Feng Lijuan

Characterization of Dust and Non-dust Aerosols with SEM/EDX

Total suspended particulate (TSP) samples were collected at three sites along the coast of Qingdao, China, before and during a major dust storm in March, 2002. For comparison, PM10 (particulate matter with aerodynamic diameters less than 10 μm) samples were collected at one of the three sites. The morphological observation and compositional analysis of bulk and individual particles were performed by using scanning electron microscopy equipped with an energy dispersive X-ray system (SEM/EDX) for the TSP and PM10 samples. The results showed that the particles of different kinds of morphology had different elemental compositions, but the particles of similar morphology did not always have the same elemental composition for non-dust samples. The morphology and composition of non-dust particles were different at different sites. The fractal and spherical particles existed mainly in the coarse fraction for non-dust samples, while in the fine mode (<10 μm) there were floccules formed by fine particles flocking together and containing crustal elements. Compared with the non-dust particles, the dust particles were more homogeneous in terms of morphology, particle size and composition. Particles with irregular shapes and well-distributed sizes dominated in the dust samples, containing crustal elements such as Mg, Al, Si, Ca, Fe,etc. The high sulfur content indicated that homogeneous and heterogeneous reactions took place on the surfaces of the dust particles in the specific environment of Qingdao.

Application of sulfonated activated-carbon solid acid in ethanol thermal liquefaction of algae

Sulfonated activated-carbon solid acid (AC-SO 3 H) was synthesized by sulfuric acid sulfonation of activated-carbon. The effects of sulfonation temperature and particle size of activated-carbon on total acid amount of AC-SO 3 H was investigated. Results showed that the higher the sulfonation temperature was and the finer the activated-carbon was, the higher the total acid amount of AC-SO 3 H was. The maximal total acid amount was 0.878 mmol g −1 . The catalytic properties of AC-SO 3 H on Chlorella vulgaris ( C. vulgaris ) and Enteromorpha prolifera ( E. prolifera ) ethanol thermal liquefaction were investigated. Results showed that the catalytic activity was improved along with the increase of total acid amount of AC-SO 3 H. The suitable dosage of AC-SO 3 H was 5%. Under the optimized catalytic liquefaction condition, bio-oil yield of C. vulgaris and E. prolifera increased 12.32% and 10.33%, respectively. Residue yield of C. vulgaris and E. prolifera decreased 4.11% and 4.49%, respectively. Higher heating value of bio-oil slightly increased 1.18 and 2.38 MJ kg −1 , respectively. Solid acid AC-SO 3 H mainly promotes esterification and decarboxylation, and probably changes the decomposition and conversion pathway of proteins and inhibits Maillard Reaction, which play an important role in improving the quality of bio-oil.

Typical persistent organic pollutants (POPs) in sediments from the Yellow and East China Seas and adjacent coastal areas, China

Organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), short-chain chlorinated paraffins (SCCPs), polybrominated diphenyl ethers (PBDEs) and perfluoroalky chemicals (PFCs) are five kinds of typical persistent organic pollutants (POPs), which can be transported from emission sources to marine environments via many pathways, including riverine inputs, surface runoff of contaminated soils and atmospheric deposition. Due to their hydrophobicity and lipophilicity, they are preferentially adsorbed onto particles with higher organic contents and finally buried in marine sediments, which are generally regarded as one of the major sinks of POPs. Once absorbed by organisms, they are more easily accumulated in tissues with higher lipid contents. Meanwhile, under certain weather and environmental conditions, POPs adsorbed on sediments can be re-released to aquatic environments, leading to secondary pollution of water systems. POPs are of environmental persistence, bioaccumulation and biomagnification in biota and long-range transport potential, and thus may cause seriously adverse effects on marine ecosystems after they entered into marine environments. These effects are important to the safety of marine system. The present review mainly summarizes the pollution characteristics of the above POPs in sediments from the Yellow and East China Seas and adjacent coastal areas, China. In addition, their potential sources, mechanisms for migration from the land to the sea, as well as the ecological risk assessment for some of these POPs, are also reviewed. Future researches urgently needed are proposed.