Adsorption kinetics of the interaction between Pt, Pd and Rh (defined here as platinum group elements, PGEs) ions and macromolecular organic compounds (MOCs, >10 kDa), including humic acid, carrageenan and bovine serum albumin, and different cutoff fractions of natural organic matter (>1 kDa and >3 kDa) obtained from seawater using centrifugal ultrafiltration devices were investigated. For a given element, all the adsorption kinetics did not reach equilibrium except the interaction between Pt and >1 kDa cutoff, and between Pd and humic acid. For all the tested MOCs, the adsorption kinetics could be divided into two stages, a rapid adsorption process in the first 8 h and the desorption stage after the first 8 h until the equilibrium. The change trend of partition coefficient (log₁₀K_d) values with experiment time was consistent with that of the kinetic curves. However, in the interaction between PGE ions and natural dissolved organic matter (NDOM), an obvious difference in the change trends of log₁₀K_d and kinetic curves was observed. It indicated that the partition behavior of PGE ions interacting with NDOM in seawater was a combined effect of different organic constituents. The adsorption and log₁₀K_d of PGEs in the >1 kDa NDOM fraction were higher and more stable than those in the >3 kDa NDOM fraction. The results also indicated that the 1–3 kDa NDOM may dominate the interaction between PGEs ions and NDOM. Moreover, no kinetic model could perfectly simulate the adsorption process. It indicated that the colloidal struction and morphology of MOCs or NDOM in seawater might be inhomogeneous. Hence, the interaction between PGE ions and organic matter in seawater was a complicated process and needs further research.

Dimethylsulfide (DMS) is generally thought to be lost from the surface oceans by evasion into the atmosphere as well as consumption by microbe.However, photochemical process might be important in the removal of DMS in the oceanic photic zone.A kinetic investigation into the photochemical oxidation of DMS in seawater was performed.The photo-oxidation rates of DMS were influenced by various factors including the medium, dissolved oxygen, photosensitizers, and heavy metal ions.The photo-oxidation rates of DMS were higher in seawater than in distilled water, presumably due to the effect of salinity existing in seawater.Three usual photosensitizers (humic acid, fulvic acid and anthroquinone), especially in the presence of oxygen, were able to enhance the photo-oxidation rate of DMS, with the fastest rate observed with anthroquinone.Photo-oxidation of DMS followed first order reaction kinetics with the rate constant ranging from 2.5×10^-5 to 34.3×10^-5 s^-1.Quantitative analysis showed that approximately 32% of the photochemically removed DMS was converted to dimethylsulfoxide.One of the important findings was that the presence of Hg²⁺ could markedly accelerate the photo-oxidation rate of DMS in seawater.The mechanism of mercuric catalysis for DMS photolysis was suggested according to the way of CTTM (charge transfer to metal) of DMS-Hg²⁺ complex.

The crude enzyme, which was extracted from viscera of Lunella coronata coreensis (Recluz), was salted out and dialysed. Three enzymatic peaks isolated from DEAE-cellulose column chromatography were refered to as lyase Ⅰ, Ⅱ and Ⅲ, respectively. Then these lyases underwent gel-filtration on Sephadex G-25 respectively, and three purer lyases were derived therefrom, the highest purification being 73 fold.
The kinetics of the three lyases was tested respectively. The optimum pH was as follows:lyase Ⅰ was 7.6±0.02 Tris-HCl buffer; lyase Ⅱ was 6.6±0.02 Na₂HPO₄-NaH₂PO₄ buffer; and lyase Ⅲ was 5.6±0.02 HAc-NaAc buffer. In the rang of tested concentration, KCl and Nad were the activator and MnCl₂ was the inhibitor, all for the three lyases; MgCl₂ was the activator for lyases Ⅰ and Ⅱ, but the MgCl₂ of high concentration was the inhibitor for lyase Ⅲ; Pb (OAc)₂ acted differently for three lyases. The Km values of these lyases were 0.2, 0.6 and 0.04 mg/ml in order of precedence.

Light-saturation curves of Dicrateriia inornata at various temperatures were determined by using ¹⁴C-labelling technique.Kinetics of light-intensity adapation was also analyzed in combination with Chl.a determination and cell enumeration measurements.The responx of cellular Chl.a in light transition processes can be appoximately described with the first order kinetic model The model between temperature and maximum growth rate was established by using the Arrhenius equation.

A principle, which has usually been applied to biochemical treatment for waste water is presently introduced into the study on marine microbiological ecology and employed in the estimation of environmental capacity.By means of a selection of 3 models for the microbial growth or for its oxygen consumption and determinations of concerned parameters in the field and the laboratory, the environmental capacity for the Restern Xiamen Harbour is evaluated to be 37 t·d^-1 of BOD₅ in gross or 28 t·d^-1 in net (with some 2500 of the gross capacity consumed by a present ecosystem) if BOD₅ is controlled without excess of 3 mg·dm^-3 in the sea water; it means that an amount of domestic waste water equal to 28 t of BOns can be naturally self-purified in this sea area everyday.Furthermore it is found that the K value, a constant of oxygen-consumed kinetics, shows possitive correlation to the concentration of BOD₅ in the same system and total bacterial number (T_B) in the seawater also to BOD₅ with a regression equation T_B (10⁸ dm^-3)=9.91×BOD₅ (mg·dm^-3)+1.74 (n=32.r=0.544 1, p<0.01).

