Experimental Study on the Effect of Sediment Composition Ratio on Shallow Water Delta

1 Introduction Shallow water delta in the middle-newborn Stratum Widely developed with huge oil and gas in China(Hu Shengwu et al.,2013).The control factors on the deltadevelopment like Climate,sea level,tectonic subsidence,sediment supply(flow,type),the geometric characteristics of the upstream river,the energy(wave,

A study on some elements and their phases in sediments of Changjiang Estuary by X-ray spectrometer and X-ray diffractometer

INTRODUCTIONThe studies on the quantitative distribution of the conventional elements and their phases in the sediments of the Changjiang Estuary are of great importance to the understanding of the chemical processes of ion exchange, absorption, desorption and flocculation in the estuary.

A study on chemical forms of heavy metals in the sediments of Zhujiang River and its estuary

The five chemical bound forms of Fe, Al and Mn in sediments in the main channel of the Zhujiang River.and its estuary, namely, exchangeable, carbonic, oxidative, organic and residual (in crystal) forms, were determined. The method of sequential extraction was used for separating the five bound forms.The main chemical form of the three elements in the sediments of the Zhujiang River and its estuarine zone is the residual one. The exchangeable form exists only in a small fraction.Correlationships between the concentration of a certain form of heavy metals and Eh. pH and salinity were discussed. The principles of geochemistry are used to explain the mechanism of heavy metal transport in the river.It was also found that the distribution rule of the chemical forms of Fe, Al and Mn in sediments in the lower reaches of the Zhujiang River was similar to the one in the lower reaches of the Yamaska River.

Neutron activation analysis (NAA) and geochemical studies of 38 elements in surface sediments from lower reach and estuary of Huanghe (Yellow) River

Using a neutron activation analysis technique, which involves gamma-spectrometry with a Ge(Li) detector coupled to a S40 multichannel analyzer and interfaced to a PDP-11 computer, we determined thirty-eight elements in sediments from the lower reach (downstream from Jinan) and estuary of Huanghe. The results are discussed in this paper.From inter-elemental correlations, it ts found that a large number of metals (Mn.As, Co, Cr.Cs, Rb, Sc, Ti, Ta, V and Zn) correlate positively with Fe. Ba and Ca correlate positively with Al. Whereas some elements (e. g. , Ti and lanthanides) show no correlation with either Fe or Al. On the other hand, Hf and Zr show a negative correlation with Fe. Elements which tend to be scavenged by Fe and Al colloids or suspended particles are enriched in sediments at the Huanghe Estuary relative to its lower reach. On the other hand, the contents of some elements (e. g. , Zr,Hf,U, Ba, etc. )are higher in sediments from the lower reach of Huanghe than in the estuarine sediments,which may be related to the sorting during deposition of source materials. On the basis of their chemical property and geochemical behavior, the 38 elements we studied are classified into seven groups. (1) weathering-prone elements,group A:K,Rb, Cs and Na; (2) weathering-prone elements, group B:Mg, Ca, Ba and Al; (3) transition elements:Fe, Co.Ni, Zn, As, Sb, Mn, Cr, W,Mo,V, Ta and Sc; (4) rare elements:group A (Zr and Hf) and group B (Ti); (5) rare earth elements:the lanthanides; (6) halogens: Cl and Br; amd (7) natural radioactive elements:U and Th. The basis for this classification is discussed and we emphasize that geochemical associations of elements in the natural environment are not necessarily in accord with their chemical properties as dictated by position at the periodic table.

Formation and water environmental evolution of the Nansihu Lake

Through high-resolution research of sedimental chronology and the sediment environmental indexes, such as graininess, minerals, magnetic parameters, pigment content, organic carbon and chronology in Ds-core and Ws-core in Nansihu Lake, the authors analyze the formation cause of the Nansihu Lake and its water environmental changes. Historical documents are also analyzed here in order to reach the conclusion. Researches indicate that the Nansihu Lake came into being about 2500 aBP and its evolution succession can be divided into four stages. In this evolution process, several scattered lakes merge into one large lake in the east of China. This process is distinctively affected by the overflow of the Yellow River, the excavation of the Grand Canal and other human activities.

STUDY ON THE EFFECT OF SEDIMENT MOTION ON TRANSPORT TRANSFORMATION OF HEAVY METAL POLLUTANTS

By combining laboratorial experiments,theoretical analysis and mathematical model,theeffect of sediment motion on transport-transformation of heavy-metal pollutants is studied. (1)Previous studies on adsorption-desorption of heavy-metal pollutants by sedimentparticles are systematically summarized.Based on this summary,subjects that need to be furtherstudied are put forward. In rivers most heavy-metal pollutants concentrate on sediment particles.In order tocontrolling water pollution aused by heavy-metal pollutants following topics should beemphasized:studies on the effect of suspended matter and deposit on transport-transformation of