In SR, with the help of high pH and sponge cubes with various bacteria, 97.5% of sulfide conversion efficiency and 540 mgS/L of sulfide were obtained. In MR, sulfide was removed up to 100% and was partially oxidized to sulfur. The extent of heterotrophic denitrification, which ranged from 35.8 to 59.8%, depended on the categories of electron acceptors.

Model Identification for Autonomous Underwater Vehicles Based on Maximum Likelihood Relaxation Algorithm

In order to obtain a precise mathematical model of an autonomous underwater vehicle (AUV), model identification based on maximum likelihood relaxation algorithm is proposed in this paper. With experiment data of zigzag motion, the hydrodynamic derivatives of the AUV are estimated, and ideal convergence of maximum likelihood relaxation algorithm can be obtained from the contrast with normal approach. The simulation system based on these parameters is established to verify the validity. The results show the model is credible, which is very useful for the research of maneuverability and adaptive control of AUVs.

Simulation of Submarine Pipeline Oil Spill Based on Wave Motion

In order to explore the motion law of oil spill to conduct cleaning, simulation for submarine oil spill based on wave motion is carried out by user defined function and volume of fluid in FLUENT, and the dispersion and diffusion of oil spill in deep sea is simulated dynamically. Also the oil spill processes with different wavelength and current velocity are compared and analyzed. The results show that wave and current have important effects on the location and oil film area on sea surface. With wavelength increasing, the water depth influenced by wave, the scope of oil dispersion underwater and the oil film area on surface increase, respectively. With current velocity decreasing, the oil film area on sea surface, the distance between the oil film and oil spill source increased.

Study on the Risk Analysis and Emergency Measures to the PX Projects of Dalian Dagushan which Impact on the Marine Environment

By investigating and analyzing PX demand in recent years and the distribution of PX projects in Dagushan chemical industrial park, combining its physical and chemical properties and marine environment near Dalian Dagushan, aim to make environmental assessments on the damage caused by PX to the marine environment and propose appropriate emergency measures.

Discussion of Seawater Exchange Rate

Seawater exchange capacity of a bay is a key factor to determine the water environment quality,research of which is a basic issue in marine environmental science. Seawater exchange rate can directly estimate the marine environment capacity. This paper summarizes the computing methods of seawater exchange rate in a tidal estuary, analyzes the methods systematically and proposes some existing problems to explore in depth ,which prospects the development trends and the main research aspects in the future.

Numerical Simulation of Heavy Metal (Pb) Distribution in Luoyuan Bay Based on Tidal Current

Compared with the data measured by other ones, the concentration of heavy metal (Pb), which is investigated by us in July 2011, has increased significantly in Luoyuan Bay, especially near Baishui Zone. The main reason is the discharged waste water from some recently founded large-scale steel plants around Luoyuan Bay. A numerical tidal current model in Luoyuan Bay is established based on FVCOM, with which a heavy metal transport model is developed to simulate the distribution of Pb discharged from steel plants.Reasonable agreement between the model results and field data has been obtained, indicating that the numerical model can be used as computational tool for environment management and the prediction of heavy metals in Luoyuan Bay.

Draft Genome Sequence of the Crude Oil-Degrading and Biosurfactant-Producing Strain Cobetia sp. QF-1

ABSTRACT We report here the draft genome of Cobetia sp. QF-1, a cold-adapted bacterium isolated from crude oil-contaminated seawater of the Yellow Sea, China. This genome is approximately 4.1 Mb (G+C content, 57.44%) with 3,513 protein-coding sequences. Cobetia sp. QF-1 shows crude oil degradation and biosurfactant production activity at low temperature.

Selection of Liaoning Ocean Observation Station Site in Baishawan and Impact Analysis of Shoreline Ecological Environment

According to the fact that the layout of Liaoning ocean observation stations is not perfect, through the comprehensive research, ocean observation station is sited in Yingkou, Baishawan, and simulates hydropower and the change of tidal flat accretion-erosion in the sea area after engineering to analysis the impact of building ocean observation station on Baishawan inshore. As a result, that ocean observation station is sited in Baishawan and takes oils on land to build an artificial island, hardly change hydropower and sediment accretion-erosion variation in the waters and it has no discernible effect on adjoined sea areas and shorelines. So the building scheme of the engineering has an extremely important meaning on protecting shorelines and natural environment this sea area and carrying out management and supervision.

Heavy Metal Distribution Inflected by Baishui Reclamation in Luoyuan Bay

According to the features of Luoyuan Bay, such as the complex terrain, flexural coastline and the large area of tidal flat, well-known 3-D hydrodynamic moving-boundary numerical model FVCOM based on unstructured mesh is used to simulate this area. Based on this model, the tidal current field and tide-induced Eulerian residual current field of Luoyuan Bay can be obtained. The concentrations of 4 heavy metals were determined in 8 water bodies in Luoyuan Bay by an inductively coupled plasma mass spectroscopy (ICP-MS). The average concentrations of Cu, As, Cd and Pb are 3.92, 4.22, 0.201 and 5.27 μg/L, respectively. The results manifest that average levels of heavy metals in the vicinity of the reclamation project has increased significantly in recent years. According to the simulated hydrodynamic results analysis, the water power intensity weakens near the reclamation project with a residual current reducing water exchange capacity.