Liu Chunying

Viscosity of sea surface microlayer in Jiaozhou Bay and adjacent sea area

This study on the temporal and spatial variability of the viscosity and some chemical parameters in the sea surface microlayer (SML), the relationship between the viscosity and chemical parameters, and the influence of the viscosity on the mass transfer coefficient (K) in the flux of materials through the air-sea interface revealed that: The values of viscosity and some chemical parameters in the SML are higher than those in the sub-surface layer (SSL), and at daytime are higher than those at night. The viscosity has positive corelation with chemical oxygen demand (COD), dissolved organic carbon (DOC) and salinity. The “SML effect” on K need not be considered because the SML effect on materials concentration is so small.

Physicochemical Studies of the Sea-Surface Microlayer

In physicochemical studies on the sea-surface microlayer (SML) in seawater, the main researches conducted were as follows: (1) It was found that there is an objective layer of sudden change in physical and chemical properties between the SML and the subsurface layer in seawater. (2) The SML thickness was determined and should be about 50±10 μm. (3) The Gibbs model of the SML was extended, and the multilayer model of the SML was advanced. (4) The original-location method, which corresponds with the traditional removal-location method, was founded and used to determine the SML thickness. The results obtained from the two methods were almost identical. (5) An abnormal phenomenon was found when the Gibbs solution adsorption was applied to the seawater system, the reason for which was discussed preliminarily.

The study on the effect of NO on the growth of Chaetoceros curvisetus

This article studied nitric oxide (NO) effect on the growth ofChaetoceros, curvisetus in chemistry for the first time. Nitric oxide was added into the media with 4 different nutrient concentrations f/2, f/50, f/100, and f/200 when the alga was growing. The growth ofC. curvisetus could be obviously promoted or inhibited during the cultivation process in No enriched media of different concentrations. The growth curve in such media showed a sharp single peak that is the optimal NO concentration for the alga growth, which is consistent with the influence of NO on the growth of high plants. In addition,C. curvisetus can produce NO by itself during, the growth. Therefore, using NO could effectively regulate the algae growth, which is important in real tide control and remediation.

Study on dissolved trace metals in sea surface microlayer in Daya Bay

Glass-plate sampling during 1988–1999 in Daya Bay and suitable corresponding analytical methods were used for the measurement of dissolved trace metals, dissolved organic carbon, biological oxygen demand, chemical oxygen demand, salinity of the sea surface microlayer and subsurface water. Apparent enrichment mechanism and diurnal variation have been revealed for dissolved trace metals in the microlayer in Daya Bay. The more dissolved organic matter was enriched in the sea surface microlayer, the more dissolved trace metals were enriched in the layer. The organic matter played an important role in the enrichment process. The diurnal variations of dissolved trace metals showed that their concentration was apparently inversely related to the tide activity that the concentration was low during rising tide, but high during falling tide. The behavior of dissolved trace metals expressed by the diurnal variation was clearly opposite to that of salinity.

The Fundamental Experiments of Red Tide Chemical Forecast

Many food algae and red tide algae were cultivated in the f/2 medium, and the nitric oxide (NO) concentration of the medium and the cell density were determined. The experiments on algae were conducted when different concentrations of NO were added into the medium using two methods. The results show that low concentrations of NO were self-produced by marine algae during the exponential growth period and were about nmol/L level. But at the end of the period, i.e., 2 or 3 days before the cell density reaches the maximum, an NO peak appeared, with the NO concentration reaching 10 nmol/L. The NO threshold concentration exists according to the influence of exogenous NO on the marine phytoplankton growth. One type is the threshold concentration that can promote algae growth, and its value is between 10 and 1 nmol level, or even lower. The other type can inhibit the phytoplankton growth, which is about μmol level or higher. The results indicate that red tide algae are far more sensitive to NO than are food algae. The fundamental experimental outcome above may provide a new clue for red tide chemical forecast by inspecting the NO change.

Determination of copper complexation in surface microlayer of Daya Bay and Jiaozhou Bay

Copper complexing ligands concentration (C C) and conditional stability constant of the sea surface microlayer (SML) and subsurface layer (SSL) samples, collected from Baya Bay of Guangdong Province and Jiaozhou Bay of Shandong Province, were determined by anodic stripping voltammetry (ASV) technique. C C of Daya Bay in the SML ranged from 6.19×10−7 to 3.52×10−7 mol/L.C C of Jiaozhou Bay in the SML ranged from 5.30×10−7 to 3.03×10−7 mol/L in August 1998 and from 3.46×10−7 to 1.36×10−7 mol/L in May 2000. TheC C concentrations were higher in all surface microlayer samples, compared with corresponding subsurface samples. The average enrichment factors of copper complexation in the SML observed above were 1.58, 1.41 and 1.56, respectively. The enrichment ofC C concentration in the microlayer demonstrated that organic ligands had certain buffer action on the toxicity of the enriched trace metals in the same layer. Conditional stability constants of the SML in Jiaozhou Bay were lower than those of the SSL; however, it showed just opposite for Daya Bay.BOD (biological oxygen demand) andCOD (chemical oxygen demand) indicated the organic matter content, also showed enriched in the SML.C C had an obvious relationship withBOD orCOD.