Study Of The Speciation Of Phosphorus In The Estuary Of The Huanghe And Its Adjacent Waters

Based on the observation of September of 2004 in the estuary of Huanghe and its adjacent waters, Three major aspects are addressed: ①Distribution and changes of different speciation of phosphorus in the sea water of the Estuary of Huanghe and its adjacent waters. ②Distribution and changes of different speciation of phosphorus in the surface sediment of the Estuary of Huanghe and its adjacent waters. ③Adsorption- Desorption of phosphate on suspended particulate matter in Huanghe. The major results can be summarized as following:1. The study of different speciation of phosphorus in sea water of the estuary of Huanghe and its adjacent waters①The average concentrations of dissolved inorganic phosphorus(DIP),dissolved organic phosphorus(DOP),particle phosphorus(PP) in the Estuary in summer are 0.27, 1.02, 4.25μmol/L. PP which is the main existing forms of the total phosphorus( TP) accounts for 76.8% of TP. PP was the main factor which affect the distribution of TP. Dissolved inorganic phosphorus(DIP) only accounts for 4.9% of TP. ②The average concentrations of DIP, DOP, PP in the estuary of Huanghe and its adjacent waters are 0.21, 0.85, 0.70 μmol/L. DOP is the main forms of TP, accounts for 48.3% of TP, PP ,DIP separately accounts for 11.9%, 439.8% of TP. In the South west of Laizhou Bay(adjacent to Xiaoqinghe River), the contents of DIP is 3.87μmol/L, it may due to the influence of the Xiaoqinghe River. The distribution of DOP in the surface water characterizes as high concentration in the adjacent of estuary of Huanghe. But in the bottom water, there is high concentration in the adjacent of the Laizhou Bay. The high concentration of PP is found in the South of Laizhou Bay.③Correlative analysis between environmental factors and different speciation of phosphorus in sea water show that salinity has negative correlated with different forms of phosphorus. The negative relationship between the salinity and differentforms of phosphorus suggested the phosphorus discharges. The positive correlation between DIP and DOP suggested that DIP and DOP maybe have the same source. 2. Analysis the speciation of phosphorus in the surface sediment of the estuary of Huanghe and its adjacent watersA six sequential extraction method has been used to determine the speciation of phosphorus in the surface sediment. The speciation of phosphorus is separated: loosely absorbed inorganic phosphorus (Lsor-P), iron-bound inorganic phosphate(Fe-P), Absorbed inorganic phosphate and leachable organic phosphate(Fe/Al-P), Authigenic apatite and CaCC>3-bound inorganic phosphorus(AU-P),Detrital apatite(De-P),Refractory organic phosphorus(Ref-OP). The environmental factors which affect the distribution of speciation of phosphorus were studied.(Din the estuary of Huaghe and its adjacent waters, the contents of De-P is the highest in the six forms of phosphorus, its average concentration is 353.6ug/g, accounts for 75.6% of total phosphorus(TP) /ollowed by Ref-OP ,80.8ug/g,accounts forl7.3%, then Fe-P, 15.0ug/g, accounts for 3.2%. The contents of Lsor-P, Fe/Al-P, AU-P are all about l%ofTP.@The content of Lsor-P in the estuary of Huanghe and its adjacent waters is higher than that in the estuary. The content of Fe-P is characterized as high concentration in Laizhou Bay, which is influenced by sedimentary environment. The content of Fe/Al-P is low in the coastal of Laizhou Bay ,but is high in the adjacent zones of the estuary of Huanghe .The rise of salinity increase the content of Fe/Al-P. In the north of the Laizhou Bay ,there are high contents of AU-P. The distribution of De-P is same as the Fe/Al-P. The rise of pH in the sea water slightly decrease the De-P, but the rise of temperature slightly increase the De-P. The distribution of Ref-OP is complexity.(3)The correlations between different forms of phosphorus and the contents of different particulate size were analyzed. It is positive correlative between the content of the particles below 32um and Lsor-P, AU-P, Fe/Al-P, as to the contents of particles above 32um,it is negative correlative. Fe-P, De-P and Ref-OP have nocorrelations with the contents of different particles size.3.Adsorption-Desorption of phosphate on suspended participate matter inHuangheThe characteristic adsorption isotherm of phosphate to the suspended particulate matter, Kinetic adsorption and the environmental factors which affect the desorption of phosphate are studied.?The Kinetic adsorption experiment indicate that the progress of phosphorus adsorption on the suspended particulate matter basically reach equilibrium in 12h. ?The amount of phosphate desorbs by the Huanghe suspended particulate matter are affected by salinity ,temperature and pH. The experiment shows :The rise of temperature(20°C ~35°C)will increase the desorption ; The rise of salinity will slightly increase the desorption; The rise of pH(3~10) will decrease desorption.