In order to investigate the hydrocarbon generation process and gas potentials of source rocks in deepwater area of the Qiongdongnan Basin, kinetic parameters of gas generation (activation energy distribution and frequency factor) of the Yacheng Formation source rocks (coal and neritic mudstones) was determined by thermal simulation experiments in the closed system and the specific KINETICS Software. The results show that the activation energy (E_a) distribution of C₁-C₅ generation ranges from 50 to 74 kcal/mol with a frequency factor of 2.4×10¹⁵s^-1 for the neritic mudstone and the E_a distribution of C₁-C₅ generation ranges from 49 to 73 kcal/mol with a frequency factor of 8.92×10¹³s^-1 for the coal. On the basis of these kinetic parameters and combined with the data of sedimentary burial and paleothermal histories, the gas generation model of the Yacheng Formation source rocks closer to geological condition was worked out, indicating its main gas generation stage at R_o (vitrinite reflectance) of 1.25%-2.8%. Meanwhile, the gas generation process of the source rocks of different structural locations (central part, southern slope and south low uplift) in the Lingshui Sag was simulated. Among them, the gas generation of the Yacheng Formation source rocks in the central part and the southern slope of the sag entered the main gas window at 10 and 5 Ma respectively and the peak gas generation in the southern slope occurred at 3 Ma. The very late peak gas generation and the relatively large gas potential indices (GPI: 20×10⁸-60×10⁸ m³/km²) would provide favorable conditions for the accumulation of large natural gas reserves in the deepwater area.

To find out the decay character of residual chlorine (RC) in the sea water, the concentration of RC was analyzed by N, N-diethyl-p-phenylenediamine (DPD) method under different simulation experimental conditions, in which salinity, temperature, and Chemical Oxygen Demand (COD) were selected. The water used in the experiment was the mixture of aging ocean water, coastal water and extracting solution of coastal sediment at appropriate level. Results are shown as follows:(1) Piecewise function can well reflect the decay dynamics of RC in the cooling seawater. Concretely, the decay dynamics of first 1 min is too rapid to ascertain using a specific kinetic function, and that of the time from 1 to 30 min is fit for the first-order kinetic model. (2) The results could be the foundation of the chemical behavior of RC in seawater, and be used as not only the guidance of the coastal power plants production and sea water desalting companies, but also the establishment of the correlative trade standard.

The natural gas generation process is simulated by heating source rocks of the Yacheng Formation, including the onshore-offshore mudstone and coal with kerogens of Type II₂-III in the Qiongdongnan Basin. The aim is to quantify the natural gas generation from the Yacheng Formation and to evaluate the geological prediction and kinetic parameters using an optimization procedure based on the basin modeling of the shallow-water area. For this, the hydrocarbons produced have been grouped into four classes (C₁, C₂, C₃ and C_4-6). The results show that the onset temperature of methane generation is predicted to occur at 110℃ during the thermal history of sediments since 5.3 Ma by using data extrapolation. The hydrocarbon potential for ethane, propane and heavy gaseous hydrocarbons (C_4-6) is found to be almost exhausted at geological temperature of 200℃ when the transformation ratio (TR) is over 0.8, but for which methane is determined to be about 0.5 in the shallow-water area. In contrast, the end temperature of the methane generation in the deep-water area was over 300℃ with a TR over 0.8. It plays an important role in the natural gas exploration of the deep-water basin and other basins in the broad ocean areas of China. Therefore, the natural gas exploration for the deep-water area in the Qiongdongnan Basin shall first aim at the structural traps in the Ledong, Lingshui and Beijiao sags, and in the forward direction of the structure around the sags, and then gradually develop toward the non-structural trap in the deep-water area basin of the broad ocean areas of China.

The adsorption kinetics of Pb, Cu and Cd on hydrous ferrk oxide (HFO) has been approached in tthe simulated environmental conditions of the Changjiang Estuary.The forward adsorption rate constants of different systems under different temperatures have been determined, and the activation energies of the adsorption for Pb and Cu evaluated (Pb=7 kcal/mol, Cu=11 kcal/mol).The results show that Pb and Cu are strongly adsorbed by HFO; the order of their adsorption rate is found to be Pb ≥ Cu ≥ Cd, which follows thte order of their theonody-namic equilibrium constants.It has been demonstrated that the surface exchange-adsorption is the determining step of the solid-liquid interface process.The field investigation results are theoretically explained by the kinetic mechanism.

Five fucoidan fractions from Laminaria japonica with different sulfate content and molecular weight were prepared by anion-exchange chromatography and mild acid hydrolysis. Their antioxidant effects on azo radicals 2-2'-Azobis (2-amidinopropane) dihydrochloride (AAPH) induced oxidation of human low-density lipoprotein (LDL) were evaluated by monitoring cholesteryl ester hydroperoxides (CHL-OOH) formation kinetics through reverse-phase high performance liquid chromatography (RP-HPLC) analysis. Fucoidan F-C with a low molecular mass of 2 000~8 000 and a sulfate content of 24.3% had much stronger protective antioxidant effect than other four fucoidan fractions on the hydrophilic radical AAPH induced LDL oxidation. However, the highly sulfated fucoidan fraction L-B with a molecular mass of 20 000 was completely ineffective in protecting LDL from the AAPH induced oxidation. The results suggested that both molecular mass and sulfate content of fucoidan played very important roles in their effects on the AAPH induced LDL oxidation.